NAMEn:p one line summary of purpose of card (* describes meaning of *NAMEn:p)
# in [] is maximum number of entries allowed if a maximum number exists
PARAMETER1{default value, if any} ... (see command description section)
allowed values of n (e.g., tally or command sequence number), if any
p is the particle type (N, P, or E), if required
PARAMETER1 values are defined
"Keyword" in front of a parameter list means input of the form
PARAMETER1(k)=n1 ... nk for a total of k entries (= is optional)
AREA whole surface area specifications [number of surfaces] (3-20)
AWTAB user specified atomic weight in pairs of zaid aw (3-95)
BBREM bias for high energy bremsstrahlung photons (3-38)
blank blank lines separate MESSAGE, cell, surface, data sets of commands (1-21)
C INP file comment card (no continuation is allowed) (1-21)
Cn specify cosine bins for a type 1 tally (3-70)
cell cards:define geom cells with materials (see Mm card) or void (0) (3-9,4-1,4-19)
CFn tally contributions from flagged cells separately for tally n[# cells](3-78)
CMn multipliers for cosine bins of tally n for type 1 tallies (3-77)
CONTINUE first card in INP for continue run(C on execute line or MESSAGE block) (3-2)
CTME computer time limit in minutes for the problem [1] (3-109)
CUT:p time, energy, and weight cutoffs for particle type p [5] (3-107)
DBCN debug information card(event logs,timing,vov,random number,etc) [20] (3-112)
DDn detector and DXTRAN diagnostics and contribution card (3-85)
DEn dose energy card (used with the DFn card) (3-76,H-4)
DFn dose function card (used with the DEn card) (3-76,H-4)
DRXS discrete reaction neutron cross-section card (3-93)
DSn dependent source distribution card (3-49,4-47)
DXCm:p DXTRAN contribution for DXTRAN sphere m and particle type p[# cells] (3-37)
DXT:p defines DXTRAN spheres for particle type p [28] (3-87)
En upper bounds of energy bins (MeV) for tally n (1-25,3-69)
ELPT:p cell energy cutoff(> of this or CUT:p applies) for particle p[cells] (3-108)
EMn multipliers for the energy bins of tally n on the En card (3-76)
ESPLT:p energy split and Russian roulette card for particle type p [10] (3-104)
EXT:p exponential transform for part p(use wgt window-no forced coll)[cells](3-30)
Fn:p create cell, surface, point tally n for part p(*F for energy)(1-25,3-61,5-1)
FCn user supplied comment for tally n (blank continuation is not allowed) (3-69)
FCL:p force collisions by cell for particle type p [number of cells] (3-32)
FILES user file creation card [30] (3-116)
FILL fill cell with universe or lattice elements with universes(*=degrees) (3-25)
FMn general tally multiplier card for tally n (3-72,4-34,4-36,5-1,G-1)
FQn tally print hierarchy card for ordering of printed output [8] (3-71,5-1)
FSn subdivide cell or surface into segments for tallying [surfaces] (3-79,4-37)
FTn special treatments(# collisions,detector by cell,etc) for tally n(3-89,4-38)
FUn user-defined TALLYX tally input that is required by some FTn options (3-82)
IDUM integer array in MCNP COMMON available to user (also see RDUM) [50] (3-110)
IMP:p definition of cell importances for each particle p [# cells] (1-25,3-28)
KCODE define a criticality eigenvalue (keff) problem [7] (3-57,5-64)
KSRC neutron source point locations for KCODE (or SRCTP file or SDEF card) (3-58)
LAT used to define a lattice as part of a cell card description [cells] (3-24)
LOST lost particle abort/debug print control card [2] (3-112)
Mm material definition card for cells containing material m (1-27,3-92,G-1)
MESSAGE optional card(s) in front of INP file containing execution information (3-1)
MGOPT multigroup forward/adjoint transport option card (3-98)
MODE definition of particles to be run in the problem (1-24,3-19)
MPLOT produce plots of tallies while the problem is running (3-118,B-11)
MTm S(alpha,beta) thermal neutron treatment for material m (3-106,G-2)
NONU treat fission as a capture as a function of cell [number of cells] (3-94)
NPS number of particles to run in the problem from the source [1] (1-28,3-109)
# input cell/surface/source parameters in columns(can use more than once)(3-6)
PDn detector contribution control by cell for tally n [number of cells] (3-37)
PHYS:p control physics used for the transport of particle p [9] (3-100,3-101)
PIKMT photon-production bias card for coupled neutron-photon problems (3-96)
PRDMP print(OUTP)/dump(RUNTPE)/MCTAL/max dumps(RUNTPE)/TFC control card[9] (3-111)
PRINT control the printing of various tables to the OUTP file (3-116)
PTRAC generate an file named PTRAC of user-filtered particle events (3-119,I-1)
PWT control number of neutron-induced photons produced by [cell](MODE N P)(3-29)
RDUM real array in MCNP COMMON available to the user (also see IDUM) [50] (3-110)
SBi bias for source distribution i (3-45)
SCi comment card for source distribution i for OUTP (no & continuation) (3-50)
SDn segmented cell volumes or surface areas defined by the FSn card (3-81)
SDEF general fixed source specification (1-25,3-39,3-51,4-47)
SFn surface flagging card for tally n [number of surfaces] (3-79)
SIi source information for distribution i (3-45)
SPi source probability for distribution i (3-46,H-1)
SSR surface source read card for file RSSA (3-54)
SSW write surface source(s) to WSSA file (3-52)
surface cards: equation coefficients or points (*=reflecting) (3-12)
Tn create time bins in shakes (=1e-8 seconds) for tally n (1-25,3-70)
TFn define one bin for tally n to be used in tally fluctuation chart [8] (3-84)
THTME times for thermal neutron temperatures of cells on TMPi card(s) [99] (3-105)
title card:one line of required input after MESSAGE block to describe problem (1-21)
TMn time bin multiplier card (3-77)
TMPj free-gas thermal temperature card for time j on THTME card [cells] (3-105)
TOTNU total fission card to include delayed neutrons for steady state [1] (3-94)
TRj geometry coordinate transformation(*TRn is for Bi in degrees)[13](3-26,4-14)
TRCL cell transformation to describe multiple cells once(* for degrees) (3-23)
