Mainz 2014 – scientific programme

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T: Fachverband Teilchenphysik

T 56: Dunkle Materie 3

T 56.6: Talk

Tuesday, March 25, 2014, 18:10–18:25, P11

Two-Photon Excitation of Scintillating Crystals — •Andreas Ulrich¹, Walter Henning¹, Jean-Côme Lanfranchi¹, Walter Potzel¹, Franz Pröbst², Sabine Roth¹, and Stefan Schönert¹ — ¹Physik-Department E12/E15, TU-München, James-Franck-Str. 1, 85748 Garching — ²Max-Planck-Institut für Physik, Föhringer Ring 6, 80805 München

Particle identification in scintillating crystals is often performed by measuring the ratio of light output and phonon signal. Heavier particles lead to a reduced light output. This effect is referred to as "quenching". The microscopic processes which contribute to the quenching factors have recently been studied and modeled including self-quenching mechanisms of the excitons. In the presentation we will describe a setup in which scintillating crystals such as the CaWO₄ crystals of the CRESST experiment are excited via two-photon absorption with a 355 nm sub-nanosecond laser. It is expected that the power density will be high enough to induce the self quenching which has so far only been observed with heavy ion-beam excitation in our experiments. The controlled, table-top experiments will be used to define a complete set of parameters for modeling the quenching effect in CaWO₄ and various other scintillating materials. It will also be described how the setup can be extended for applying pulsed electron-beam and x-ray excitation.

This research was supported by the DFG cluster of excellence ’Origin and Structure of the Universe’.