A 36-pixel superconducting tunnel junction soft X-ray detector for environmental science applications

We are operating a superconducting tunnel junction detector for high-resolution soft X-ray spectroscopy at the Advanced Biological and Environmental X-ray Facility at the Advanced Light Source synchrotron. We have recently upgraded the instrument from 9 to 36 pixels for increased sensitivity. We have also acquired a new digital signal readout to increase the total count rate capabilities to ∼106 counts/s while maintaining a high peak-to-background ratio. We report on the performance of the spectrometer, and discuss speciation measurements of chromium in welding aerosols as a typical application of the instrument in environmental science.