[Gate-users] How to measure the X-rays scattered by the phantom when they enter the detector?

[mas]

* { font-size: 13px; font-family: 'MS Pゴシック', sans-serif;}p, ul, ol, blockquote { margin: 0;}a { color: #0064c8; text-decoration: none;}a:hover { color: #0057af; text-decoration: underline;}a:active { color: #004c98;}
Dear David,




Thanks to your reply, I understood that I should use the phase space actor.

After reading the documentation, I tried using phase space actor.




I got a one-dimensional profile.

It was certainly like a point spread function.

However, some questions remained.




1)The output is a one-dimensional profile, but how do I know which location on the detector is profiled?




2)Which function of the phase space actor is used to separate scattered and direct lines?

 [/gate/actor/MyActor/storeOutgoingParticles true] is used?




3)How do I output the actual values from the root file, e.g. a txt file? I am sorry that this is not the original question.




Thank you.

mas





----- Original Message -----




From: "David Leibold" <D.Leibold at tudelft.nl>

To: "mas" <fight1_fight2 at yahoo.co.jp>

Cc: "gate-users at lists.opengatecollaboration.org" <gate-users at lists.opengatecollaboration.org>

Date: 2022/09/02 金 00:35

Subject: Re: [Gate-users] How to measure the X-rays scattered by the phantom when they enter the detector?







Dear Masa,




May I summarise your requirements:




1) You mention that you want to simulate a CsI detector, but with 100 % detection efficiency and no interaction within the detector. 




2) You would like to distinguish between scattered and primary rays.




3) A monochromatic pencil beam enters a phantom.







My suggestion:




I would suggest using a phase space actor (see the documentation here), which registers each particle's energy, position, velocity etc. crossing its surface. Since you do not want to simulate interaction in your CsI detector material, there is no need to use it in the first place.




Since you are using a pencil beam, all primary photons will go straight through your phantom, intersecting your detector at, for example, point (0,0). All scattered radiation will intersect your detector away from point (0,0). Hence, you can filter out the scatter and primary rays purely based on where they end up on your detector.




To set up your detector, use e.g. a box volume with the desired size, fill it with vacuum, and attach a phase space actor to it. 




If you need more help, please let us know.




Best regards,

David 










On 30 Aug2022, at 00:46, mas <fight1_fight2 at yahoo.co.jp> wrote:



Hi GATE users.
I am masa at japan and new to Gate.

I am currently working on a simple simulation.
I am trying to find the point spread function of the scattered rays detected by a CsI detector by injecting a pencil beam of monochromatic X-rays into an acrylic phantom.

Assuming a detector detection efficiency of 100%, I want to output the spread of scattered radiation when it enters the detector.
No interaction occurs with the detector.　I also want to output scattered rays and primary rays separately.
How should I set up the detector in such a case?

Should I use Fluence Actor for detection?
Or should I use a sensitive detector?

I would appreciate it if you could help me.

Thank you.



_______________________________________________

 Gate-users mailing list

 Gate-users at lists.opengatecollaboration.org

 https://urldefense.com/v3/__http://lists.opengatecollaboration.org/mailman/listinfo/gate-users__;!!PAKc-5URQlI!5R6DdcwuD-nXX0bmvN3RckxZ2HEAgen9ExhbGuDcz_52hS9V1Rohx8vBP7HBR0msh9Bx0lNmj5dJ866ftlukHHjC8jk0_A$  



-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.opengatecollaboration.org/pipermail/gate-users/attachments/20220902/36f26020/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: phase_root_x.png
Type: image/png
Size: 142781 bytes
Desc: not available
URL: <http://lists.opengatecollaboration.org/pipermail/gate-users/attachments/20220902/36f26020/attachment-0001.png>