Semiconductor energy dispersive spectrometers (EDS), the most commonly used detectors for x-ray microanalysis, have matured to the point that significant improvement in energy resolution is not expected in the future. We believe a revolutionary advance in x-ray microanalysis will occur in the next few years due to the development of new x-ray spectrometers based on microcalorimeters. Energy resolution comparable with wavelength dispersive spectrometers, 3 eV to 10 eV, has already been achieved; future detectors may reach a fundamental limit as low as 0.5 eV to 1 eV.In a microcalorimeter, the energy of an x-ray is converted into heat, and a measurement of the temperature rise of the detector gives the deposited photon energy. Our microcalorimeter detector consists of a superconducting transition edge thermometer cooled to an operating temperature of 100 mK by a compact adiabatic demagnetization refrigerator, a read-out SQUID (Superconducting Quantum Interference Device) preamplifier followed by pulse-shaping amplifier and pile-up rejection circuitry, and a multi-channel analyzer with real-time computer interface.
A fully integrated 16 channel digitally trimmed pulse shaping amplifier