U describe what universe a cell is in (usually on cell cards) [cells] (3-22)
VECT define any number of vectors for exponential transform or user patches(3-23)
VOID delete cell material to check geometry/sources, calculate volumes(1-28,3-96)
VOL whole cell volume specifications [number of cells] (3-20)
WWE:p define wgt window energies(or times) for part p(use with WWNi:p)[99] (3-33)
WWG weight window generation card [7] (3-36)
WWGE:p weight window generation energies for particle type p [15] (3-37)
WWNi:p lower wgt window bounds for ith WWE:p energy bin for part p [cells] (3-34)
WWP:p weight window parameter card for particle type p [5] (3-35)
XSn load cross-section evaluation n not listed in XSDIR file directory[10](3-96)
ZA,ZB,ZC are separate cards for inputing user data to code patches
CONTINUE first card in INP for continue run(C on execute line or MESSAGE block) (3-2)
MODE definition of particles to be run in the problem (1-24,3-19)
GEOMETRY (3-19)
AREA whole surface area specifications [number of surfaces] (3-20)
FILL fill cell with a universe, lattice elements with universes(*=degrees) (3-25)
LAT used to define a lattice as part of a cell card description [cells] (3-24)
TRj geometry coordinate transformation(*TRn is for Bi in degrees)[13](3-26,4-14)
TRCL cell transformation to describe multiple cells once (* for degrees) (3-23)
U describe what universe a cell is in (usually on cell cards) [cells] (3-22)
VOL whole cell volume specifications [number of cells] (3-20)
SOURCE (1-25,3-39)
(subroutine source and srcdx (3-59) are needed if SDEF,SSR, or KCODE are not used)
DSn dependent source distribution card (3-49,4-47)
KCODE define a criticality eigenvalue (keff) problem [7] (3-57,5-64)
KSRC neutron source point locations for KCODE (or SRCTP file or SDEF card) (3-58)
SBi bias for source distribution i (3-45)
SCi comment card for source distribution i for OUTP (no & continuation) (3-50)
SDEF general fixed source specification (1-25,3-39,3-51,4-47)
SIi source information for distribution i (3-45)
SPi source probability for distribution i (3-46,H-1)
SSR surface source read card for file RSSA (3-54)
SSW write surface source(s) to WSSA file (3-52)
VARIANCE REDUCTION (3-28)
BBREM bias of high energy bremsstrahlung photons (3-38)
DXCm:p DXTRAN contribution card for DXTRAN sphere m and particle p[# cells] (3-37)
DXT:p defines DXTRAN spheres for particle type p [28] (3-87)
EXT:p exponential transform for part p(use wgt window-no forced coll)[cell] (3-30)
FCL:p force collisions by cell for particle type p [number of cells] (3-32)
IMP:p definition of cell importances for each particle type p[# cells] (1-24,3-28)
PDn detector contribution control card by cell for tally n [# cells] (3-37)
PIKMT photon-production bias card for coupled neutron-photon problems (3-96)
PWT control number of neutron-induced photons produced by [cell](MODE N P)(3-29)
VECT define any number of vectors for exponential transform or user patches(3-23)
WWE:p define wgt window energies(or times) for part p(use with WWNi:p)[99] (3-33)
WWG weight window generation card [7] (3-36)
WWGE:p weight window generation energies for particle type p [15] (3-37)
WWNi:p lower wgt window bounds for ith WWE:p energy bin for particle p[cells](3-34)
WWP:p weight window parameter card for particle type p [5] (3-35)
TALLY (3-59)
Cn specify cosine bins for a type 1 tally (3-70)
CFn tally contributions from flagged cells separately for tally n [cells] (3-78)
CMn multipliers for cosine bins of tally n for type 1 tallies (3-77)
DDn detector and DXTRAN diagnostics and contribution card (3-85)
DEn dose energy card (used with the DFn card) (3-76,H-4)
DFn dose function card (used with the DEn card) (3-76,H-4)
En upper bounds of energy bins (MeV) for tally n (1-25,3-69)
EMn multipliers for the energy bins of tally n on the En card (3-76)
Fn:p create cell, surface, point tally n for part p(*F for energy)(1-25,3-61,5-1)
FCn user supplied comment for tally n (& continuation is not allowed) (3-69)
FMn general tally multiplier card for tally n (3-72,4-34,4-36,5-1,G-1)
FQn tally print hierarchy for ordering of printed output [8] (3-71,5-1)
FSn subdivide cell or surface into segments for tallying[# surfaces] (3-79,4-37)
FTn special treatments(# collisions,detector by cell,etc) for tally n(3-89,4-38)
FUn user-defined TALLYX tally input that is required by some FTn options (3-82)
SDn segmented cell volumes or surface areas defined by the FSn card (3-81)
SFn surface flagging card for tally n [number of surfaces] (3-79)
Tn create time bins in shakes (=1e-8 seconds) for tally n (1-25,3-70)
TFn define one bin for tally n to be used in tally fluctuation chart [8] (3-84)
TMn time bin multiplier card (3-77)
MATERIAL (3-91)
AWTAB user specified atomic weight in pairs of zaid aw (3-95)
DRXS discrete reaction neutron cross-section card (3-93)
Mm material definition card for cells containing material m (1-27,3-92,G-1)
MGOPT multigroup forward/adjoint transport option card (3-98)
NONU treat fission as a capture as a function of cell [number of cells] (3-94)
TOTNU total fission card to include delayed neutrons for steady state [1] (3-94)
VOID delete cell material to check geometry/sources, calculate volumes(1-28,3-96)
XSn load cross-section evaluation n not listed in XSDIR file directory[10](3-96)
ENERGY & THERMAL (3-99)
ESPLT:p energy split and Russian roulette card for particle type p [10] (3-104)
MTm S(alpha,beta) thermal neutron treatment for material m (3-106,G-2)
PHYS:p control the physics used for the transport of particle p [9] (3-100,3-101)
THTME times for thermal neutron temperatures of cells on TMPi card(s) [99] (3-105)
TMPj free-gas thermal temperature card for time j on THTME card [cells] (3-105)
PROBLEM CUTOFFS (3-107)
CTME computer time limit in minutes for the problem [1] (3-109)
CUT:p time, energy, and weight cutoffs for particle type p [5] (3-107)
ELPT:p cell energy cutoff(larger of this or CUT:p applies) for part p[cells](3-108)
