Design and performance of a lead fluoride detector as a luminosity monitor

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 826; no. C; pp. 6 - 14
• Main Authors: Pérez Benito, R., Khaneft, D., O'Connor, C., Capozza, L., Diefenbach, J., Gläser, B., Ma, Y., Maas, F.E., Rodríguez Piñeiro, D.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.08.2016; Elsevier
• Subjects: Bhabha scattering; Computer simulation; Design engineering; Detectors; Electronics; Fluorides; Lead fluoride; Luminosity; Monte Carlo methods; Møller scattering; OLYMPUS; Scattering; Møller scattering; OLYMPUS; Bhabha scattering; Lead fluoride
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2016.04.071

Precise luminosity measurements for the OLYMPUS two-photon exchange experiment at DESY were performed by counting scattering events with alternating beams of electrons and positrons incident on atomic electrons in a gaseous hydrogen target. Final products of Møller, Bhabha, and pair annihilation interactions were observed using a pair of lead fluoride Cherenkov calorimeters with custom housings and electronics, adapted from a system used by the A4 parity violation experiment at MAMI. This paper describes the design, calibration, and operation of these detectors. An explanation of the Monte Carlo methods used to simulate the physical processes involved both at the scattering vertices and in the detector apparatus is also included.