Eur. Phys. J. C (2014) 74: 3131
https://doi.org/10.1140/epjc/s10052-014-3131-9

Regular Article - Experimental Physics

Three-dimensional photograph of electron tracks through a plastic scintillator

¹ Erlangen Centre for Astroparticle Physics, University of Erlangen-Nuremberg, Erwin-Rommel-Straße 1, 91058, Erlangen, Germany
² Max-Planck Institute for the Science of Light, Günther-Scharowsky-Straße 1/Bau 24, 91058, Erlangen, Germany
³ Experimental Astrophysics Group, Space Science Laboratory, University of California, Berkeley, CA, 94720, USA
⁴ European Organization for Nuclear Research, CERN, 1211, Geneve 23, Switzerland

^* e-mail: mykhaylo.filipenko@physik.uni-erlangen.de

Received: 27 April 2014
Accepted: 14 October 2014
Published online: 11 November 2014

Abstract

The reconstruction of particle trajectories makes it possible to distinguish between different types of charged particles. In high-energy physics, where trajectories are rather long (several meters), large size trackers must be used to achieve sufficient position resolution. However, in low-background experiments like the search for neutrinoless double beta decay, tracks are rather short (some mm to several cm, depending on the detector in use) and three-dimensional trajectories could only be resolved in gaseous time-projection chambers so far. For detectors of a large volume of around one cubic meter (large in the scope of neutrinoless double beta search) and therefore large drift distances (several decimeters to 1 m), this technique is limited by diffusion and repulsion of charge carriers. In this work we present a “proof-of-principle” experiment for a new method of the three-dimensional tracking of charged particles by scintillation light: we used a setup consisting of a scintillator, mirrors, lenses, and a novel imaging device (the hybrid photon detector) in order to image two projections of electron tracks through the scintillator. We took data at the T-22 beamline at DESY with relativistic electrons with a kinetic energy of 5 GeV and from this data successfully reconstructed their three-dimensional propagation path in the scintillator. With our setup we achieved a position resolution in the range of 170–248 µm.