Zero energy deposition with Thermal Neutrons on He3

Help: Forums, postings and threads

Forums, postings and threads

Click on the Forum title, e.g. on the "Forums by Category" page, to read a sequence of postings to the Forum and its threads all in one page. If you are only interested in one thread or the thread following a specific posting, click the thread or the posting, which takes you to a smaller page, which contains only the part you are interested in and may be easier to navigate.

Layout of the posting thread(s)

The posting threads can be shown with/without the text of the postings ("Inline depth"). In addition the depth of the thread can be controlled ("Outline depth"). For both cases several values are provided, which can be toggled. Note that the displayed values are those, which can be chosen, they do not correspond to the actual display status of the thread(s).

Add message

Add a new posting thread to this Forum

Show subscribers

Click "Show subscribers" to get the List of all subscribers, who receive e-mail from postings to this Forum, if they have not explictly unsubscribed from a posting thread. This includes:

Subscribers to the forum
Explicit subscribers to the posting or any of its ancestors
The author of the posting (if he has not unsubscribed)
The authors of any ancestor posting (if they have not unsubscribed)

Some browsers display old pages from the cache

Some browsers (e.g. Firefox) display a page from the cache even though the page has been updated. As a result, one may not get the latest messages in the forum's outline or the logon ID of the previous session appears on the upper right corner. If one suspects that he or she does not get the latest content of a page, try clearing up the personal data from the browser's cache as the following:

Tools -> Clear Private Data -> Clear Private Data (from browser Firefox)

Tools -> Delete Private Data (from browser Opera)

then reflesh the current page to get the latest content.

Details on "Inline depth" and "Outline depth"

Threads and the follow-up messages are numbered. There is one line per posting, normally starting with the posting number. The URLs of a posting and its responses reflect the depth of the follow-up postings. Watch the URLs to see how this is done. Depending on the chosen display options, the thread-display may be incomplete; the number of messages at the next level is, however, displayed, e.g. "…3 message(s)". You may not see all contributors unless you choose "All".

Messages are "chained" if there are only replies at the first level, i.e. 1/1.html, 1/1/1.html etc. In case of "chained" messages the message number is replaced by the icon and there is no indentation.

Inline: Display the subject line only or also the text of the posting(s); for the choice "All" the "Outline" choices are switched off.

Argument Default value Alternative Comment

1 0 1 no text / full text of posting

2 1 All text for level 1 only / text for All postings

Argument	Default value	Alternative		Comment
1	0	1		no text / full text of posting
2	1	All		text for level 1 only / text for All postings

Outline: Choose the depth of the posting thread, successive toggle controls provide increasing detail.

Argument Default value Alternative Comment

1 2 1 2 levels / 1 level (original posting)

2 3 2 3 levels / 2 levels

3 3 All 3 levels / all levels (all postings)

Argument	Default value	Alternative	Comment
1	2	1	2 levels / 1 level (original posting)
2	3	2	3 levels / 2 levels
3	3	All	3 levels / all levels (all postings)

Zero energy deposition with Thermal Neutrons on He3

Hi,

I wrote a physics list for a simulation program in which I am throwing thermal neutrons (0.025 eV) on a he3 tube. There is obviously a major problem with my physics list since I get 0.0000 keV deposited in my tube for every single one of 500 thermal neutrons thrown: these neutrons are NOT interacting.

I read a presentation by Koi Tatsumi at SLAC (which he was kind enough to point to me), which shows how Elastic scattering should be implemented for thermals. The reaction that matters most for He3 is thermal neutron capture: I am pretty sure I am not implementing capture correctly. In Dr. Tatsumi's talk there is a "G4NeutronHPThermalScatteringData" and a "G4NeutronHPThermalScattering" model. My questions:

1). Is there a "G4NeutronHPThermalCaptureData" and a "G4NeutronHPThermalCapture" model?

2). If yes, is the cutoff from simple HP at 4eV like for scattering?

3). I am attaching my physics list. I would apreciate if an expert could read it and point to me how to correct it (for now, I am ONLY interested in thermals; in the future I may simulate a real attenuated neutron source with neutrons ranging in energy from thermal to a few MeV; the detector would be different, something like a 10B loaded liquid maybe).

Thank you, Clarisse

   Attachment:
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2009/03/30/14.28-53504-_src_myDetPhysicsList.cxx
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2009/03/30/14.28-33358-clude_myDetPhysicsList.hh
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2009/03/30/14.28-14594-rimaryGeneratorAction.cxx

Re: Zero energy deposition with Thermal Neutrons on He3 by Koi, Tatsumi <Koi, Tatsumi>, 31 Mar, 2009 Re: Zero energy deposition with Thermal Neutrons on He3 (Clarisse) I did check that 0.025 eV neutrons are captured by He3 and it cross section was about 5x10-5 barn. This value is similar ENDF Values. The check is done with physics list on the slide which you mentioned. > 1). Is there a "G4NeutronHPThermalCaptureData" and a > "G4NeutronHPThermalCapture" model? No, there isn't. Tatsumi

Add Message

to: "Zero energy deposition with Thermal Neutrons on He3"