Controlled etching of copper electrodes in Gas Electron Multiplier foils allows a reduction of the material budget by more than a factor of two for a triple-GEM detector. Detectors making use of thinned foils provide performances similar to those obtained with standard devices: a gain above 10^4 for a double-GEM, with energy resolution of 27 % fwhm for 5.9 keV X-rays.
SHiP (Search for Hidden Particles) is a beam dump experiment proposed at the CERN SPS aiming at the observation of long lived particles very weakly coupled with ordinary matter mostly produced in the decay of charmed hadrons. The beam dump facility of SHiP is also a copious factory of neutrinos of all three kinds and therefore a dedicated neutrino detector is foreseen in the SHiP apparatus. The neutrino detector exploits the Emulsion Cloud Chamber technique with a modular structure, alternating walls of target units and planes of electronic detectors providing the time stamp to the event. GEM detectors are one of the possible choices for this task. This paper reports the results of the first exposure to a muon beam at CERN of a new hybrid chamber, obtained by coupling a GEM chamber and an emulsion detector. Thanks to the micrometric accuracy of the emulsion detector, the position resolution of the GEM chamber as a function of the particle inclination was evaluated in two configurations, with and without the magnetic field
This contribution investigates a prototype of a TPC readout with a highly pixelated CMOS ASIC, which is an option for charged particles tracking of the ILC. A triple GEM stack was joined with a TimePix and MediPix2 chip (pixel size of 55$times$55 $mu m^2$) and its readout properties were investigated with 5 GeV electrons. The spatial resolution of the cluster center reconstruction was determined as a function of drift distance using different cluster alhoritms and compared with Monte Carlo predictions.
BESIII is a particle physics experiment located at the Institute of High-Energy Physics (BEPC-II) e+e- collider at IHEP in Beijing. The Italian collaboration is leading the effort for the development of a cylindrical GEM (CGEM) detector with analog readout to upgrade the current inner drift chamber that is suffering early ageing due to the increase of the machine luminosity. Within the CGEM project, this work aims to perform full detector simulation for the optimisation of the tracker geometry and its operational parameters. The goal is achieved by means of three different, but well connected, studies: a background estimation, a simulation of the detection elements and the data analysis of a beam test. I participated to the construction of the cathode electrode, that was produced in Ferrara, helping during the assembling and manufacturing procedures. For the background studies and the detector simulation I took care both of the framework development and of the data analysis. Finally, I participated to installation and data taking of the beam test at CERN, and I was involved in the production of the reconstruction and analysis software. During and after the beam test I participated to the processing and analysis of the data.
Gaseous detectors are used in high energy physics as trackers or, more generally, as devices for the measurement of the particle position. For this reason, they must provide high spatial resolution and they have to be able to operate in regions of intense radiation, i.e. around the interaction point of collider machines. Among these, Micro Pattern Gaseous Detectors (MPGD) are the latest frontier and allow to overcome many limitations of the pre-existing detectors, such as the radiation tolerance and the rate capability. The gas Electron Multiplier (GEM) is a MPGD that exploits an intense electric field in a reduced amplification region in order to prevent discharges. Several amplification stages, like in a triple-GEM, allow to increase the detector gain and to reduce the discharge probability. Reconstruction techniques such as charge centroid (CC) and micro-Time Projection Chamber ($upmu$TPC) are used to perform the position measurement. From literature triple-GEMs show a stable behaviour up to $10^8,$Hz/cm$^2$. A testbeam with four planar triple-GEMs has been performed at the Mainz Microtron (MAMI) facility and their performance was evaluated in different beam conditions. In this article a focus on the time performance for the $upmu$TPC clusterization is given and a new measurement of the triple-GEM limits at high rate will be presented.
At NISER-IoP detector laboratory an initiative is taken to build and test Gas Electron Multiplier (GEM) detectors for ALICE experiment. The optimisation of the gas flow rate and the long-term stability test of the GEM detector are performed. The method and test results are presented.