Nineteen-element high-purity Ge solid-state detector array for fluorescence X-ray absorption fine structure studies

We describe a 19-element high-purity Ge solid-state detector array developed for high-throughput fluorescence X-ray absorption fine structure (XAFS) experiments in ultra-high vacuum (UHV). The packing ratio is 57%, a significant improvement over that of standard 13-element arrays (37%). The average energy resolution in the 19 channels is ∼170 eV at 5.9 keV with an amplifier shaping time of 6 μs. The detector array can be used up to a count rate of 200 kcps per channel using a shaping time of 0.5 μs and a dead-time correction. A total count rate of 3.8 × 106 cps is obtained with an energy resolution of 240 eV. Capability of the new detector for fluorescence-detected XAFS applications is demon-strated for 1000 Å thick YBa2Cu3O7 on SrTiO3 substrate and ∼0.1 monolayer of As atoms on an InP(001).