Using a bulk Micro-Megas (MM) detector an energy measurement can be obtained collecting the total charge reaching the mesh electrode connected to a low noise charge sensitive preamplifier. When ...operating such a device in a low-pressure gas regime, it is necessary to modify the amplification gap geometry to reach the optimal detector gain. This implies changes in the input capacitance of the preamplifier influencing its signal to noise ratio and thus the detector energy resolution. An ad-hoc high-gain and low-noise charge preamplifier has been developed to cope with the requirements of our application field. In this short report, we present the development activities focused to the study of a configurable charge amplifier to be connected to a MM detector having different mesh capacitances.
Within the family of the Micro Strip Gas Detectors (MSGD), the intrinsic characteristics of the bulk Micro-Megas (MM) device represent the most promising features for the construction of a new ...instrument to be operated as a TPC gas chamber in a low-pressure regime. In this study, we present the main properties of a low-pressure bulk MM detector in which the amplification gap was slightly increased to improve the gas gain. Two configurations have been deeply studied: the first one with a gap of 128μm and a second one with a 192μm gap, both filled and operated with a gas mixture (Ar-CO2) at pressures below 100 mbar. The dependence of the gain and the energy resolution on the amplification field, gas pressure and drift field have been evaluated. The reliability of the measured performance, combined with the simple and robust structure of the detector even with an increased length of amplification gap, make it an attractive choice for applications where the track length of low energy particles is detected by using a low-pressure filling gas.
The INFN–FBK “Phase-2” R&D program Dalla Betta, G.-F.; Boscardin, M.; Bomben, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2016, Letnik:
824
Journal Article
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We report on the 3-year INFN ATLAS–CMS joint research activity in collaboration with FBK, started in 2014, and aimed at the development of new thin pixel detectors for the High Luminosity LHC Phase-2 ...upgrades. The program is concerned with both 3D and planar active-edge pixel sensors to be made on 6” p-type wafers. The technology and the design will be optimized and qualified for extreme radiation hardness (2×1016neqcm−2). Pixel layouts compatible with present (for testing) and future (RD53 65nm) front-end chips of ATLAS and CMS are considered. The paper covers the main aspects of the research program, from the sensor design and fabrication technology, to the results of initial tests performed on the first prototypes.
We designed, realized, and tested a 2.5-Gb/s optical wireless communication (OWC) system prototype, that should be employed in high energy physics (HEP) experiments, such as the compact muon solenoid ...(CMS). The system consists of off-the-shelf components, mainly a vertical cavity surface emitting laser (VCSEL) and a PIN photodiode with a proper ball lens. Since it should be used to transmit data among particle sensors in neighboring rings of the CMS, its target distance is 10 cm. Its most attractive feature is that it does not require a (complex) active tracking system because its measured tolerance to misalignment is around <inline-formula><tex-math notation="LaTeX">\pm</tex-math> </inline-formula>1 mm (at <inline-formula><tex-math notation="LaTeX">10^{-12}</tex-math></inline-formula> bit error rate). We also report the X-rays irradiation tests of all components (Quartz lens, VCSEL, and PIN photodiode): None of them showed any degradation up till 238-Mrad (Si) dose. These results indicate that the designed OWC can be a viable solution for future HEP experiments.
The paper reports on a detailed study of the radiation resistance of p/sup +/ on n silicon microstrip detectors for the CMS tracking system. From this study, it is seen that the use of ...low-resistivity substrates with crystal lattice orientation promises excellent performance of the Inner Tracker after heavy irradiation in the Large Hadron Collider environment. Furthermore, the advantage of using detectors thicker than 300 /spl mu/m in the Outer Tracker is discussed together with experimental measurements on prototypes.
Proton-proton interactions resulting in final states with two photons are studied in a search for the signature of flavor-changing neutral current interactions of top quarks ( t ) and Higgs bosons ( ...H ). The analysis is based on data collected at a center-of-mass energy of 13 TeV with the CMS detector at the LHC, corresponding to an integrated luminosity of 137 fb-1 . No significant excess above the background prediction is observed. Upper limits on the branching fractions ( B ) of the top quark decaying to a Higgs boson and an up ( u ) or charm ( c ) quark are derived through a binned fit to the diphoton invariant mass spectrum. The observed (expected) 95% confidence level upper limits are found to be 0.019% (0.031%) for B ( t → Hu ) and 0.073% (0.051%) for B ( t → Hc ) . These are the strictest upper limits yet determined.
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