Module-level Variables

average of currents in PF circuits (kA)

maximum stored energy in the PF circuits (MJ)

Switch for PF coil energy storage option:

• =1 all power from MGF (motor-generator flywheel) units
• =2 all pulsed power from line
• =3 PF power from MGF, heating from line

number of PF coil circuits

total PF coil circuit bus length (m)

sum of PF power supply ratings (MVA)

sum of resistive PF coil power (kW)

PF coil voltage (kV)

Peak absolute rate of change of stored energy in poloidal field (MW)

Maximum permitted absolute rate of change of stored energy in poloidal field (MW)

Poloidal power usage at time t (MW)

ipnvars FIX : total number of variables available for iteration

ipeqns FIX : number of constraint equations available

ipnfoms FIX : number of available figures of merit

ioptimz /1/ : code operation switch:

• = -2 for no optimisation, no VMCOM or HYBRD;
• = -1 for no optimisation, HYBRD only;
• = 0 for HYBRD and VMCON (not recommended);
• = 1 for optimisation, VMCON only

minmax /7/ : switch for figure-of-merit (see lablmm for descriptions) negative => maximise, positive => minimise

lablmm(ipnfoms) : labels describing figures of merit:

• ( 1) major radius
• ( 2) not used
• ( 3) neutron wall load
• ( 4) P_tf + P_pf
• ( 5) fusion gain Q
• ( 6) cost of electricity
• ( 7) capital cost (direct cost if ireactor=0, constructed cost otherwise)
• ( 8) aspect ratio
• ( 9) divertor heat load
• (10) toroidal field
• (11) total injected power
• (12) hydrogen plant capital cost OBSOLETE
• (13) hydrogen production rate OBSOLETE
• (14) pulse length
• (15) plant availability factor (N.B. requires iavail=1 to be set)
• (16) linear combination of major radius (minimised) and pulse length (maximised) note: FoM should be minimised only!
• (17) net electrical output
• (18) Null Figure of Merit
• (19) linear combination of big Q and pulse length (maximised) note: FoM should be minimised only!

ncalls : number of function calls during solution

neqns /0/ : number of equality constraints to be satisfied

nfev1 : number of calls to FCNHYB (HYBRD function caller) made

nfev2 : number of calls to FCNVMC1 (VMCON function caller) made

nineqns /0/ : number of inequality constraints VMCON must satisfy (leave at zero for now)

nvar /16/ : number of iteration variables to use

nviter : number of VMCON iterations performed

icc(ipeqns) /0/ : array defining which constraint equations to activate (see lablcc for descriptions)

active_constraints(ipeqns) : Logical array showing which constraints are active

lablcc(ipeqns) : labels describing constraint equations (corresponding itvs)

• ( 1) Beta (consistency equation) (itv 5)
• ( 2) Global power balance (consistency equation) (itv 10,1,2,3,4,6,11)
• ( 3) Ion power balance DEPRECATED (itv 10,1,2,3,4,6,11)
• ( 4) Electron power balance DEPRECATED (itv 10,1,2,3,4,6,11)
• ( 5) Density upper limit (itv 9,1,2,3,4,5,6)
• ( 6) (Epsilon x beta poloidal) upper limit (itv 8,1,2,3,4,6)
• ( 7) Beam ion density (NBI) (consistency equation) (itv 7)
• ( 8) Neutron wall load upper limit (itv 14,1,2,3,4,6)
• ( 9) Fusion power upper limit (itv 26,1,2,3,4,6)
• (10) Toroidal field 1/R (consistency equation) (itv 12,1,2,3,13 )
• (11) Radial build (consistency equation) (itv 3,1,13,16,29,42,61)
• (12) Volt second lower limit (STEADY STATE) (itv 15,1,2,3)
• (13) Burn time lower limit (PULSE) (itv 21,1,16,17,29,42,44,61) (itv 19,1,2,3,6)
• (14) Neutral beam decay lengths to plasma centre (NBI) (consistency equation)
• (15) LH power threshold limit (itv 103)
• (16) Net electric power lower limit (itv 25,1,2,3)
• (17) Radiation fraction upper limit (itv 28)
• (18) Divertor heat load upper limit (itv 27)
• (19) MVA upper limit (itv 30)
• (20) Neutral beam tangency radius upper limit (NBI) (itv 33,31,3,13)
• (21) Plasma minor radius lower limit (itv 32)
• (22) Divertor collisionality upper limit (itv 34,43)
• (23) Conducting shell to plasma minor radius ratio upper limit (itv 104,1,74)
• (24) Beta upper limit (itv 36,1,2,3,4,6,18)
• (25) Peak toroidal field upper limit (itv 35,3,13,29)
• (26) Central solenoid EOF current density upper limit (ipfres=0) (itv 38,37,41,12)
• (27) Central solenoid BOP current density upper limit (ipfres=0) (itv 39,37,41,12)
• (28) Fusion gain Q lower limit (itv 45,47,40)
• (29) Inboard radial build consistency (itv 3,1,13,16,29,42,61)
• (30) Injection power upper limit (itv 46,47,11)
• (31) TF coil case stress upper limit (SCTF) (itv 48,56,57,58,59,60,24)
• (32) TF coil conduit stress upper limit (SCTF) (itv 49,56,57,58,59,60,24)
• (33) I_op / I_critical (TF coil) (SCTF) (itv 50,56,57,58,59,60,24)
• (34) Dump voltage upper limit (SCTF) (itv 51,52,56,57,58,59,60,24)
• (35) J_winding pack/J_protection upper limit (SCTF) (itv 53,56,57,58,59,60,24)
• (36) TF coil temperature margin lower limit (SCTF) (itv 54,55,56,57,58,59,60,24)
• (37) Current drive gamma upper limit (itv 40,47)
• (38) First wall coolant temperature rise upper limit (itv 62)
• (39) First wall peak temperature upper limit (itv 63)
• (40) Start-up injection power lower limit (PULSE) (itv 64)
• (41) Plasma current ramp-up time lower limit (PULSE) (itv 66,65)
• (42) Cycle time lower limit (PULSE) (itv 17,67,65)
• (43) Average centrepost temperature (TART) (consistency equation) (itv 13,20,69,70)
• (44) Peak centrepost temperature upper limit (TART) (itv 68,69,70)
• (45) Edge safety factor lower limit (TART) (itv 71,1,2,3)
• (46) Equation for Ip/Irod upper limit (TART) (itv 72,2,60)
• (47) NOT USED
• (48) Poloidal beta upper limit (itv 79,2,3,18)
• (49) NOT USED
• (50) IFE repetition rate upper limit (IFE)
• (51) Startup volt-seconds consistency (PULSE) (itv 16,29,3,1)
• (52) Tritium breeding ratio lower limit (itv 89,90,91)
• (53) Neutron fluence on TF coil upper limit (itv 92,93,94)
• (54) Peak TF coil nuclear heating upper limit (itv 95,93,94)
• (55) Vacuum vessel helium concentration upper limit iblanket =2 (itv 96,93,94)
• (56) Pseparatrix/Rmajor upper limit (itv 97,1,3)
• (57) NOT USED
• (58) NOT USED
• (59) Neutral beam shine-through fraction upper limit (NBI) (itv 105,6,19,4 )
• (60) Central solenoid temperature margin lower limit (SCTF) (itv 106)
• (61) Minimum availability value (itv 107)
• (62) taup/taueff the ratio of particle to energy confinement times (itv 110)
• (63) The number of ITER-like vacuum pumps niterpump < tfno (itv 111)
• (64) Zeff less than or equal to zeffmax (itv 112)
• (65) Dump time set by VV loads (itv 56, 113)
• (66) Limit on rate of change of energy in poloidal field (Use iteration variable 65(tohs), 115)
• (67) Simple Radiation Wall load limit (itv 116, 4,6)
• (68) Psep * Bt / qAR upper limit (itv 117)
• (69) ensure separatrix power = the value from Kallenbach divertor (itv 118)
• (70) ensure that teomp = separatrix temperature in the pedestal profile, (itv 119 (tesep))
• (71) ensure that neomp = separatrix density (nesep) x neratio
• (72) central solenoid shear stress limit (Tresca yield criterion) (itv 123 foh_stress)
• (73) Psep >= Plh + Paux (itv 137 (fplhsep))
• (74) TFC quench < tmax_croco (itv 141 (fcqt))
• (75) TFC current/copper area < Maximum (itv 143 f_coppera_m2)
• (76) Eich critical separatrix density
• (77) TF coil current per turn upper limit
• (78) Reinke criterion impurity fraction lower limit (itv 147 freinke)
• (79) Peak CS field upper limit (itv 149 fbmaxcs)
• (80) Divertor power lower limit pdivt (itv 153 fpdivlim)
• (81) Ne(0) > ne(ped) constraint (itv 154 fne0)
• (82) toroidalgap > tftort constraint (itv 171 ftoroidalgap)
• (83) Radial build consistency for stellarators (itv 172 f_avspace)
• (84) Lower limit for beta (itv 173 fbetatry_lower)
• (85) Constraint for CP lifetime
• (86) Constraint for TF coil turn dimension
• (87) Constraint for cryogenic power
• (88) Constraint for TF coil strain absolute value
• (89) Constraint for CS coil quench protection
• (90) Lower Limit on number of stress load cycles for CS (itr 167 fncycle)
• (91) Checking if the design point is ECRH ignitable (itv 168 fecrh_ignition)

ixc(ipnvars) /0/ : array defining which iteration variables to activate (see lablxc for descriptions)

