https://doi.org/10.1140/epjc/s10052-020-7800-6
Regular Article - Experimental Physics
Measurements of angle-resolved reflectivity of PTFE in liquid xenon with IBEX
1
Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, CA, 94720, USA
2
Department of Physics, University of California Berkeley, Berkeley, CA, 94720, USA
3
Department of Physics, Yale University, 217 Prospect St., New Haven, CT, 06511, USA
4
Present address: Lawrence Livermore National Laboratory, Livermore, CA, USA
* e-mail: swkravitz@lbl.gov
Received:
18
September
2019
Accepted:
2
March
2020
Published online:
21
March
2020
Liquid xenon particle detectors rely on excellent light collection efficiency for their performance. This depends on the high reflectivity of polytetrafluoroethylene (PTFE) at the xenon scintillation wavelength of 178 nm, but the angular dependence of this reflectivity is not well-understood. IBEX is designed to directly measure the angular distribution of xenon scintillation light reflected off PTFE in liquid xenon. These measurements are fully described by a microphysical reflectivity model with few free parameters. Dependence on PTFE type, surface finish, xenon pressure, and wavelength of incident light is explored. Total internal reflection is observed, which results in the dominance of specular over diffuse reflection and a reflectivity near 100% for high angles of incidence.
© The Author(s), 2020
