Construction and Performance of the Barrel Electromagnetic Calorimeter for the GlueX Experiment
physics.ins-det
/ Authors
Tegan Beattie, Ahmed Foda, Colleen Henschel, S Katsaganis, Shaun Krueger, George Lolos, Zisis Papandreou, E. L. Plummer, Irina Semenova, Andrei Semenov
and 29 more authors
Fernando Barbosa, Eugene Chudakov, Mark Dalton, David Lawrence, Yi Qiang, Nicholas Sandoval, Elton Smith, Christopher Stanislav, Justin Stevens, Simon Taylor, Timothy Whitlatch, Benedikt Zihlmann, William Levine, William McGinley, Curtis Meyer, Michael Staib, Efstratios Anassontzis, Christina Kourkoumelis, Georgios Vasileiadis, George Voulgaris, William Brooks, Hayk Hakobyan,
/ Abstract
The barrel calorimeter is part of the new spectrometer installed in Hall D at Jefferson Lab for the GlueX experiment. The calorimeter was installed in 2013, commissioned in 2014 and has been operating routinely since early 2015. The detector configuration, associated Monte Carlo simulations, calibration and operational performance are described herein. The calorimeter records the time and energy deposited by charged and neutral particles created by a multi-GeV photon beam. It is constructed as a lead and scintillating-fiber calorimeter and read out with 3840 large-area silicon photomultiplier arrays. Particles impinge on the detector over a wide range of angles, from normal incidence at 90 degrees down to 11.5 degrees, which defines a geometry that is fairly unique among calorimeters. The response of the calorimeter has been measured during a running experiment and performs as expected for electromagnetic showers below 2.5 GeV. We characterize the performance of the BCAL using the energy resolution integrated over typical angular distributions for $π^0$ and $η$ production of $σ_E/E$=5.2\%/$\sqrt{E(\rm{GeV})} \oplus$ 3.6\% and a timing resolution of $σ$\,=\,150\,ps at 1\,GeV.