Problem 2346

Summary:	Mess in density effect data for hydrogen and helium
Product:	Geant4	Reporter:	Konstantin <konstik>
Component:	materials	Assignee:	Vladimir.Ivantchenko
Status:	RESOLVED FIXED
Severity:	minor
Priority:	P4
Version:	10.7
Hardware:	All
OS:	All

Description Konstantin 2021-03-09 21:45:31 CET

Density effect parameters m,x0,x1 for liquid hydrogen and gaseous hydrogen and helium are different in G4IonisParamMat.cc and G4DensityEffectData.cc.
  Material "G4_H" and 'manually' made kStateGas hydrogen get their density effect parameters from G4DensityEffectData, correction from G4IonisParamMat::ComputeDensityEffectParameters (line 333) isn't used.
  The same about "G4_He" and manually made kStateGas helium: parameters from line 338 of G4IonisParamMat.cc aren't used.
  Material "G4_lH2" gets its parameters from G4DensityEffectData, but 'manually' made kStateLiquid hydrogen gets parameters from G4IonisParamMat (line 310).
  Is the behaviour of the program correct?

Comment 1 Vladimir.Ivantchenko 2022-04-17 14:03:33 CEST

Hello,

sorry for the late reaction to this report. The concern is correct. The problem is fixed and the fix will be available in the next public release and in the next patch for Geant4 11.0.

This fix provides published density effect parameterisations for liquid and gaseous hydrogen. We do not have specific parameterisations for liquid helium, so for any helium state the same parameterisation is used.

VI