Possible extensions of XIA's digital spectrometer technology to portable and remote monitoring instrumentation

The XIA DXP-4C, a 4 channel, CAMAC based X-ray spectrometer, is based on digitally processing directly digitized preamplifier signals. Designed for instrumenting multi-detector arrays for synchrotron radiation applications, the DXP-4C was optimized for very high count rates at a low cost per detector channel. These design constraints coincidentally lead to an instrument which is very compact and relatively low power (3.4 W/channel), considering its count rate and MCA capabilities, and which therefore offers interesting possibilities for effective extension to portable applications. Further, because all functions (gain, filter parameters, pileup inspection criteria and internal calibrations) are digitally controlled, the design can be readily adapted to a large variety of user interfaces, including remote access interfaces. Here we present the basics of the design and examine approaches to lowering the power to less than 300 mW/channel while retaining count rate capabilities in excess of 50,000 cps. We then consider the engineering issues associated with portable and remote spectrometry applications, examining in detail the three cases of a lead paint detector, a remote contamination monitor, and a space mission spectrometer.