Re: Cosmic physics Study

From: Francesco Cerutti <>
Date: Sat Sep 20 2008 - 23:10:23 CEST

( []); Sat, 20 Sep 2008 23:09:38 +0200 (CEST)

Dear Sharmalee,

the Silicon residues produced by your proton field in the Al slab have
such a range in Al that they cannot leave the slab, unless they have been
created just at the scoring boundary (not farther than a few microns for
the highest energy protons). To try to see something by your USRYIELD
detector (where the charge limits are in fact inverted, as in the other
one), you should build a thin layer upstream, significantly decrease the
nuclear interaction length of protons in that new region (WHAT(2) of the
LAM-BIAS card, applied to a fake material, identical to aluminum, assigned
to such a layer), and lower the ion transport threshold (with the choice
PRECISIO in the DEFAULTS card you have 100 keV/nucleon). You can switch
off the transport of photons, electrons and positrons (SDUM EMF-OFF in
the card EMF). All this if the effort to seek a meaningful statistics is
On the other hand, no way to see Iron nuclei through your boundary. The
re-interaction of Al&Si residues of range/kinetic energy as above looks
less than negligible and anyway the (im)possible Fe products would have a
practically zero range.
By a RESNUCLEi card, you could see which nuclei are in fact generated
(and deposited) in the Al region(s) (keep in mind that no nucleus-nucleus
re-interaction is performed below 100 MeV/n).
For neutrons and protons, I would suggest to score by your USRBDX cards
differential fluence instead of current, as physically more meaningful.
Note that all your primaries impact perpendicularly the slab, this way
sistematically minimizing their path in Al.

Hope this helps



Francesco Cerutti
CH-1211 Geneva 23
tel. ++41 22 7678962
fax ++41 22 7668854
Received on Sun Sep 21 21:20:26 2008

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