lablxc(ipnvars) : labels describing iteration variables

• ( 1) aspect
• ( 2) bt
• ( 3) rmajor
• ( 4) te
• ( 5) beta
• ( 6) dene
• ( 7) rnbeam
• ( 8) fbeta (f-value for equation 6)
• ( 9) fdene (f-value for equation 5)
• (10) hfact
• (11) pheat
• (12) oacdcp
• (13) tfcth (NOT RECOMMENDED)
• (14) fwalld (f-value for equation 8)
• (15) fvs (f-value for equation 12)
• (16) ohcth
• (17) tdwell
• (18) q
• (19) enbeam
• (20) tcpav
• (21) ftburn (f-value for equation 13)
• (22) NOT USED
• (23) fcoolcp
• (24) NOT USED
• (25) fpnetel (f-value for equation 16)
• (26) ffuspow (f-value for equation 9)
• (27) fhldiv (f-value for equation 18)
• (28) fradpwr (f-value for equation 17), total radiation fraction
• (29) bore
• (30) fmva (f-value for equation 19)
• (31) gapomin
• (32) frminor (f-value for equation 21)
• (33) fportsz (f-value for equation 20)
• (34) fdivcol (f-value for equation 22)
• (35) fpeakb (f-value for equation 25)
• (36) fbetatry (f-value for equation 24)
• (37) coheof
• (38) fjohc (f-value for equation 26)
• (39) fjohc0 (f-value for equation 27)
• (40) fgamcd (f-value for equation 37)
• (41) fcohbop
• (42) gapoh
• (43) NOT USED
• (44) fvsbrnni
• (45) fqval (f-value for equation 28)
• (46) fpinj (f-value for equation 30)
• (47) feffcd
• (48) fstrcase (f-value for equation 31)
• (49) fstrcond (f-value for equation 32)
• (50) fiooic (f-value for equation 33)
• (51) fvdump (f-value for equation 34)
• (52) NOT USED
• (53) fjprot (f-value for equation 35)
• (54) ftmargtf (f-value for equation 36)
• (55) NOT USED
• (56) tdmptf
• (57) thkcas
• (58) thwcndut
• (59) fcutfsu
• (60) cpttf
• (61) gapds
• (62) fdtmp (f-value for equation 38)
• (63) ftpeak (f-value for equation 39)
• (64) fauxmn (f-value for equation 40)
• (65) tohs
• (66) ftohs (f-value for equation 41)
• (67) ftcycl (f-value for equation 42)
• (68) fptemp (f-value for equation 44)
• (69) rcool
• (70) vcool
• (71) fq (f-value for equation 45)
• (72) fipir (f-value for equation 46)
• (73) scrapli
• (74) scraplo
• (75) tfootfi
• (76) NOT USED
• (77) NOT USED
• (78) NOT USED
• (79) fbetap (f-value for equation 48)
• (80) NOT USED
• (81) edrive
• (82) drveff
• (83) tgain
• (84) chrad
• (85) pdrive
• (86) frrmax (f-value for equation 50)
• (87) NOT USED
• (88) NOT USED
• (89) ftbr (f-value for equation 52)
• (90) blbuith
• (91) blbuoth
• (92) fflutf (f-value for equation 53)
• (93) shldith
• (94) shldoth
• (95) fptfnuc (f-value for equation 54)
• (96) fvvhe (f-value for equation 55)
• (97) fpsepr (f-value for equation 56)
• (98) li6enrich
• (99) NOT USED
• (100) NOT USED
• (101) NOT USED
• (102) fimpvar # OBSOLETE
• (103) flhthresh (f-value for equation 15)
• (104) fcwr (f-value for equation 23)
• (105) fnbshinef (f-value for equation 59)
• (106) ftmargoh (f-value for equation 60)
• (107) favail (f-value for equation 61)
• (108) breeder_f: Volume of Li4SiO4 / (Volume of Be12Ti + Li4SiO4)
• (109) ralpne: thermal alpha density / electron density
• (110) ftaulimit: Lower limit on taup/taueff the ratio of alpha
• (111) fniterpump: f-value for constraint that number
• (112) fzeffmax: f-value for max Zeff (f-value for equation 64)
• (113) ftaucq: f-value for minimum quench time (f-value for equation 65)
• (114) fw_channel_length: Length of a single first wall channel
• (115) fpoloidalpower: f-value for max rate of change of
• (116) fradwall: f-value for radiation wall load limit (eq. 67)
• (117) fpsepbqar: f-value for Psep*Bt/qar upper limit (eq. 68)
• (118) fpsep: f-value to ensure separatrix power is less than
• (119) tesep: separatrix temperature calculated by the Kallenbach divertor model
• (120) ttarget: Plasma temperature adjacent to divertor sheath [eV]
• (121) neratio: ratio of mean SOL density at OMP to separatrix density at OMP
• (122) oh_steel_frac : streel fraction of Central Solenoid
• (123) foh_stress : f-value for CS coil Tresca yield criterion (f-value for eq. 72)
• (124) qtargettotal : Power density on target including surface recombination [W/m2]
• (125) fimp(3) : Beryllium density fraction relative to electron density
• (126) fimp(4) : Carbon density fraction relative to electron density
• (127) fimp(5) : Nitrogen fraction relative to electron density
• (128) fimp(6) : Oxygen density fraction relative to electron density
• (129) fimp(7) : Neon density fraction relative to electron density
• (130) fimp(8) : Silicon density fraction relative to electron density
• (131) fimp(9) : Argon density fraction relative to electron density
• (132) fimp(10) : Iron density fraction relative to electron density
• (133) fimp(11) : Nickel density fraction relative to electron density
• (134) fimp(12) : Krypton density fraction relative to electron density
• (135) fimp(13) : Xenon density fraction relative to electron density
• (136) fimp(14) : Tungsten density fraction relative to electron density
• (137) fplhsep (f-value for equation 73)
• (138) rebco_thickness : thickness of REBCO layer in tape (m)
• (139) copper_thick : thickness of copper layer in tape (m)
• (140) dr_tf_wp : radial thickness of TFC winding pack (m)
• (141) fcqt : TF coil quench temperature < tmax_croco (f-value for equation 74)
• (142) nesep : electron density at separatrix [m-3]
• (143) f_copperA_m2 : TF coil current / copper area < Maximum value
• (144) fnesep : Eich critical electron density at separatrix
• (145) fgwped : fraction of Greenwald density to set as pedestal-top density
• (146) fcpttf : F-value for TF coil current per turn limit (constraint equation 77)
• (147) freinke : F-value for Reinke detachment criterion (constraint equation 78)
• (148) fzactual : fraction of impurity at SOL with Reinke detachment criterion
• (149) fbmaxcs : F-value for max peak CS field (con. 79, itvar 149)
• (150) REMOVED
• (151) REMOVED
• (152) fgwsep : Ratio of separatrix density to Greenwald density
• (153) fpdivlim : F-value for minimum pdivt (con. 80)
• (154) fne0 : F-value for ne(0) > ne(ped) (con. 81)
• (155) pfusife : IFE input fusion power (MW) (ifedrv=3 only)
• (156) rrin : Input IFE repetition rate (Hz) (ifedrv=3 only)
• (157) fvssu : F-value for available to required start up flux (con. 51)
• (158) croco_thick : Thickness of CroCo copper tube (m)
• (159) ftoroidalgap : F-value for toroidalgap > tftort constraint (con. 82)
• (160) f_avspace (f-value for equation 83)
• (161) fbetatry_lower (f-value for equation 84)
• (162) r_cp_top : Top outer radius of the centropost (ST only) (m)
• (163) f_t_turn_tf : f-value for TF coils WP trurn squared dimension constraint
• (164) f_crypmw : f-value for cryogenic plant power
• (165) fstr_wp : f-value for TF coil strain absolute value
• (166) f_copperaoh_m2 : CS coil current /copper area < Maximum value
• (167) fncycle : f-value for minimum CS coil stress load cycles
• (168) fecrh_ignition: f-value for equation 91
• (169) te0_ecrh_achievable: Max. achievable electron temperature at ignition point
• (170) beta_div : field line angle wrt divertor target plate (degrees)
• (171) casths_fraction : TF side case thickness as fraction of toridal case thickness
• (172) casths : TF side case thickness [m]
• (173) EMPTY : Description
• (174) EMPTY : Description
• (175) EMPTY : Description

sqsumsq : sqrt of the sum of the square of the constraint residuals

Description of the objective function

Normalised objective function (figure of merit)

epsfcn /1.0e-3/ : finite difference step length for HYBRD/VMCON derivatives

epsvmc /1.0e-6/ : error tolerance for VMCON

factor /0.1/ : used in HYBRD for first step size

ftol /1.0e-4/ : error tolerance for HYBRD

boundl(ipnvars) /../ : lower bounds used on ixc variables during VMCON optimisation runs

allowable first wall/blanket neutron fluence (MW-yr/m2) (blktmodel=0)

allowable divertor heat fluence (MW-yr/m2)

blanket direct cost (M$)

total account 221 cost (M$) - first wall, blanket, shield, support structure and div plates

total account 222 cost (M$) - TF coils + PF coils

total capital cost including interest (M$)

fixed cost of superconducting cable ($/m)

cost of PF coil steel conduit/sheath ($/m)

cost of TF coil steel conduit/sheath ($/m)

current drive direct costs (M$)

total plant direct cost (M$)

lifetime of heating/current drive system (y)

Total plant availability fraction; input if iavail=0

Total plant capacity factor

indirect cost factor (func of lsa) (cost model = 0)

cost of land (M$)

cost of electricity ($/MW-hr)

capital cost of electricity (m$/kW-hr)

'fuel' (including replaceable components) contribution to cost of electricity (m$/kW-hr)

operation and maintenance contribution to cost of electricity (m$/kW-hr)

plant construction cost (M$)

cost exponent for scaling in 2015 costs model

cost exponent for pebbles in 2015 costs model

cost scaling factor for buildings

cost scaling factor for land

cost scaling factor for TF coils

cost scaling factor for fwbs

cost scaling factor for remote handling

cost scaling factor for vacuum vessel

cost scaling factor for energy conversion system

cost scaling factor for remaining subsystems

Maintenance cost factor: first wall, blanket, shield, divertor

Maintenance cost factor: All other components except coils, vacuum vessel, thermal shield, cryostat, land

amortization factor (fixed charge factor) "A" (years)

