Problem 1768 - Time life of excited states
Summary: Time life of excited states
Status: RESOLVED FIXED
Alias: None
Product: Geant4
Classification: Unclassified
Component: processes/hadronic/models/radioactive_decay (show other problems)
Version: 10.0
Hardware: All All
: P5 trivial
Assignee: dennis.herbert.wright
URL:
Depends on:
Blocks:
 
Reported: 2015-07-10 12:24 CEST by michel.maire
Modified: 2015-11-12 02:04 CET (History)
1 user (show)

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Description michel.maire 2015-07-10 12:24:04 CEST
Many lifetimes within an IT cascade are not taken into account.
This is due to mismatch between G4ENSDFSTATE (or G4NuclideTable) and PhotonEvaporation data set (1 eV tolerance ...)
Refere to macros in rdecay01/references
Comment 1 dennis.herbert.wright 2015-11-12 02:04:18 CET
This is now fixed.  There is currently a default threshold of 1000 ns on the mean life of nuclides which is set in G4NuclideTable.  Any nuclide mean life shorter than this will be treated as decaying instantly.  To allow shorter life times, you must add the lines

 G4NuclideTable* nuclideTable = G4NuclideTable::GetInstance();
 nuclideTable->SetThresholdOfHalfLife(0.001*ns);

somewhere in your user code, perhaps main().  Here the smallest mean life is set to 1 ps and the resulting run shows that the lifetime for the 2505.753 is now non-zero.  We eventually plan to have a UI command to set this.   

Also note that because the energy level tolerance in G4NuclideTable is 1 eV, the energy levels specified in macro files must be listed to that precision.  So, for example,   

/gun/ion 28 60 0 2505.75 will not work, but
/gun/ion 28 60 0 2505.753 will work.

We also plan to have a UI command to set the energy level tolerance.