Comparison of analogue and digital silicon drift detectors in PIXE analysis

The AXAS-A silicon drift detector that has been a part of the University of Guelph PIXE system for over a decade has recently been replaced by an AXAS-D unit. The calibration process previously performed on the AXAS-A, which uses a suite of high purity, "thick-target" single element and simple compound standards, was repeated for the AXAS-D. This allows for comparison between the analogue and digital approach to measuring PIXE spectra. The similarities between the results of the two detectors and the high accuracy found in geological applications affirm the validity of the use of an energy-dependent calibration factor within the GUPIX software. The upgrade to a digital detector offers multiple advantages. Unlike the AXAS-A, the AXAS-D contains a preamplifier and digital pulse processing circuitry and therefore requires significantly less supporting equipment. The improved count rate of the AXAS-D decreases the time required to complete projects.