Re: [fluka-discuss]: Difference between FLUKA and NIST Unrestricted Electron Stopping Powers

From: paola sala <>
Date: Fri, 22 Mar 2019 10:44:20 +0100

Dear Daniela,
the DELTARAY cards controls delta ray production by hadrons and muons.
It does not affect electron/positron transport.
The "delta ray production" threshold for electrons is the same as the
electron production threshold, and is set through
the EMFCUT card with SDUM=PROD-CUT

Thus, you are printing RESTRICTED energy loss by electrons/positrons,
with a threshold that depends on the DEFAULT† and EMFCUT cards
you are using. This fully explains the supposed difference wrt NIST .

Please look in the manual for further information.

You can also have a look to the Ionization and Transport lectutr in the
last fluka course

Have a nice day

On 3/21/19 4:36 PM, Daniela Botnariuc wrote:
> Dear FLUKA experts,
> I am simulating a proton beam in a water region where I am also
> considering secondary particles, including electrons. My goal is to
> print out the electron stopping power used by FLUKA and for that I
> activated the PRINT option in the EMFFIX card. To make sure I am
> getting unrestricted electron stopping powers, I set the DELTRARAY
> production threshold to infinite, so there is no delta ray production.
> I compared the stopping power values printed in the output file to the
> NIST unrestricted stopping powers and I find a large discrepancy as
> you can see in the figures below.
> Could someone explain why are these values so different? Am I
> simulating it wrong?
> I have been trying to understand this for some time and I would really
> appreciate any help.
> Best wishes,
> Daniela
> Following the recent revision to the International System of Units
> (SI), we will be looking at one of the seven SI base units each month.
> This month itís the second
> <>.
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Received on Fri Mar 22 2019 - 12:05:53 CET

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