H1 Forward Tracker Delta-ray Study
A GEANT simulation consisting of
The first is the z position of 'primary' tracks entering
the gas. Where 'primary' means that the production vertex of the track had z < 1 cm AND it's
momentum was > 0.5 GeV/c
The second is the z position of 'secondary' tracks entering the gas. Where 'secondary' means
that the production vertex of the track had z > 1 cm
The third is the ratio of the second to the first, and is therefore the probability that a
'primary' track will be accompanied by a secondary at the entrance to the gas.
For each run 100000 single track events were generated, with the minimum CUTELE the first plot
of 'primary' tracks entering has dropped to only 60000, and I want to investigate this further.
The implication is that my p > 0.5 GeV/c has failed more tracks than in the other two cases.
The plots at the 3 CUTELE values are available as PS files:
For incident electrons
wall gas wall gas wall gas wall
| | | | | | | |
| | | | | | | |
| | | | | | | |
| | | | | | | |
| | | | | | | |
z = 130
where the wall is just carbon and the gas is air , in the position of planar 0 was setup.
Single pions of energy 1 GeV where fired, always at the same theta, phi, and the entrance
position of all tracks into the gas volume were placed in a ntuple. Delta ray production
and tracking were turned on with IDRAY = 1 and ILOSS = 1, and the CUTELE tracking cut was
varied from 100 KeV, to 1 Mev to 10MeV.
There are 3 plots at each CUTELE:
For incident pions
pi / CUTELE = 10 MeV
pi / CUTELE = 1 MeV
pi / CUTELE = 100 KeV
e / CUTELE = 10 MeV
e / CUTELE = 1 MeV
e / CUTELE = 100 KeV
Maintained by gdp@hep.ph.liv.ac.uk