Density in TRIM

I am a beginner of SRIM and I have some questions .

  1. I want to simulate the ionization of α in air using TRIM, but the target density makes me confused.It is well known that the density of air is 1.29 g/cm^3,however,if I tick the gas option ,the desity is 1.57E-03,if I don’t tick the gas option ,the density is 1.1268. I want to know how to set the density?Can I change the density to 1.29 and tick the gas option? What is the difference between ticking or not ticking the gas option
  2. How to set “Total number of ion"?The more the better?What factors should be considered?

Maybe it is better to ask your questions on an “SRIM forum”. If it exists…

Or maybe @hschindl knows or can provide some pointers here… :slight_smile:

  • TRIM uses different models for solid and gas targets. You can find some information in the TRIM manual (
  • “Total number of Ions”: this depends on how many tracks you want to simulate.