Production of a diffuse very high reflectivity material for light collection in nuclear detectors

A diffuse very high reflectivity material, based on polytetrafluorethylene (PTFE) for optimization of light-collection efficiency has been developed. PTFE powder was used to produce reflector block material. The powder was pr essed with 525 kPa in a form and sintered at 375 degrees C. The reflectivit y was above 98% within the spectral range from 350 to 1000 nm. The blocks o f this material are machinable with saws, drilling and milling machines. Th e reflector is used as a housing for scintillating crystals in a nuclear me dicine application (small animal positron emission tomograph). It is also u sed as a light collector in very high-energy gamma-ray astrophysicas experi ments, HEGRA and MAGIC. The application of this inexpensive, easy to make d iffuse reflector may allow the optimization of light collection in a wide r ange of low-level light-detector configurations. (C) 2000 Elsevier Science B.V. All rights reserved.