NJOY2016 errors out of processing the JEF 2.2 U233 evaluation with the following message:
***error in acelf5***sorry. acer cannot handle lf=5.
you will have to patch the evaluation to use lf=1.
The following input file reproduces the issue:
u3.txt
The lf=5 option (general evaporation spectrum) is used for fission (MT18) and delayed neutrons (MT455). ACER errors out when processing the fission data (but it would probably have done the same if the delayed neutrons were the only section using lf=5).
For some reason, the coding for this option is complete but the error message prevents it's execution. There is actual code after the error message (unreachable since NJOY errors out before) used to read the theta(x) function after which the g(x) function is read. Both are subsequently processed and written to the xss array. The ACE format manual even contains the formatting details for LAW=5 in the DLW block.
Looking through older versions of NJOY, it appears that the error message was introduced in NJOY99.20, on August 16, 2000:
*/ acer-- 16aug00
*/ we are not currently handling law=5 for energy distributions.
*/ this occurs for u-233 fission from jef-2.2. the evaluation can
*/ be patched by converting the lf=5 part of the distribution to
*/ lf=1, which is sampled much better by mcnp using cummulative
*/ probability distributions anyway.
*i acer.6098
call error('acelf5','sorry. acer cannot handle lf=5.',
& 'you will have to patch the evaluation to use lf=1.')
The U233 evaluation from JEF 2.2 is explicitly mentioned in the update comments. The coding for LF=5 in the acelf5 subroutine has not changed since NJOY91. The JEF 2.2 evaluation dates back to 1992 but the error message was only introduced in 2000 so the data must have been used at some point.
More work is required to understand why this error message was added.
NJOY2016 errors out of processing the JEF 2.2 U233 evaluation with the following message:
The following input file reproduces the issue: u3.txt
The lf=5 option (general evaporation spectrum) is used for fission (MT18) and delayed neutrons (MT455). ACER errors out when processing the fission data (but it would probably have done the same if the delayed neutrons were the only section using lf=5).
For some reason, the coding for this option is complete but the error message prevents it's execution. There is actual code after the error message (unreachable since NJOY errors out before) used to read the theta(x) function after which the g(x) function is read. Both are subsequently processed and written to the xss array. The ACE format manual even contains the formatting details for LAW=5 in the DLW block.
Looking through older versions of NJOY, it appears that the error message was introduced in NJOY99.20, on August 16, 2000:
The U233 evaluation from JEF 2.2 is explicitly mentioned in the update comments. The coding for LF=5 in the acelf5 subroutine has not changed since NJOY91. The JEF 2.2 evaluation dates back to 1992 but the error message was only introduced in 2000 so the data must have been used at some point.
More work is required to understand why this error message was added.