A new high sensitivity spectrometer for 3-D thermoluminescence analysis

The features of a new spectrometer for measuring wavelength-resolved TL emission are described: the system is based on wide angle mirror optics and the dispersive element is a flat-field holographic grating, with numerical aperture f/2. The detector is a two-stage MCP (micro-channel plate) followed by a 512 photodiode array. The whole system, cooled by a Peltier control unit, reaches a signal-to-noise ratio comparable with a photomultiplier one. The high sensitivity of the apparatus allows the measurement in dosimetric materials, TL due to irradiations lower than 100 μGy. In quartz extracted from ancient ceramics the TL produced by natural irradiation has been detected. (author)