Plotting energy-angle distributions

[Mahdi-20]

Hello experts,
I am trying to plot the energy-angle distributions of 197Au(g,xn) using NJOY.
My questions are:
1- Is there a way to plot the energy-angle distributions (b/MeV/sr) of 197Au(g,xn) reaction from the ACE file? I used the viewr module but it outputs only the sigma in a unit of barn versus the photon energy.

2- I was trying to get the energy-angle distributions from the ENDF6 format for the incident photon energy of 16 MeV and output angles of 60 and 150 degrees using the plotr module (input below). However, I was stuck with the parameters of Card 8 as indicated with "?". How can I define the incident energy and output angle? I have attached the tape40 for this input file.

plotr
31/
1 1/
1/
'JENDL'/
'ang dist'/
4/
/
/
/
/
6 40 7925 6 5 ? ? ?/
/
99/
viewr
31 46/
stop

tape40.txt

Thanks for any comment and help.

[whaeck]

I've transferred this question to the NJOY2016 repository since this is an input related question.

To answer your first question: yes, there is a way to plot data from the ACE file although - as a user - you have no control over what will be plotted by using iopt=7. This will only plot some of the data in the ACE file that does not require interpretation (i.e. most tabulated data would be plotted). I assume that this is what you have tried already. If not, you can use the following input to do this:

acer
0 20 50 41 42 /
7 1 1 /
/
viewr
50 51
stop

From the particular case you want to handle, I assume that you want to plot photoatomic or photonuclear data. We're actively working on ACEtk to extract data from ACE files and we are already using it for some plotting purposes. However, we're currently focusing on incident neutron and charged particle files first. In the end, ACEtk will help you do what you want to do, but for photon data we still have to do a lot of work.

As for your second question, once you have specified the MAT, MF, MT this is followed by the temperature value (I think you can set this to zero for incident photon data) and then by nth, ntp and nkh. This is part of the input instructions:

! temper temperature for endf data (degK, default=0.)
! nth,ntp,nkh see below (defaults=1)
!
! special meanings for nth,ntp,nkh for file 3 or 5 data
! nth number of subsection to plot
! (works for isomer prod, delayed n, etc.)
! ntp not used
! nkh not used
!
! special meanings for nth for file 4 Legendre data
! nth index for Legendre coefficient (p1, p2, ...)
!
! special meanings for nth,ntp,nkh for file 6 data
! nth index for incident energy
! ntp number of dep. variable in cyle to plot
! (or angle number for law 7)
! nkh number of outgoing particle to plot
!
! special meanings for nth,ntp,nkh for gendf mf=3 data
! nth=0 for flux per unit lethargy
! nth=1 for cross section (default)
! ntp=1 for infinite dilution (default)
! ntp=2 for next lowest sigma-zero values, etc.
! nkh=1 for p0 weighting (default)
! nkh=2 for p1 weighting (total only)
!
! special meaning for nth for gendf mf=6 data
! nth=1 plot 2-d spectrum for group 1
! nth=2 plot 2-d spectrum for group 2
! etc.
! no special flags are needed for mf=6 3d plots
!
! special meanings for nth and ntp for mf7 plots
! nth is index for indep. variable (alpha or beta)
! ntp=1 selects alpha as indep. variable (default)
! ntp=2 selects beta as indep. variable
! nkh=1 selects normal s(alpha,beta)
! nkh=2 selects script s(alpha,-beta)
! nkh=3 selects script s(alpha,beta)

You can also find some more information on how to use these in sections 20.5 to 20.8 (in the PLOTR chapter).

Best regards,
Wim

[Mahdi-20]

@whaeck Thank you for your comments. I have ACEtk installed but I could not use it for extractign photonuclear data from the format. So, I turned to NJOY.

I case of
acer
0 20 50 41 42 /
7 1 1 /
/
viewr
50 51
stop

I already tried it, and as you mentioned some conventional plots are printed and double differential cross sections are not shown.

Regarding the second case, what I cannot understand is the following explanation:

! special meanings for nth,ntp,nkh for file 6 data
! nth index for incident energy
! ntp number of dep. variable in cyle to plot
! (or angle number for law 7)
! nkh number of the outgoing particles to plot

How can I determine the nth index of the incident energy? ntp and nkh? to output the DDX of 197Au(g,xn) in b/MeV/Sr.

I am not well familiar with ENDF and ACE formatted data. Sorry for asking many questions.

Thank you.
Mahdi