Problem 2530 - Unusual behaviour for the "AddEmRegion" macro command
Summary: Unusual behaviour for the "AddEmRegion" macro command
Status: RESOLVED FIXED
Alias: None
Product: Geant4
Classification: Unclassified
Component: processes/electromagnetic (show other problems)
Version: 11.1
Hardware: Other Linux
: P4 normal
Assignee: Vladimir.Ivantchenko
URL:
Depends on:
Blocks:
 
Reported: 2023-02-13 09:56 CET by ronny.stanzani
Modified: 2023-03-06 12:10 CET (History)
2 users (show)

See Also:

Attachments
The macro (sandia.mac) containing the modified commands. (1.07 KB, text/plain)
2023-02-13 09:56 CET, ronny.stanzani 		Details
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Description ronny.stanzani 2023-02-13 09:56:11 CET 
Created attachment 802 [details]
The macro (sandia.mac) containing the modified commands.

Test setup:
TestEm11 example with Geant4 11.1. I modified the sandia.mac macro to launch 100 keV protons with "/testem/applyAutomaticStepMax false" setting and "/tracking/verbose 1" to see details of processes happening. 
When I try different combinations of Physics Lists, the following behaviour occurs: 

1. if I use emstandard_opt4, I see mainly msc and hIoni processes;
2. if I use emstandardSS, I see mainly coulombscat;

Both those behaviours seems ok to me. But:

3. if I use emstandard_opt4 and the command "/process/em/AddEmRegion DefaultRegionForTheWorld G4EmStandardSS", I see only hIoni processes (no scattering at all). This seems a bit strange to me.

As test purpose, if I increase the protons energy (to about 1000 keV) in case 3, coulombscattering appears.

Could this behaviour be related to the MscThetaLimit parameter? If I set MscThetaLimit to zero in PhysicsList.cc, coulombscattering appears also at 100 keV. It seems that the command "AddEmRegion" does not change the theta limit.