Experimental tests of a single-photon calorimeter for X-ray spectroscopy
Tests have been made of a nondispersive spectroscopic X-ray detector which operates by measuring the temperature rise following absorption of a single photon. Thermal pulses from 6-keV X-rays have been observed, and the different amplitudes resulting from Mn K-alpha and K-beta events have been resolved. This device was assembled to make quantitative tests of theoretical calculations of the properties of such detectors, and its high heat capacity does not allow it to attain the very high resolution predicted for detectors made by more sophisticated, but still straightforward, techniques. Both the measured resolution of 270-eV full width at half maximum and the absolute amplitude of the response are consistent with predictions. Nonthermal effects in the thermistor limit the precision of this comparison to about 30 percent.