|Message: Synchrotron radiation path length cutoff?||Not Logged In (login)|
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Hi - I have been looking at the output of examples/extended/electromagnetic/TestEm16, which explores synchrotron radiation. My application is in the atmosphere, so I am looking at very long distances (>100 km), high energies (>10 TeV), and low field strength (B_perp = 0.5 gauss). A histogram of the path length is created, and a statistic is printed out about it as well. I extended the size of the histogram to look at path lengths beyond 1 km, but to my surprise none were present. There is a cutoff at 1 km. For a 10 TeV electron in a field of 0.5 gauss, the mean free path is calculated to be 3.3 km. However, statistics printout at the end of each event says ~500 m, which is expected for a flat distribution cut off at 1 km. Why the cutoff at 1 km in path length? Here is an input file which can be used with TestEm16 to see this cutoff. You must modify the histogram upper ends to be on scale. # $Id: TestEm16.in,v 1.3 2006/05/24 12:58:49 maire Exp $ # # Macro file for "TestEm16.cc" # (can be run in batch, without graphic) # # /control/verbose 2 /run/verbose 2 # /run/initialize # # inactivate other processes to make SynchrotronRadiation more visible /process/inactivate msc /process/inactivate eIoni /process/inactivate eBrem /process/inactivate annihil /process/inactivate phot /process/inactivate compt /process/inactivate conv # /gun/particle e- /gun/energy 10000 GeV # /testem/det/setSize 200 km /testem/det/setMat Vacuum /testem/det/update # /testem/det/setField 0.5 gauss # /run/beamOn 2000 Scott Nutter Northern Kentucky University
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