摘要:
A structure including a substrate, an intermediate layer provided and formed directly onto the substrate, a transition region, and a group II-VI bulk crystal material provided and formed as an extension of the transition region. The transition region acts to change the structure from the underlying substrate to that of the bulk crystal. In a method of manufacture, a similar technique can be used for growing the transition region and the bulk crystal layer.
摘要:
A method is described for the combined processing of spectral data from a plurality of radiation detectors (4,6), in particular with a plurality of response functions, comprising: obtaining a response matrix for each detector (4,6); collecting data from radiation incident at each detector (4,6); producing a spectral histogram for the collected data from each detector (4,6); deconvoluting the histograms from each detector by applying a suitable numerical deconvolution such as a Bayesian deconvolution that makes use of the response matrix for each detector to derive a single spectral histogram that representatively combines information from the plurality of detectors. An apparatus, such as a hybrid detector apparatus, to which the method can be applied is also described.
摘要:
A method and system for facilitating the identification and/ or authentication of objects, and to a method and system for the marking of objects with an identity and/ or as of authentic origin, anda set of objects marked to facilitate subsequent identification and/ or authentication are described. The marking comprises incorporating into an object or part thereof or onto a tag mechanically engaged therewith a marker material exhibiting a characteristic radiation interaction response to incident high- energy ionizing radiation from a test source that is known to vary spectroscopically across the spectrum of the source. The presence or otherwise of the marker material may be determined by subsequent interrogation of an object with a suitable radiation source and detector to infer whether an object is of marked identity or origin.
摘要:
Method for the identification of a homogeneous material (e.g. a liquid) in a container (e.g. a bottle) by measuring its X-ray or gamma spectrum and deriving its specific attenuation function. The method comprises building a database of the attenuation functions of empty containers, of containers filled with various fluid materials and of the contained fluid materials itself (by subtracting or devoluting the empty-container-attenuation-function from the filled-container-attenuation-function), recording the spectrum of an unknown material in a container and comparing this spectrum to the spectra in the database.
摘要:
A method of operation of a scintillator detector comprising a scintillator and a photodetector is described, together with a device embodying the method. The method comprises the steps of: periodically producing a light pulse; impinging at least some of the light from a successive plurality of such light pulses onto a light-receptive part of the photodetector; measuring the electrical response of the photodetector; processing the electrical response of the photodetector to determine a pulse height and a variance of pulse height; numerically processing the pulse height and variance of pulse height so determined to obtain at least a first data item characteristic of the response of the photodetector. The method additionally or alternatively comprises the steps of: periodically producing a light pulse including light in the ultraviolet spectrum; impinging at least some of the UV light from a successive plurality of such light pulses onto a light-receptive part of the scintillator; inducing photon emission in the scintillator in the visible spectrum; measuring the electrical response of the scintillator; processing the electrical response of the scintillator to obtain at least a data item characteristic of the response of the scintillator; and optionally verifying the electrical response of the scintillator by comparing at least the said data item against a predetermined reference response; and optionally additionally or alternatively outputting a control signal to the photodetector, which signal is modified in part responsive at least to the value of the said data item.