Message: Re: Energy distribution of source as histogram (GPS) Not Logged In (login)
 Next-in-Thread Next-in-Thread
 Next-in-Forum Next-in-Forum

None Re: Energy distribution of source as histogram (GPS) 

Forum: Event and Track Management
Re: Question Energy distribution of source as histogram (GPS) (Suhaili Zakaria)
Date: 02 Mar, 2010
From: Fan Lei <Fan Lei>

On Thu, 25 Feb 2010 03:52:51 GMT, Suhaili Zakaria wrote:
> Hello
> 
> I have referred to http://reat.space.qinetiq.com/gps/ and examples in
> /extended/eventgenerator/exgps/, but I still have questions and
> uncertainties on how to use/define energy distribution as histogram
> using GPS.
> 
> 1. I am interested with two of the options that can be used to defined
> energy distribution, i.e. energy (/gsp/ene/type User ), and arbitrary
> point-wise spectrum (/gps/ene/type Arb). However, I am not sure what is
> the difference between this two options, and in what conditions they are
> best used. Can someone please explain it?

User: user defined histogram, i.e. step function like spectrum Arb: point-wise spectrum

> 
> 2. To choose a histogram, the command /gps/hist/type is used. In case of
> energy it should be /gps/hist/type energy and /gps/hist/type arb for
> arbitrary point-wise.
> 
> I suppose you use /gsp/ene/type User with /gps/hist/type energy; and
> (/gps/ene/type Arb) with /gps/hist/type arb. Am I correct?

Correct!

> 
> 3. Next, /gps/hist/point <X> <Y> command is used to load the histogram,
> where <X> is the energy in MeV and Y is the weight (or area) of the bin.

Correct for the "energy" case. <X> is the lower-edge of the the bin, <Y> is the area of the bin. Please follow test18.g4mac in http://reat.space.qinetiq.com/gps/examples/examples.htm

> How do I determine the weight in this case?
> 
> Is <Y> the number of particles per energy, but that doesn&#65533;t seem right.
> 

In this case you should use the "Arb and "arb" combination, i.e. point-wise distribution. Please follow test19.g4mac in http://reat.space.qinetiq.com/gps/examples/examples.htm

> I really appreciate and looking forward to any insights/answers/comments
> on this matter. Many, many thanks
> 

Inline Depth:
 1 1
 All All
Outline Depth:
 1 1
 2 2
 All All
Add message: (add)

1 None: Re: Energy distribution of source as histogram (GPS)   (Suhaili Zakaria - 08 Mar, 2010)
 Add Message Add Message
to: "Re: Energy distribution of source as histogram (GPS)"

 Subscribe Subscribe

This site runs SLAC HyperNews version 1.11-slac-98, derived from the original HyperNews


[ Geant 4 Home | Geant 4 HyperNews | Search | Request New Forum | Feedback ]