Electron beam studies of light collection in a scintillating counter with embedded fibers

TL;DR

This study investigates how different fiber configurations embedded in a plastic scintillating counter affect light collection efficiency, using electron beam scans and modeling to optimize detector design for dark matter experiments.

Contribution

It provides a detailed analysis of light collection dependence on fiber placement and compares fiber-embedded counters to traditional ones, advancing detector development for dark matter searches.

Findings

Light yield depends strongly on distance from beam to fibers.

Embedded fibers improve light collection compared to no-fiber counters.

Modeling captures both direct and indirect light contributions.

Abstract

The light collection of several fiber configurations embedded in a box-shaped plastic scintillating counter was studied by scanning with minimum ionizing electrons. The light was read out by silicon photomultipliers at both ends. The light yield produced by the 855-MeV beam of the Mainz Microtron showed a strong dependence on the transverse distance from the beam position to the fibers. The observations were modeled by attributing the collection of indirect light inside of the counter and of direct light reaching a fiber to the total light yield. The light collection with fibers was compared to that of a scintillating counter without fibers. These studies were carried out within the development of plastic scintillating detectors as an active veto system for the DarkMESA electron beam-dump experiment that will search for light dark matter particles in the MeV mass range.