53 results about "High count rate" patented technology

A method and associated apparatus for detecting concealed fissile, fissionable or special nuclear material in an article, such as a shipping container, is provided. The article is irradiated with a source of fast neutrons, and fast neutrons released by the fissile or fissionable material, if present, are detected between source neutron pulses. The method uses a neutron detector that can detect and discriminate fast neutrons in the presence of thermal neutrons and gamma radiation. The detector is able to process high count rates and is resistant to radiation damage, and is preferably a solid state neutron detector comprised of silicon carbide.

A method of TOF-PET image reconstruction using time-truncated TOF-PET projection data. The time-truncated TOF-PET data is obtained by narrowing the scanner time window to a smaller “time window field of view,” which reduces the field of view of a TOF-PET scanner. This results in a lower list mode stream transfer rate, which can be useful in high count rate data acquisitions, in particular 82Rb cardiac studies.

A CT detector capable of energy discrimination and direct conversion is disclosed. The detector includes multiple layers of semiconductor material with the layers having varying thicknesses. The detector is constructed to be segmented in the x-ray penetration direction so as to optimize count rate performance as well as avoid saturation. The detector also includes variable pixel pitch and a flexible binning of pixels to further enhance count rate performance.

There are provided a storage section 220 that stores an output value read out by counting a pulse signal of incident X-rays, by a photon-counting type semiconductor detector; and a calculation section 230 that calculates a count value based on the output value that has been read out, wherein the calculation section 230 uses a model in which an apparent time constant of the pulse signal monotonously decreases against increase in pulse detection ratio with respect to exposure. According to such a model, the corresponding apparent time constant is able to be obtained even in any higher count rate. As a result of this, reduced can be the influence of count loss even on the count rate that has not been able to be covered by the conventional method.

Method and system are provided for calibrating a nuclear medical imaging apparatus for DC shift caused by gamma event afterglow pulses. Detector responses to weak and to high count rate radiation sources are compared with each other, and a zero correction value is incremented until the detector response is the same for the weak source and the high count rate source. The zero correction value is then stored as a static zero correction value, which multiplies a dynamic zero correction value obtained just prior to the occurrence of a gamma event, in order to remove the effects of DC shifts from the output energy signal Esum.

A method for real-time processing of pulse accumulation events, comprising the steps of: generating a fitted baseline value lookup table and a fitted energy value lookup table for pulse falling edges, using a multi-voltage threshold sampling method to complete the identification of piled-up pulses and the triggering of the pulse signal processing process ; Using the pulse prior information and the collected pulse information to obtain the information of the incorrectly sampled part due to the pulse accumulation in the form of a look-up table, the real-time recovery of the accumulated pulse information is completed. The present invention first uses the multi-voltage threshold sampling method to complete the recognition of the accumulation pulse at a high count rate and the triggering of the pulse signal processing process, and then uses the pulse prior information and the collected pulse information to obtain The information of the sampling part completes the real-time recovery of the accumulation pulse information. The method of the present invention is simple and efficient, and is easy to implement on a real-time data acquisition system at the detector level, and can still achieve better accumulation of pulse information recovery effect under the condition of low sampling rate.

The invention provides a CuI crystal growth method, which belongs to the field of crystal growth in photoelectric functional material technology. The method uses a low-temperature aqueous solution cooling method to grow crystals, using NH4Cl, NH4Br, NH4I, etc. as cosolvents, copper sheets as reducing agents, paraffin oil seals, growth temperature range of 30-60°C, and cooling rate of 0.1-0.5°C / day. The cooling method crystal growth technology adopted in the present invention has the advantages of low growth temperature, low solution viscosity, simple and easy device, and the growth process can be directly observed. The grown CuI crystal has high purity, good uniformity, and large size. The ultrafast scintillation crystal is expected to play an important role in the future measurement of ultra-high count rate electrons, γ-rays and X-rays. It is also used as a semiconductor material for solar cell materials, superconducting materials and photocatalytic materials.

The invention discloses a high-counting-rate multi-air-gap resistive plate chamber detector, which comprises: a plurality of MRPCs; at least one insulating stopper, at least one insulating stopper is used to separate the plurality of MRPCs from each other by a predetermined distance; a plurality of MRPCs Connector; two insulating films and two readout circuit boards, at least one insulating stopper and a plurality of MRPCs between the two insulating films, two insulating films between the two readout circuit boards, two readout The circuit boards are connected by a number of connectors. In the high count rate multi-air-gap resistive plate chamber detector of the present invention, multiple MRPCs are spliced ​​between two readout circuit boards, without stacking, low cost, small required space (or thickness), and the detection efficiency of each MRPC Can be as high as 95%, with a time resolution better than 100ps.

A quantitative pulse count (event detection) algorithm with linearity to high count rates is accomplished by combining a high-speed, high frame rate camera with simple logic code run on a massively parallel processor such as a GPU or a FPGA. The parallel processor elements examine frames from the camera pixel by pixel to find and tag events or count pulses. The tagged events are combined to form a combined quantitative event image.