The OPAL Discussion Forum

[Nicole Neveu <nneveu AT hawk.iit.edu>]

Hi Andreas, 

Thanks for the email and answers. Good luck finishing V1.4, I'm looking forward to it. :)

As for 3, I couldn't say for sure since an admin for the cluster installed it, but I did direct him to the downloads page of binaries. I'll ask about the installation today. 

In the mean time, I downloaded my input file to our dropbox along with the T7 files. I have an R collimator around the linac, a 4cm radius will do.  

This also reminds me of another questions I had. Can monitors overlap elements (rf cavities, etc) or is that bad practice? I was using one to look at the beam near the cathode, but that forces it to overlap with the gun and solenoids. 

Thanks!

Nicole

On Tue, Nov 17, 2015 at 1:02 AM, Adelmann Andreas (PSI) <andreas.adelmann AT psi.ch> wrote:

Hello Nicole 

​Hello OPAL experts,

 

I've been using OPAL for the past few months and things are going well. Thanks again for your help with my thermionic gun simulations when I first started. I am currently running V1.2, but plan to switch to V1.4 when it is released. I have a few questions about the differences, ect.

Yes 1.4 is a bit late :( but we are close :-)

 

1. Does OPAL scale magnetic field maps to the max B value in the file, or max Bz on axis? Pg. 183 of the manual says: "the input field map will be normalized so the peak field magnitude value is equal to ...1 T in the case of magnetic field maps."  I think I see this behavior in my simulations, but appendix C (pg. 203) says scaling is done using max Bz on axis values. Is this a feature that is changed from V1.2 to V1.4?

The behaviour is as described on P. 183 and the description on P 203 is corrected in the new version of the manual.

@Steve: can you check please 

 

2. Should I use the R or E collimator? When we were emailing about the thermionic gun, it was suggested that I use the R collimator. The manual says E is supported in OPAL-T (pg.98). Is this difference an artifact of using V1.2? 

In 1.4 you can use both, indeed there was a problem in 1.2.

3. I have been running on a cluster at ANL, and I've been able to run on multiple processors, but not on multiple nodes. I get segmentation faults (11). Is this an artifact of using V1.2 that will be fixed in V1.4, or is it something I am doing wrong?  The cluster uses Torque PBS manager and Maui PBS scheduler, and my run commands look like the following:

mpirun -np 16 opal OTR.in --info 0 | tee OTR.out

That should work. Are you using the pre-build binaries for the closure runs? 

If you send me the input file I can have a look and check on our cluster.

Also tell me where do you want to have the E-collimator so I can try. 

Do we have a Dropbox?

Cheers Andreas