Switch for cost model:

• =0 use $ 1990 PROCESS model
• =1 use $ 2014 Kovari model
• =2 use user-provided model

Switch for the centrepost lifetime constraint 0 : The CP full power year lifetime is set by the user via cplife_input 1 : The CP lifetime is equal to the divertor lifetime 2 : The CP lifetime is equal to the breeding blankets lifetime 3 : The CP lifetime is equal to the plant lifetime

owner cost factor

User input full power year lifetime of the centrepost (years) (i_cp_lifetime = 0)

Calculated full power year lifetime of centrepost (years)

ST centrepost direct cost (M$)

allowable ST centrepost neutron fluence (MW-yr/m2)

reactor core costs (categories 221, 222 and 223)

allowance for site costs (M$)

cost of turbine building (M$)

proportion of constructed cost required for decommissioning fund

diff between borrowing and saving interest rates

divertor direct cost (M$)

Full power lifetime of divertor (y)

period prior to the end of the plant life that the decommissioning fund is used (years)

average cost of money for construction of plant assuming design/construction time of six years

average cost of money for replaceable components assuming lead time for these of two years

fraction of current drive cost treated as fuel (if ifueltyp = 1)

project contingency factor

fixed charge rate during construction

multiplier for Nth of a kind costs

first wall cost (M$)

Switch for plant availability model:

• =0 use input value for cfactr
• =1 calculate cfactr using Taylor and Ward 1999 model
• =2 calculate cfactr using new (2015) model
• =3 calculate cfactr using ST model

Switch for fw/blanket lifetime calculation in availability module:

• =0 use neutron fluence model
• =1 use fusion power model (DEMO only)

Allowable DPA from DEMO fw/blanket lifetime calculation in availability module

Number of fusion cycles to reach allowable DPA from DEMO fw/blanket lifetime calculation

Minimum availability (constraint equation 61)

Unit cost for tokamak complex buildings, including building and site services ($/m3)

Unit cost for unshielded non-active buildings ($/m3)

F-value for minimum availability (constraint equation 61)

Number of remote handling systems (1-10)

c parameter, which determines the temperature margin at which magnet lifetime starts to decline

Divertor probability of failure (per op day)

Divertor unplanned maintenance time (years)

Reference value for cycle cycle life of divertor

The cycle when the divertor fails with 100% probability

Reference value for cycle life of blanket

The cycle when the blanket fails with 100% probability

Fwbs probability of failure (per op day)

Fwbs unplanned maintenance time (years)

Vacuum system pump redundancy level (%)

Number of redundant vacuum pumps

Operational time (yrs)

time taken to replace blanket (y) (iavail=1)

time taken to replace both blanket and divertor (y) (iavail=1)

time taken to replace divertor (y) (iavail=1)

unplanned unavailability factor for balance of plant (iavail=1)

unplanned unavailability factor for current drive (iavail=1)

unplanned unavailability factor for divertor (iavail=1)

unplanned unavailability factor for fuel system (iavail=1)

unplanned unavailability factor for first wall (iavail=1)

unplanned unavailability factor for magnets (iavail=1)

unplanned unavailability factor for vessel (iavail=1)

Switch for fuel type:

• =2 treat initial blanket, divertor, first wall as capital costs. Treat all later items and fraction fcdfuel of CD equipment as fuel costs
• =1 treat blanket divertor, first wall and fraction fcdfuel of CD equipment as fuel cost
• =0 treat these as capital cost

Switch for net electric power calculation:

• =0 scale so that always > 0
• =1 let go < 0 (no c-o-e)

Switch for net electric power and cost of electricity calculations:

• =0 do not calculate MW(electric) or c-o-e
• =1 calculate MW(electric) and c-o-e

Level of safety assurance switch (generally, use 3 or 4):

• =1 truly passively safe plant
• =2,3 in-between
• =4 like current fission plant

interest portion of capital cost (M$)

Switch for costs output:

• =0 do not write cost-related outputs to file
• =1 write cost-related outputs to file

effective cost of money in constant dollars

ratio of additional HCD power for start-up to flat-top operational requirements

cost associated with additional HCD system power required on start-up ($)

Switch for superconductor cost model:

• =0 use $/kg
• =1 use $/kAm

Full power year plant lifetime (years)

Maintenance time for replacing CP (years) (iavail = 3)

User-input CP unplanned unavailability (iavail = 3)

unit cost for administration buildings (M$/m3)

unit cost for aux facility power equipment ($)

unit cost for aux heat transport equipment ($/W**exphts)

unit cost of auxiliary transformer ($/kVA)

unit cost for blanket beryllium ($/kg)

unit cost for breeder material ($/kg) (blktmodel>0)

unit cost for blanket lithium ($/kg) (30% Li6)

unit cost for blanket Li_2O ($/kg)

unit cost for blanket Li-Pb ($/kg) (30% Li6)

unit cost for blanket stainless steel ($/kg)

unit cost for blanket vanadium ($/kg)

vacuum system backing pump cost ($)

cost of aluminium bus for TF coil ($/A-m)

cost of superconductor case ($/kg)

unit cost for control buildings (M$/m3)

cost of high strength tapered copper ($/kg)

cost of TF outboard leg plate coils ($/kg)

vacuum system cryopump cost ($)

unit cost for cryogenic building (M$/vol)

heat transport system cryoplant costs ($/W**expcry)

unit cost for vacuum vessel ($/kg)

unit cost for copper in superconducting cable ($/kg)

cost per 8 MW diesel generator ($)

cost of divertor blade ($)

detritiation, air cleanup cost ($/10000m3/hr)

vacuum system duct cost ($/m)

ECH system cost ($/W)

unit cost for electrical equipment building (M$/m3)

MGF (motor-generator flywheel) cost factor ($/MVA**0.8)

MGF (motor-generator flywheel) cost factor ($/MJ**0.8)

cost of fuelling system ($)

outer PF coil fence support cost ($/kg)

cost of 60g/day tritium processing unit ($)

unit cost of D-T fuel (M$/year/1200MW)

first wall armour cost ($/m2)

first wall passive stabiliser cost ($)

first wall structure cost ($/m2)

cost of reactor structure ($/kg)

cost of helium-3 ($/kg)

cost of heat rejection system ($)

cost of heat transport system equipment per loop ($/W); dependent on coolant type (coolwh)

cost of instrumentation, control & diagnostics ($)

ICH system cost ($/W)

superconductor intercoil structure cost ($/kg)

lower hybrid system cost ($/W)

low voltage system cost ($/kVA)

unit cost for reactor maintenance building (M$/m3)

cost of maintenance equipment ($)

miscellaneous plant allowance ($)

NBI system cost ($/W)

cost of nuclear building ventilation ($/m3)

annual cost of operation and maintenance (M$/year/1200MW**0.5)

penetration shield cost ($/kg)

cost of PF coil buses ($/kA-m)

cost of PF coil DC breakers ($/MVA**0.7)

cost of PF burn power supplies ($/kW**0.7)

cost of PF coil AC breakers ($/circuit)

cost factor for dump resistors ($/MJ)

cost of PF instrumentation and control ($/channel)

cost of PF coil pulsed power supplies ($/MVA)

primary heat transport cost ($/W**exphts)

cost of primary power transformers ($/kVA**0.9)

cost of reactor building (M$/m3)

cost of superconductor ($/kg)

cost of superconductor ($/kA m) at 6.4 T, 4.2 K

cost of shops and warehouses (M$/m3)

cost of shield structural steel ($/kg)

switchyard equipment costs ($)

cost of TF coil breakers ($/W**0.7)

cost of TF coil bus ($/kg)

cost of TF coil dump resistors ($/J)

additional cost of TF coil dump resistors ($/coil)

cost of TF coil instrumentation and control ($/coil/30)

cost of TF coil power supplies ($/W**0.7)

cost of TF coil slow dump switches ($/A)

cost of turbomolecular pump ($)

cost of tritium building ($/m3)

cost of turbine plant equipment ($) (dependent on coolant type coolwh)

vacuum system valve cost ($)

vacuum duct shield cost ($/kg)

vacuum system instrumentation and control cost ($)

cost of PF coil superconductor windings ($/m)

cost of TF coil superconductor windings ($/m)

cost of active assembly shop ($/m3)

cost of waste disposal (M$/y/1200MW)

external case area per coil (inboard leg) (m2)

external case area per coil (outboard leg) (m2)

area of the cable conduit (m2)

Winding pack conductor area [m2] Does not include the area of voids and central helium channel

Cable space area (per turn) [m2] Includes the area of voids and central helium channel

single turn insulation area (m2)

winding pack turn insulation area per coil (m2)

Allowable maximum shear stress (Tresca criterion) in TF coil case (Pa)

Allowable maximum shear stress (Tresca criterion) in TF coil conduit (Pa)

Allowable Tresca stress in TF coil structural material (Pa)

outboard TF leg area (m2)

winding pack structure area (m2)

winding pack void (He coolant) area (m2)

winding pack He coil area (m2)

upper critical field (T) for Nb3Sn superconductor at zero temperature and strain (i_tf_sc_mat=4, =bc20m)

mean peak field at TF coil (T)

peak field at TF conductor with ripple (T)

case strain

inboard TF coil case plasma side thickness (m) (calculated for stellarators)

inboard TF coil case plasma side thickness as a fraction of tfcth

logical switch to make casthi a fraction of TF coil thickness (casthi_fraction)

inboard TF coil sidewall case thickness (m) (calculated for stellarators)

inboard TF coil sidewall case thickness as a fraction of tftort

logical switch to make casths a fraction of TF coil thickness (casths_fraction)

Conductor (cable + steel conduit) area averaged dimension [m]

TF coil turn edge length including turn insulation [m] If the turn is not a square (i_tf_turns_integer = 1) a squared turn of equivelent size is use to calculated this quantity If the t_turn_tf is non zero, cpttf is calculated

