Bremen 2017 – scientific programme

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K: Fachverband Kurzzeitphysik

K 5: Laseranwendungen und Laserstrahlwechselwirkung III

K 5.2: Talk

Wednesday, March 15, 2017, 09:35–09:55, GW2 B2890

Characterization of scintillating CaWO₄ crystals for the CRESST experiment using two-photon excitation — •Raphael Hampf, Thomas Dandl, Alexander Langenämper, Andrea Münster, Lothar Oberauer, Stefan Schönert, and Andreas Ulrich — Physik-Department and Excellence Cluster Universe, Technische Universität München, D-85747 Garching

In the CRESST experiment for direct dark matter search, phonon and photon signals from cryogenic CaWO₄ crystals are used to search for WIMP-induced nuclear recoil events. We present a table-top setup in which the scintillation of CaWO₄ is induced by 0.7ns laser pulses of 355nm wavelength. The short laser pulses allow measurements with good time resolution. The excitation occurs via two-photon absorption in the bulk material. The extremely small cross-section for two-photon excitation enables us to induce excitation at any position in the volume of the crystal and not only at the surface. With this experiment models for scintillation properties of CaWO₄-crystals were tested and will be presented in this talk.

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