From: Stefan Roesler (sroesler@mail.cern.ch)
Date: Fri Jun 08 2007 - 09:04:21 CEST
Hello Yuanjie Bi,
I can confirm your FLUKA-result of 2.0406E+11Bq/cm^3. The 7Be production
cross section predicted with the most recent FLUKA version is actually
15mb.
However, I cannot reproduce your analytical result: the saturation yield
is 1.002E-7 7Be/primary, the beam intensity is 1.248E15 p/second and the
built-up factor is (for tirr=42.72days) 0.4263. The product of the three
factors divided by the volume of your region (foil) gives 2.0011E11
Bq/cm^3.
Regards
Stefan
On Mon, 4 Jun 2007, Yuanjie BI wrote:
> Hi Fluka users,
>
> I am reserching the radioactivity of a thin carbon foil bombed by 100MeV proton.
> The production of Be7 calculated by FLUKA is 2.03E+11Bq/cmc, but my analytic
> result using the cross section of 13mb is 1.95E+12Bq/cmc.
>
> I have checked the input many times and can't find the reason,is my input file
> correct ?
>
> By the way, how could I know the cross section used by FLUKA?
>
>
> Many thanks for your help
> Best regards
>
> Yuanjie Bi
> -------------------------------------------------------------------------------
> TITLE
> C foil bombarded by 100MeV protons
> GLOBAL 1.0 1.0
> DEFAULTS NEW-DEFA
> BEAM -0.1 0.5 0.8 PROTON
> BEAMPOS 0.0 0.0 -0.0001
> PHYSICS 3.0 EVAPORAT
> PHYSICS 1.0 COALESCE
> GEOBEGIN COMBNAME
> 0 0 C foil inside vacuum
> * Black body
> RPP blkbody -500.0 500.0 -500.0 500.0 -500.0 500.0
> * void
> RPP void -100.0 100.0 -100.0 100.0 -10.0 100.0
> * target
> RPP target -1.0 1.0 -1.0 1.0 0.0 6.66D-05
> END
> * Black hole
> BLKBODY 5 +blkbody -void
> * Void around
> VOID 5 +void -target
> * Target
> TARGET 5 +target
> END
> GEOEND
> * ..+....1....+....2....+....3....+....4....+....5....+....6....+....7..
> ASSIGNMA BLCKHOLE BLKBODY
> ASSIGNMA VACUUM VOID
> ASSIGNMA CARBON TARGET
> LOW-NEUT 1.0
> EMF EMF-OFF
> DISCARD ELECTRON POSITRON PHOTON MUON+ MUON- PIZERO
> LAM-BIAS 0.0002 CARBON PROTON NEUTRON 7.0INEALL
> LOW-BIAS 73.0 72.0 0.85 VOID TARGET 1.0
> RADDECAY 1.0 3.0 0.0 99999
> IRRPROFI 3691008.0 1.248D+15
> DCYTIMES 0.0 28800.0 86400.0 604800.0 2592000.0 10368000.
> DCYSCORE 1.0 A A RESNUCLE
> RESNUCLE 1.0 -21.0 TARGET 0.000266A
> DCYSCORE 2.0 B B RESNUCLE
> RESNUCLE 1.0 -22.0 TARGET 0.000266B
> RANDOMIZ 1.0
> START 1.D8 0.0
> STOP
>
>
>
-- ___________________________________ Stefan Roesler CERN, SC/RP CH-1211 Geneva 23 Switzerland Phone: +41-22-7679891 Fax: +41-22-7669639 E-mail: Stefan.Roesler@cern.ch
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