Users Manual¶

Card 1 - Input & Output Files¶

In NJOY, unit numbers from 20 through 99 are used for storing results or linking modules, units 10 through 19 are reserved for scratch files, which will be destroyed after a module has completed its job, and units below 10 are reserved for the system. Negative unit numbers indicate binary mode. The following file specifications appear as numbers and correspond to those tapes (e.g. nendf = 20 corresponds to tape20).

nendf

ENDF tape for the MF7 format.

nin

Old PENDF tape

nout

New PENDF tape

Note that while nin and nout are required for each THERMR run, the nendf specification is optional. If nendf is set to zero, then no LEAPR input file will be read in, and a free gas scattering component will be used to create the output PENDF file nout. If this option is exercised and nendf is set to zero, then the inelastic option flag iin of Card 2 may no be set to 2.

Card 2 - Material Information¶

matde

Material ID on the ENDF tape

matdp

Material ID on the PENDF tape

nbin

Number of equi-probable bins

ntemp

Number of temperatures (default = 1)

iin

Inelastic options

0 - None

1 - Compute as free gas

2 - Read \(S(\alpha,\beta)\) and compute matrix

icoh

Elastic options

0 - None

1 - Graphite (coherent)

2 - Beryllium (coherent)

3 - Beryllium Oxide (coherent)

11 - Polyethylene (incoherent)

12 - H(ZrH) (incoherent)

13 - Zr(ZrH) (incoherent)

iform

Ordering for Inelastic Scattering

0 - E-E’-mu

1 - E-mu-E’

natom

Number of principle atoms

mtref

MT for the inelastic reaction (221-250 only)

iprint

Print option

0 - Minimum

1 - Maximum

2 - Maximum, Normal + Intermediate results

Card 3 - Temperatures¶

tempr

temperatures (Kelvin)

Card 4 - Limitations¶

tol

tolerance

emax

maximum energy for thermal treatment. For temperatures greater than 3000.0, emax and the energy grid are scaled by temp/3000.0.)