RE: [fluka-discuss]: Discrepancy between FLUKA and ICRU 49/NIST in He stopping powers for alphas

From: Luke Bird <>
Date: Tue, 15 Jul 2014 08:37:39 +0000

Dear Mario and others, I created a test geometry to compare the stopping powers of helium to that of SRIM and the ICRU 49 report. The alphas were initialised with an energy of ~0.00548 GeV with two mylar cylindrical bodies upstream. I compared the dE/dx values printed in the output file from a run of 1000 initials with those of ICRU 49, NIST and SRIM. I can attach the raw data for comparison if required. The density of the helium is the default value of 0.00016632 g/cm^3, which was used to compare the other data also. Find attached the input file - apologies for not attaching it earlier. Thanks for the assistance. Luke ________________________________________ From: Santana, Mario [] Sent: 15 July 2014 01:36 To: Luke Bird; Subject: Re: [fluka-discuss]: Discrepancy between FLUKA and ICRU 49/NIST in He stopping powers for alphas Luke, Are you using 5 MeV momentum or energy for your initial beam? What are your transport thresholds and DEFAULT cards? What is the density of the helium medium? Are you comparing to the stopping power in dE/dx or (dP/dX = FLUKA output)? Could you send your input file? Mario On 7/14/14 7:06 AM, "Luke Bird" <> wrote: >Dear FLUKA experts and users, > >When simulating alphas moving through helium in SRIM and FLUKA I found >that FLUKA tallied higher energies than SRIM, so I investigated and >found that FLUKA outputs lower stopping powers for helium (Using SDUM = >PRINT in the deltaray card) and those given in > the TRIM/NIST databases as well as those in ICRU 49 (See figure >attached). > >Is this a known issue or am I going wrong somewhere - although I don't >see where. I am just initialising alphas with ~0.005 GeV and printing >the stopping power to the output with he DELTARAY card. > >Thanks, > >Luke

Received on Tue Jul 15 2014 - 12:04:41 CEST

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