|Message: Magnetic Field from field01 Example||Not Logged In (login)|
Click on the Forum title, e.g. on the "Forums by Category" page, to read a sequence of postings to the Forum and its threads all in one page. If you are only interested in one thread or the thread following a specific posting, click the thread or the posting, which takes you to a smaller page, which contains only the part you are interested in and may be easier to navigate.
Messages are "chained" if there are only replies at the first level, i.e. 1/1.html, 1/1/1.html etc. In case of "chained" messages the message number is replaced by the icon and there is no indentation.
Inline: Display the subject line only or also the text of the posting(s); for the choice "All" the "Outline" choices are switched off.
|1||0||1||no text / full text of posting|
|2||1||All||text for level 1 only / text for All postings|
Outline: Choose the depth of the posting thread, successive toggle controls provide increasing detail.
|1||2||1||2 levels / 1 level (original posting)|
|2||3||2||3 levels / 2 levels|
|3||3||All||3 levels / all levels (all postings)|
It is probabbly apparent by my multiple magnetic field postings on the forum that I am having difficulties getting my magnetic field to work. The basic run down of my situation is as follows. I am using code from TestEm1 (Geant/examples/extended/electromagnetic/TestEm1) and exGPS (Geant/examples/extended/eventgenerator/exGPS). I am using the GeneralParticleSource to create positron emitting point sources and examining their the distance that these positrons travel prior to annihilation with electrons in a tissue like material. I also want to utilize a uniform transverse magnetic field to see how the field alters the distance the positrons travel. The distance should be reduced, because the magnetic field will cause the charged particles to spiral inwards due to the transverse nature of the field. For the magnetic field code I have used the F01FieldSetup.cc/hh and F01FieldMessenger.cc/hh found in example field01 (Geant/examples/extended/field/field01). Everything compiles, links, and runs beautifully. The problem is that I do not believe that the magnetic field is taking any effect. I know I have introduced a magnetic field because the simulation is hard coded to print out the magnetic field paramaters. These are the paramaters that were printed: PreInit> /control/execute Mono.in F01FieldSetup: magnetic field set to Uniform( 0, 0, 9.4 ) EpsilonStep: set min= 1e-05 max= 0.0001 G4ClassicalRK4 (default) is called The minimal step is equal to 0.01 mm The Box is 2 m of Tissue PhysicsList::SetCuts:CutLength : 1 mm To simplyify a test of the magnetic field's effect, I use the following macro file to shoot monoentergetic positrons: /pr/det/setMat Tissue /pr/det/setSize 2 m /run/initialize # /process/eLoss/verbose 1 /tracking/verbose 1 /pr/stepMax 6 mm /gps/particle e+ /gps/ene/type Mono /gps/ene/mono 4 MeV /gps/direction 1 0 0 /run/beamOn 1 I do this with both the field set to 0 Tesla and then 9.4 Tesla and I change nothing else. The outputs are identical. The track length, ending position in x-y-z, and range of the particles are the same. This indicated that the effect of the magnetic field is not being realized. I intend on shooting ions using the gps commands, but it is easier to test the magnetic field via positrons for now. Do you have any suggestions or assistance that can help in this matter. I have been working on getting this magnetic field to operate properly for weeks. I sincerely appreciate any input you may provide. Thanks, Matthew Middione
|Inline Depth:||Outline Depth:||Add message:|