Problem 2234 - Problem with the Wendt fission model
Summary: Problem with the Wendt fission model
Status: RESOLVED FIXED
Alias: None
Product: Geant4
Classification: Unclassified
Component: processes/hadronic/models/neutron_hp (show other problems)
Version: 10.6
Hardware: All All
: P4 normal
Assignee: dennis.herbert.wright
URL:
Depends on:
Blocks:
 
Reported: 2020-04-05 11:09 CEST by Federico.Carminati
Modified: 2020-07-02 19:16 CEST (History)
0 users

See Also:

Attachments
Add an attachment (proposed patch, testcase, etc.)

Note You need to log in before you can comment on or make changes to this problem.
Description Federico.Carminati 2020-04-05 11:09:48 CEST 
I have circumstantial evidence that the Wendt fission model is not thread-safe. The method 

G4DynamicParticleVector* G4FissionProductYieldDist::G4GetFission( void )

in particular generates one fission fragment and then it subtracts its Z and A from the fissible atom to obtain the second. When running in single thread the code works and the distribution is reasonable. When running in MT mode, the method produces fragments with negative A and Z values when more than one thread access the method and subtracts from the variables  RemainingA_ and  RemainingZ_. 

I think the method should be at least locked. Best,
Comment 1 dennis.herbert.wright 2020-07-02 19:16:12 CEST 
G4AutoLock placed on G4FissionProductYieldDist::G4GetFission() .