Microcalorimeter-arrays and quantum-gas-target for experiments at GSI/FAIR

In the framework of the APPA collaborative research center for the first time the unique combination of properties of magnetic micro-calorimeters for high resolution x-ray spectroscopy of highly charged ions at storage rings will be fully realized and thus will enable a new quality of precision experiments for example for testing quantum electrodynamics in high fields. Based on the successful microcalorimeter concept maXs, having world leading energy resolution, excellent linearity and fast intrinsic signal rise time, two novel detector arrays with 64 X-ray absorbers each will be produced. The geometry of the detector arrays and the cryogenic setup will be optimally designed for operating at the 0° port of the electron cooler of CRYRING. Under this angle the Doppler broadening and the angle related uncertainties in the Doppler shifts are both minimal. In addition, high precision methods to manipulate atoms near absolute zero will be exploit to realize a novel quantum gas target for accelerator facilities. It is planned to setup an advanced UHV chamber including an optical dipole trap and to condition it for use at GSI. Within the quantum gas target a precise atomic state preparation will be possible including the realization of a Bose-Einstein condensate. As preparation for the first experiments at FAIR we will also investigate the interaction of singly charged ions with such a target. These experiments will enable us to develop the necessary ion optics in order to transfer the ions into the experimental chamber in a controlled way and to optimized the overlap with the target.