[en] Some of the less recognized and potentially important parameters of the electronics and detectors used in X-ray fluorescence spectrometers are discussed. Detector factors include window (dead-layer) effects, time-dependent background and excess background. Noise parameters of field-effect transistors and time-variant pulse shaping are also discussed

[en] An historical review of the development of semiconductor detectors is presented. Detector physics, material requirements, and signal processing are discussed

[en] This paper discusses the use of boron implantation on high resistivity P-type silicon before oxide growth to compensate for the presence of charge states in the oxide and oxide/silicon interface. The presence of these charge states on high resistivity P-type silicon produces an inversion layer which causes high leakage currents on N⁺P junctions and high surface conductance. Compensating the surface region by boron implantation is shown to result in oxide passivated N⁺P junctions with very low leakage currents and with low surface conductance

[en] GAMMASPHERE uses 110 very large germanium detectors. Such detectors exhibit charge trapping effects on energy resolution initially due to a native electron trap that is present in virtually all germanium. Furthermore, radiation damage is a serious problem in GAMMASPHERE experiments, producing hole traps that degrade resolution and eventually require annealing to restore the original performance. The technique discussed here uses the current pulse shape from a detector to develop a parameter related to the radius of the largest interaction in the ''track'' of a gamma ray in the detector. Since the charge trapping loss in a signal can be related to the distance carriers travel, the ''radius'' parameter can be used by software to apply a trap correction to the signal

[en] The usual requirement for a spectrometer system is to provide the best energy resolution that can be obtained with a set of given experimental constraints. These constraints can change with each experiment, and the experimenter should be able to optimize the parameters of the spectrometer to obtain the best results. The detector, either silicon or germanium, is connected to a charge-sensitive preamplifier. The detector produces short current pulses of a width equal to the collection time of the detector. These are integrated by the charge-sensitive preamplifier which produces a voltage step at its output. The output step rise time is equal to the collection time of the detector, its amplitude is equal to the input charge divided by the capacitance of the feedback capacitor, and its decay time constant is determined by the preamplifier feedback components

No abstract available

[en] A balanced perspective is provided on the processing of signals produced by semiconductor detectors. The general problems of pulse shaping to optimize resolution with constraints imposed by noise, counting rate and rise time fluctuations are discussed

[en] A comparison is made between the limits of detection for trace elements when charged-particle and photon excited X-ray fluorescence analysis are performed on a specific type of sample (5 mg/cm² organic based). Large-scale analysis (approximately 30,000 samples per year) at levels of 1 ppM or lower is shown to be practical with either technique when well executed. Determining the physical reason for unexplained detector background is shown to be very important particularly for the potential improvement that might be realized in photon-excited analysis applications

[en] This patent describes a non-invasive method for measuring lung density comprising the steps of: irradiating a target lung with a single collimated beam of monochromatic photons; using a single high-resolution detector, detecting photons which are Compton backscattered by the target lung; measuring energies of the backscattered photons; determining relative intensities of scattering at successive points along the collimated beam inside the target lung by comparing the intensity of each of the successive points with the intensity of each adjacent point along the collimated beam; determining attenuation constant of the target lung from the relative intensities; and determining density of the target lung from the attenuation constant. The patent also describes a Compton densitometer for measuring lung density through a wall of unknown composition and thickness

No abstract available