Boolean switch to activated when the user set the TF coil turn dimensions Not an input

f-value for TF turn edge length constraint If the turn is not a square (i_tf_turns_integer = 1) a squared turn of equivelent size is use for this constraint iteration variable ixc = 175 constraint equation icc = 86

TF turn edge length including turn insulation upper limit [m] If the turn is not a square (i_tf_turns_integer = 1) a squared turn of equivelent size is use for this constraint constraint equation icc = 86

TF coil superconducting cable squared/rounded dimensions [m] If the turn is not a square (i_tf_turns_integer = 1) a squared cable of equivelent size is use to calculated this quantity If the t_cable_tf is non zero, cpttf is calculated

Boolean switch to activated when the user set the TF coil cable dimensions Not an input

Area of space inside conductor (m2)

TF outboard leg current density (A/m2) (resistive coils only)

centering force on inboard leg (per coil) (N/m)

length of TF coil inboard leg ('centrepost') (i_tf_sup = 1)

TF coil current per turn (A). (calculated for stellarators) (calculated for integer-turn TF coils i_tf_turns_integer=1) (iteration variable 60)

Max TF coil current per turn [A]. (for stellarators and i_tf_turns_integer=1) (constraint equation 77)

density of coil case (kg/m3)

density of superconductor type given by i_tf_sc_mat/isumatoh/isumatpf (kg/m3)

density of conduit + ground-wall insulation (kg/m3)

diameter of central helium channel in TF winding (m)

total stored energy in the toroidal field (GJ)

upper critical field of GL_nbti

critical temperature of GL_nbti

Maximal (WP averaged) force density in TF coils at 1 point. (MN/m3)

copper fraction of cable conductor (TF coils) (iteration variable 59)

technology adjustment factor for critical current density fit for isumat..=2 Bi-2212 superconductor, to describe the level of technology assumed (i.e. to account for stress, fatigue, radiation, AC losses, joints or manufacturing variations; 1.0 would be very optimistic)

Radial strain in insulator

Switch for the TF coil stress model 0 : Generalized plane strain formulation, Issues #977 and #991, O(n^3) 1 : Old plane stress model (only for SC) 2 : Axisymmetric extended plane strain, Issues #1414 and #998, O(n)

Switch for TF coil conduit Tresca stress criterion: 0 : Tresca (no adjustment); 1 : Tresca with CEA adjustment factors (radial+2%, vertical+60%)

Switch for TF WP geometry selection 0 : Rectangular geometry 1 : Double rectangular geometry 2 : Trapezoidal geometry (constant lateral casing thickness) Default setting for backward compatibility if i_tf_turns_integer = 0 : Double rectangular if i_tf_turns_integer = 1 : Rectangular

Switch for TF case geometry selection 0 : Circular front case (ITER design) 1 : Straight front case

Switch for TF coil integer/non-integer turns: 0 : non-integer turns 1 : integer turns

Switch for superconductor material in TF coils:

• =1 ITER Nb3Sn critical surface model with standard ITER parameters
• =2 Bi-2212 high temperature superconductor (range of validity T < 20K, adjusted field b < 104 T, B > 6 T)
• =3 NbTi
• =4 ITER Nb3Sn model with user-specified parameters
• =5 WST Nb3Sn parameterisation
• =6 REBCO HTS tape in CroCo strand
• =7 Durham Ginzburg-Landau critical surface model for Nb-Ti
• =8 Durham Ginzburg-Landau critical surface model for REBCO
• =9 Hazelton experimental data + Zhai conceptual model for REBCO

Switch for TF coil conductor model:

• =0 copper
• =1 superconductor
• =2 Cryogenic aluminium

Switch for TF coil toroidal shape:

• =0 Default value : Picture frame coil for TART / PROCESS D-shape for non itart
• =1 PROCESS D-shape : parametrise with 2 arcs
• =2 Picture frame coils

Switch for the behavior of the TF coil conductor elastic axial properties

• =0 Young's modulus is set to zero, and the conductor is not considered in the stress calculation. This corresponds to the case that the conductor is much less stiff than the conduit, or the case that the conductor is prevented (isolated) from taking axial loads.
• =1 Elastic properties are set by user input, using the variable eyoung_cond_axial
• =2 Elastic properties are set to reasonable defaults taking into account the superconducting material i_tf_sc_mat

Switch for the behavior of the elastic properties of the TF coil conductorin the transverse direction. Only active if i_tf_cond_eyoung_axial == 2

• =0 Cable not potted in solder. Transverse Young's modulus set to zero.
• =1 Cable potted in solder. If i_tf_cond_eyoung_axial == 2, the transverse Young's modulus of the conductor is equal to the axial, which is set to a sensible material-dependent default.

Number of pancakes in TF coil. Only used if i_tf_turns_integer=1

Number of layers in TF coil. Only used if i_tf_turns_integer=1

Size of the arrays per layers storing the radial dependent stress quantities (stresses, strain displacement etc..)

Switch for TF inboard suport structure design:

Default setting for backward compatibility - if copper resistive TF (i_tf_sup = 0) : Free standing TF without bucking structure - if Superconducting TF (i_tf_sup = 1) : Free standing TF with a steel casing - if aluminium TF (i_tf_sup = 2) : Free standing TF with a bucking structure Rem : the case is a bucking structure - =0 : Free standing TF without case/bucking cyliner (only a conductor layer) - =1 : Free standing TF with a case/bucking cylinder made of - if copper resistive TF (i_tf_sup = 0) : used defined bucking cylinder - if Superconducting TF (i_tf_sup = 1) : Steel casing - if aluminium resisitive TF (i_tf_sup = 2) : used defined bucking cylinder - =2 : The TF is in contact with the CS : "bucked and wedged design" Fast version : thin TF-CS interface neglected in the stress calculations (3 layers) The CS is frictionally decoupled from the TF, does not carry axial tension - =3 : The TF is in contact with the CS : "bucked and wedged design" Full version : thin TF-CS Kapton interface introduced in the stress calculations (4 layers) The CS and kaptop are frictionally decoupled from the TF, do not carry axial tension

Number of layers of different stress properties in the WP. If n_tf_graded_layers > 1, a graded coil is condidered

Number of layers considered for the inboard TF stress calculations set in initial.f90 from i_tf_bucking and n_tf_graded_layers

Maximum number of layers that can be considered in the TF coil composited/smeared stress analysis. This is the layers of one turn, not the entire WP. Default: 5. void, conductor, copper, conduit, insulation.

bussing current density (A/m2)

j_crit_str : superconductor strand critical current density under operating conditions (A/m2). Necessary for the cost calculation in $/kAm

j_crit_str_pf_0 : superconductor strand critical current density at 6 T and 4.2 K (A/m2) Necessary for the cost calculation in $/kAm

critical current density for winding pack (A/m2)

allowable TF coil winding pack current density, for dump temperature rise protection (A/m2)

winding pack engineering current density (A/m2)

Overall current density in TF coil inboard legs midplane (A/m2) Rem SK : Not used in tfcoil to set the current any more. Should not be used as iteration variable 12 any more. It is now calculated.

Insulator Young's modulus [Pa]. Default value (1.0D8) setup the following values - SC TF, eyoung_ins = 20 Gpa (default value from DDD11-2 v2 2 (2009)) - Al TF, eyoung_ins = 2.5 GPa (Kapton polymer)

Steel case Young's modulus (Pa) (default value from DDD11-2 v2 2 (2009))

SC TF coil conductor Young's modulus in the parallel (along the wire/tape) direction [Pa] Set by user input only if i_tf_cond_eyoung_axial == 1; otherwise set by the behavior of that switch.

SC TF coil conductor Young's modulus in the transverse direction [Pa] Set by user input only if i_tf_cond_eyoung_axial == 1; otherwise set by the behavior of that switch.

Resistive TF magnets bucking cylinder young modulus (Pa)

Copper young modulus. Default value taken from wikipedia

Aluminium young modulus. Default value taken from wikipedia

Steel Poisson's ratio, Source : https://www.engineeringtoolbox.com/metals-poissons-ratio-d_1268.html

Copper Poisson's ratio. Source : https://www.engineeringtoolbox.com/poissons-ratio-d_1224.html

Aluminium Poisson's ratio. Source : https://www.engineeringtoolbox.com/poissons-ratio-d_1224.html

Insulation Poisson's ratio. Default: Kapton. Source : DuPont™ Kapton® HN datasheet.

SC TF coil conductor Poisson's ratio in the parallel-transverse direction

SC TF coil conductor Poisson's ratio in the transverse-transverse direction

Radius of maximum TF B-field (m)

TF coil leg resistance (ohm)

Minimal distance between two toroidal coils. (m)

F-value for minimum tftort (constraint equation 82)

aximum allowable toroidal field ripple amplitude at plasma edge (%)

peak/average toroidal field ripple at plasma edge (%)

total (summed) current in TF coils (A)

Size of the radial distribution arrays per layers used for stress, strain and displacement distibution

Array refining the radii of the stress calculations arrays

TF Inboard leg radial stress in steel r distribution at mid-plane [Pa]

TF Inboard leg tangential stress in steel r distribution at mid-plane [Pa]

TF coil radial deflection (displacement) radial distribution [m]

TF Inboard leg vertical tensile stress in steel at mid-plane [Pa]

TF Inboard leg Von-Mises stress in steel r distribution at mid-plane [Pa]

TF Inboard leg maximum shear stress (Tresca criterion) in steel r distribution at mid-plane [Pa]

Maximum shear stress (Tresca criterion) in CS structures at CS flux swing [Pa]:

• If superconducting CS (ipfres = 0): turn steel conduits stress
• If resistive CS (ipfres = 1): copper conductor stress

Quantity only computed for bucked and wedged design (i_tf_bucking >= 2) Def : CS Flux swing, instant when the current changes sign in CS (null current)

Maximum shear stress (Tresca criterion) in TF casing steel structures (Pa)

Residual manufacturing strain in CS superconductor material

Residual manufacturing strain in PF superconductor material

Residual manufacturing strain in TF superconductor material If i_str_wp == 0, used to compute the critical surface. Otherwise, the self-consistent winding pack str_wp is used.

