Design of ultra-fast soft x-ray sensorics for spectral monitoring of high-temperature plasmas

Abstract The 2D ultra-fast soft x-ray sensorics for spectral monitoring of high-temperature plasmas opens the possibility to study spectrally resolved emission in the 4–20 keV range with a typical spatial resolution of several millimeters on a sub-millisecond scale. The camera core consists of an innovative monolithic active pixel sensor, derived from the SpacePix3 sensor family, capable of measuring individual photon energies, complemented by system-on-chip-based readout electronics and an optical link. We present a design that targets the harsh environments near fusion devices, therefore fully aimed at remote control. The design offers high flexibility for adjusting the camera field-of-view and spatial resolution, even with the pixel sensor located in a vacuum. As a differentially pumped diagnostic with an entrance gate valve, the camera can be easily mounted to or dismounted from the device. The use and integration of the camera is supported by an Ethernet interface, HDF5 data format, web interface, and C++ library. The initial sensor tests, based on the measurement of ⁵ ⁵ Fe emitter x-ray spectra and the energy calibration curve, are presented.