LAW=66 description omits distribution data

[whaeck]

The LAW=66 write up in the ACE specifications do not mention the distribution data that is also produced by ACER and put there. See acefc.f90 (roughly around line 13400)

[jlconlin]

@whaeck and/or @HunterBelanger, do you have an example ACE file where we can see the output?

[HunterBelanger]

This ACE file uses the NBody for MT=16. It starts at index 40113 in the XSS block (C-style indexing).
H2.txt

[paulromano]

Interesting -- I never realized ACER spits out tabulated distributions for LAW=66 after the main parameters. The density function has an analytical form that can be easily sampled, so that data is superfluous (not used by MCNP, Serpent, or OpenMC).

[whaeck]

It's actually not a problem since we have locators that point to specific pieces in the XSS array. If you look at the XSS array as a contiguous data array, then you might get into trouble if you do not know those distributions are there.

[paulromano]

Understood. I'm just curious as to why it was put in there in the first place. I suppose MCNP might have used that data once upon a time?

[whaeck]

I assume so.