|Message: Magnetic field with parallel world||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)|
I am simulating a scanned proton beam nozzle. The target is a parametrized patient CT volume. I want to embed spherical gold markers in the patient volume to estimate the effect of dose shadowing. However, it seems that parametrized volumes cannot be mother volumes. So I have been trying to place the gold markers in a parallel world. It seems to work as long as I don't activate the scanning magnets. I've traced it down in my code to a call to G4FieldManager::SetDetectorField(). If I leave this line of code in, the program crashes (Access violation) in G4PathFinder::ComputeStep()
// Prepare the information to return
pNewSafety = fCurrentPreStepSafety[ navigatorNo ]; > limitedStep = fLimitedStep[ navigatorNo ]; fRelocatedPoint= false;
I can see that "navigatorNo" is 1, so I'm assuming that the arrays are not being allocated for the parallel world for some reason. If I comment out the call to SetDetectorField(), then it runs OK, but I have no steering magnets.
I've been reading "Parallel Geometries in Geant4: foundation and recent enhancements" and there seems to be something about magnetic fields and parallel worlds. Should I try using "G4SafetyHelper"?
In the attached image, the gold marker is the red sphere. It is in the parallel world. The gold marker is the only thing in the parallel world.
Thanks for any advice!
|Inline Depth:||Outline Depth:||Add message:|