Systems and methods to estimate mean randoms include acquisition of list mode data describing true coincidences and delay coincidences detected during a scan of an object, determination of a plurality of time periods of the scan based on a distance moved by a bed supporting the object during each of the plurality of time periods, determination, for each crystal and for each of time period, of delay coincidences including the crystal based on the list mode data, determination, for each crystal, of a singles rate associated with each time period based on the delay coincidences determined for the crystal over the time period, determination, for each time period, of estimated mean randoms for each crystal pair based on the singles rate associated with the time period, and reconstruction of an image of the object based on the estimated mean randoms for each time period and the detected true coincidences.

A combined thermal neutron detector and gamma-ray spectrometer system, including: a detection medium including a lithium chalcopyrite crystal operable for detecting thermal neutrons in a semiconductor mode and gamma-rays in a scintillator mode; and a photodetector coupled to the detection medium also operable for detecting the gamma rays. Optionally, the detection medium includes a .sup.6LiInSe.sub.2 crystal. Optionally, the detection medium comprises a compound formed by the process of: melting a Group III element; adding a Group I element to the melted Group III element at a rate that allows the Group I and Group III elements to react thereby providing a single phase I-III compound; and adding a Group VI element to the single phase I-III compound and heating; wherein the Group I element includes lithium.

The invention concerns a method for improving the energy resolution of a gamma ray detector comprising a monolithic scintillator and a photodetector segmented during a scintillation event characterised by the following steps:detecting the time of arrival of the first photons on said photodetector;counting, during a period T, which is between 2 and 6 times a transfer time (Te), the number and location of the first detected non-scattered photons;determining the diameter and the position of a disk defined by a set of first non-scattered photons;determining the position (X, Y) of a scintillation event from the location of said first detected non-scattered photons;counting the number of the first detected non-scattered photons inside said disk during a period Td greater than a decay time () of the scintillator;defining the energy of a gamma photon, said energy being proportional to the number of non-scattered photons counted inside the disc. The invention also concerns the associated detection system, the microelectronic component and a scintillator crystal treated for use in a PET application, and the use of the detection system according to the invention in PET and SPECT imagers.

A fiberscope comprises a scintillator arranged to produce light of a first wavelength upon exposure to radiation; an optical system arranged to receive and direct light of the first wavelength emitted from the scintillator, the light being received at one end of the optical system, and wherein one or more elements of the optical system emits scintillation light of a second wavelength upon exposure to radiation; and an optical filter, disposed at the other end of the optical system, and arranged to transmit light of the first wavelength and block light of the second wavelength. The scintillator is chosen such that the light of the first wavelength is spectrally distinct from the light of the second wavelength.

A substrate processing apparatus includes a process chamber providing a process space, a stage located in the process chamber and configured to support a substrate, a window coupled to a side of the process chamber, and a scintillator layer coupled to one side surface of the window. The scintillator layer covers a portion of the one side surface of the window which is less than the full window surface. A second surface corresponding to another portion of the one side surface of the window is exposed. Light emitted by a plasma in the process space passes through the window and is collected by an optical system and analyzed. Ultraviolet light passing through the scintillator is converted to longer wavelength, generally visible, light. Comparing the light passing through the bare window with the light passing through the scintillator layer enables analysis of the plasma.

This invention enables highly accurate sample analysis by analyzing energy spectra obtained using a radiation detector, even under a high dose-rate environment. In a radiation analysis method disclosed here, first, a spectrum of a sample (measured spectrum) is measured by a radiation detector (sample measurement step: S1). The measured spectrum is obtained for each of different setting conditions, where a plurality of scintillators having different sizes and a plurality of shields having different thicknesses are used, respectively. Next, similar measurement is performed on a reference source (reference source measurement step: S2). Next, from reference spectra thus obtained in S2, a background nuclide-originating component, which is a component originating from a background nuclide (.sup.137Cs) included in the measured spectra, is estimated (background nuclide-originating component estimation step: S3). Next, a corrected spectrum is calculated as the difference between the measured spectrum and the background nuclide-originating component (corrected spectrum calculation step: S4).

Systems and methods for detecting depleted uranium contamination in a surface layer of soil comprise: a gamma detector assembly; a location referencing mechanism for detecting a set of geographic coordinates of each location; and a processor in communication with the detector assembly and the location referencing mechanism. The processor is configured to: record each gamma spectrum and the corresponding set of geographic coordinates of each location; calculate a midpoint spectrum between two sequential locations; calculate a number of counts for an energy range of each midpoint spectrum, each calculated number of counts associated with a midpoint location; compare the calculated number of counts to a threshold number of counts representing a number of counts for the energy range of a background gamma spectrum of the surface layer of soil.

The method uses the Monte Carlo calculation code MCNP6.1 for: 1) The real modelling of a LaBr.sub.3(Ce) scintillation based radiation detector and a physical structure comprised of multiple sections that contain a large-sized glass fibre filter subdivided into 15 active circular areas. This structure is part of a high volume airborne particulate sampling system; 2) maximizing the position of the LaBr.sub.3(Ce) radiation detector with respect to the above-cited physical structure, in which each of the 15 active areas of the filter contributes towards the calculation of the absolute detection efficiency curve, which is necessary for the quantitative analysis of the natural and artificial radionuclides, each with their own probability of deposition of the aspirated particulate. This method can be used mainly in automatic radiological monitoring systems that operate for the purposes of radiological/nuclear early alarm, for which the state of the art does not provide the calculation of the absolute detection efficiency with respect to the probability of deposition of the particulate on the filter and, as a result, the accurate measurement of the natural and/or anthropic radionuclides in the aspirated particulate.