Scientific Results

The calibration system of the Muon g–2 experiment

Year: 2019

Authors: Driutti A., Basti A., Bedeschi F., Cantatore G., Cauz D., Corradi G., Dabagov S., Di Falco S., Di Sciascio G., Di Stefano R., Donati S., Escalante O., Ferrari C., Fioretti A., Gabbanini C., Gioiosa A., Hampai D., Iacovacci M., Incagli M., Karuza M., Lusiani A., Marignetti F., Mastroianni S., Moricciani D., Nath A., Pauletta G., Piacentino G.M., Raha N., Santi L., Smith M., Sorbara M., Venanzoni G.

Autors Affiliation: INFN, Sezione di Trieste e G.C. di Udine, Trieste, Italy; Università di Udine, Udine, Italy; INFN, Sezione di Pisa, Pisa, Italy; Università di Trieste, Trieste, Italy; Laboratori Nazionali Frascati dell\’INFN, Frascati, Italy; PN Lebedev Physical Institute, Moscow, Russian Federation; NR Nuclear University MEPhI MEPhI, Moscow, Russian Federation; INFN, Sezione di Roma Tor Vergata, Roma, Italy; Università di Cassino, Cassino, Italy; INFN, Sezione di Napoli, Napoli, Italy; Università di Napoli, Napoli, Italy; Istituto Nazionale di Ottica del C.N.R., UOS Pisa, Pisa, Italy; Università del Molise, Pesche, Italy; University of Rijeka, Rijeka, Croatia; Scuola Normale Superiore, Pisa, Italy

Abstract: The Muon [Formula presented]–2 experiment at Fermilab (E989) plans to measure the muon anomalous magnetic moment to a precision of 140 parts per billion (ppb), which corresponds to a total uncertainty of [Formula presented]. To achieve this level of precision the experiment must detect more than [Formula presented] decay positrons by using the 24 calorimeters distributed around the muon storage ring. Each calorimeter consists of 54Pb[Formula presented] crystals read out by SiPMs. The response of each of the 1296 channels must be calibrated and monitored to keep uncertainties due to gain fluctuations at the sub-per mil level in the time interval corresponding to one beam fill ([Formula presented]) and at the sub-percent level on longer time scales. These requirements are much more demanding than those needed by most high energy physics experiments. This paper presents a novel laser-based calibration system that distributes light to all calorimeter cells, while allowing one to correct for laser intensity fluctuations and to monitor the distribution chain stability at unprecedented levels of accuracy. Results on the system performance during the first few months of stored muon operation in 2018 are also presented.

Journal/Review: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT

Volume: 936      Pages from: 98  to: 101

More Information: This research was supported by Instituto Nazionale di Fisica Nucleare(Italy), by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy, and by theEU Horizon 2020 Research and Innovation Program under the MarieSkłodowska-Curie grant agreements No. 690385 (MUSE), No. 734303(NEWS).
KeyWords: Electromagnetic calorimeter, Laser system, Muon g-2, Calibration methods, Optics
DOI: 10.1016/j.nima.2018.10.045

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