GROUPR produces infinity

[jlconlin]

When using the attached input ( H1.njoy.txt) initial ENDF Tape (tape40.txt)

GROUPR will calculates Inf-309 shown (partially) here:

 1.001000+3 0.000000+0          5          1          0        618 12522102    1
 2.936000+2 0.000000+0        246          1       1230          0 12522102    2
 0.000000+0    Inf-309 0.000000+0 0.000000+0 2.228361+1 0.000000+0 12522102    3
 4.843853-8 4.843853-8 4.843853-8 4.843853-8 0.000000+0 4.843853-8 12522102    4
 4.843853-8 4.843853-8 4.843853-8 0.000000+0 4.843853-8 4.843853-8 12522102    5
 4.843853-8 4.843853-8 0.000000+0 4.843853-8 4.843853-8 4.843853-8 12522102    6
 4.843853-8 0.000000+0 4.843853-8 4.843853-8 4.843853-8 4.843853-8 12522102    7
 0.000000+0 4.843853-8 4.843853-8 4.843853-8 4.843853-8 0.000000+0 12522102    8
 4.843853-8 4.843853-8 4.843853-8 4.843853-8 0.000000+0 4.843853-8 12522102    9
 4.843853-8 4.843853-8 4.843853-8 0.000000+0 4.843853-8 4.843853-8 12522102   10

If the line:

 22  102 /

near the end of the GROUPR input is removed, then the Inf-309 isn't calculated.

Now I'm not sure where the data for MF=22/MT=102 comes from. It seems that MF=22 is used internally by NJOY. Some insight on that would be helpful.

I've noticed this processing a variety of other ENDF Tapes. All of them have errors when processing MF=2*/MT=102 where * is 2,3,5, or 6. That is, MF=22, 23, 25, or 26 with MF=102 will all produce Inf-309 in the same place.

[whaeck]

The 'MF=22' is actually an NJOY MFD number for charged particle production matrices. MFD=2x (x equal to 1 to 6) are the production matrices for protons, deuterons, tritons, helions, alpha and the residual nuclide from MF=6. MFD=3x (x also equal to 1 to 6) is the same, but calculated from MF=4 data.

I'll have a look.

[jlconlin]

Today I learned that in order to process MF=22 and MT=102 (probably some other MT combinations as well), you also need to process MF=6 MT=102 through GROUPR. It is not enough to simply to process MF=6; you have to explicitly call out the MT that you are interested in.