A radiation detector according to an embodiment includes a photodiode array and a scintillator array. The photodiode array has a plurality of active areas arranged in a grid formation. The scintillator array is laminated on the photodiode array, is configured to emit light in response to incidence of radiation thereto, and has a plurality of modification parts that do not penetrate therethrough, in regions each corresponding to a position between two of the active areas, for a purpose of preventing crosstalk.

Disclosed herein is a photomultiplier tube (PMT) comprising: an electron ejector configured for emitting primary electrons in response to an incident photon; a detector configured for collecting electrons and providing an output signal representative of the incident photon; and a series of electrodes between the electron ejector and the detector, wherein each of the electrodes is configured for emitting secondary electrons in response to incident electrons, and each of the electrodes includes a bi-metal arc-shaped sheet.

A charged particle detector according to the embodiment is provided with an MCP and a PD arranged with a focus electrode interposed therebetween in order to improve a response characteristic as compared to a conventional one in a configuration in which the MCP having a bias angle and the PD are combined. The MCP includes a plurality of through holes each inclined by a bias angle and the PD is eccentrically arranged such that a center of an electron incident surface deviates by a predetermined distance in a bias angle direction S3 with respect to a central axis AX1 of the MCP.

A charged particle detector according to the embodiment is provided with an MCP and a PD arranged with a focus electrode interposed therebetween in order to improve a response characteristic as compared to a conventional one in a configuration in which the MCP having a bias angle and the PD are combined. The MCP includes a plurality of through holes each inclined by a bias angle and the PD is eccentrically arranged such that a center of an electron incident surface deviates by a predetermined distance in a bias angle direction S3 with respect to a central axis AX1 of the MCP.

A photomultiplier tube (PMT) suitable for detecting a photon, comprising: an electron ejector configured for emitting primary electrons in response to an incident photon; a detector configured for collecting electrons and providing an output signal representative of the incident photon; and a series of vertical electrodes between the electron ejector and the detector, wherein each of the vertical electrodes is configured for emitting secondary electrons in response to incident electrons, and each of the vertical electrodes is parallel to a straight line connecting the electron ejector and the detector.

Techniques for imaging radioactive emission in a target volume include receiving data indicating a set of one or more known emission energies associated with a high energy particle source and determining a Compton line for each emission energy in the set. A Compton camera collects location and deposited energy from an interaction associated with a single source event from a target volume of a subject. For the single source event, an earliest deposited energy, E.sub.1, and first scattering angle, .sub.1, and a cone of possible locations for the source event are determined. A particular location for the high energy particle source within the target volume without including the single source event, if E.sub.1 is not within a predetermined interval of the Compton line for at least one of known emission energies. A solution is presented on a FILTER display device.

A downhole gamma ray detector having improved resistance to shocks and vibrations encountered during use of modern drilling techniques. The detector includes a scintillator with a window for emitting photons upon receipt of gamma rays. The window faces a photon-receiving end of a photomultiplier tube. The scintillator and the photomultiplier tube are held in a fixed arrangement with respect to each other to provide an empty gap between the window and the photon-receiving end of the photomultiplier tube.

A method for manufacturing a detector of a first and a second incident ionizing radiation including determining the abscissa e.sub.m of a point of intersection between a first and a second curve, with the first and second curves representing the evolution of the number of photons or electrical charges generated per second by a transducing material as a function of the total thickness of an amplifying material when the transducing material is irradiated, through this thickness of transducing material, by the first and second incident ionizing radiation, respectively; then selecting the total thickness of amplifying material between 0.9 e.sub.m and 1.1 e.sub.m and producing the detector with the selected thickness of amplifying material.

A method for manufacturing a detector of a first and a second incident ionizing radiation including determining the abscissa e.sub.m of a point of intersection between a first and a second curve, with the first and second curves representing the evolution of the number of photons or electrical charges generated per second by a transducing material as a function of the total thickness of an amplifying material when the transducing material is irradiated, through this thickness of transducing material, by the first and second incident ionizing radiation, respectively; then selecting the total thickness of amplifying material between 0.9 e.sub.m and 1.1 e.sub.m and producing the detector with the selected thickness of amplifying material.

An enhanced electron amplifier structure includes a substrate configured to amplify a signal of an incident particle by causing a cascade of secondary electron emissions and an enhancement layer configured to increase a sensitivity of the substrate to the incident particle. The enhancement layer is provided on an upper surface of the substrate.