Speaker
Description
The newly upgraded Swiss Light Source (SLS) 2.0, a fourth-generation synchrotron, has begun
operation. Photons with energies up to 80 keV will be available at increased flux compared to the
third-generation source it replaces. In particular, the brilliance is expected to increase by two orders of
magnitude. In this energy range, silicon is no longer an efficient detection material. High-Z
semiconductors are therefore required, with GaAs:Cr, CdTe, and CdZnTe (CZT) being promising
candidates.
Developed at PSI, JUNGFRAU is a charge-integrating ASIC designed to cope with the extremely
intense X-ray pulses from SwissFEL. Three gain levels, combined with dynamic per-pixel switching,
extend the dynamic range to 10⁴ photons at 12.4 keV in silicon. However, JUNGFRAU was designed for
hole-collection in silicon. In contrast, electron-collection is preferred in high-Z materials due to their
superior charge transport properties.
The dynamic range of JUNGFRAU in the highest gain mode (G0) has been optimized for
hole-collection, resulting in a linear dynamic range of ~330 keV, compared to electron-collection which
is limited to a linear dynamic range of ~110 keV. Methods are in development to better characterise and
improve the dynamic range performance. In this contribution, we will use these methods to investigate
techniques and detector configurations, aimed at extending the dynamic range of G0 in
electron-collection mode.