A Monte Carlo triple-GEM simulation tuned with data

摘要

Triple-GEM detectors are a well known technology used in high energy physics experiments. A reliable Monte Carlo simulation has to be developed to reproduce the performance which have been measured experimentally, for example in beam tests, and be able to infer the future behavior in real conditions. In detail, the software has to simulate the response of the detector to the passage of particles, from the primary ionization, to the amplification and diffusion of the electrons and eventually to the induction of the charge on the anode strips. In the case of gas detectors, existing softwares such as GARFIELD++ already perform a very detailed simulation of the physical processes but are CPU time consuming. In this presentation a description of a faster simulation is presented. It models the results about the electron production (primary ionization and avalanche) and diffusion in a triple-GEM obtained from GARFIELD++ and then it reconstructs the signal induced on each anode strip according to the Shockley-Ramo theorem. The simulation has been tuned on the data collected in several beam tests and it can reproduce the real values of time and charge measured by the strip. When the reconstruction algorithms used in the field of Micro Pattern Gas Detectors, such as the Charge Centroid or the micro-Time Projection Chamber readout, are applied on the simulated data, the model shows performance comparable to the experimental one. This provides a validation of this model and allows to extend its usage in different conditions, i.e. geometries, presence of magnetic field, high voltage settings, different direction of the incident particles, to evaluate the expected outcome of the triple-GEM in those cases.