Axial (vertical) strain in the TF coil winding pack found by self-consistent stress/strain calculation. if i_str_wp == 1, used to compute the critical surface. Otherwise, the input value str_tf_con_res is used. Constrain the absolute value using constraint equation 88 You can't have constraint 88 and i_str_wp = 0 at the same time

Maximum allowed absolute value of the strain in the TF coil (Constraint equation 88)

Switch for the behavior of the TF strain used to compute the strain-dependent critical surface:

• =0 str_tf_con_res is used
• =1 str_wp is used

switch for TF coil quench model (Only applies to REBCO magnet at present, issue #522):

• ='exponential' exponential quench with constant discharge resistor
• ='linear' quench with constant voltage

Time at which TF quench is detected (s)

critical temperature (K) for superconductor at zero field and strain (i_tf_sc_mat=4, =tc0m)

fast discharge time for TF coil in event of quench (s) (iteration variable 56)

For REBCO model, meaning depends on quench_model:

• exponential quench : e-folding time (s)`
• linear quench : discharge time (s)

Area of inboard midplane TF legs (m2)

TF coil bus length (m)

TF coil bus mass (kg)

available DC power for charging the TF coils (kW)

Peak power per TF power supply (MW)

Peak resistive TF coil inboard leg power (MW)

TF joints resistive power losses (MW)

surface area of toroidal shells covering TF coils (m2)

TF coil half-width - inner bore (m)

TF coil inductance (H)

TF coil WP insertion gap (m)

TF coil outboard leg resistive power (MW)

TF coil inboard leg resistivity [Ohm-m]. If itart=0, this variable is the average resistivity over the whole magnet

Resistivity of a TF coil leg (Ohm-m)

Resistivity of a TF coil bus (Ohm-m). Default value takes the same res as the leg one

Centrepost resistivity enhancement factor. For itart=0, this factor is used for the whole magnet

Ouboard legs resistivity enhancement factor. Only used for itart=1.

Switch for CP demoutable joints type -= 0 : Clampled joints -= 1 : Sliding joints Default value (-1) choses : Sliding joints for resistive magnets (i_tf_sup = 0, 2) Clampled joints for superconducting magents (i_tf_sup = 1)

TF joints surfacic resistivity [ohm.m]. Feldmetal joints assumed.

Number of contact per turn

Number of joints Ex: n_tf_joints = 2 for top and bottom CP joints

TF sliding joints contact pad width [m]

Calculated TF joints resistive power losses [W]

TF coil circumference (m)

TF cryoplant efficiency (compared to pefect Carnot cycle). Using -1 set the default value depending on magnet technology:

• i_tf_sup = 1 : SC magnet, eff_tf_cryo = 0.13 (ITER design)
• i_tf_sup = 2 : Cryo-aluminium, eff_tf_cryo = 0.4

Number of TF coils (default = 50 for stellarators). Number of TF coils outer legs for ST

TF coil half-width - outer bore (m)

area of the inboard TF coil legs (m2)

area of the outboard TF coil legs (m2)

peak helium coolant temperature in TF coils and PF coils (K)

TF coil toroidal thickness (m)

conduit insulation thickness (m)

Additional insulation thickness between layers (m)

inboard TF coil case outer (non-plasma side) thickness (m) (iteration variable 57) (calculated for stellarators)

radial thickness of winding pack (m) (iteration variable 140) (issue #514)

TF coil conduit case thickness (m) (iteration variable 58)

Thickness of the ground insulation layer surrounding (m) - Superconductor TF (i_tf_sup == 1) : The TF coil Winding packs - Resistive magnets (i_tf_sup /= 1) : The TF coil wedges Rem : Thickness calculated for stellarators.

minimum allowable temperature margin : TF coils (K)

minimum allowable temperature margin : CS (K)

minimum allowable temperature margin : TFC AND CS (K)

temperature margin (K)

TF coil temperature margin (K)

maximum temp rise during a quench for protection (K)

CroCo strand: maximum permitted temp during a quench (K)

CroCo strand: Actual temp reached during a quench (K)

coil temperature for cryogenic plant power calculation (K)

number of turns per TF coil

max voltage across TF coil during quench (kV) (iteration variable 52)

vertical tension on inboard leg/coil (N)

Fraction of the total vertical force taken by the TF inboard leg tension Not used for resistive itart=1 (sliding joints)

Vertical tension on outboard leg/coil (N)

coolant fraction of TFC 'cable' (i_tf_sup=1), or of TFC leg (i_tf_ssup=0)

volume of each TF coil outboard leg (m3)

TF coil voltage for resistive coil including bus (kV)

voltage across a TF coil during quench (kV)

mass per coil of external case (kg)

TF coil conductor mass per coil (kg/coil). For itart=1, coil is return limb plus centrepost/n_tf

copper mass in TF coil conductor (kg/coil). For itart=1, coil is return limb plus centrepost/n_tf

Aluminium mass in TF coil conductor (kg/coil). For itart=1, coil is return limb plus centrepost/n_tf

conduit insulation mass in TF coil conductor (kg/coil)

superconductor mass in TF coil cable (kg/coil)

steel conduit mass in TF coil conductor (kg/coil)

mass of ground-wall insulation layer per coil (kg/coil)

total mass of the TF coils (kg)

width of first step of winding pack (m)

width of second step of winding pack (m)

angle of arc i (rad)

radius of arc i (m)

x location of arc point i on surface (m)

x location of arc centre i (m)

y location of arc point i on surface (m)

y location of arc centre i (m)

Horizontal radius of inside edge of TF coil (m)

Vertical radius of inside edge of TF coil (m)

centrepost taper maximum radius adjustment (m)

centrepost taper height adjustment (m)

centrepost coolant pump efficiency

coolant fraction of TF coil inboard legs (iteration variable 23)

coolant fraction of TF coil outboard legs

Centrepost cooling area toroidal cross-section (constant over the whole CP)

number of centrepost coolant tubes

centrepost coolant pump power (W)

resistive power in the centrepost (itart=1) [W]. If itart=0, this variable is the ressitive power on the whole magnet

Summed resistive power in the TF coil legs [W]. Remain 0 if itart=0.

maximum peak centrepost temperature (K) (constraint equation 44)

average radius of coolant channel (m) (iteration variable 69)

centrepost coolant inlet temperature (K)

inlet / outlet TF coil coolant temperature rise (K)

Average temperature of centrepost called CP (K). Only used for resistive coils to compute the resisitive heating. Must be an iteration variable for ST (itart=1) (iteration variable 20)

Computed centrepost average temperature (K) (for consistency)

Average temperature of the TF outboard legs [K]. If tlegav=-1.0, the ouboard legs and CP temperatures are the same. Fixed for now, should use a contraints eq like tcpav

peak centrepost temperature (K)

inlet centrepost coolant flow speed at midplane (m/s) (iteration variable 70)

Exact conductor volume in the centrepost (m3)

mass of TF coil inboard legs (kg)

mass of the TF coil legs (kg)

Cryo cooling requirement at helium temp 4.5K (kW)

The angle of the outboard arc forming the TF coil current center line [deg]

The angle of the outboard arc forming the Vacuum Vessel current center line [deg]

The allowable peak maximum shear stress in the vacuum vessel due to quench and fast discharge of the TF coils [Pa]

ratio of specific heats for helium (primary_pumping=3)

temperature in FW and blanket coolant at blanket entrance (primary_pumping=3) [K]

temperature in FW and blanket coolant at blanket exit (primary_pumping=3) [K]

pressure in FW and blanket coolant at pump exit (primary_pumping=3) [Pa]

pressure drop in FW and blanket coolant including heat exchanger and pipes (primary_pumping=3) [Pa]

mechanical pumping power for FW and blanket including heat exchanger and pipes (primary_pumping=3) [MW]

residual hoop stress in strucutal material (Pa)

Allowable number of cycles for CS stress model

Minimum llowable number of cycles for CS stress model

Initial depth of crack in thickness of conduit (m)

Inital vertical crack size (m)

Thickness of CS conductor conduit (m)

Vertical thickness of CS conductor conduit (m)

Switch to pass bkt_life cycles to n_cycle_min

Safety factor for vertical crack size (-)

Safety factor for radial crack size (-)

safety factor for stress intensity factor (-)

Paris equation material coefficient (-)

Paris equation material power law (-)

walker coefficent (-)

fracture toughness (MPa m^1/2)

area divertor / area main plasma (along separatrix)

angle of incidence of field line on plate (rad)

field line angle wrt divertor target plate (degrees)

poloidal plane angle between divertor plate and leg, inboard (rad)

poloidal plane angle between divertor plate and leg, outboard (rad)

reference B_p at outboard divertor strike point (T)

fitting coefficient to adjust ptpdiv, ppdiv

fitting coefficient to adjust ptpdiv, ppdiv

fitting coefficient to adjust ptpdiv, ppdiv

fitting coefficient to adjust ptpdiv, ppdiv

fitting coefficient to adjust ptpdiv, ppdiv

fitting coefficient to adjust ptpdiv, ppdiv

coeff for power distribution along main plasma

plasma density at divertor (10**20 /m3)

density at plate (on separatrix) (10**20 /m3)

divertor coolant fraction

divertor structure density (kg/m3)

switch for divertor Zeff model:

• =0 calc
• =1 input

divertor structure vertical thickness (m)

divertor plate mass (kg)

divertor plate thickness (m) (from Spears, Sept 1990)

divertor surface area (m2)

radial gradient ratio

divertor area fudge factor (for ITER, Sept 1990)

fraction of power to outboard divertor (for single null)

coefficient for gamdiv

The plasma flux expansion in the divertor (default 2; Wade 2020)

fraction of radiated power to plate

divertor heat load (MW/m2)

switch for user input hldiv:

