Abstract: A position-sensitive ionizing-radiation counting detector includes a first substrate and a second substrate, and a defined gas gap between the first substrate and the second substrate. The first and second substrates comprise dielectrics and a discharge gas is contained between the first and second substrate. A microcavity structure comprising microcavities is coupled to the second substrate. An anode electrode is coupled to the first substrate and a cathode electrode is coupled to the microcavity structure on the second substrate. The detector further includes pixels defined by a microcavity and an anode electrode coupled to a cathode electrode, and a resistor coupled to each of the cathode electrodes. Each pixel may output a gas discharge counting event pulse upon interaction with ionizing-radiation. The detector further includes a voltage bus coupled to each of the resistors and a power supply coupled to at least one of the electrodes.

Abstract: The readout electrode assembly of an avalanche particle detector can be effectively protected against sparks and discharges by means of a plurality of resistor pads formed in a dielectric cover layer above the readout pads. The resistor pads may either be connected directly to the readout pads, or may be coupled capacitively by means of a charge spreading pad embedded into the dielectric cover layer and spatially separated from the readout pads. The charge spreading pad allows the distribution of charges to neighboring readout pads, and may hence increase the spatial resolution of the detector device.

Abstract: A micro-sized gas detecting device with two electrodes separated by a gap of width ranging from 1 to 500 microns, where the detection is based on emission spectroscopy of gases in an electric discharge across the gap (discharge region) as the gas flows through the region. The characteristic light emitted by molecules during the discharge can be detected directly with photodiodes or transferred through optical fiber and detected with remote optical sensing components. The device can have single or multiple discharge regions in an array so that light emitted can be monitored at different wavelengths simultaneously. The device can operate under gaseous pressure ranging from a few milli-Torr to a few atmospheres. The device consumes little power (50 mW-100 mW) and can be powered with an alternating current and has the potential to be battery powered.

Abstract: A detector for detection of ionizing radiation comprises a first cathode and a first anode between which a first voltage is applicable; an ionizable gas arranged at least partly between the first cathode and the first anode; a radiation entrance arranged such that ionizing radiation can enter and ionize the ionizable gas; and a read-out arrangement. The detector further comprises a second cathode and a second anode between which a second voltage is applicable; and a solid state ionizable material arranged between the second cathode and the second anode such that part of the radiation entered into the ionizable gas can propagate through the gas, enter the solid state material and ionize it; wherein the read-out arrangement is arranged for detection of the electrons and/or holes drifted towards the second anode and/or cathode, respectively, separately of detection of the electrons drifted towards the first anode.

Abstract: A detector (64) for detection of ionizing radiation, an apparatus for use in planar beam radiography, comprising such a detector, and a method for detecting ionizing radiation. The detector comprises: a chamber filled with an ionizable gas; first and second electrode arrangements (2, 1, 18, 19) provided in said chamber with a space between them, said space including a conversion volume (13); means for electron avalanche amplification (17) arranged in said chamber; and, at least one arrangement of read-out elements (15) for detection of electron avalanches. A radiation entrance is provided so that radiation enters the conversion volume between the first and second electrode arrangements. In order to achieve well-defined avalanches the means for electron avalanche amplification includes a plurality of avalanche regions.