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arXiv · 1106.0167

Low-Temperature Light Detectors: Neganov-Luke Amplification and Calibration

C. Isaila·C. Ciemniak·F. v. Feilitzsch·A. Gütlein·J. Kemmer·T. Lachenmaier·J. -C. Lanfranchi·S. Pfister·W. Potzel·S. Roth·M. v. Sivers·R. Strauss·W. Westphal·F. Wiest
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Abstract

The simultaneous measurement of phonons and scintillation light induced by incident particles in a scintillating crystal such as CaWO4 is a powerful technique for the active rejection of background induced by gamma's and beta's and even neutrons in direct Dark Matter searches. However, less than ~1% of the energy deposited in a CaWO4 crystal is detected as light. Thus, very sensitive light detectors are needed for an efficient event-by-event background discrimination. Due to the Neganov-Luke effect, the threshold of low-temperature light detectors based on semiconducting substrates can be improved significantly by drifting the photon-induced electron-hole pairs in an applied electric field. We present measurements with low-temperature light detectors based on this amplification mechanism. The Neganov-Luke effect makes it possible to improve the signal-to-noise ratio of our light detectors by a factor of ~9 corresponding to an energy threshold of ~21 eV. We also describe a method for an absolute energy calibration using a light-emitting diode.

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C. Isaila, C. Ciemniak, F. v. Feilitzsch, A. Gütlein, J. Kemmer, T. Lachenmaier, J. -C. Lanfranchi, S. Pfister, W. Potzel, S. Roth, M. v. Sivers, R. Strauss, W. Westphal, F. Wiest. 2012-09-17. Low-Temperature Light Detectors: Neganov-Luke Amplification and Calibration. https://doi.org/10.1016/j.physletb.2012.08.003

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