• = 0: divtart model turned off and user inputs hldiv
• = 1: divtart model calculates hldiv
• = 2: divwade model calculates hldiv

heat load limit (MW/m2)

power fraction for outboard double-null scrape-off plasma

power flow width (m)

minimum strike angle for heat flux calculation

pressure ratio (nT)_plasma / (nT)_scrape-off

power spillage to private flux factor

peak heat load at plate (with radiation) (MW/m2)

n-scrape-off / n-average plasma; (input for ipedestal=0, = nesep/dene if ipedestal>=1)

peak temperature at the plate (eV)

connection length ratio, outboard side

ratio of collision length / connection length

maximum value for length ratio (rlclolcn) (constraintg eqn 22)

effective separatrix/divertor radius ratio

main plasma connection length (m)

temperature at divertor (eV) (input for stellarator only, calculated for tokamaks)

temperature at the separatrix (eV)

parallel heat transport coefficient (m2/s)

perpendicular heat transport coefficient (m2/s)

Zeff in the divertor region (if divdum/=0)

switch for vacuum pumping model:

• ='old' for old detailed ETR model
• ='simple' for simple steady-state model with comparison to ITER cryopumps

number of high vacuum pumps (real number), each with the throughput of one ITER cryopump (50 Pa m3 s-1), all operating at the same time (vacuum_model='simple')

switch for vacuum pump type:

• =0 - for turbomolecular pump (magnetic bearing) with speed of 2.0 m3/s (1.95 for N2, 1.8 for He, 1.8 for DT)
• =1 - for compound cryopump with nominal speed of 10.0 m3/s (9.0 for N2, 5.0 for He and 25.0 for DT)

number of ducts (torus to pumps)

vacuum system duct length scaling

base pressure during dwell before gas pre-fill(Pa)

divertor chamber pressure during burn (Pa)

Pump throughput (molecules/s) (default is ITER value)

plasma chamber wall outgassing rate (Pa-m/s)

neutral gas temperature in chamber (K)

mass of vacuum duct shield (kg)

diameter of duct passage (m)

number of high vacuum pumps

switch for dwell pumping options:

• =0 pumping only during tdwell
• =1 pumping only during tramp
• =2 pumping during tdwell + tramp

area of one pumping port as a fraction of plasma surface area

maximum pumping speed per unit area for deuterium & tritium, molecular flow

effective pumping speed reduction factor due to duct impedance

initial neutral pressure at the beginning of the dwell phase (Pa)

outgassing decay index

outgassing prefactor kw: outgassing rate at 1 s per unit area (Pa m s-1)

power plant type

short descriptive title for the run

switch for turning on/off diagnostic messages

• =0 turn off diagnostics
• =1 turn on diagnostics

turns on built-in tests if set to 1

maximum number of VMCON iterations

input file prefix

output file prefix

scan parameter description label

scan value name label

scan parameter description label (2nd dimension)

scan value name label (2nd dimension)

Makes iscan available globally.

VMCON convergence parameter "sum"

first wall bulk coolant temperature (C)

maximum allowable temperature change in stainless steel thermal storage block (K) (istore=3)

Switch for thermal storage method:

• =1 option 1 of Electrowatt report, AEA FUS 205
• =2 option 2 of Electrowatt report, AEA FUS 205
• =3 stainless steel block

Switch for first wall axial stress model:

• =1 total axial constraint, no bending
• =2 no axial constraint, no bending
• =3 no axial constraint, bending

Switch for reactor model:

• =0 continuous operation
• =1 pulsed operation

Dimensionless winding pack width

Dimensionless winding pack radial thickness

Ratio of peak field with ripple to nominal axisymmetric peak field

Current in each TF coil

Total cross-sectional area of winding pack including GW insulation and insertion gap [m2]

Total cross-sectional area of winding pack without ground insulation and insertion gap [m2]

Inboard coil steel coil cross-sectional area [m2]

Inboard coil insulation cross-section per coil [m2]

Inboard coil steel fraction [-]

Inboard coil insulation fraction [-]

Vertical distance from the midplane to the top of the tapered section [m]

Radial position of plasma-facing edge of TF coil outboard leg [m]

Radial position of outer edge of TF coil inboard leg [m]

Radial position of inner edge and centre of winding pack [m]

Radial position of outer edge and centre of winding pack [m]

Radial position of centre and centre of winding pack [m]

Conductor layer radial thickness at centercollumn top [m] Ground insulation layer included, only defined for itart = 1

CP turn insulation volume [m3]

CP ground insulation volume [m3]

Volume of the CP outer casing cylinder

Minimal toroidal thickness of of winding pack [m]

Averaged toroidal thickness of of winding pack [m]

Average lateral casing thickness [m]

Front casing area [m2]

Nose casing area [m2]

Inboard mid-plane cross-section area of the WP ground insulation [m2]

TF ouboard leg turn insulation area per coil [m2]

TF outboard leg ground insulation area per coil [m2]

Exact TF ouboard leg conductor area [m2]

Half toroidal angular extent of a single TF coil inboard leg

Tan half toroidal angular extent of a single TF coil inboard leg

Conductor area radial and toroidal dimension (integer turn only) [m]

Conductor area radial and toroidal dimension (integer turn only) [m]

Cable area radial and toroidal dimension (integer turn only) [m]

Cable area radial and toroidal dimension (integer turn only) [m]

Turn radial and toroidal dimension (integer turn only) [m]

Turn radial and toroidal dimension (integer turn only) [m]

Cable area averaged dimension (square shape) [m]

Total inboard vertical tension (all coils) [N]

The Tresca stress experienced by the Vacuum Vessel when the SCTF coil quenches [Pa]

Area of cable space inside jacket

FW armour density [kg/m3]

FW density [kg/m3]

Blanket density [kg/m3]

Shield density [kg/m3]

Vacuum vessel density [kg/m3]

Blanket exponent (tonne/m2)

Shield exponent (tonne/m2)

Unit nuclear heating in TF coil (W per W of fusion power)

Unit heating of FW and armour in FW armour (W/kg per W of fusion power)

Unit nuclear heating in shield (W per W of fusion power)

Total nuclear power deposited in blanket covered sector (FW, BLKT, SHLD, TF) (MW)

Exponential factors in nuclear heating calcs

Exponential factors in nuclear heating calcs

Exponential factors in nuclear heating calcs

thickness of REBCO layer in tape (m) (iteration variable 138)

thickness of copper layer in tape (m) (iteration variable 139)

thickness of Hastelloy layer in tape (m)

Mean width of tape (m)

thickness of tape, inc. all layers (hts, copper, substrate, etc.) (m)

Outer diameter of CroCo strand (m)

Inner diameter of CroCo copper tube (m)

Thickness of CroCo copper tube (m) (iteration variable 158)

residual resistivity ratio copper in TF superconducting cable

TF coil current / copper area (A/m2)

Maximum TF coil current / copper area (A/m2)

f-value for constraint 75: TF coil current / copper area < copperA_m2_max

CS coil current / copper area (A/m2) (sweep variable 61)

Maximum CS coil current / copper area (A/m2)

f-value for constraint 88: CS coil current / copper area < copperA_m2_max

Volume of inboard and outboard shield (m3)

Volume of inboard and outboard shield (m3)

Volume of inboard and outboard Vacuum Vessel (m3)

Volume of inboard and outboard Vacuum Vessel (m3)

Clearance between uppermost PF coil and cryostat lid (m)

Inboard/outboard void fraction of blanket

Inboard/outboard void fraction of blanket

Inboard/outboard blanket coolant channel length (radial direction) (m)

Inboard/outboard blanket coolant channel length (radial direction) (m)

Inboard/outboard blanket mid-plan toroidal circumference for segment (m)

Inboard/outboard blanket mid-plan toroidal circumference for segment (m)

Inboard/outboard blanket segment poloidal length (m)

Inboard/outboard blanket segment poloidal length (m)

Inboard/outboard primary blanket flow lengths (m)

Inboard/outboard primary blanket flow lengths (m)

Inboard/outboard secondary blanket flow lengths (m)

Inboard/outboard secondary blanket flow lengths (m)

Inboard/outboard first wall nuclear heating (MW)

Inboard/outboard first wall nuclear heating (MW)

Inboard/outboard first wall peak temperature (K)

Inboard/outboard first wall peak temperature (K)

Inboard/outboard total mass flow rate to remove inboard FW power (kg/s)

Inboard/outboard total mass flow rate to remove inboard FW power (kg/s)

Inboard/outboard total mass flow rate to remove inboard FW power (kg/s)

Inboard/utboard total number of pipes

Inboard/utboard total number of pipes

Inboard/outboard mass flow rate per coolant pipe (kg/s)

Inboard/outboard mass flow rate per coolant pipe (kg/s)

Neutron power deposited inboard/outboard blanket blanket (MW)

Neutron power deposited inboard/outboard blanket blanket (MW)

Inboard/outboard blanket mass flow rate for coolant (kg/s)

Inboard/outboard blanket mass flow rate for coolant (kg/s)

Inboard/outboard blanket mass flow rate for coolant (kg/s)

Inboard/outboard blanket mass flow rate for liquid breeder (kg/s)

Inboard/outboard blanket mass flow rate for liquid breeder (kg/s)

Inboard/outboard blanket mass flow rate for liquid breeder (kg/s)

Total mass flow rate for coolant (kg/s)

Inboard/outboard total num of pipes

Inboard/outboard total num of pipes

Inboard/outboard mass flow rate per coolant pipe (kg/s)

Inboard/outboard mass flow rate per coolant pipe (kg/s)

Inboard/outboard coolant velocity in blanket (m/s)

Inboard/outboard coolant velocity in blanket (m/s)

Inboard/outboard first wall pumping power (MW)

Inboard/outboard first wall pumping power (MW)

Inboard/outboard blanket pumping power (MW)

Inboard/outboard blanket pumping power (MW)

