A radiation source arrangement causes interaction between pump radiation (340) and a gaseous medium (406) to generate EUV or soft x-ray radiation by higher harmonic generation (HHG). The operating condition of the radiation source arrangement is monitored by detecting (420/430) third radiation (422) resulting from an interaction between condition sensing radiation and the medium. The condition sensing radiation (740) may be the same as the first radiation or it may be separately applied. The third radiation may be for example a portion of the condition sensing radiation that is reflected or scattered by a vacuum-gas boundary, or it may be lower harmonics of the HHG process, or fluorescence, or scattered. The sensor may include one or more image detectors so that spatial distribution of intensity and/or the angular distribution of the third radiation may be analyzed. Feedback control based on the determined operating condition stabilizes operation of the HHG source.

An apparatus for measuring radon and thoron using an ionization chamber is proposed. The apparatus includes: a pump for air inflow suctioning and sending external air to at least one channel; a first sensor module outputting an alpha particle detection signal of an electrical signal by detecting alpha (α) particles discharged from radon and thoron; an air inflow delay module delaying air for a predetermined delay time and then outputting the air; a second sensor module outputting an alpha particle detection signal of an electrical signal by detecting alpha (α) particles discharged from radon and thoron; and a control module discriminating normal or abnormal alpha particle detection signals, counting the normal alpha particle detection signals discriminated for a predetermined measurement time, and calculating radioactive ray concentration values on the basis of the counted number of times of the normal alpha particle detection signals.

Disclosed is a low pressure wire ion plasma discharge source including an elongated ionization chamber housing at least two parallel anode wires extending longitudinally within the ionization chamber. A first of the at least two anode wires is connected to a DC voltage supply and a second of the at least two anode wires is connected to a pulsed voltage supply.

An apparatus for measuring ionizing radiation includes a detector having a cathode, an anode, a counting gas between the cathode and the anode for generating gas ionization by ionizing radiation, a voltage source for applying a voltage between the cathode and the anode, and a current measuring device for measuring a detector current between the cathode and the anode. The detector current is generated in the counting gas by the ionizing radiation. The apparatus further includes a setting device, wherein the setting device is configured for independently setting the apparatus into different operating modes depending on the measured detector current, and/or wherein the setting device is configured for independently setting the apparatus into different measurement ranges depending on the measured detector current.

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.

An apparatus for measuring radon and thoron using an ionization chamber is proposed. The apparatus includes: a pump for air inflow suctioning and sending external air to at least one channel; a first sensor module outputting an alpha particle detection signal of an electrical signal by detecting alpha (?) particles discharged from radon and thoron; an air inflow delay module delaying air for a predetermined delay time and then outputting the air; a second sensor module outputting an alpha particle detection signal of an electrical signal by detecting alpha (?) particles discharged from radon and thoron; and a control module discriminating normal or abnormal alpha particle detection signals, counting the normal alpha particle detection signals discriminated for a predetermined measurement time, and calculating radioactive ray concentration values on the basis of the counted number of times of the normal alpha particle detection signals.

Disclosed is a low pressure wire ion plasma discharge source including an elongated ionization chamber housing at least two parallel anode wires extending longitudinally within the ionization chamber. A first of the at least two anode wires is connected to a DC voltage supply and a second of the at least two anode wires is connected to a pulsed voltage supply.

A radiation source arrangement causes interaction between pump radiation (340) and a gaseous medium (406) to generate EUV or soft x-ray radiation by higher harmonic generation (HHG). The operating condition of the radiation source arrangement is monitored by detecting (420/430) third radiation (422) resulting from an interaction between condition sensing radiation and the medium. The condition sensing radiation (740) may be the same as the first radiation or it may be separately applied. The third radiation may be for example a portion of the condition sensing radiation that is reflected or scattered by a vacuum-gas boundary, or it may be lower harmonics of the HHG process, or fluorescence, or scattered. The sensor may include one or more image detectors so that spatial distribution of intensity and/or the angular distribution of the third radiation may be analyzed. Feedback control based on the determined operating condition stabilizes operation of the HHG source.

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.

A device for detecting includes a cathode forming a hollow sphere, filled with an ionisation and amplification gas, and an anode placed at the centre of the hollow sphere by the intermediary of a maintaining cane, wherein the anode is formed by an insulating ball and by at least two conductive balls positioned around the insulating ball and at the same predetermined distance from the insulating ball.