Re: [FLUKA] Secondary electron emission

From: Alfredo Ferrari <>
Date: Sat, 9 Jun 2012 09:48:47 +0200

Dear Stefano

yes in future please send the questions directly to fluka-discuss, there
is always one of us "on shift" to answer questions like the one you are
posing now.

Now, it is difficult to answer without knowing your input file, however I
would guess that you did not change the default choices for delta ray
(secondary electrons) production and electron transport.

A 20 MeV proton beam can roughly produce 40 keV maximum energy electrons,
and the default thresholds are surely higher since in many problems there
is no need to go down to those energies.

Start with the following:

a) set with the DEFAULTS card the PRECISIOn default (see the manual)
b) set with the DELTARAY card the threshold for delta ray production
     down to 1 keV (the minimum FLUKA can do) for all materials
c) set with the EMFCUT card (sdum PROD-CUT) the production threshold
     for electrons and photons down to 1 keV

Please look carefully in the manual for the details of how to do those
steps. Send me the resulting input for check.

                     Best regards

| Alfredo Ferrari || Tel.: + |
| CERN-EN/STI || Fax.: + |
| 1211 Geneva 23 || e-mail: |
| Switzerland || |

On Fri, 8 Jun 2012, Stefano Sinigardi wrote:

> Dear Dr. Ferrari,
> I'm starting to use FLUKA and I'm already stuck with some problems, so
> as you'll understand how, I was told to write to you.
> The goal that was given to me few days ago was to study a proton bunch
> passing through a foil of copper (0,5 mm thick). Since I had to
> estimate the energy lost by protons and the emission of secondary
> electrons, I though that Fluka was the right tool and Prof. De
> Martinis, with whom I'm working on some problems related to proton
> transport, confirmed me the choice and also told me to write (in
> english) to you in case I had some problems. So here it is my email.
> I don't know if you prefer that I write to the fluka mailing list, in
> that case please tell me so. I also tried to search in the mailing
> list archive for similar problems, but I didn't get any useful hint.
> So, back to my problem. I hope I'll be clear. At the end of the work,
> I'll have to read protons from an input file which contain their
> individual phase space (so I thought of using the source card and a
> source.f file, with many problems for now, so for the moment I'm just
> using the beam card and asking for 20 MeV protons). Then I defined a
> slab of copper (I hope it's correct in the way I'm doing, the most
> important thing is that it must be 500 microns thick) and put some
> detectors for protons and electrons after the target.
> While I can see that the protons at the end have lost some energy in
> the output #58, I cannot see any electron in my output #57: those
> zeros start to change to "something different" (> 0) only when I'm
> using incoming protons of "hundreds of MeV".
> They told me that I should see some electrons, so I'm asking to you,
> in case you have some time to help me, if everything is correct.
> Thanks a lot for your time.
> Best regards,
> Stefano Sinigardi
Received on Sat Jun 09 2012 - 10:35:11 CEST

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