[fluka-discuss]: Strange binning in DETECT card [NP]

From: Sebastian Galer <sebastian.galer_at_npl.co.uk>
Date: Mon, 9 Sep 2013 10:10:36 +0100

Classification: NPL Management Ltd - Public



Hi,

 

I have been using the DETECT card to score the energy deposited in a gas
region on an event-by-event basis for a tissue equivalent proportional
counter. I have been trying to reproduce some results from a paper
published a little while ago for a 2um site size and a cobalt 60 beam.

 

What I have found is that certain bins seem to get significantly more
events than others giving my resulting histogram a somewhat spiked
effect! Whilst this could be a physical thing I have a tried changing
the settings and seeing what happens and this only occurs under certain
circumstances.

 

For a 1um site size (determined by changing the gas pressure) this
effect is not present. For different gas compositions (my own, propane
based TE gas from the materials database and air) the same thing occurs
when increasing the density.

 

I did find that if I smooth the spikes I get good agreement with the
published shape but I am not sure what is causing it. I have tried
changing transport and physics options and nothing seems to change it. I
have also tried using a proton beam for different energies but still the
same thing occurs. Finally I have tried changing the bins (so using 2
DETECT cards; one for low energy events and and one for higher energy
events) and the problem is the same (only in the low energy events
card).

 

Any thoughts would be appreciated.

 

Thanks,

Seb

 

--
If you have received this message in error, please notify us and remove it from your system.
NPL Management Ltd cannot guarantee that the e-mail or any attachments are free from viruses.
 
NPL Management Ltd is a company registered in England and Wales, number: 2937881
Registered office: Serco House | 16 Bartley Wood Business Park | Hook, Hampshire | UK | RG27 9UY

Received on Mon Sep 09 2013 - 12:05:27 CEST