NPS number of particles to run in the problem from the source [1] (1-28,3-109)
USER (3-110)
C INP file comment card (no continuation is allowed) (1-21)
IDUM integer array in MCNP COMMON available to user (also see RDUM) [50] (3-110)
RDUM real array in MCNP COMMON available to user (also see IDUM) [50] (3-110)
ZA,ZB,ZC are separate cards for inputing user data to code patches
PERIPHERAL (3-110)
DBCN debug information card(event logs,timing,vov,random number,etc) [20] (3-112)
FILES user file creation card [30] (3-116)
LOST lost particle abort/debug print control card [2] (3-112)
MESSAGE optional card(s) in front of INP file containing execution information (3-1)
MPLOT plot one tally while the problem is running (3-118,B-11)
# input cell/surface/source parameters in columns(can use more than once)(3-6)
PRDMP print(OUTP)/dump(RUNTPE)/MCTAL/max dumps(RUNTPE)/TFC control [9] (3-111)
PRINT control the printing of various tables to the OUTP file (3-116)
PTRAC generate output file PTRAC of user-filtered particle events (3-119,I-1)
GENERIC INP FILE (3-4)
blank blank lines separate MESSAGE, cell, surface, and data sets of commands (1-21)
cell cards:define geom cells with materials(see Mm card) or void(0) (3-9,4-1,4-19)
surface cards: equation coefficients or points (*=reflecting) (3-12)
title card:one line of required input after MESSAGE block to describe problem (1-21)
AREA whole surface area specifications [number of surfaces] (3-20)
A1 ... AJ (J=number of problem surfaces) {calculated areas if available}
Ai=area of surface i
AWTAB user specified atomic weight in pairs of zaid aw (3-95)
ZAID1 AW1 ZAID2 AW2 ...
ZAIDi=zaid used on the Mm material card without the nn specification
AWi=atomic weight ratios for neutrons or photons for the ith entry pair
BBREM bias of high energy bremsstrahlung photons (3-38)
B1 B2 ... B49 M1 M2 ... MN (N=number of materials in the problem)
B1=any positive value (currently unused)
Bi=bias factors for the bremsstrahlung energy spectrum
Mi=material number Mi for which the biasing is to be used
blank blank lines separate MESSAGE, cell, surface, and data sets of commands (1-21)
C INP file comment card (no blank or & continuation is allowed) (1-21)
columns after C blank to 80 available for user comments about the INP file
(this comment is printed only in the input file listing of the problem:
other comments available are $(end of line), FCn(tally) and SCn(source))
Cn specify cosine bins for a type 1 tally (3-70)
B1 B2 ... Bk T
n=tally number with a last digit of 1 or 0 for tallies without Cn card
Bi=monotonically increasing upper cosine for the ith bin (B0=-1.)
(B1>-1. and Bk=1 for type 1 tally by cosines)
T is optional and will create a total over all cosine bins
required for a CMn card
cell cards:define geometry cells with materials(see Mm card) or void(0)(3-9,4-1,4-19)
J m D GEOM Keyword PARAMETERS or J LIKE N BUT LIST
J=cell number starting in the first five columns (00 entry is atom density in units of atoms/barn-cm (1E-24 atoms/cc)
<0 entry is mass density in units of grams/cc
GEOM(list)=signed surface numbers and Boolean operators which are:
blank means the intersection of space which is the default
: means the union of space
#i means space not in cell i
#(list of signed surfaces) means space with opposite sense
PARAMETERS=DXC,EXT,FCL,FILL,IMP,LAT,NONU,PD,PWT,TMP,TRCL,U,VOL and WWN
with particle designator may go on cell cards instead of data cards
LIKE N BUT=gives cell J all attributes of problem cell N except LIST
LIST=PARAMETERS Keyword list plus MAT (material number) and RHO (density)
CFn tally contributions from flagged cells separately for tally n [cells] (3-78)
C1 C2 ...
n=tally number not ending in 5 or 8
Ci=problem cells where tracks leaving are flagged for a separate tally
CMn multipliers for cosine bins of tally n for type 1 tallies (3-77)
M1 M2 ... Mk (k=number of entries on the Cn card)
n=tally number ending in 1 or 0 for type 1 tallies without own CMn card
Mi=multiplier to be applied to the ith cosine bin
CONTINUE first card in INP for continue run(C on execute line or MESSAGE block) (3-2)
allowed cards after CONTINUE are: CTME, DBCN, DD, FQ, IDUM, KCODE,
LOST, MPLOT, NPS, PRDMP, PRINT, RDUM, ZA, ZB, and ZC
CTME computer time limit in minutes for the problem [1] (3-109)
T=problem time limit in minutes
CUT:p time, energy, and weight cutoffs for particle type p [5] (3-107)
T{large} E{0 or 0.001(P)} WC1{-0.5} WC2{-0.25} SWTM
p=N for neutrons, P for photons, E for electrons
T=time cutoff in shakes
E=lower energy cutoff in MeV
WC1=upper weight cutoff (negative value for relative to source weight)
=0 for analog capture
WC2=lower weight cutoff (negative value for relative to source weight)
SWTM=minimum source weight
DBCN debug info card (event logs, timing, vov, random number, etc) [20] (3-112)
X1{6647299061401} X2 X3 X4 X5{600} X6{0} X7{0} X8 X9 X10{10}
X11{0} X12 X13{152917} X14{5E19} X15{0} X16{1.0} X20{0}
X1=the starting pseudorandom number
X2=print history #,colls,random #, and first random # every X2 particle
X3 and X4=lower and upper history numbers for event log printing (5-97)
X5=maximum number of events in the event log to print per history
X6=1 to produce a file (SAMFIL) containing code timing statistics
X7=1 for detailed print from the volume and surface area calculations
X8=history number whose starting pseudorandom number will start problem
X9=collision number for the collision loop breakpoint in HSTORY
X10=seconds between time interrupts
X11=1 causes collision lines to print in lost particle event log
X12=expected number of random numbers for tracking comparisons
X13=random number stride between starting random numbers
X14=random number multiplier
X15 not equal to zero produces variance of variance for all tally bins
X16 scales the history score grid for creating the empirical f(x) pdf
X20 not equal to zero tracks the previous MCNP version
DDn detector and DXTRAN diagnostics and contribution card (3-85)
K1{0.1} M1{1000} K2 M2 ...
