The Muon g-2 Experiment at Fermilab (E989) will measure the muon magnetic anomaly with unprecedented precision (0.14 ppm), which yields a factor of 4 improvement with respect to the previous ...measurements at Brookhaven National Laboratory (BNL) (E821). To achieve this goal, the relative response of each calorimeter channel must be calibrated and monitored at a level better than <inline-formula> <tex-math notation="LaTeX">10^{-3} </tex-math></inline-formula> in the time window of the muon fill. The calibration system uses a laser source and photodetectors. The data acquisition (DAQ) of the system is designed around two field-programmable gate array (FPGA)-based boards and a custom crate bus. The front-end board manages the photodetector operation and signal processing and performs a first-level data concentration task. Up to 12 FPGA boards can be housed in a 6U crate. A readout master controls the boards, implements event-building functionalities, manages the monitoring interface, and facilitates calibration and debugging tasks. A gigabit-ethernet interface is used to transfer data to the on-line farm for storage and further processing. Presently, the system is working at Fermi National Accelerator Laboratory (FNAL). In this article, we present the DAQ system design, run control user interface, and system evaluation.
The Muon g−2 experiment, E989, is currently taking data at Fermilab with the aim of reducing the experimental error on the muon anomaly by a factor of four and possibly clarifying the current ...discrepancy with the theoretical prediction. A central component of this four-fold improvement in precision is the laser calibration system of the calorimeters, which has to monitor the gain variations of the photo-sensors with a 0.04% precision on the short-term (∼1ms). This is about one order of magnitude better than what has ever been achieved for the calibration of a particle physics calorimeter. The system is designed to monitor also long-term gain variations, mostly due to temperature effects, with a precision below the per mille level. This article reviews the design, the implementation and the performance of the Muon g−2 laser calibration system, showing how the experimental requirements have been met.
In high energy physics experiments, calorimeters are calibrated to produce precise and accurate results. Laser light can be used for calibration when the detectors are sensitive to photons in that ...particular energy range, which is often the case. Moreover, it is not unusual that detection systems consist of hundreds of channels that have to be calibrated independently, which produce stringent requirements on the light distribution system in terms of temporal and spatial stability, energy distribution and timing. Furthermore, the economic factor and the ease of production have to be taken into account. We present a prototype light distribution system, based on a series of optical beamsplitters, developed for the Muon g-2 experiment at Fermilab.
The Muon g−2 Experiment at Fermilab is expected to start data taking in 2017. It will measure the muon anomalous magnetic moment, aμ=(gμ−2)/2 to an unprecedented precision: the goal is 0.14 parts per ...million (ppm). The new experiment will require upgrades of detectors, electronics and data acquisition equipment to handle the much higher data volumes and slightly higher instantaneous rates. In particular, it will require a continuous monitoring and state-of-art calibration of the detectors, whose response may vary on both the millisecond and hour long timescale. The calibration system is composed of six laser sources and a light distribution system will provide short light pulses directly into each crystal (54) of the 24 calorimeters which measure energy and arrival time of the decay positrons. A Laser Control board will manage the interface between the experiment and the laser source, allowing the generation of light pulses according to specific needs including detector calibration, study of detector performance in running conditions, evaluation of DAQ performance. Here we present and discuss the main features of the Laser Control board.
The anomalous muon dipole magnetic moment can be measured (and calculated) with great precision thus providing insight on the Standard Model and new physics. Currently an experiment is under ...construction at Fermilab (U.S.A.) which is expected to measure the anomalous muon dipole magnetic moment with unprecedented precision. One of the improvements with respect to the previous experiments is expected to come from the laser calibration system which has been designed and constructed by the Italian part of the collaboration (INFN). An emphasis of this paper will be on the calibration system that is in the final stages of construction as well as the experiment which is expected to start data taking this year.
Calorimeters implemented in future lepton colliders will inevitably suffer from leakage on account of space restrictions and will need to operate in strong magnetic fields. Both these circumstances ...will affect the reconstruction of jets and will give rise to the need for corrections. In dual readout calorimeters, these corrections are complicated by the need to deal with more than one signal. In this article we describe simulation studies of these corrections in a total absorption dual readout calorimeter.
The Muon $g - 2$ experiment Driutti, Anna
Il Nuovo Cimento C,
01/2018, Volume:
C41, Issue:
1-2
Journal Article
Peer reviewed
Open access
Measurements of the anomalous magnetic moment of the muon, aμ, with increased precision are motivated by the ~3 standard deviation discrepancy between the most recent measurement performed at the ...Brookhaven National Laboratory (BNL) by the experiment E821 and the Standard-Model prediction. Furthermore, a brief summary of the current theoretical and experimental status is reported in these proceedings.
Silicon photomultipliers are silicon devices that in recent times have been proposed as candidates for the replacement of photomultiplier tubes in many experimental situations. In this article we ...describe the performance of SiPMs as a readout system of a shashlik calorimeter composed of 41 8×8 cm 2 , 3.27-mm-thick tiles of scintillator and 40 8×8 cm 2 , 3.27-mm-thick tiles of lead, for a total of ~24 radiation lengths; the light is collected by 64 0.8-mm wave-length-shifter (WLS) fibers grouped in bundles of four for, a total of 16 channels. The SiPMs are manufactured by FBK-irst and have a sensitive area of 1 mm 2 . The calorimeter has been tested at CERN using both a low (PS T10 beamline) and high (SPS H4 beamline) energy beam during the summer 2009 data taking.
Scintillating glasses are a potentially cheaper alternative to crystal - based calorimetry with common problems related to light collection, detection and processing. As such, their use and ...development are part of more extensive R&D aimed at investigating the potential of total absorption, combined with the readout (DR) technique, for hadron calorimetry. A recent series of measurements, using cosmic and particle beams from the Fermilab test beam facility and scintillating glass with the characteristics required for application of the DR technique, serve to illustrate the problems addressed and the progress achieved by this R&D. Alternative solutions for light collection (conventional and silicon photomultipliers) and signal processing are compared, the separate contributions of scintillation and Cherenkov processes to the signal are evaluated and results are compared to simulation.
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