# US 2014/0151562 A1 · Adaptive reflectivity for performance improvement on radiation detectors > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0151562 A1 - Document ID: US20140151562A1 - Status: Published application - Kind: A1 - Application number: 13/691,132 - Filed: 2012-11-30 - Published: 2014-06-05 - Earliest claimed: 2012-11-30 - Assignees: Kabushiki Kaisha Toshiba; Toshiba Medical Systems Corporation - Inventors: Gin-Chung WANG; Jerry Wang; Huini Du - Web page: https://patentgrep.com/patent/US20140151562A1 ## CPC - G01T 1/2002: {Optical details, e.g. reflecting or diffusing layers} - G01T: MEASUREMENT OF NUCLEAR OR X-RADIATION (radiation analysis of materials, mass spectrometry G01N23/00; tubes for determining the presence, intensity, density or energy of radiation or particles H01J47/00) ## Abstract Systems, devices, processes, and algorithms for adapting and/or adjusting a reflectivity of a reflector in a radiation detector. The reflectivity can be changed by a reflectivity control signal that is generated based on an estimated count rate of events so as to adjust a probability of a photosensor detecting light resulting from the event via, for example, a scintillation event. By adjusting the probability, an energy resolution of the radiation detector can be optimized. The reflectivity of a reflector can be changed by changing a state of a thin film, a liquid crystal layer, or a suspended magnetic particle layer. ## Claims ### Claim 1 A system for radiation detection, comprising: a rate counter configured to estimate, based on an output signal from a radiation detector, a count rate of events detected by the radiation detector; and a controller configured to generate a reflectivity control signal, based on the estimated count rate, and to output the reflectivity control signal to a reflector of the radiation detector, the reflectivity control signal causing the reflector to adjust a reflectivity of the reflector to optimize an energy resolution of the radiation detector. ### Claim 2 (depends on 1) The system according to claim 1, further comprising: the radiation detector, which includes a scintillator, a photosensor, and the reflector, wherein the reflector is configured to reflect light resulting from a scintillation event within the scintillator, so as to increase a probability of the light being detected by the photosensor. ### Claim 3 (depends on 2) The system according to claim 2, wherein the radiation detector is a photomultiplier tube. ### Claim 4 (depends on 2) The system according to claim 2, wherein the reflector includes an inner reflector and an outer reflector, such that the radiation detector has a layered structure, including, in this order: the inner reflector, the scintillator, the photosensor, and the outer reflector. ### Claim 5 (depends on 4) The system according to claim 4, wherein the reflectivity control signal causes the reflector to adjust a reflectivity of one or more of the inner reflector and the outer reflector. ### Claim 6 (depends on 2) The system according to claim 2, wherein the reflector includes a liquid crystal portion that is controlled by the reflectivity control signal so as to control a reflectivity of the reflector. ### Claim 7 (depends on 6) The system according to claim 6, wherein the liquid crystal portion is configured to change a reflectivity of the reflector, based on the reflectivity control signal, between a mirror state having a near 100% reflectance, and a black-body state having a near 0% reflectance. ### Claim 8 (depends on 1) The system according to claim 1, further comprising: a plurality of radiation detectors, each including a corresponding scintillator, a photosensor and a reflector, wherein each reflector is configured to reflect light resulting from a scintillation event within the scintillator, so as to increase a probability of the light being detected by the photosensor, and the controller is configured to generate a reflectivity control signal to adjust a reflectivity of each reflector of the plurality of radiation detectors. ### Claim 9 (depends on 8) The system according to claim 8, wherein the controller is configured to generate the reflectivity control signal to adjust the reflectivity of each reflector of the plurality of radiation detectors, such that the reflectivity of each reflector of the plurality of radiation detectors is controlled separately, so as to individually optimize an energy resolution of each of the radiation detectors. ### Claim 10 A radiation detector, comprising: a scintillator to generate light from a scintillation event; a photosensor configured to detect light generated from a scintillation event; and a reflector configured to reflect light resulting from a scintillation event, so as to increase a probability of light being detected by the photosensor when the light is generated from a scintillation event, wherein the reflector has an adjustable reflectivity. ### Claim 11 (depends on 10) The radiation detector according to claim 10, wherein the reflector includes a liquid crystal portion that is electronically controlled to adjust a reflectivity of the reflector. ### Claim 12 (depends on 10) The radiation detector according to claim 10, wherein the reflector includes a plurality of liquid crystal layers that are electronically controlled to adjust a reflectivity of the reflector. ### Claim 13 (depends on 10) The radiation detector according to claim 10, wherein the reflector includes a black-body layer having near 0% reflectance and a reflective particle layer including suspended reflective particles. ### Claim 14 (depends on 13) The radiation detector according to claim 13, wherein the suspended reflective particles in the reflective particle layer can be oriented based on an applied magnetic or electric field that is adjustable by a reflectivity control signal. ### Claim 15 (depends on 10) The radiation detector according to claim 10, wherein the reflector includes means for adjusting a reflectivity of the reflector. ### Claim 16 A radiation detection method, comprising: estimating, by a rate counter, a count rate of events detected by a radiation detector based on an output signal of the radiation detector; generating, based on the estimated count rate, a reflectivity control signal to adjust a reflectivity of a reflector of the radiation detector, the reflector configured to reflect light resulting from a scintillation event, so as to increase a probability of light being detected by a photosensor of the radiation detector when the light is generated from a scintillation event by a scintillator of the radiation detector; and outputting the reflectivity control signal to the reflector of the radiation detector to optimize an energy resolution of the radiation detector. ### Claim 17 (depends on 16) The method according to claim 16, wherein the reflector includes an inner reflector and an outer reflector, such that the radiation detector has a layered structure, in this order: the inner reflector, the scintillator, the photosensor, and the outer reflector. ### Claim 18 (depends on 17) The method according to claim 17, wherein the reflectivity control signal causes the reflector to adjust a reflectivity of one or more of the inner reflector and the outer reflector. ### Claim 19 (depends on 16) The method according to claim 16, wherein the reflector includes a liquid crystal portion that is controlled by the reflectivity control signal so as to control a reflectivity of the reflector. ### Claim 20 (depends on 19) The method according to claim 19, wherein the liquid crystal portion is configured to change a reflectivity of the reflector, based on the reflectivity control signal, between a mirror state having a near 100% reflectance, and a black-body state having a near 0% reflectance.