Stopping power of proton

Physics, Transport and Magnetic Fields
1

Dear experts,
I tried to get stopping power of proton, and in .out file ,I get a result like the picture,
I want to the meaning of each column. Also there are four columns in low energy and five in higer proton energy.

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the first colum is proton energy, is the second unrestricted electron stopping power? I am comfused about this.

2

I have seen that the second column is restricted stopping power, but when I change the delta ray production threshold, the second column data was not changed. The proton beam energy is 230 MeV, and I use DEFAULT=HARDOTHE.

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4

Hello Qinqin,

I want to the meaning of each column.

The data are tabulated as following:

  1. Kinetic energy of the projectile
  2. Unrestricted stopping power
  3. Relativistic eta
  4. Shell correction, taking into account the effect of atomic bounds when the projectile velocity is comparable with the one of atomic electrons. This correction is important at low energies.
  5. Restricted stopping power, according to the value specified in DELTARAY card

If you require DPA scoring, you can enable even a 6th and a 7th columns which describe the nuclear stopping power, but it’s another topic.

I have seen that the second column is restricted stopping power, but when I change the delta ray production threshold, the second column data was not changed.

When you increase the delta ray production threshold, you are increasing the restricted stopping power, since more electrons will be below your cut. However, the unrestricted stopping power stays the same.

Also there are four columns in low energy and five in higer proton energy.

When the unrestricted stopping power is equal to the restricted one, FLUKA does not print the 5th column. You start printing the restricted stopping power only for protons which are energetic enough to produce delta ray above the threshold.

Let me know in case of other doubts,
Cheers,
Daniele.