n=0 or blank is the global DD card
=1 for neutron DXTRAN spheres
=2 for photon DXTRAN spheres
=tally number ending in 5 for a specific detector tally
Ki=criterion for using small score tally contribution Russian roulette
>0,<1 all contributions for first 200 histories are made; Ki is factor
<0, contributions > -Ki are always made; otherwise use Russian roulette
Mi=criterion for printing large detector tally or DXTRAN contributions
=0 means no diagnostic prints
>0, Ki>0 first 100 contributions after 200 histories>Mi*avg tally
>0, Ki<0 prints the first 100 contributions > Mi*(-Ki)
DEn dose energy card (used with the DFn card) (3-76,H-4)
A{LOG} E1 E2 ... Ek
n=tally number or 0 to be applied to all tallies without DEn cards
A=blank (or "LOG") or "LIN" interpolation method for energy table
Ei=monotonically increasing energy value in MeV
DFn dose function card (used with the DEn card) (3-76,H-4)
B{LOG} F1 F2 ... Fk (k must equal k on the DEn card)
n=tally number or 0 to be applied to all tallies without DEn cards
B=blank (or "LOG") or "LIN" interpolation method for dose function table
Fi=the corresponding (DEn card) value of the dose function
DRXS discrete reaction neutron cross-section card (3-93)
blank or ZAID1 ZAID2 ...
blank=use discrete reaction cross sections for all nuclides
ZAIDi=nuclide number of the form ZZZAAA.nn for discrete reaction
DSm dependent source distribution card (3-49)
option J1 J2 ... Jk or
T I1 J1 I2 J2 ... Ik Jk or
Q V1 S1 V2 S2 ... Vk Sk
m=source distribution number from 1 to 999
option=blank or H(continuous,scaler), L(discrete), or S(distributions)
Ji=values of the dependent source variable
T means dependent variable values follow independent (discrete scaler)
Ii=values of the independent source variable
Q means distribution numbers follow the independent variable (scaler)
Vi=monotonically increasing values of the independent variable
Si=distribution numbers for the dependent variable
DXCm:p DXTRAN contribution for DXTRAN sphere m and particle type p [# cells] (3-37)
P1 P2 ... PI (I=number of cells in the problem) {all Pis=1.}
m=DXTRAN sphere the DXC card applies to
=0 or blank applies to all DXTRAN spheres in the problem
p=N for neutrons, P for photons, not available for electrons
Pi=probability of contribution to DXTRAN spheres from cell i
consider using the DD card
DXT:p defines DXTRAN spheres for particle type p [28] (3-87)
X1 Y1 Z1 RI1 RO1 X2 Y2 Z2 RI2 RO2 ... DWC1{0} DWC2{0} DPWT{0}
p=N for neutrons, P for photons, not available for electrons
Xi,Yi,Zi=coordinates of the center of the ith pair of DXTRAN spheres
RIi=radius of the ith inner sphere in cm
ROi=radius of the ith outer sphere in cm
DWC1=upper weight cutoff in the spheres
DWC2=lower weight cutoff in the spheres
DPWT=minimum photon weight (entered on DXT:N card only)
maximum number of DXTRAN spheres is 5 for each particle (mxdx=5) (3-126)
En upper bounds of energy bins (MeV) for tally n (1-25,3-69)
B1 B2 ... Bk NT
n=tally number or 0 applies to all tallies without an En card
Bi=monotonically increasing upper energy of ith bin, B0=energy cutoff
NT is optional and will delete the total energy bin
required in an EMn card is present
ELPT:p cell energy cutoff (> of this or CUT:p applies) for particle p[cells] (3-108)
E1 E2 ... EI (I=number of problem cells) {CUT:p card energy cutoff}
p=N for neutrons, P for photons, E for electrons
Ei=lower energy cutoff (MeV) for cell i
EMn multipliers for the energy bins of tally n on the En card (3-76)
M1 M2 ... Mk (k bins on the En card)
n=tally number or 0 for all tallies without their own EMn card
Mi=multiplier applied to the ith energy bin (eg, 1/delta E)
ESPLT:p energy split and Russian roulette card for particle type p [10] (3-104)
N1 E1 N2 E2 ... Nk Ek (k<6)
p=N for neutrons, P for photons, E for electrons
Ni>1 is number of tracks particle will be split into
>0 and <1 is the Russian roulette survival probability
Ei=energy (MeV) at which splitting or Russian roulette occur
EXT:p part p exponential transform (use wgt window-no forced coll) [cell] (3-30)
A1 A2 ... AI (I=number of cells in the problem) {all 0}
p=N for neutrons, P for photons, not available for electrons
Ai=QVm (Q=stretching, Vm=direction m(VECT)) or S for distance to scatter
Fn:p create cell, surface, point tally n for part p(*F for energy) (1-25,3-61,5-1)
C1 C2 ... Ck T or C1 (C2 C3 ... Ci) ... Ck T
n=a unique three or less digit tally number not ending in 0, 3, or 9
=..1 tallies particle current integrated over a surface (3-62)
=..2 tallies particle flux averaged on surface (3-62)
=..4 tallies particle flux averaged in cell(s) (3-62)
=..5 tallies particle flux at a point (X Y Z +or-R0{0} ND) (3-63)
=..5X,5Y, or 5Z tallies particle flux on a ring (A R +or-R0{0} ND) (3-63)
=..6 tallies energy deposition averaged over a cell (3-62,4-36)
=..7 tallies fission energy deposition averaged over a cell (3-62)
=..8 is a pulse height tally (*F is an energy deposition tally) (3-64)
p=N, P, or E for 1,2,3,4; N or P for 5; N,P for 6; N for 7; P,E for 8
Ci=problem number of cell or surface for tallying (see ..5 for detectors)
(C2 C3 ... Ci) creates a union of Cs: sum (unnormed) or average (normed)
T creates a tally over all cells or surfaces if present
X Y Z=coordinates of the detector location
R0=radius of the constant flux sphere to remove the tally singularity
>0 is the spherical neighborhood radius in cm
=0 no spherical neighborhood which is used in a void
<0 is a radius of -R0 mean free paths (do not use in a void region)
A=the letter X,Y, or Z to define a ring detector around a major axis
R=radius of the ring in cm
ND is optional to not print direct detector contributions in tally n
maximum number of tallies (Fn:p) in one problem is 100 (ntalmx=100) (3-126)
maximum number of detector tallies (F..5) is 20 (mxdt=20) (3-126)
use variance reduction carefully with F..8 tallies (3-65)
individual repeated structure/lattice tallies (F1,2,4,6,7,8): (3-65,4-19)
general form: S1(S2 ... S3)((S4 S5)<(C1 C2[I1 ... I2])<(C3 C4 C5)) ...
