Re: Antiproton annihilation products

From: Stefan Roesler <>
Date: Fri, 17 Oct 2008 19:33:55 +0200

Hi Roy,

The table which you mention gives the average over all inelastic
interactions, thus, also of all secondary particles.

Which scoring option to choose depends somewhat on the experiment with
which you would like to benchmark the simulation. Here are two

- USRBDX detector scoring fluence or current of particles emerging from
  your target. Here you can score individual particle types but also
  generalized particles such as all charged particles. Scoring is with
  respect to the normal of the boundary from which the particle emerges.

- USRYIELD detector: here you can score double differential distributions
  for a long list of quantities (see manual for details). By default it
  also scores at region boundaries, but, in contrast to USRBDX, with
  respect to a fixed direction (beam direction by default). With
  What(4)=-1.0 and WHAT(5)=-2.0 you can also restrict scoring to particles
  emerging from inelastic interactions. In case you are interested only in
  the interaction of the beam particle you could make your target very
  small and force interactions (shorten the inelastic interaction length)
  using biasing (LAM-BIAS with Sdum=INEPRI, see Manual for details).

I hope the above is of some help in finding the best scoring method.


On Thu, 16 Oct 2008, Roy Keyes wrote:

> Hello,
> I am trying to benchmark FLUKA against data for the multiplicity of
> antiproton annihilation products from a 220 MeV beam incident on liquid
> propane. Can anyone give me advice on the best way to calculate the
> multiplicity? I'm specifically interested in pions, kaons, and ions.
> So far I've found the following section in the standard output file
> (e.g. pbar001.out):
> Number of secondaries generated in inelastic interactions per beam particle:
> Prompt radiation Radioactive decays
> 1.0441E+01 (100.%) 0.0000E+00 (100.%)
> 1.0680E+00 (10.2%) 0.0000E+00 ( 0.0%) 4-HELIUM
> 2.1800E-01 ( 2.1%) 0.0000E+00 ( 0.0%) 3-HELIUM
> 1.9300E-01 ( 1.8%) 0.0000E+00 ( 0.0%) TRITON
> 3.9200E-01 ( 3.8%) 0.0000E+00 ( 0.0%) DEUTERON
> 0.0000E+00 ( 0.0%) 0.0000E+00 ( 0.0%) HEAVYION
> ...
> Is this the best place to find what I'm looking for? Should I be using
> one of the scoring cards instead?
> Thanks,
> Roy

Stefan Roesler
CH-1211 Geneva 23
Phone:  +41-22-7679891
Fax:    +41-22-7669639
Received on Sat Oct 18 2008 - 08:51:56 CEST

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