Inboard/outboard fw and blanket pumping power (MW)

Inboard/outboard fw and blanket pumping power (MW)

Blanket internal half-height (m)

Shield internal half-height (m)

Vacuum vessel internal half-height (m)

Switch used to specify selected component: blanket=0, shield=1, vacuum vessel=2

administration building volume (m3)

volume of administration buildings (m3)

aux building supporting tokamak processes length, width, height (m)

aux building supporting tokamak processes length, width, height (m)

aux building supporting tokamak processes length, width, height (m)

Site-Wide Auxiliary Cooling Water facility length, width, height (m)

Site-Wide Auxiliary Cooling Water facility length, width, height (m)

Site-Wide Auxiliary Cooling Water facility length, width, height (m)

Radial thickness of bio-shield around reactor (m)

Chemistry labs and treatment buldings length, width, height (m)

Chemistry labs and treatment buldings length, width, height (m)

Chemistry labs and treatment buldings length, width, height (m)

vertical clearance from TF coil to cryostat (m) (calculated for tokamaks)

clearance beneath TF coil to foundation (including basement) (m)

control building length, width, height (m)

control building length, width, height (m)

control building length, width, height (m)

control building volume (m3)

volume of control, protection and i&c building (m3)

vertical dimension of crane arm, operating over reactor (m)

horizontal clearance to building wall for crane operation (m)

vertical clearance for crane operation (m)

Cryogenic Buildings for Magnet and Fuel Cycle length, width, height (m)

Cryogenic Buildings for Magnet and Fuel Cycle length, width, height (m)

Cryogenic Buildings for Magnet and Fuel Cycle length, width, height (m)

Magnet Cryo Storage Tanks length, width, height (m)

Magnet Cryo Storage Tanks length, width, height (m)

Magnet Cryo Storage Tanks length, width, height (m)

vertical clearance from TF coil to cryostat (m)

volume of cryoplant building (m3)

effective total floor space (m2)

Transformers and electrical distribution facilities length, width, height (m)

Transformers and electrical distribution facilities length, width, height (m)

Transformers and electrical distribution facilities length, width, height (m)

Electric (eesential and non-essential) load centres length, width, height (m)

Electric (eesential and non-essential) load centres length, width, height (m)

Electric (eesential and non-essential) load centres length, width, height (m)

Energy Storage facilities length, width, height (m)

Energy Storage facilities length, width, height (m)

Energy Storage facilities length, width, height (m)

volume of electrical equipment building (m3)

volume of energy storage equipment building (m3) (not used if lpulse=0)

Fuel Cycle facilities length, width (m)

Fuel Cycle facilities length, width (m)

foundation thickness (m)

air & gas supply (amalgamated) buildings length, width, height (m)

air & gas supply (amalgamated) buildings length, width, height (m)

air & gas supply (amalgamated) buildings length, width, height (m)

clearance beneath TF coil (m)

HCD building length, width, height (m)

HCD building length, width, height (m)

HCD building length, width, height (m)

clearance around components in hot cell (m)

hot cell wall thickness (m)

heat sinks length, width, height (m)

heat sinks length, width, height (m)

heat sinks length, width, height (m)

hot cell storage component separation distance (m)

hot cell storage and maintenance facility height (m)

hazardous waste storage building length, width, height (m)

hazardous waste storage building length, width, height (m)

hazardous waste storage building length, width, height (m)

switch between routines estimating building sizes (0 = default; 1 = updated)

switch to select verbose output for buildings (1 = verbose)

radioactive waste smelting facility length, width, height (m)

radioactive waste smelting facility length, width, height (m)

radioactive waste smelting facility length, width, height (m)

ILW waste storage building length, width, height (m)

ILW waste storage building length, width, height (m)

ILW waste storage building length, width, height (m)

LLW waste storage building length, width, height (m)

LLW waste storage building length, width, height (m)

LLW waste storage building length, width, height (m)

pulsed magnet power building length, width, height (m)

pulsed magnet power building length, width, height (m)

pulsed magnet power building length, width, height (m)

steady state magnet power trains building length, width, height (m)

steady state magnet power trains building length, width, height (m)

steady state magnet power trains building length, width, height (m)

maintenance control building length, width, height (m)

maintenance control building length, width, height (m)

maintenance control building length, width, height (m)

maintenance building volume multiplication factor

NBI system length, width (m)

NBI system length, width (m)

volume of PF coil power supply building (m3)

power injection building volume (m3)

quantity safety factor for component use during plant lifetime

reactor building volume multiplication factor

reactor building roof thickness (m)

reactor building volume (m3)

reactor building wall thickness (m)

clearance around reactor (m)

reactor building foundation thickness (m)

reactor building length, width, height (m)

reactor building length, width, height (m)

reactor building length, width, height (m)

reactor building roof thickness (m)

reactor building wall thickness (m)

volume of maintenance and assembly building (m3)

robotics buildings length, width, height (m)

robotics buildings length, width, height (m)

robotics buildings length, width, height (m)

clearance to building wall for crane operation (m)

clearance around reactor (m)

security & safety buildings length, width, height (m)

security & safety buildings length, width, height (m)

security & safety buildings length, width, height (m)

fraction of shield mass per TF coil to be moved in the maximum shield lift

shops and warehouse volume (m3)

volume of shops and buildings for plant auxiliaries (m3)

footprint of staff buildings (m2)

staff buildings height (m)

clearance above crane to roof (m)

volume of TF coil power supply building (m3) (calculated if TF coils are superconducting)

transportation clearance between components (m)

transportation clearance between components (m)

volume of tritium, fuel handling and health physics buildings (m3)

turbine hall length, width, height (m)

turbine hall length, width, height (m)

turbine hall length, width, height (m)

tritiated waste storage building length, width, height (m)

tritiated waste storage building length, width, height (m)

tritiated waste storage building length, width, height (m)

internal volume of reactor building (m3)

sum of nuclear buildings volumes (m3)

warm shop length, width, height (m)

warm shop length, width, height (m)

warm shop length, width, height (m)

water, laundry & drainage buildings length, width, height (m)

water, laundry & drainage buildings length, width, height (m)

water, laundry & drainage buildings length, width, height (m)

reactor building crane capacity (kg) (calculated if 0 is input)

hot cell crane capacity (kg) (calculated if 0 is input)

[cold] workshop buildings length, width, height (m)

[cold] workshop buildings length, width, height (m)

[cold] workshop buildings length, width, height (m)

distance from centre of machine to building wall (m)

volume of warm shop building (m3)

warm shop building volume multiplication factor

Floor area of reactor building in m^2

Floor area of electrical equipment and power supply building in m^2

Floor area of auxiliary services building in m^2

Floor area of hot cell building in m^2

Floor area of reactor service building in m^2

Floor area of service water building in m^2

Floor area of fuel handling and storage building in m^2

Floor area of controlroom building in m^2

Floor area of AC power supply building in m^2

Floor area of admin building in m^2

Floor area of site service building in m^2

Floor area of cryogenics and inert gas storage building in m^2

Floor area of security building in m^2

Total number of materials in IFE device. Material numbers are as follows:

• =0 void
• =1 steel
• =2 carbon cloth
• =3 FLiBe
• =4 lithium oxide Li2O
• =5 concrete
• =6 helium
• =7 xenon
• =8 lithium

radial thickness of IFE blanket (m; calculated if ifetyp=4)

radial thickness of IFE curtain (m; ifetyp=4)

vertical thickness of IFE blanket below chamber (m)

vertical thickness of IFE blanket above chamber (m)

IFE blanket material fractions

IFE blanket material masses (kg)

IFE blanket material volumes (m3)

IFE blanket volume (m3)

IFE generic/laser driver cost at edrive=0 (M$)

IFE low energy heavy ion beam driver cost extrapolated to edrive=0 (M$)

IFE high energy heavy ion beam driver cost extrapolated to edrive=0 (M$)

IFE driver cost ($/J wall plug) (ifedrv==3)

vertical thickness of IFE chamber below centre (m)

vertical thickness of IFE chamber above centre (m)

IFE chamber material fractions

IFE chamber material masses (kg)

IFE chamber material volumes (m3)

radius of IFE chamber (m) (iteration variable 84)

IFE chamber volume (m3)

IFE generic/laser driver cost gradient (M$/MJ)

HIB driver cost gradient at low energy (M$/MJ)

HIB driver cost gradient at high energy (M$/MJ)

IFE driver wall plug to target efficiency (ifedrv=0,3) (iteration variable 82)

IFE driver energy (J) (iteration variable 81)

IFE driver wall plug to target efficiency

IFE lithium pump wall plug efficiency (ifetyp=4)

IFE driver efficiency vs driver energy (ifedrv=-1)

fraction of gross electric power to balance-of-plant (IFE)

fraction of breeder external to device core

IFE burn fraction (fraction of tritium fused/target)

radius of FLiBe/lithium inlet (m) (ifetyp=3,4)

f-value for maximum IFE repetition rate (constraint equation 50, iteration variable 86)

radial thickness of IFE first wall (m)

vertical thickness of IFE first wall below chamber (m)

vertical thickness of IFE first wall above chamber (m)

IFE first wall material fractions

IFE first wall material masses (kg)

IFE first wall material volumes (kg)

IFE first wall volume (m3)

IFE target gain

IFE target gain vs driver energy (ifedrv=-1)

IFE heat transport system electrical pump power (MW)

Switch for IFE option:

• =0 use tokamak, RFP or stellarator model
• =1 use IFE model

Switch for type of IFE driver:

• =-1 use gainve, etave for gain and driver efficiency
• =0 use tgain, drveff for gain and driver efficiency
• =1 use laser driver based on SOMBRERO design
• =2 use heavy ion beam driver based on OSIRIS
• =3 Input pfusife, rrin and drveff

Switch for type of IFE device build:

• =0 generic (cylindrical) build
• =1 OSIRIS-like build
• =2 SOMBRERO-like build
• =3 HYLIFE-II-like build
• =4 2019 build

