Kopytine's homepage

GEANT-based Monte Carlo simulation of the detector response

I have written a Monte Carlo detector response simulation program to study the experiment's sensitivity to the potential signals and to the expected backgrounds. The program uses the GEANT 3 [78] Detector Description and Simulation Tool. The following aspects of the actual experiment are (more or less realistically) reflected in the MC:

• Geometry, sizes, materials and mutual distances of the $Pb$ target, the Si pad array, and of the T0 counters. The geometry is shown on Fig. 3.2.
• Magnetic field: it is taken to be uniform; the maximal magnitude of field in the first dipole is taken to be true ``everywhere'', thus somewhat exaggerating the bending ability of the field. This exaggeration, though, seems important only for the $\delta$-electron simulation.
• Interaction of emitted particles (hadrons, leptons and gammas) with the materials of the target, air and the T0 counters on their way from the vertex to the detector. Included are: pair production, bremsstrahlung, decays, Compton scattering and photoelectric effect, $\delta$-ray production and multiple scattering, hadronic processes. Multiple scattering inside the Si was switched off because the simulated setup has nothing behind the Si.
• Fluctuations of ionization energy loss in the detector (via Landau's theory [76]); the observed resolution of the channels, custom fitted to every channel's calibrated characteristics with the level of detail used in the calibration fits, as described in section 6.3.

An interface was created to feed RQMD events (or other events written out in the RQMD-like format) into the detector response simulation.