Si=problem number of cell or surface, U=#, or T
Ci=problem number of a cell filled with a universe or U=#
#=universe number used on the FILL card
Ii=index data for a lattice cell element with three possible formats:
I1 I1th lattice element of cell C2 as defined in the FILL array
I1:I2 I3:I4 I5:I6 range of lattice elements (same as FILL card)
I1 I2 I3, I4 I5 I6 lattice elements (I1,I2,I3) and (I4,I5,I6)
there is a special use of the SD card in this case (3-68)
FCn user comment for tally n (1-5 blank for continuation-& not allowed) (3-69)
comment is entered after FCn and a blank {none}
n=tally number and cannot be zero or blank
FCL:p force collisions by cell for particle type p [number of cells] (3-32)
X1 X2 ... XI (I=number of cells in the problem) {all 0}
p=N for neutrons, P for photons, not available for electrons
Xi=number of forced collisions in cell i (Xi between -1 an 1 inclusive)
>0 forced collisions for entering and collided particles in cell i
=0 means no forced collisions
<0 forced collisions apply only to entering particles in cell i
FILES user file creation card [30] (3-116)
UNIT FILENAME ACCESS{S} FORM{F if S, U if D} RECORD-LENGTH
UNIT=1 to 99
FILENAME=name of the file to be created
ACCESS=sequential (S) or direct (D)
FORM=formatted (F) or unformatted (U)
RECORD-LENGTH=record length in a direct access file
FILL fill cell or lattice elements with universe(s) (*=degrees) (3-25)
J (T) or L1:L2 L3:L4 L5:L6 N1 N2 ... Nk
J=universe number
T=a transformation number or the transformation itself
Li=lattice array locations
Ni=universe for the ith element of the lattice array with k elements
FMn general tally multiplier card for tally n (3-72,4-34,4-36,5-1,G-1)
(BIN SET 1) (BIN SET 2) ... T
n=tally number not ending in 8 and cannot be zero or blank
BIN SET i=((MULTIPLIER SET 1)(MULTIPLIER SET 2)...(ATTENUATOR SET))
T=total over all bin sets if present
ATTENUATOR SET=C -1 m1 PX1 m2 PX2 ...
MULTIPLIER SET=C m (reaction list 1) (reaction list 2) ...
C>0 is multiplicative constant for all tallies except type 8
<0 for type 4 tally means multiply by -C times cell atom density
-1 is a flag indicating attenuator rather than multiplier set
mi=material number identified on an Mm card
special case: C=1 and mi=anything tallies the number of particle tracks
PX=density times thickness of attenuating material
reaction list i=sum(:) and product of ENDF or special reaction numbers
special reaction numbers-neutrons:
-2 absorption cross section (barns)
-4 average heating number (MeV/collision)
-5 gamma-ray production cross section (barns)
-6 total fission cross section (barns)
-7 fission nu (neutrons per fission)
-8 fission Q (MeV/fission)
p. G-1 (Appendix G) has a list of neutron reaction numbers
special reaction numbers-photons:
-1 incoherent scattering cross section (barns)
-2 coherent scattering cross section (barns)
-3 photoelectric cross section (barns)
-4 pair production cross section (barns)
-5 total cross section (barns)
-6 photon heating number (MeV/collision)
FQn tally print hierarchy card for ordering of printed output [8] (3-71,5-1)
A1 ... A7 A8 (A7 is vertical and A8 is horizontal) {default order below}
n=tally number or 0 to change print default for tallies without own FQn
Ai=F---cell, surface, or detector tally
=D---direct or flagged tally
=U---user bins
=S---segment tallies
=M---multiplier bins
=C---cosine bins
=E---energy bins
=T---time bins
FSn subdivide cell or surface into segments for tallying [surfaces] (3-79,4-37)
S1 S2 ... T
n=tally number not ending in 5 or 8 and cannot be zero or blank
Si=signed problem number of a segmenting surface
T=total of all tallies if desired
this card may require an SDn card and should consider an FQn card
FTn special treatments(# collisions,detector by cell,etc) for tally n (3-89,4-38)
ID1 P1,1 P1,2 ... ID2 P2,1 P2,2 ...
