Problem 1965

Summary: Large memory usage for high energy primary and bug in bertini-coalescence
Product: Geant4 Reporter: Andrea Dotti <andrea.dotti>
Component: processes/hadronic/models/cascadeAssignee: Michael Kelsey <kelsey>
Status: RESOLVED FIXED    
Severity: major    
Priority: P4    
Version: 10.3   
Hardware: All   
OS: All   

Description Andrea Dotti 2017-04-13 19:16:04 CEST
When used at high energy the coalescence code tries combinatorics of all exiting nucleons to form light fragments.
This code has two problems: it uses very large amounts of memory when energy of the primary is very high that can be a problem in MT mode due to a support std::set where the tested combinations are stored.
In addition the code that calculates "hashes" of the candidate light fragments (to be used in aforementioned set) is bugged and the hash function has high probability of collision. The effect of the bug is to suppress light fragments production.

Fortunately after close inspection and testing we have realized the use of the support std::set and of the hash function are not needed and can simply be removed. This solves the memory and the bug at the same time.
Comment 1 Andrea Dotti 2017-04-13 19:28:25 CEST
fix being tested in hadr-casc-V10-03-00