Portal monitors, container scanners, and mobile search systems, constructed with high resolution germanium (HPGe) detectors, are currently being installed at locations world-wide. This reflects a general desire for improved performance and a reduction in the time to make a good decision in interdiction cases. An integrated gamma-ray spectrometer, incorporating a mechanically-cooled HPGe detecto...

Raman spectroscopy and microscopy can provide molecular information for complex materials such as biological tissue and cells. In these applications, light-collection throughput is essential for speedy acquisition of high-quality data. To improve throughput, two-dimensional detectors and high numerical aperture (NA) optical systems have been employed. However, owing to the out-of-plane diffract...

BACKGROUND AND PURPOSE Photon-counting detectors offer the potential for improved image quality for brain CT but have not yet been evaluated in vivo. The purpose of this study was to compare photon-counting detector CT with conventional energy-integrating detector CT for human brains. MATERIALS AND METHODS Radiation dose-matched energy-integrating detector and photon-counting detector head CT...

INTRODUCTION The contamination of soil with gamma-ray emitters can be measured in two ways: soil sampling method and in situ spectrometry of the ambient gamma-ray radiation. The conventional soil sampling method has two disadvantages: samples may not be representative for a large areas and determination of the depth distribution of radionuclide requires the measurement of several samples taken ...

The detection rate of a gamma-ray burst detector can be increased by using a count rate trigger with many accumulation times ∆t and energy bands ∆E. Because a burst’s peak flux varies when averaged over different ∆t and ∆E, the nominal sensitivity (the numerical value of the peak flux) of a trigger system is less important than how much fainter a burst could be at the detection threshold as ∆t ...

The use of a dual-ended readout PET detector module based on Geiger-mode avalanche photodiodes (GAPDs) with large-area microcells was proposed to obtain high photon detection efficiency (PDE) and overcome energy non-linearity problems. A simulation study was performed and experimental measurement were taken for the singleand dual-ended PET detector modules consisting of the two types of GAPDs w...

Sir,—MacDonald and Mackenzie (1976) reported an alinear relationship between peak height and halothane concentration when measuring halothane (0.2—4.0%) with a gas chromatograph equipped with a flame ionization detector. Alinearity persisted when the sample loop size was reduced from 2 ml to 0.1 ml, and a linear response was obtained only when the flame ionization detector was replaced with a k...

Coherent (X-ray) diffractive imaging (CDI) is an increasingly popular form of X-ray microscopy, mainly due to its potential to produce high-resolution images and the lack of an objective lens between the sample and its corresponding imaging detector. One challenge, however, is that very high dynamic range diffraction data must be collected to produce both quantitative and high-resolution images...

The optimum detector for a random signal, the estimator-correlator, is difficult to implement. If the power spectral density (PSD) of a continuous time signal is known, a locally optimum detector is available. It maximizes the deflection ratio (DR), a measure of the detector output signal-to-noise ratio (SNR). A discrete version of this detector is developed here, called the discrete-MDRD, whic...