n=tally number and cannot be zero or blank
IDi=the alphabetic Keyword identifier for a special treatment which are
FRV V1 V2 V3 (fixed reference direction V's for tally 1 cosine)
GEB a b (Gaussian energy broadening of a tally result)
TMC a b (time convolution for a square wave pulse from time a to b)
INC (tally by the number of particle collisions-FUn card required)
ICD (tally detector contributions by cell-FUn card required)
SCX k1 k2 ... (tally by SIk source type plus total)
SCD (tally specific source distributions-FUn card required)
PTT (tally by multigroup particle type-FUn card required)
ELC C (electron current tally depending on C:
C=1 means electrons make negative scores
C=2 puts positrons/electrons into separate user bins plus total
C=3 for the effect of C=1 and C=2 plus total)
FUn user-defined TALLYX (3-83,4-44) input required by some FTn options (3-82)
X1 X2 ... Xk NT or blank
n=tally number and cannot be zero or blank
Xi=input parameter establishing user bin i for tally n
NT is optional and will delete the total created over the user bins
IDUM integer array in MCNP COMMON available to user (also see RDUM) [50] (3-110)
I1 I2 ... I50 {all 0}
Ii=integer number for the ith entry
IMP:p define cell importances for each particle type p[number of cells] (1-25,3-28)
X1 X2 ... XI (I=number of cells in the problem)
p=N for neutrons, P for photons, E for electrons, N,P or P,E or N,P,E
Xi=importance for cell i for particle type p (may be non integer)
=0 to terminate particle type p when entering cell i
KCODE define a criticality eigenvalue (keff) problem [7] (3-57,5-64)
NSRCK RKK{1} IKZ{5} KCT{0} MSRK{>4499} KNRM{0} MRKP{>201,2*KCT}
NSRCK=nominal neutron source size per cycle (neutron generation)
RKK=initial guess for keff
IKZ=number of cycles to be skipped before beginning tally accumulation
KCT=total number of cycles (neutron generations) to be calculated
MSRK=number of neutron source points to allocate storage for
KNRM=method of tally normalization (0 for weight, otherwise number)
MRKP=number of keff cycles stored in the RKPL array (plotting, etc)
make IKZ large enough so that fundamental spatial mode is achieved (2-141)
KSRC neutron source point locations for KCODE (or SRCTP file or SDEF card) (3-58)
X1 Y1 Z1 X2 Y2 Z2 ...
Xi Yi Zi=neutron source points (cm) in fissile material for first cycle
this card is omitted if SDEF or SRCTP source is used
LAT define a lattice as part of a cell card description [# of cells] (3-24)
L (usually specified on a cell card as LAT=L)
L=1 defines a hexahedra lattice of solids with six faces
L=2 defines a lattice of hexagonal prisms
LOST lost particle abort/debug print control card [2] (3-112)
LOST1{10} LOST2{10}
LOST1=number of particles which can be lost before the job aborts
LOST2=maximum number of debug prints made for lost particles
the cause(s) for lost particles should be found and corrected
Mm material definition card for cells containing material m (3-92,G-1)
ZAID1 FRAC1 ZAID2 FRAC2 ... Keywords GAS{0} ESTEP NLIB PLIB ELIB
m corresponds to the material number on the cell cards
ZAID1=a full ZZZAAA.nnX or partial ZZZAAA identifier for constituent i
FRAC1=atomic fraction (or weight fraction if negative) of constituent i
ZZZ=atomic number, AAA=atomic mass, nn=library identifier, X=data class
Keywords GAS=l is flag for density correction to electron stopping power
=0 for a solid or liquid material
=1 for a gaseous material
ESTEP=n for n electron substeps per energy step (use > n, default)
NLIB=id to change default neutron table identifier to id
PLIB=id to change default photon table identifier to id
ELIB=id to change default electron table identifier to id
MESSAGE optional card(s) in front of INP file containing execution information (3-1)
A=B OVERLAY{IXR} Keywords C m DBUG n NOTEK FATAL D PRINT
A=standard default file name such as OUTP, RUNTPE, etc (not INP)
B=substitute name to be used in place of A for this problem
OVERLAY=overlays to run (I,IMCN; P,PLOT; X,XACT; R,MCRUN; Z,MCPLOT)
any message is input in columns 9-80 plus 1-80 on continuation cards
Keywords include C m(continue with dump m), DBUG n(write debug info
every n particles), NOTEK(terminal with no graphics),
FATAL(run problem even with fatal errors),
D(destroy drop file),PRINT(create full OUTP file)
MGOPT multigroup forward/adjoint transport option card (3-98)
MCAL IGM IPLT{0} ISB{0} ICW{0} FNW{1} RIM{1000}
MCAL=F for forward problem or A for adjoint problem
IGM=total number of energy groups (negative=special electron-photon prob)
IPLT=0 so that IMP sets cell importances (weight windows are ignored)
=1 for weight windows that become energy-dependent cell importances
=2 for weight windows with the standard treatment
ISB=0 means adjoint collisions are biased by infinite-medium fluxes
=1 means adjoint collisions are biased by weight windows functions
=2 means adjoint collisions are not biased
ICW=0 means weight windows are not generated
otherwise is # of reference cell for generated weight windows
FNW=normalization value for generated weight windows
RIM=compression limit for generated weight windows
MODE definition of particles to be run in the problem (1-24,3-19)
X1{N} X2 X3 (the type of source particle is set with PAR on SDEF card)
Xi=E for electron transport
=N for neutron transport
=P for photon transport
MPLOT produce plots of tallies while the problem is running (3-118,B-11)
MCPLOT FREQ N{5000,5 cycles} Keyword1=PARAMETER1 Keyword2=PARAMETER2 ...
Keywordi=all tally plot Keywords except END, RMCTAL, RUNTPE, and DUMP
N=number of particle histories or keff cycles between automatic plots
see the tally plot command section of this file (B-11)
MTm S(alpha,beta) thermal neutron treatment for material m (3-106,G-2)
X1 ...
Xi=S(alpha,beta) identifier corresponding to a component in Mm
review S(alpha,beta) identifiers for the MTm card (G-2)
NONU treat fission as a capture as a function of cell [number of cells] (3-94)
A1 A2 ... AI (I=number of cells) or blank
Ai=0 for fission in cell i treated as capture; gammas produced
=1 for fission in cell i treated as real; gammas produced
=2 for fission in cell i treated as capture; gammas not produced
blank means that all Ais=1
NPS number of particles to run in the problem from the source [1] (1-28,3-109)
N=total number of histories to be run
<0 in CONTINUE run means reprint OUTP from RUNTPE (without INP) and quit
# input cell/surface/source parameters in columns(can use more than once) (3-6)
# S1 S2 ... Sm (the Si must not be anywhere else in the INP file)
K1 D11 D12 ... D1m {Kj defaults for cell values are the input order}
K2 D21 D22 ... D2m
.. ... ... ... ...
