Any Light Particle Search II - Status Overview

The Any Light Particle Search II (ALPS II) experiment (DESY, Hamburg) searches for photon oscillations into Weakly Interacting Sub-eV Particles (WISPs). This second generation of the ALPS light-shining-through-a-wall (LSW) experiment approaches the finalization of the preparation phase before ALPS IIa (search for hidden photons). In the last years, efforts have been put for the setting up of two optical cavities as well as the characterization of a single-photon Transition-Edge Sensor (TES) detector. In the following, we put some emphasis on the detector development. In parallel, the setting up of ALPS IIc (search for axion-like particles), including the unbending of 20 HERA dipoles, has been pursued. The latest progress in these tasks will b

First sensitivity limits of the ALPS TES detector

The Any Light Particle Search II (ALPS II) requires a sensitive detection of 1064~nm photons. Thus, a low dark count rate ($DC$) and a high detection efficiency ($DE$) is needed. ALPS has set up a transition-edge sensor (TES) detector system, namely the ALPS TES detector. It is found that thermal photons from room temperature surfaces are the main contribution of dark counts for 1064~nm photon signals. Furthermore, the current setup of the ALPS TES detector shows an improvement compared to using the ALPS I detector