Hi everyone, we have updated the process TRestElectronDiffusionProcess to add the simulation for electron excitation. Before, we always have a fix number of electrons to be excited in a fixed event, i.e., total eDep / w-Value, or fMaxHits. Now, we are able to randomize this number, with Poisson distribution. This can be turned on by using parameter poissonElectronExcitation:
When simulating electron excitation, the energy of each excited electrons is meaningless. We only care about the total number of electrons. It is now possible to unify them. This can be turned on by using parameter unitElectronEnergy:
The actual process is like that: For each hits inside input event, we calculate its average number of electrons, then we get a Poisson random value from this number. If fMaxHits is set, we calculate a scale factor by w-Value / totalE * fMaxHits, and scale all the Poisson random value with it. This will reduce the computation. Then, when adding hits(each hit is a simulated electron) to the output event, the energy of each hits is always 1.
People working on this topic:
Ni Kaixiang, Yan Xiyu (SJTU)
Wen XiCheng (USTC)
The excited electrons in TPCs usually have their kinetic energy close to zero. That’s why recording energy is meaningless. To detect excited electrons we usually build our detectors with charge sensitive readout, which only counts the number of electrons being received. It doesn’t add the energy of the electrons like using calorimeter.
In our simulation, previously, we set all the electrons’ energy to w-value. Then we add them up in TRestHitsToSignalProcess. This is logically inpersuasive since the energy of them are actually zero. But is it still right because all of the energies are same. Mathematically it is equivalent to counting the electron number.
Hi @nkx, it is this topic closed or there are further developments? If future work is planned perhaps it would be a good idea to create an issue at rest-for-physics/detectorlib