Create a fan beam using gps

Particles, Track, Event, Run and Biasing
1

Hi,

I have been trying to find a way to generate a fan beam with gps, but I don’t seem to get it.

I could give a cone-shaped source with an input of my intensity distribution in the theta angle.

/gps/ang/type user
/gps/hist/type theta
/gps/hist/point angle intensity

But in the azimuthal angle, I don’t know how to set it so that I get a fan shape that I want.

Does anybody know some other ways of creating a fan beam?
Thanks in advance.

2

https://geant4-userdoc.web.cern.ch/UsersGuides/ForApplicationDeveloper/html/GettingStarted/generalParticleSource.html?highlight=general#angular-distribution

this will give you a fan in -x direction in the x-z plane. opening angle would be calculated from the formula 𝜃 = arccos(1−2×RNDM). no idea how to rotate it though, please share if you find out:

/gps/ang/type iso
/gps/hist/type biast
/gps/hist/point 0. 0.
/gps/hist/point 0.45 0.
/gps/hist/point 0.5 1.
/gps/hist/point 0.55 1.
/gps/hist/point 1. 0.
/gps/hist/type biasp
/gps/hist/point 0. 0.
/gps/hist/point 1. 0.