Kn Dn1 Dn2 ... Dnm
"#", "Kj" begin in columns 1 to 5; after blank, Si, Dji follow to column 80
Si=valid card names of same type with particle type; eg, cell, source, etc
Kj=optional integer values for cells, source distributions, etc
PDn detector contribution control by cell for tally n [number of cells] (3-37)
P1 P2 ... PI (I=number of cells in the problem) {all Pis=1.}
n=tally number ending with 5
=0 applies to all point detector tallies without a PDn card
Pi=probability of contributing to a detector from cell i (Pi=0 is valid)
PHYS:E electron physic card [9] (3-101)
EMAX{100} IDES{0} IPHOT{0} IBAD{0} ISTRG{0} BNUM{1} XNUM{1} RNOK{1} ENUM{1}
EMAX=upper limit for electron energy (MeV)
IDES=0 means photons will produce electrons
=1 means photons will not produce electrons
IPHOT=0 means electrons will produce photons
=1 means electrons will not produce photons
IBAD=0 means full bremsstrahlung tabular angular distribution
=1 means simple bremsstrahlung angular distribution approximation
ISTRG=0 means sampled straggling for electron energy loss
=1 means expected-value straggling for electron energy loss
BNUM>0 produces BNUM times the analog number of bremsstrahlung photons
=0 means bremsstrahlung photons will not be produced
XNUM>0 produces XNUM times analog number of electron-induced x-rays
=0 means x-ray photons will not be produced by electrons
RNOK>0 produces RNOK times the analog number of knock-on electrons
=0 means knock-on electrons will not be produced
ENUM>0 makes ENUM times analog # of photon-induced secondary electrons
=0 means photon-induced secondary electrons will not be produced
PHYS:N neutron physics card [2] (3-100)
EMAX{very large} EMCNF{0 MeV}
EMAX=upper limit for neutron energy (MeV) to remove unneeded xsecs
EMCNF=energy boundary (MeV); > is implicit capture; < is analog capture
PHYS:P photon physics card [3] (3-100)
EMCPF{100 MeV} IDES{1} NOCOH{0}
EMCPF=upper energy limit (MeV) for detailed photon physics treatment
IDES=0 photons make electrons (MODE E) or bremsstrahlung (thick target)
=1 means photons will not produce electrons as above
NOCOH=0 means coherent photon scattering occurs
=1 means coherent scattering will not occur (improves point det errors)
PIKMT photon-production bias card for coupled neutron-photon problems (3-96)
Z1 IPIK1{-1} MT1,1 PMT1,1 ... MT1,IPIK1 PMT1,IPIK1 Z2 IPIK2{-1} ...
Zi=full or partial zaid of the ith data set entry
IPIKi=0 means no photon-production biasing for zaid Zi
>0 photon-production biasing for ZAIDi with IPIKi pairs of data
=-1 means no photons are produced from ZAIDi
MTi,j=numbers for photon-production reactions to be sampled (IPIKi>0)
PMTi,j=numbers that control the frequency of MTi,j sampling (IPIKi>0)
use file DISCEGAM in /x6xs/ctss to select neutron-photon reactions
PRDMP print(OUTP)/dump(RUNTPE)/MCTAL/max dumps(RUNTPE)/TFC control card [9] (3-111)
NDP{end of problem} NDM{15 minutes} MCT{0} NDMP{large} DMMP{0}
NDP>0 print after every NDP histories or NDP criticality cycles
<0 print after NDP minutes of computer time
NDM>0 dump to RUNTPE file every NDM histories or criticality cycles
<0 dump to RUNTPE file every NDM minutes
MCT>0 means write a MCTAL file at the end of problem
<0 means write a MCTAL with no time-dependent quantities (for QAing)
NDMP>0 means keep only the last NDMP dumps on the RUNTPE file
DMMP<0 makes TFC entry every 1000 histories to 20000, 2000 to 40000, ...
=0 is same as <0 for sequential MCNP operation
=0 makes 10 TFC entries during run for multiprocessing
>0 makes TFC entry every DMMP histories
PRINT control the printing of various tables to the OUTP file (3-116)
X (see manual for a listing of the 30 table numbers)
X=no entry produces the full output print of all tables
X=X1 X2 ... prints minimum output plus tables X1, X2 ...
X=-X1 -X2 ... prints the full output except tables X1, X2 ...
the order of the Xis does not matter
PTRAC generate a file named PTRAC of user-filtered particle events (3-119,I-1)
Keyword1=parameter(s) Keyword2=parameter(s) ...
output control Keywords (one entry for each Keyword):
BUFFER=amount of storage available{100}
FILE=ASC for ASCII file
=BIN for a binary file {default}
MAX= maximum number of events to write to the PTRAC file {10000}
MEPH=maximum number of events per history to write {write all}
WRITE=POS for only x,y,z locations, cells, and materials {default}
=ALL is POS plus direction cosines, energy, weight, and time
event filter Keywords:
EVENT specifies type of events written (one or more can be used):
=SRC for initial source events
=BNK for bank events
=SUR for surface events
=COl for collision events
=TER for terminal events
FILTER specifies additional MCNP variables for filtering (3-121)
TYPE=N, P, and/or E to filter by particle type
History filter Keywords:
NPS=A,B where A,B are history numbers (A0 photons produced with weights > Wi times source to cell importance
Wi<0 makes photon production relative to the starting source weight
RDUM real array in MCNP COMMON available to user (also see IDUM) [50] (3-110)
R1 R2 ... R50 {all 0.}
Ri=real number for the ith entry
SBi bias for source distribution i (3-45)
option B1 ... Bk or f A B
i=source distribution number
option,f,A, and B same as SPi card except f can only be -21 and -31
Bi=source variable biased probability
SCi comment card for source distribution i for OUTP (no & continuation) (3-50)
comment is entered after FCn and a blank {none}
i=source number >0 and <1000 and cannot be zero or blank
SDn segmented cell volumes or surface areas defined by the FSn card (3-81)
(D11 D12 ... D1m) (D21 D22 ... D2m) ... (Dk1 Dk2 ... Dkm)
n=tally number not ending in 5 or 8 and cannot be zero or blank
k=number of cells or surfaces on the Fn card including T if present
m=# of segmenting bins on FSn card including remainder segment and T
