Bug #1577
Longitudinal beam generation not working as expected
Added by Rogers, Chris over 8 years ago.
Updated over 8 years ago.
Start date:
22 October 2014
Description
The beam.py longitudinal beam generation in the Twiss model is not doing what I expected. Not sure if I am screwing up the analysis or MAUS is screwing up somewhere.
I made a workaround to add a correlation using "cov(t,p)", "cov(t,pz)" "cov(t,energy)" when in gaussian mode.
I haven't had a chance to look at it. It looks weird. It may be the alpha sign. I note that in longitudinal phase space things are different because faster particles arrive earlier, i.e. with lower t. On the other hand particles with higher px arrive with larger x). I haven't really had a chance to dig into the details. If it is working okay then maybe this is a false alarm...
Looks like I was generating a beam using pz as longitudinal variable, then calculating longitudinal optical functions using energy - which doesn't work if transverse emittance is non-zero
- Status changed from Open to Rejected
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