search

njoy / NJOY2016

Nuclear data processing with legacy NJOY
https://www.njoy21.io/NJOY2016
Other
98 stars 86 forks source link

GROUPR sets the first sigma0 to 1e+10 BY DEFAULT #40

Open whaeck opened 7 years ago

whaeck commented 7 years ago

In subroutine ruinb (which reads and initialises the sigz array), njoy2016 will always override the first user defined value with 1e+10. When putting 1e+10 as a first value, this is a non issue, but you can get into trouble for other applications.

When generating multigroup data for NDI, the routines that read the NJOY data only read the results for the first sigma0 value, so by default always the infinite dilute ones. Tom Saller would like to override this behaviour so he can easily generate NDI libraries with a sigma zero value different from 1e+10.

According to Tom Saller, older versions of unresr might have done this as well but the source code for unresr from njoy2016 does not appear to have this in it.

jlconlin commented 7 years ago

I'm reluctant to make this change. This has been the operation for a long time; I don't want to mess up input decks that already work.