Dear Geant4 users and experts,
I am studing the detector responses/corelations to gamma-rays using Na-22 source. In the experiment, the Na-22 source emits two back-to-back 511-keV gamma-rays besides the 1274 keV. But in the simulation, I did not figure out how to define the back-to-back gamma rays in each event using GPS (General Particle Source).
A naive way I tried is defining two gamma sources, and confine the theta and phi angles in each event, by turning the “multiplevetex” as ture, as shown in the picture. But in this way I have to change the theta and phi confinment in each run repeatly in order to cover more simualited angles. What getting worse is that the repeated runs by changing the angle confinements lead to repeated patterns of separated gamma lines (The simulated spectrum is supposed to be continuous distrubution rather than seprated lines), when merging these runs together in the analysis.
Can anyone give me any suggestion of defining the Na-22 gamma-source using GPS in a proper way?
Thank you for reading, and in advance for the help!