GSI Forum
GSI Helmholtzzentrum für Schwerionenforschung

Home » Fairroot » General Discussion » Radiation length units
Re: Radiation length units [message #18199 is a reply to message #13533] Mon, 11 May 2015 18:54 Go to previous message
Volker Friese is currently offline  Volker Friese
Messages: 365
Registered: April 2004
Location: GSI CBM
first-grade participant
From: *
Radiation length is a material property, so it must not vary with the step size in the simulation. The large values you see are possibly due to your encountering vacuum, the radiation length of which is infinite.

Usually, the radiation length is given in units of g/cm^2, so to arrive at the unit cm you would have to divide by the density in g/cm^3. It is unclear which value FairRadLenPoint::GetRadLength() returns. It would be nice if at least the unit of the return value could be specified in the class documentation.

Assuming the unit is cm, then what you calculate is the material budget along the trajectory step described by the FairRadLenPoint, in units of the radiation length of the material. Since this is a measure of the energy loss of electrons by Bremsstrahlung and also for multiple scattering, it makes sense tu sum up this value along the trajectory, even if different materials are involved.
Read Message
Read Message
Read Message
Previous Topic: Problem on running FairRoot tutorial macro
Next Topic: Question about environmental varaibles[Solved]
Goto Forum:

Current Time: Tue Jun 25 21:48:23 CEST 2024

Total time taken to generate the page: 0.01054 seconds