arXiv subjects

Lorenzo Massa

Publications and source records attributed to Lorenzo Massa.

3 recordsLinked to original sources

arXiv2020

The BIS78 Resistive Plate Chambers upgrade of the ATLAS Muon Spectrometer for the LHC Run-3

Resistive Plate Chambers are used in the ATLAS experiment for the muon trigger and two coordinate measurements in the central region. In preparation for the coming years of LHC running at higher luminosity, besides the New Small Wheel project which is expected to complement the ATLAS muon spectrometer in the endcap regions, a smaller size project, known as BIS78, is being developed with a foreseen installation during the LHC Long Shutdown 2. The BIS78 project will reinforce the fake muon rejection and the selectivity of the muon trigger in the transition region between the ATLAS barrel and end-caps by adding 32 RPC triplets on the edges of the Inner Barrel even sectors (BIS7 and BIS8) as this region is characterized by high rate due to secondary charged tracks generated by beam halo protons and a lack of detector instrumentation. Due to the narrow available space, the project foresees to replace the existing Monitored Drift Tubes, used for the precise position measurement in this area, with muon stations formed by integrated smaller diameter tubes and a new generation of RPCs, capable of withstanding the higher rates and provide a robust standalone muon confirmation. These new RPCs are based on novel design of the gas volume with a thinner gas gap and resistive electrodes, a lower operating voltage and new high gain front-end electronics with respect to the legacy RPCs. Besides the use in Run-3 and onwards, this project is also of particular relevance as a pilot test for the HL-LHC upgrade when an additional full layer of new RPC triplets is expected to complement the full barrel region in the innermost plane. The core of the project is presented, together with a description of the production and the test results. Details on the detector infrastructure and services along with a roadmap towards the final installation and commissioning during the Long Shutdown 2 are also discussed.

physics.ins-det↗

arXiv2018

Design a TDC in SiGe for RPC's electronics Front-end for the use in a high-rate experiment

With the new generation of the RPC, it is possible to work with induced signals of hundreds $μV$, hence the front-end electronics is an important and delicate part of the detector in order to get a detectable signal. The electronic chain is made up of an amplifier, a discriminator, a TDC. The new front-end is realized with the use of silicon-germanium (SiGe) components, provided by IHP microelectronics. With this technology we can implement BJT and CMOS transistors on the same chip. The benefit of this improvement is to minimize: power consumption of the channels ($2 ÷3$ $ \frac{mW}{ch}$), noise (500 $e^-$ r.m.s), radiation hardness (10 kGy,$10^3$ $\frac{n}{cm}$) and it maximizes the speed of response electronics. In this work I will highlight the first TDC prototypes' results. The TDC uses a local oscillator, that has an oscillation range between $0.6 ÷3 $ GHz, and a the temporal jitter of 15 ps. The data output from the TDC are presented in binary in order to lighten data processing to the acquisition system. Moreover, we are studying a way to minimize system latency. This optimization involves the addition of a serializer (PISO) that sends the TDC data output to the acquisition system at 2 GHz.

physics.ins-det↗

arXiv2018

Development of a new Front End electronics in Silicon and Silicon-Germanium technology for the Resistive Plate Chamber detector for high rate experiments

The upgrade of the Resistive Plate Chamber (RPC) detector, in order to increase the detector rate capability and to be able to work efficiently in high rate environment, consists in the reduction of the operating voltage along with the detection of signals which are few hundred μV small. The approach chosen by this project to achieve this objective is to develop a new kind of Front End electronics which, thanks to a mixed technology in Silicon and Silicon-Germanium, enhance the detector performances increasing its rate capability. The Front End developed is composed by a preamplifier in Silicon BJT technology with a very low inner noise (1000 $e^{-}$ rms) and an amplification factor of 0.3-0.4 mV/fC and a new kind of discriminator in SiGe HJT technology which allows a minimum threshold of the order of 0.5 mV. The performances of this kind of Front End will be shown. The results are obtained by using the CERN H8 beamline with a full-size RPC chamber of 1 mm gas gap and 1.2 mm thickness of electrodes equipped with this kind of Front End electronics.

physics.ins-det↗