[fluka-discuss]: Secondary protons from a scattering clinical proton beam in water and graphite phantoms

From: Ferreira De Almeida Lourenco, Ana <am.lourenco_at_ucl.ac.uk>
Date: Fri, 23 Oct 2015 15:18:47 +0000

Dear Fluka experts,

I have simulated in FLUKA a clinical 62 MeV proton scattering beam and I'm studying the dose due to secondary protons in a phantom of water and graphite.

I'm using a USRBIN card to score dose due to primary protons (by scoring BEAMPART) and protons (by scoring PROTON). Please find attached the results of the USRBIN card for primaries and protons in the water and graphite phantom, where the phantom is at position z=184 cm.

The results show that the contribution from PROTON is significantly different in water and graphite. Also, considering that PROTON-BEAMPART = secondary protons, we conclude that these difference comes from secondary protons (since the difference from BEAMPART is very small).

Looking at the production cross section for secondary protons from ICRU 63 (graph in attachment) it is unrealistic to obtain such a big difference between water and graphite for secondary protons. I can't find a logical interpretation that explain these results, unless that the cross sections implemented in FLUKA are considerable different from those in ICRU 63.

Why the contribution of sec protons is so different in water and graphite? Could you please provide info regarding the nuclear data that is implemented in FLUKA?

I have also attached the input files for water and graphite.

Many thanks,


You can manage unsubscription from this mailing list at https://www.fluka.org/fluka.php?id=acc_info

(image/png attachment: ICRU63data.png)

(image/png attachment: protons_water.png)

(image/png attachment: prim_water.png)

(image/png attachment: protons_graphite.png)

(image/png attachment: prim_graphite.png)

Received on Fri Oct 23 2015 - 20:08:19 CEST

This archive was generated by hypermail 2.3.0 : Fri Oct 23 2015 - 20:08:23 CEST