Re: neutron fluence study

Hi,

I need some help to set the physics for a hadron therapy simulation.
The beam is protons. The beam transport nozzle and all the apertures
are made of brass. I want to look at the neutron fluence down steam of
the nozzle.

These are the physics cards I set.

*...+....0....+....1....+....2....+....3....+....4....+....5....+....6....+....0
DEFAULTS PRECISIO
PHYSICS 3.0 EVAPORAT
EVENTYPE 2.0 DPMJET
*...+....0....+....1....+....2....+....3....+....4....+....5....+....6....+....0

Please advice me if these aren't correct.

Thank you!!

Sharmalee

Quoting Sharmalee Randeniya <randeniya_at_rice.edu>:

>
> Hi Everyone,
>
> I did a simulation involving a nozzle and a water phantom. The beam =20
> is protons of 159 MeV kinetic energy. The beam passes through the =20
> nozzle on to the phantom. I was looking at the neutron fluence at a =20
> surface between the nozzle and the phantom. The protons coming out =20
> of the nozzle are roughly 70 MeV.
>
>
> In my results, I am seen lots of low energy neutrons(less 20 MeV) =20
> but not really much high energy protons (~ 70 MeV). I have attached =20
> a lin-log plot of (integral binned fluence)*energy versus energy. I =20
> am guessing that I should be seen a peak between 10 Mev and 100 MeV.
>
> I have attached the inp file and the output unit 81 in which I have =20
> used USRBDX to calculate fluence. The plot is produced using the =20
> same output.
>
> I would appreciate any help. Sunil if u could also kindly take a =20
> look and see I have made any mistake that would be great.
>
> Thank you !!
>
> Sharmalee Randeniya
> Rice University
>
Received on Thu Dec 04 2008 - 09:23:27 CET