31 results about "Gas electron multiplier" patented technology

A dosimeter based on a gas electron multiplier and method of use thereof for measurement of doses of therapeutic radiation to which a tissue-phantom is exposed. Subsequent to the in-phantom measurement and verification of radiation beam delivery, radiation can be effectively delivered to a human target organ, based on the verification of radiation quantities to which the phantom was exposed. Use of a gas electron multiplier-based dosimeter facilitates precise and accurate verification of the radiation dose within a phantom by taking measurements in real time, with no need for subsequent film processing.

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 readout board for use in a micropattern gas detector comprises a plurality of detector pads arranged into a plurality of consecutive layers that are separated by dielectric spacer material. An electron cloud hitting the front side of the readout board will induce a charge on one of the detector pads of the uppermost layer. By capacitive coupling, the signal will propagate downwards through the consecutive layers until it reaches the bottom layer, from which the charges are read out and analyzed. The position of the impact can be determined by comparing the charges that have spread to neighboring readout pads. Since only the bottommost layer of the readout pads needs to be connected to readout electronics, incident particles can be localized at high precision despite the relatively large size of the readout pads in the bottom layer. The invention is effective both in a gas electron multiplier (GEM) and in a MicroMegas detector.

Methods for manufacturing a gas electron multiplier. One method comprises a step of preparing a blank sheet comprised of an insulating sheet with first and second metal layers on its surface, a first metal layer hole forming step in which the first metal layer is patterned by means of photolithography, such as to form holes through the first metal layer, an insulating sheet hole forming step, in which the holes formed in the first metal layer are extended through the insulating layer by etching from the first surface side only, and a second metal layer hole forming step, in which the holes are extended through the second metal layer. Alternatively, the second metal layer hole forming step is performed by electrochemical etching, such that the first metal layer remains unaffected during etching of the second metal layer. In another embodiment, in the second metal layer hole forming step, the first and second metal layers are etched from the outside, thereby reducing the initial thicknesses of the first and second metal layers and the second metal layer is simultaneously etched through the holes in the first metal layer and the insulating sheet, said etching being maintained until the holes extend through the second metal layer, wherein said initial average thickness of the first and second metal layers is between 6.5 μm and 25 μm, preferably between 7.5 μm and 12 μm.