|Message: Re: highly un reasonable positron penetration depth in Fe. (LowEnergy, Penelope and default)||Not Logged In (login)|
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On Tue, 29 Jul 2008 00:51:38 GMT, Or Chen wrote: > Hey, > > I'm working on a PAS (Positron Annihilation Spectroscopy) simulation, > > In the experimental system's most basic structure, positrons leave the > source at about ~200*keV, loose about 10*keV ant the source's house and > then loose energy in the Iron and annihilate at around thermal energy. > > From what I understand, the Penelope model is best for my geometrical > setup and energy ranges. > > As a first and basic validation of my simulation I looked at the > penetration depth of the positron in the Iron. > > Using both Penelope, LowEnergy and the Default model I got about 20 > micron, when I know that a reasonable result should be around the 100 > micron. > > (give or take 30 is still fine) > I ran $G4INSTALL/examples/extended/electromagnetic/TestEm11 with the following macro :
# $Id: orchen.mac,v 1.4 2006/09/18 17:26:20 maire Exp $ # # /control/verbose 2 /run/verbose 2 # /testem/det/setMat Iron /testem/det/setSizeX 200 um /testem/det/setSizeYZ 200 um # /testem/phys/addPhysics standard # em physics # /run/initialize # /testem/phys/setCuts 1 um # /gun/particle e+ /gun/energy 190 keV # /control/execute vis.mac /testem/event/drawTracks charged # /run/beamOn 100
Interactively, to see the tracks : PreInit> /control/execute orchen.mac
On the output, you can read that the projected range of e+ is ~70 um
Cheers, Michel Maire
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