Re: What the parameters mean in material properties tables?

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)

  G4double LXe_Energy[LXe_NUMENTRIES]    = { 7.0*eV , 7.07*eV, 7.14*eV };

// they should be optics photon's energy, right?

right!

// another question, how about the emission spectrum is continuous?

  G4double LXe_SCINT[LXe_NUMENTRIES] = { 0.1, 1.0, 0.1 };

In this case, the emission spectrum IS continuous. The emission spectrum has a peak at 7.07eV and drops to 10% on either side within +-0.07eV. A linear interpolation is done between points of this triangular spectrum.

// what's these? Are they the relative light output or others?

Yes, relative light output.

  G4double LXe_RIND[LXe_NUMENTRIES]  = { 1.59 , 1.57, 1.54 };

//refractive index,right?

correct

  G4double LXe_ABSL[LXe_NUMENTRIES]  = { 35.*cm, 35.*cm, 35.*cm};

//absorbed length, just equal to attenuation length?

correct

  LXe_mt = new G4MaterialPropertiesTable();
  LXe_mt->AddProperty("FASTCOMPONENT", LXe_Energy, LXe_SCINT, LXe_NUMENTRIES);
  LXe_mt->AddProperty("SLOWCOMPONENT", LXe_Energy, LXe_SCINT, LXe_NUMENTRIES);

//time component array.

  LXe_mt->AddProperty("RINDEX",LXe_Energy, LXe_RIND,  LXe_NUMENTRIES);

//refractive index array

 LXe_mt->AddProperty("ABSLENGTH",LXe_Energy, LXe_ABSL,  LXe_NUMENTRIES);

//absorbed lenght array.

all correct

LXe_mt->AddConstProperty("SCINTILLATIONYIELD",12000./MeV);

//scintillation yield,just mean that produce 12000. photons per 1 MeV.

correct

  LXe_mt->AddConstProperty("RESOLUTIONSCALE",1.0);

//is it resolution scale? Can somebody tell me its definition.

This (and everything above) is explained (I'd hope - but let me know - if not) sufficiently in the documentation:

http://wwwasd.web.cern.ch/wwwasd/geant4/G4UsersDocuments/UsersGuides/ForApplicationDeveloper/html/TrackingAndPhysics/physicsProcess.html#5.2.5

and an intrinsic resolution, RESOLUTIONSCALE, which generally broadens the statistical distribution of generated photons. A wider intrinsic resolution is due to impurities which are typical for doped crystals like NaI(Tl) and CsI(Tl). On the other hand, the intrinsic resolution can also be narrower when the Fano factor plays a role. The actual number of emitted photons during a step fluctuates around the mean number of photons with a width given by ResolutionScale*sqrt(MeanNumberOfPhotons).

  LXe_mt->AddConstProperty("FASTTIMECONSTANT",20.*ns);          
  LXe_mt->AddConstProperty("SLOWTIMECONSTANT",45.*ns);

//arise time and decay time,right?

No! You can specify two decay constants, one for the fast scintillation component and one for a slow component (rise-time is instant).

  LXe_mt->AddConstProperty("YIELDRATIO",1.0);

//energy transfer efficiency?

The relative strength of the fast component as a fraction of total scintillation yield is given by the YIELDRATIO

  LXe->SetMaterialPropertiesTable(LXe_mt);