Re: Introduction to MCNP

[Craig Harmon <charmon@skid.ps.uci.edu>]

On Wed, 25 Oct 1995 hodgdon@homer.yankee.com wrote:

> Are radsafers interested in learning about monte carlo simulation
> of radiation doses on a PC or workstation?  The short course
> "Introduction to MCNP" will be given in the Boston area Dec. 5 to
> 8.  The course is good for 16 ABHP CECs and 2.8 CECs from
> Worcester Polytechnic Institute.

How well does it work on a PC?  And what software do you need to have to 
use it?

> The HP who wants to invest some time can predict doses and
> instrument responses from simple or complex neutron, photon, and
> electron sources.  Graphical and statistical outputs simplify and
> speed up model creation.  The code is distributed by the
> Radiation Shielding Center at Oak Ridge.

According to the manual I have, MCNP can be used for the following: 
neutron, photon, electron, or coupled neutron/photon/electron transport...
Thermal neutrons are described by both the free gas and S(alpha,beta)
models.  For photons, the code takes account of incoherent and coherent 
scattering, the possibility of fluorescent emission after photoelectric 
absorption, absorption in pair production with local emission of 
annihilation radiation, and bremstrahlung.  The electron and photon energy 
ranges are 1 keV to 1 GeV (though I'm pretty sure it doesn't do 
photopions nor take into account the delta resonance regions so if that 
is important to you, you need something else), and the neutron energies 
are from 10^-11 MeV to 20 MeV.

The only flaw I can see for dosimetry in the 10's of MeV region is the 
lack of photoneutron or electroneutron (really the same thing) production.
Otherwise it looks like a great MC, and the manual that comes with it is 
about 3 inches thick and is full of great physics stuff on the 
approximations and the Monte Carlo techniques used.  So even if this isn't 
for you, the manual itself is a great resource if you like writing your 
own MC's.  

I'd still be interested in how well this works on a PC though.

Craig
charmon@skid.ps.uci.edu