Alpha particle filter in Geant4?

Particles, Track, Event, Run and Biasing
1

Dear users/experts,

I am simulating the radioactive decay for alpha particle dose estimations. I want to use the alpha particle filter in my simulation to score the dose only from the alpha particle, is there an alpha filter to do that? I have seen electrons, gammas filters but not the alpha filters! OR, if there is no alpha filter, do you suggest me to kill the electrons and gamma emissions generated from the decay mechnism to score only the alpha dose from the radioactive decay process? For these simulations, I am using the ion source using the particle gun command emitting isotropically. Any hints or suggestions are highly appreciated.

2

have you tried
/score/filter/particle alphaFilter alpha
?

3

Yes, I tried that before - not sure why that was not working! I have just tried one more time but it seems working now. But the visualization displays all particles - how can we show only the filtered particle in visualization?

`

This is how I set the commands - see below:

/vis/enable
/control/verbose 0
/run/verbose 0
/event/verbose 0
/tracking/verbose 0

/run/initialize

/process/list

Radium ion source

/gun/particle ion
/gun/ion 88 223
/gun/energy 0. MeV
/gun/number 1

define scoring mesh

/score/create/boxMesh box1
/score/mesh/boxSize 100.5 100.5 100.5 um
/score/mesh/translate/xyz 0. 0. 0. um
/score/mesh/nBin 201 201 201

Now: score edep, dose in each cell of the mesh

/score/quantity/doseDeposit dose Gy
/score/quantity/energyDeposit eDep MeV

Filter only alphas

/score/filter/particle alphaFilter alpha

/score/close

Print the list of scorers

/score/list

/vis/enable
/run/printProgress 1
/run/beamOn 100

Visualize the middle column

/score/drawColumn box1 dose 1 100 logColorMap

Dump scorers to a file

/score/dumpQuantityToFile box1 dose dose_1e2.csv
/score/dumpQuantityToFile box1 eDep edep_1e2.csv
`

4

I think you need to issue the filtering line after each primitive scoret that you want to be filtered. in the macro you posted the dose would be unfiltered, but the deposited energy is filtered.

5 
/score/quantity/doseDeposit dose Gy
/score/filter/particle alphaFilter alpha

/score/quantity/energyDeposit eDep MeV
/score/filter/particle alphaFilter alpha

So, writing this way score only the dose and energy from alphas? Thanks.

6

At least this is my understanding… Compare with the documentation: " Please note that /score/filter comma[n]d affects on the immediately preceding scorer."
https://geant4-userdoc.web.cern.ch/UsersGuides/ForApplicationDeveloper/html/Detector/commandScore.html?highlight=filter#id4

From
https://geant4-userdoc.web.cern.ch/UsersGuides/ForApplicationDeveloper/html/Visualization/filtering.html#example-commands

you could (almost) copy paste what you need:

/vis/filtering/trajectories/create/particleFilter
/vis/filtering/trajectories/particleFilter-0/add alpha
/vis/filtering/trajectories/particleFilter-0/active true
7

I was able to visualize only the alphas…This is very neat. Thank you.