Problem 717

Summary: probrem of accumulation of energy loss in standard EM
Product: Geant4 Reporter: tkoi
Component: processes/electromagneticAssignee: Michel.Maire
Status: RESOLVED FIXED    
Severity: normal    
Priority: P2    
Version: 7.0   
Hardware: Other   
OS: Other   

Description tkoi 2005-01-27 19:53:34 CET
It looks like there is a problem of accumulation of energy loss (ionization
loss) in standard EM.

In example N03, I changed thickness of Gap and Absorber to 1 nm, then there is
no energy loss is happened when e- 50MeV passing 20nm sandwich calorimeter.
(I attached G4Track information at bottom.)
I changed primary particle to proton, similar feature is also observed,
however in this case, only 1 layer (1st lead absorber) has deposit energy of
21.0 eV.

I changed physics list to use low energy EM module, then this curios feature
disappeared.

Tatsumi



*******************************************************************************
**************************
* G4Track Information:   Particle = e-,   Track ID = 1,   Parent ID = 0
*******************************************************************************
**************************

Step#      X         Y         Z        KineE    dEStep   StepLeng
TrakLeng    Volume     Process
    0    -12 nm      0 fm      0 fm     50 MeV     0 eV      0 fm      0
fm        World    initStep
    1    -10 nm      0 fm      0 fm     50 MeV     0 eV      2 nm      2
nm        World  Transportation
    2     -9 nm      0 fm      0 fm     50 MeV     0 eV      1 nm      3
nm         Lead  Transportation
    3     -8 nm  -20.5 fm     63 fm     50 MeV     0 eV      1 nm      4 nm
liquidArgon  Transportation
    4     -7 nm  -26.8 fm    126 fm     50 MeV     0 eV      1 nm      5
nm         Lead  Transportation
    5     -6 nm   -128 fm    109 fm     50 MeV     0 eV      1 nm      6 nm
liquidArgon  Transportation
    6     -5 nm   -236 fm   99.4 fm     50 MeV     0 eV      1 nm      7
nm         Lead  Transportation
    7     -4 nm   -327 fm   91.8 fm     50 MeV     0 eV      1 nm      8 nm
liquidArgon  Transportation
    8     -3 nm   -430 fm    125 fm     50 MeV     0 eV      1 nm      9
nm         Lead  Transportation
    9     -2 nm   -532 fm    150 fm     50 MeV     0 eV      1 nm     10 nm
liquidArgon  Transportation
   10     -1 nm   -628 fm    199 fm     50 MeV     0 eV      1 nm     11
nm         Lead  Transportation
   11 -7.32e-11 fm   -720 fm    221 fm     50 MeV     0 eV      1 nm     12
nm   liquidArgon  Transportation
   12      1 nm   -758 fm    220 fm     50 MeV     0 eV      1 nm     13
nm         Lead  Transportation
   13      2 nm   -848 fm    220 fm     50 MeV     0 eV      1 nm     14 nm
liquidArgon  Transportation
   14      3 nm   -929 fm    220 fm     50 MeV     0 eV      1 nm     15
nm         Lead  Transportation
   15      4 nm -1.09e+03 fm    221 fm     50 MeV     0 eV      1 nm     16
nm   liquidArgon  Transportation
   16      5 nm -1.22e+03 fm    214 fm     50 MeV     0 eV      1 nm     17
nm         Lead  Transportation
   17      6 nm -1.39e+03 fm    236 fm     50 MeV     0 eV      1 nm     18
nm   liquidArgon  Transportation
   18      7 nm -1.55e+03 fm    253 fm     50 MeV     0 eV      1 nm     19
nm         Lead  Transportation
   19      8 nm -1.66e+03 fm    195 fm     50 MeV     0 eV      1 nm     20
nm   liquidArgon  Transportation
   20      9 nm -1.77e+03 fm    138 fm     50 MeV     0 eV      1 nm     21
nm         Lead  Transportation
   21     10 nm -1.88e+03 fm    130 fm     50 MeV     0 eV      1 nm     22
nm   liquidArgon  Transportation
   22     12 nm -2.1e+03 fm    105 fm     50 MeV     0 eV      2 nm     24
nm   OutOfWorld  Transportation
---> End of event: 0
   Absorber: total energy:       0 eV        total track length:       0 fm
        Gap: total energy:       0 eV        total track length:       0 fm
Comment 1 Michel.Maire 2005-01-28 07:30:59 CET
We have identified the origin on the problem. Under study ...