Study of light backgrounds from relativistic electrons in air light-guides

S. Riordan, Y. X. Zhao, S. Baunack, D. Becker, C. Clarke, K. Dehmelt, A. Deshpande, M. Gericke, B. Gläser, K. Imai, T. Kutz, F. E. Maas, D. McNulty, J. Pan, S. Park, S. Rahman, P. A. Souder, P. Wang, B. Wellman, K. S. Kumar

Research output: Contribution to journalArticlepeer-review


The MOLLER experiment proposed at the Thomas Jefferson National Accelerator Facility plans a precision low energy determination of the weak mixing angle via the measurement of the parity-violating asymmetry in the scattering of high energy longitudinally polarized electrons from electrons bound in a liquid hydrogen target (Møller scattering). A relative measure of the scattering rate is planned to be obtained by intercepting the Møller scattered electrons with a circular array of thin fused silica tiles attached to air light guides, which facilitate the transport of Cherenkov photons generated within the tiles to photomultiplier tubes (PMTs). The scattered flux will also pass through the light guides of downstream tiles, generating additional Cherenkov as well as scintillation light and is a potential background. In order to estimate the rate of these backgrounds, a gas-filled tube detector was designed and deployed in an electron beam at the MAMI facility at Johannes Gutenberg University, Mainz, Germany. Described in this paper is the design of a detector to measure separately the scintillation and Cherenkov responses of gas mixtures from relativistic electrons, the results of studies of several gas mixtures with comparisons to simulations, and conclusions about the implications for the design of the MOLLER detector apparatus.

Original languageEnglish (US)
Pages (from-to)96-102
Number of pages7
JournalNuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
StatePublished - Jul 11 2018


  • Beam test
  • Cherenkov
  • Gas scintillation
  • Geant4 simulation
  • MOLLER project

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Instrumentation


Dive into the research topics of 'Study of light backgrounds from relativistic electrons in air light-guides'. Together they form a unique fingerprint.

Cite this