Measurement of the Angular Distribution of Wavelength-Shifted Light Emitted by TPB

TL;DR

This study measures how light re-emitted by TPB thin films varies with angle when exposed to 128 nm light, providing data to improve models of light behavior in particle detectors.

Contribution

The paper provides the first detailed measurements of the angular distribution of wavelength-shifted light from TPB films of various thicknesses, aiding the development of accurate simulation models.

Findings

Angular distribution data for TPB films of different thicknesses

Comparison with Monte Carlo model highlights current model limitations

Preliminary results suggest areas for model improvement

Abstract

We present measurements of the angular distribution of re-emitted light from tetraphenyl butadiene thin films when exposed to \SI{128}{nm} light in vacuum. Films ranging from \SI{250}{nm} to \SI{5.5}{\micron} in thickness are measured. All films were fabricated by evaporation deposition on ultraviolet transmitting (UVT) acrylic substrates. Preliminary comparisons of the angular distribution to that produced by a detailed Monte Carlo model are also presented. The current shortcomings of the model are discussed and future plans briefly outlined.