A method for determining a spatial-sensitivity function of a gamma camera, the gamma camera observing a field of observation (?) liable to contain radiation sources, the gamma camera including a detector material; pixels, distributed over a detecting area, each pixel being configured to form a detection signal under the effect of detection of an interaction of an ionising photon in the detector material; a unit for achieving sub-pixel resolution, the unit being programmed to assign a position (x,y) to each detected interaction on the basis of detection signals formed by a plurality of pixels, the position being determined on a mesh dividing each pixel into a plurality of virtual pixels. The method includes steps allowing weights assigned to each virtual pixel to be determined, each weight corresponding to a sensitivity of each virtual pixel.

A converter unit configured to convert incident photons into electrons comprises multiple blind holes forming respective ionization chambers. The converter unit is preferably arranged in a detector, such as X-ray detector or absolute radiation dose measurement detector, additionally comprising an electron amplification device and/or a readout device.

A nuclear medicine examination apparatus is a nuclear medicine examination apparatus incorporating a Compton camera using gas amplification. The Compton camera has a chamber in which a gas is sealed. The nuclear medicine examination apparatus includes sensors that output signals each representing a gas state in the chamber and a controller that controls the gas state in the chamber on the basis of output signals from the sensors.

A radiation image forming apparatus includes a detection unit including a plurality of Compton cameras. Each of the plurality of Compton cameras including a radiation detection device that includes a plurality of pixels, each configured to detect an electron generated by the track of a recoil electron generated by Compton scattering, and is configured to output a detection signal configured to specify the position of a pixel that has detected the electron and a time when the pixel has detected the electron, and a detection module configured to detect the incident position of scattered rays generated by the Compton scattering. The plurality of the Compton cameras arranged annularly to surround a region in which a specimen is placed.

A detector for an electron multiplier comprising: a substrate comprising a dielectric material, the substrate having a first face and an opposing second face; a charge collector provided adjacent the first face of the substrate; an anode within the substrate, the anode spaced from first face, such that the anode is capacitively coupled to the charge collector, so that charge incident on the charge collector generates an image charge on the anode; and a conduit contact, coupled to the anode and passing through the substrate to the second face of the substrate layer.

The invention relates to a detecting unit for detecting ionizing radiation. The device comprises a converter unit for the amplification of ionizing radiation and a read-out unit, wherein the converter unit comprises a converter and a gas-electron multiplier, wherein said converter comprises a substrate with an ionizing radiation-receiving major surface and an electron-emitting major surface and a stack of accelerator plates in contact with the electron-emitting major side, wherein said stack comprises a plurality of perforated accelerator plates wherein the perforations of the perforated accelerator plates are aligned to form a matrix of blind holes.

A radiation detector using gas amplification, includes: an insulator having a first surface and a second surface positioned at a back surface side of the first surface; a first electrode layer that is provided on the first surface of the insulator and has a circular opening portion; a pixel electrode positioned inside the opening portion; a second electrode layer provided on the second surface of the insulator; and a via hole conductor that has one end surface thereof bonded to the second electrode layer through the interior of the insulator and has the other end surface thereof bonded to the pixel electrode, in which at least a part of the other end surface side of the via hole conductor exhibits a column or truncated cone shape and an outer diameter of the via hole conductor becomes smallest at the one end surface.

A downhole tool includes a radiation generator configured to output radiation using electrical power received from a power supply. A first portion of the radiation is emitted into a surrounding sub-surface formation. The downhole tool also includes a radiation detector coupled proximate the radiation generator. The radiation detector includes a micromesh gaseous detector, and the radiation detector is configured to output a measurement signal based at least in part on interaction between a second portion of the radiation output by the radiation generator and the radiation detector. Additionally, the downhole tool includes a control system communicatively coupled to the radiation generator and the radiation detector. The control system is configured to determine measured characteristics of the radiation output from the radiation generator based at least in part on the measurement signal and to control operation of the radiation generator based at least in part on the measured characteristics.

Various embodiments are described herein for sensors that may be used to measure radiation from radiation generating device. The sensors may use a collector plate electrode with first and second collection regions having shapes that are inversely related with one another to provide ion chambers with varying sample volumes along a substantial portion of the first and second collection regions which provides virtual spatial sensitivity during use.

A method for determining an electron density in a portion of an ionosphere includes: receiving, at a satellite in orbit, a signal transmitted from a ground-based transmitter through a portion of the ionosphere between the satellite and the ground transmitter; receiving, at the satellite, a reflection of the signal from a portion of the ionosphere above the satellite; and determining, based on the signal received at the satellite transmitted from the ground-based transmitter through the portion of the ionosphere between the satellite and the ground-based transmitter and the reflection of the signal received from the portion of the ionosphere above the satellite, an electron density of the portion of the ionosphere above the satellite.