IFE lithium pump power (MW; ifetyp=4)

IFE driver cost multiplier

total mass of FLiBe (kg)

IFE driver power reaching target (W) (iteration variable 85)

IFE input fusion power (MW) (ifedrv=3 only; itv 155)

IFE cryogenic power requirements (MW)

IFE target factory power at 6 Hz repetition rate (MW)

IFE device radial build (m)

IFE device radial build (m)

IFE device radial build (m)

IFE device radial build (m)

IFE device radial build (m)

IFE device radial build (m)

IFE device radial build (m)

IFE driver repetition rate (Hz)

Input IFE repetition rate (Hz) (ifedrv=3 only; itv 156)

maximum IFE repetition rate (Hz)

radial thickness of IFE shield (m)

vertical thickness of IFE shield below chamber (m)

vertical thickness of IFE shield above chamber (m)

IFE shield material fractions

IFE shield material masses (kg)

IFE shield material volumes (kg)

IFE shield volume (m3)

radius of cylindrical blanket section below chamber (ifetyp=2)

radius of cylindrical blanket section above chamber (ifetyp=2)

Lithium Fall Time (s)

IFE target delivery system power (MW)

IFE target factory power (MW)

IFE target gain (if ifedrv = 0) (iteration variable 83)

cost of carbon cloth ($/kg)

cost of concrete ($/kg)

cost of FLiBe ($/kg)

cost of IFE target ($/target)

radial thickness of IFE void between first wall and blanket (m)

vertical thickness of IFE void 1 below chamber (m)

vertical thickness of IFE void 1 above chamber (m)

IFE void 1 material fractions

IFE void 1 material masses (kg)

IFE void 1 material volumes (kg)

IFE void 1 volume (m3)

radial thickness of IFE void between blanket and shield (m)

vertical thickness of IFE void 2 below chamber (m)

vertical thickness of IFE void 2 above chamber (m)

IFE void 2 material fractions

IFE void 2 material masses (kg)

IFE void 2 material volumes (kg)

IFE void 2 volume (m3)

radial thickness of IFE void outside shield (m)

vertical thickness of IFE void 3 below chamber (m)

vertical thickness of IFE void 3 above chamber (m)

IFE void 3 material fractions

IFE void 3 material masses (kg)

IFE void 3 material volumes (kg)

IFE void 3 volume (m3)

IFE vertical build below centre (m)

IFE vertical build below centre (m)

IFE vertical build below centre (m)

IFE vertical build below centre (m)

IFE vertical build below centre (m)

IFE vertical build below centre (m)

IFE vertical build below centre (m)

IFE vertical build above centre (m)

IFE vertical build above centre (m)

IFE vertical build above centre (m)

IFE vertical build above centre (m)

IFE vertical build above centre (m)

IFE vertical build above centre (m)

IFE vertical build above centre (m)

nimp /14/ FIX : number of ion species in impurity radiation model

coreradius /0.6/ : normalised radius defining the 'core' region

coreradiationfraction /1.0/ : fraction of radiation from 'core' region that is subtracted from the loss power

fimp(nimp) /1.0,0.1,0.02,0.0,0.0,0.0,0.0,0.0,0.0016,0.0,0.0,0.0,0.0,0.0/ : impurity number density fractions relative to electron density

imp_label(nimp) : impurity ion species names:

• ( 1) Hydrogen (fraction calculated by code)
• ( 2) Helium
• ( 3) Beryllium
• ( 4) Carbon
• ( 5) Nitrogen
• ( 6) Oxygen
• ( 7) Neon
• ( 8) Silicon
• ( 9) Argon
• (10) Iron
• (11) Nickel
• (12) Krypton
• (13) Xenon
• (14) Tungsten

Used for reporting error in function pimpden

minimum minor radius (m)

Minimal radial space between plasma and coils (m)

blanket total surface area (m2)

inboard blanket surface area (m2)

outboard blanket surface area (m2)

inboard blanket box manifold thickness (m) (blktmodel>0)

outboard blanket box manifold thickness (m) (blktmodel>0)

inboard blanket base plate thickness (m) (blktmodel>0)

outboard blanket base plate thickness (m) (blktmodel>0)

inboard blanket breeding zone thickness (m) (blktmodel>0) (iteration variable 90)

outboard blanket breeding zone thickness (m) (blktmodel>0) (iteration variable 91)

inboard blanket thickness (m); (calculated if blktmodel>0) (=0.0 if iblnkith=0)

outboard blanket thickness (m); calculated if blktmodel>0

top blanket thickness (m), = mean of inboard and outboard blanket thicknesses

central solenoid inboard radius (m) (iteration variable 29)

cryostat lid height scaling factor (tokamaks)

cryostat thickness (m)

vacuum vessel inboard thickness (TF coil / shield) (m)

vacuum vessel outboard thickness (TF coil / shield) (m)

vacuum vessel topside thickness (TF coil / shield) (m) (= d_vv_bot if double-null)

vacuum vessel underside thickness (TF coil / shield) (m)

F-value for stellarator radial space check (constraint equation 83)

Fraction of space occupied by CS pre-compression structure

Separation force in CS coil pre-compression structure

first wall total surface area (m2)

inboard first wall surface area (m2)

outboard first wall surface area (m2)

inboard first wall thickness, initial estimate as calculated (m)

outboard first wall thickness, initial estimate as calculated (m)

gap between inboard vacuum vessel and thermal shield (m) (iteration variable 61)

gap between central solenoid and TF coil (m) (iteration variable 42)

minimum gap between outboard vacuum vessel and TF coil (m) (iteration variable 31)

gap between outboard vacuum vessel and TF coil (m)

maximum (half-)height of TF coil (inside edge) (m)

difference in distance from midplane of upper and lower portions of TF legs (non-zero for single-null devices) (m)

height to top of (upper) TF coil leg (m)

half-height of TF coil inboard leg straight section (m)

Switch for existence of central solenoid:

• =0 central solenoid not present
• =1 central solenoid exists

Switch for existence of central solenoid pre-compression structure:

• =0 no pre-compression structure
• =1 calculated pre-compression structure

Switch for placing the TF coil inside the CS

• = 0 TF coil is outside the CS (default)
• = 1 TF coil is inside the CS

Central solenoid thickness (m) (iteration variable 16)

CS coil precompression structure thickness (m)

sum of thicknesses to the major radius (m)

Required space between coil and plasma for blanket shield wall etc (m)

plasma inboard radius (m) (consistency equation 29)

radius to inboard shield (inside point) (m)

radius to outboard shield (outside point) (m)

Radial plasma facing side position of inboard vacuum vessel [m]

Radial inner side position of inboard neutronic shield [m]

Radial plasma facing side position of inboard neutronic shield [m]

Mid-plane inboard TF coil leg radius at the centre-machine side [m]

Mid-plane inboard TF coil leg radius at middle of the coil [m]

Mid-plane inboard TF coil leg radius at the plasma side [m]

Mid-plane outboard TF coil leg radius at the middle of the coil [m]

Switch selecting the he parametrization of the outer radius of the top of the CP part of the TF coil 0 : r_cp_top is set by the plasma shape 1 : r_cp_top is a user input 2 : r_cp_top is set using the CP top and midplane CP radius ratio

Top outer radius of the centropost (ST only) (m)

Ratio between the top and the midplane TF CP outer radius [-] Not used by default (-1) must be larger than 1 otherwise

TF coil horizontal inner bore (m)

TF coil vertical inner bore (m)

Gap between plasma and first wall, inboard side (m) (if iscrp=1) Iteration variable: ixc = 73 Scan variable: nsweep = 58

Gap between plasma and first wall, outboard side (m) (if iscrp=1) Iteration variable: ixc = 74 Scan variable: nsweep = 59

shield total surface area (m2)

inboard shield surface area (m2)

outboard shield surface area (m2)

inboard shield thickness (m) (iteration variable 93)

lower (under divertor) shield thickness (m)

outboard shield thickness (m) (iteration variable 94)

upper/lower shield thickness (m); calculated if blktmodel > 0 (= shldlth if double-null)

allowable stress in CSpre-compression structure (Pa)

inboard TF coil thickness, (centrepost for ST) (m) (input, calculated or iteration variable 13)

vertical distance between centre of TF coils and centre of plasma (m)

TF coil outboard leg / inboard leg radial thickness ratio (i_tf_sup=0 only) (iteration variable 75)

Outboard TF coil thickness (m)

Minimum metal-to-metal gap between TF coil and thermal shield (m)

TF-VV thermal shield thickness, inboard (m)

TF-VV thermal shield thickness, outboard (m)

TF-VV thermal shield thickness, vertical build (m)

vertical gap between vacuum vessel and thermal shields (m)

vertical gap between x-point and divertor (m) (if = 0, it is calculated)

vertical gap between top of plasma and first wall (m) (= vgap if double-null)

gap between vacuum vessel and blanket (m)

length of inboard divertor plate (m)

length of outboard divertor plate (m)

poloidal length, x-point to inboard strike point (m)

poloidal length, x-point to outboard strike point (m)

outboard strike point radius (m)

ambient air temperature (degrees Celsius)

water temperature (degrees Celsius)

wind speed (m/s)

density of water (kg/m3) for simplicity, set to static value applicable to water at 21 degC

latent heat of vaporization (J/kg) for simplicity, set to static value applicable at 1 atm (100 kPa) air pressure

volumetric heat of vaporization (J/m3)

evaporation ratio: ratio of the heat used to evaporate water to the total heat discharged through the tower

evaporated volume of water (m3)

input waste (heat) energy cooled per evaporated volume (J/m3)

volume evaporated by units of heat energy (m3/MJ)

total volume of water used in cooling tower (m3)

total volume of water used in recirculating system (m3)

total volume of water used in once-through system (m3)

Full power blanket lifetime (years)

mass of water coolant (in shield, blanket, first wall, divertor) [kg]

vacuum vessel mass [kg]