We report on experimental studies of phonon sensors which utilize quasiparticle diusion in thin aluminum films connected to tungsten transition-edge-sensors (TESs) operated at 35 mK. We show that basic TES physics and a simple physical model of the overlap region between the W and Al lms in our devices enables us to accurately reproduce the experimentally observed pulse shapes from x-rays absorbed in the Al films. We further estimate quasiparticle loss in Al lms using a simple diusion equation approach. These studies allow the design of phonon sensors with improved performance.
Yen, J. J., B. Shank, B. A. Young, B. Cabrera, P. L. Brink, M. Cherry, J. M. Kreikebaum, et al. “Measurement of Quasiparticle Transport in Aluminum Films Using Tungsten Transition-Edge Sensors.” Applied Physics Letters 105, no. 16 (October 20, 2014): 163504. doi:10.1063/1.4899130.