PT Journal
AU NEXT Collaboration (Ghosh, Sea
   Martin-Albo, J
   Carcel, S
   Carrion, JV
   Diaz, J
   Felkai, R
   Lopez-March, N
   Martinez-Vara, M
   Martinez-Lema, G
   Muñoz Vidal, J
   Novella, P
   Palmeiro, B
   Querol, M
   Romo-Luque, C
   Sorel, M
   Uson, A
   Yahlali, N
TI Dependence of polytetrafluoroethylene reflectance on thickness at visible and ultraviolet wavelengths in air
SO Journal of Instrumentation
JI J. Instrum.
PY 2020
BP P11031 - 16pp
VL 15
IS 11
DI 10.1088/1748-0221/15/11/P11031
LA English
DE Detector design and construction technologies and materials; Double-beta decay detectors; Time projection Chambers (TPC)
AB Polytetrafluoroethylene (PTFE) is an excellent diffuse reflector widely used in light collection systems for particle physics experiments. However, the reflectance of PTFE is a function of its thickness. In this work, we investigate this dependence in air for light of wavelengths 260 nm and 450 nm using two complementary methods. We find that PTFE reflectance for thicknesses from 5 mm to 10 mm ranges from 92.5% to 94.5% at 450 nm, and from 90.0% to 92.0% at 260 nm We also see that the reflectance of PIFE of a given thickness can vary by as much as 2.7% within the same piece of material. Finally, we show that placing a specular reflector behind the PTFE can recover the loss of reflectance in the visible without introducing a specular component in the reflectance.
ER