Development of the WFEE subsystem for the X-IFU instrument of the ATHENA Space Observatory

The X-IFU is one of the two instruments of the ESA ATHENA space mission, at present in feasibility phase (phase A). It is an X-Ray spectral imager designed to have an unprecedented 2.5 eV spectral resolution at 6 keV. In the readout chain of the X-IFU, the first stage working at room temperature is the WFEE subsystem, currently being developed at APC laboratory. It will include low-noise amplifiers, current sources, RS485/I 2 C digital interfaces and housekeeping elements. A first ASIC dedicated to this subsystem has been designed and tested. The basic functions of the main components of the WFEE and its radiation-hardened abilities have been evaluated. According to the measurement results, a second ASIC is being developed, aiming to comply with the WFEE requirements in the X-IFU readout chain.