A major upgrade of the readout and trigger electronics of the CMS Drift Tubes muon detector is foreseen in order to allow its efficient operation at the High Luminosity LHC. A proposal for a new L1 ...Trigger Primitives Generator for this detector is presented, featuring an algorithm operating on the time of charge collection measurements provided by the asynchronous readout of the new TDC system being developed. The algorithm is being designed around the implementation in state-of-the-art FPGA devices of the original development of a Compact Hough Transform (CHT) algorithm combined with a Majority Mean-Timer, to identify both the parent bunch crossing and the muon track parameters. The current state of the design is presented along with the performance requirements, focusing on the future developments.
A novel approach to Hough Transform for implementation in fast triggers Pozzobon, Nicola; Montecassiano, Fabio; Zotto, Pierluigi
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2016, Letnik:
834
Journal Article
Recenzirano
Telescopes of position sensitive detectors are common layouts in charged particles tracking, and programmable logic devices, such as FPGAs, represent a viable choice for the real-time reconstruction ...of track segments in such detector arrays. A compact implementation of the Hough Transform for fast triggers in High Energy Physics, exploiting a parameter reduction method, is proposed, targeting the reduction of the needed storage or computing resources in current, or next future, state-of-the-art FPGA devices, while retaining high resolution over a wide range of track parameters. The proposed approach is compared to a Standard Hough Transform with particular emphasis on their application to muon detectors. In both cases, an original readout implementation is modeled.
The operation of the compact muon solenoid drift tubes (DTs) muon detectors at the high-luminosity large hadron collider will be possible only with an upgrade of the current readout and trigger ...electronics, which are based on very old technology and directly exposed to radiation, hence particularly sensitive to aging. A new level 1 trigger primitive generator, based on the use of an original compact Hough transform (CHT) algorithm, is being designed with the goal of its implementation in the state-of-the-art field programmabla gate array (FPGA) devices. The algorithm can identify the muon track segment parameters and must be combined with a majority mean-timer in order to assign the muon to its parent bunch crossing. The algorithm is expected to be deployed on FPGAs and has a few μs latency for decision taking, with efficiency and resolution equal or higher with respect to the ones provided by the currently running algorithm. The major challenges are parallelization of the algorithm, fast readout of the CHT parameter matrix, the capability of handling data from a large array of DTs in the minimal number of FPGAs, and coping with the latency requirements. These issues will be addressed proposing constructive solutions.
The LHC program at 13 and 14TeV, after the observation of the candidate SM Higgs boson, will help clarify future subjects of study and shape the needed tools. Any upgrade of the LHC experiments for ...unprecedented luminosities, such as the High Luminosity-LHC ones, must then maintain the acceptance on electroweak processes that can lead to a detailed study of the properties of the candidate Higgs boson. The acceptance of the key lepton, photon and hadron triggers should be kept such that the overall physics acceptance, in particular for low-mass scale processes, can be the same as the one the experiments featured in 2012. In such a scenario, a new approach to early trigger implementation is needed. One of the major steps will be the inclusion of high-granularity tracking sub-detectors, such as the CMS Silicon Tracker, in taking the early trigger decision. This contribution can be crucial in several tasks, including the confirmation of triggers in other subsystems, and the improvement of the on-line momentum measurement resolution. A muon track-trigger for the CMS experiment at the High Luminosity-LHC is presented. A back-extrapolation of Drift Tubes trigger primitives is proposed to match tracks found at Level 1 with muon candidates. The main figures-of-merit are presented, featuring sharp thresholds and less contamination from lower momentum muons, and an expected rate reduction of a factor of 5–10 at typical thresholds with respect to the muon trigger configuration used in 2012.
CMS muon system overview Zotto, Pierluigi
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/1998, Letnik:
408, Številka:
1
Journal Article
Recenzirano
A complete description of the CMS muon detector is given. Results of the research and development studies on the chamber prototypes and on the trigger strategy are reported.
A thin silicon diode formed by a deep p+ implantation under a shallow n+ one is proposed as a solid state microdosimeter. The thickness of the sensitive layer of the tested device is about two ...micrometers and the active area is about 10 mm 2 . Due to the very large electric capacitance of the diode (about 1 nF) a low noise read-out circuit based on a discrete JFET has been developed. The noise due to the parasitic resistance of the detector itself dominates and fixes the lower threshold of the energy spectrum. A prototype of the proposed microdosimeter covered with a polyethylene converter has been irradiated with fast monoenergetic neutrons at the INFN-Legnaro Labs (I). The first experimental spectra are in good agreement with the simulated ones. The effect of direct interactions of thermal neutrons in silicon has been measured
The feasibility of the discrimination between protons and secondary electrons was investigated in order to decrease the lower limit of a recoil-proton spectrometer for neutrons based on a silicon ...p-i-n diode. The simulation of the ionization generated in the detector by protons and electrons and the simulation of the relevant induced currents show that such discrimination is feasible provided that the "rear side injection" configuration and a low noise setup are adopted. The difference between the collecting times of the two pulses is maximized and used for the rising time based discrimination. The neutron spectrometer consists of a 3 mm/sup 2/ area, 300 /spl mu/m-thick silicon p-i-n diode covered with a polyethylene foil on the n-side. The ENC is 720 rms electrons at 20 ns shaping time. Experimental results on monoenergetic neutrons show the effectiveness of this discrimination in decreasing the lower limit of the recoil proton energy spectrum from 1.1 to 0.6 MeV.
We investigated the possibility to use a liquid as insulator in a High Voltage generator which is wireless powered by a laser system. The liquid must be transparent to the laser light wavelength, ...must not attack the control circuits, which are immersed in it, and the support materials. An adequately performing liquid was identified and we characterized the liquid performance in intense electric field, by measuring its breakdown voltage and the leakage current, and checked its optical and thermal behaviour.
The feasibility of the discrimination between protons and secondary electrons was investigated in order to decrease the lower limit of a recoil-proton spectrometer for neutrons based on a silicon ...P-i-N diode. The simulation of the ionization generated in the detector by protons and electrons and the simulation of the relevant induced currents show that such discrimination is feasible provided that the "rear side injection" configuration and a low noise set-up are adopted. The difference between the collecting times of the two pulses is maximized and used for the rising time based discrimination. The neutron spectrometer consists of a 3 mm/sup 2/ area, 300 /spl mu/m thick silicon P-i-N diode covered with a polyethylene foil on the n-side. The ENC is 720 rms electrons at 20 ns shaping time. Experimental results on monoenergetic neutrons show the effectiveness of this discrimination in decreasing the lower limit of the recoil proton energy spectrum from 1.5 to 0.9 MeV.
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