Dij=area, volume, or mass of jth segment of ith surface or cell bin
SDEF general fixed source specification (3-39,3-51,4-47)
Keywords CEL, SUR{0}, ERG{14 MEV}, TME{0}, DIR{isotropic volume or cosine
surface}, VEC, NRM{+1}, POS(3){0,0,0}, RAD{0}, EXT{0}, AXS, X, Y,
Z, CCC, ARA, WGT{1}, EFF{0.01}, PAR{neutron for MODE N ...,
photon for MODE p..., and electron for MODE E}
Keyword is followed by an explicit value, distribution number(1 to 999)
prefixed by a D, or by another Keyword prefixed by F followed
by a distribution number prefixed by a D(eg, ERG FPOS D8)
blank is 14 MeV point isotropic source at 0,0,0,time=0,weight=1
CEL=cell for starting source particles
SUR=problem surface for starting source or 0 for cell source
ERG=source energy (MeV)
TME=source time (shakes)
DIR=cosine of polar angle (azimuthal angle sampled uniformly 0-360 deg)
VEC=reference vector for DIR
NRM=1 or -1 for surface source emission relative to surface normal
POS(3)=reference point for position sampling
RAD=radial distance of the position from POS or AXS
EXT=distance from POS along AXS (cell); cosine of angle from AXS (surface)
AXS(3)=reference vector for EXT and RAD
X Y Z=x, y, and z position coordinates
CCC=cookie-cutter cell for selecting parts of cells or surfaces
ARA=surface area for plane surface direct contributions to detectors
WGT=starting source particle weight (must be an explicit value)
EFF=rejection efficiency for position sampling (must be explicit value)
PAR=1 for neutron, 2 for photon, or 3 for electron source particle type
SFn surface flagging card for tally n [number of surfaces] (3-79)
S1 S2 ... Sk
n=tally number not ending in 5 or 8 and cannot be zero or blank
Si=problem surface numbers whose tally contributions are to be flagged
SIi source information for distribution i (3-45)
option{H} I1 I2 ... Ik (requires SPi card)
i=source distribution number from 1 to 999
option=H or blank for bin boundaries Ii of a histogram
=L for discrete source variable values
=A for points at which a probability density is defined
=S for distribution numbers (these can also have the S option)
Ii=source variable values or distribution numbers
SPi source probability for distribution i (3-46,H-1)
option{D} P1 P2 ... Pk or f A B
i=source distribution number from 1 to 999
option=D bin probabilities for an H or L distribution on SIi card
=C cumulative bin probabilities for H or L distribution on SIi
=V probability is proportional to cell volume (cell distributions)
=omitted-same as D for H or L and is a probability density for A
Pi=source variable probabilities
f=-2 for a Maxwell fission spectrum (ERG) - uses A{1.2895}
=-3 for a Watt fission spectrum (ERG) - uses A{0.965} and B{2.29}
=-4 for a Gaussian fusion spectrum (ERG) - uses A{-0.01} and B{-1.}
=-5 for an evaporation spectrum (ERG) - uses A{1.2895}
=-6 Muir velocity Gaussian fusion spectrum(ERG) - uses A{-.01} and B{-1}
=-7 is a spare function for the user to add one (ERG) - uses A and B
=-21 power law p(x)=x**A(DIR,RAD,or EXT) - A{DIR,1;RAD,1 or 2;EXT,0}
=-31 for an exponential exp(Ax) (DIR or EXT) - uses A{0}
=-41 for a Gaussian distribution of time (TME) - uses A and B{0}
A,B=parameters for the built-in function (H-1)
SSR surface source read card for file RSSA (3-54)
Keywords OLD{all} CEL{all} NEW{old} COL{0} WGT{1} TR AXS EXT POA{0} BCW PSC
OLD=list of positive problem surface numbers on RSSA (written as WSSA)
CEL(list)=cells in which KCODE fission neutrons or photons were written
NEW(list)=positive problem surface numbers to start particles of form
Sa1 Sa2 ... Sak Sb1 Sb2 ... Sbk (start source at a,b,...)
COL=1 start only particles with collisions before crossing the surface
=0 start particles without regard to collisions
=-1 start only those particles directly from source (no collisions)
WGT=constant particle weight multiplier for accepted particles
TR=a transformation number (TRn) or distribution number Di (SIi,SPi,SBi)
AXS(3)=direction cosines for reference vector for EXT (sphere only)
EXT Dn=distribution n to bias sampling of cosine from AXS (sphere only)
POA=minimum polar angle cosine(sphere) for particle acceptance
BCW(3)=r zb ze;cylindrical window radius r,zb to ze from sphere center
PSC>0 power of polar angle cosine (sphere) for source det/DXTRAN result
SSW write surface source(s) to WSSA file (3-52)
S1 S2 (C1 ... Ck) S3 ... Sj Keywords SYM{0} PTY{all} CEL
Si=sensed problem surface # for particle info write to surface source
Ci=problem cell number: + for otherside cell, - for just left cell
SYM=0 assumes no symmetry for Si's
=1 for spherical symmetry with j=1 and a spherical surface
PTY(list)=N P and/or E to record neutrons, photons, and/or electrons
CEL=list of cells from which KCODE fission source particles are written
surface cards: equation coefficients or points (*=reflecting) (3-12)
J n A LIST or J n B POINTS
J=surface number starting in first five columns(00 particles entering/colliding in j are split or rouletted by WWP:p
=0 weight window off in cell j and energy bin i-weight cutoff is on
<0 any type p particle entering cell j in energy bin i is terminated
WWP:p weight window parameter card for particle type p [5] (3-35)
WUPN{5} WSURVN{0.6*WUPN} MXSPLN{5} MWHERE{0} SWITCHN{0}
p=N for neutrons, P for photons, E for electrons
WUPN=#(>or=2) that multiplies lower weight bound to check for splitting
WSURVN=#(10 means lower weight bounds are divided by the cell importance
XSn load cross-section evaluation n not in XSDIR file directory [10] (3-96)
same entries as XSDIR except no "+" for continuation & no ZA/atomic weight
n=a number from 1 to 999 to describe one cross-section set on XSn card
ZA,ZB,ZC are separate cards for inputing user data to MCNP patches
Todd Postma (tapostma@nuc.berkeley.edu)