A method and apparatus, the method comprising: forming first electrode portions on a substrate; providing a sheet of two dimensional material overlaying at least part of the first electrode portions; forming second electrode portions on a superstrate; positioning the superstrate overlaying the substrate so that the second electrode portions are aligned with the first electrode portions; and laminating the substrate and the superstrate together so that the sheet of two dimensional material is positioned between the aligned first electrode portions and the second electrode portions.

A photon counting device includes a plurality of pixels each including a photoelectric conversion element configured to convert input light to charge, and an amplifier configured to amplify the charge converted by the photoelectric conversion element and convert the charge to a voltage, an A/D converter configured to convert the voltages output from the amplifiers of the plurality of pixels to digital values; and a conversion unit configured to convert the digital value output from the A/D converter to the number of photons by referring to reference data, for each of the plurality of pixels, and the reference data is created based on a gain and an offset value for each of the plurality of pixels.

A radiation monitor includes a radiation detection unit detecting radiation, and an optical fiber transmitting photons emitted from a light emitting element of the radiation detection unit, wherein the radiation detection unit includes a first light emitting element generating a photon in response to incident radiation, a chemical compound part having chemical compounds which generate charged particles by nuclear reactions with incident neutrons, and a second light emitting element being located between the first light emitting element and the chemical compound part and generating a photon in response to radiation.

A radiation monitor includes a radiation detection unit detecting radiation, and an optical fiber transmitting photons emitted from a light emitting element of the radiation detection unit, wherein the radiation detection unit includes a first light emitting element generating a photon in response to incident radiation, a chemical compound part having chemical compounds which generate charged particles by nuclear reactions with incident neutrons, and a second light emitting element being located between the first light emitting element and the chemical compound part and generating a photon in response to radiation.

A radiation logging tool is provided that includes a scintillator detector for use on a wellbore tool string to characterize earth formations. The scintillator detector has a shutter to allow for the collection of data differentiating between incident radiation, such as backscatter signal, and system noise, such as dark current, vibration noise, electronics thermal noise, and electrostatic noise. The radiation logging tool provides for a method of calibrating and measuring incident radiation by the removal of system noise. The shutter is positioned between the photosensor and scintillation member of the scintillator detector, and is able to switch between open and closed states while the scintillation detector is deployed. Measurements of signal noise can be used to calibrate the sampling signal of incident radiation on the scintillator detector.

An ionizing radiation detector includes a first common semiconductor substrate and a first plurality of single-photon avalanche diode (SPAD) microcell structures disposed at a top face of the first common semiconductor substrate. Each SPAD microcell structure includes a first semiconductor junction that is reverse-biased beyond a first breakdown threshold. The ionizing radiation detector may also include common anode and cathode connections to each of the SPAD microcell structures that operate as an output. The ionizing radiation detector may also include control circuitry connected to the SPAD microcell structures. The control circuitry may be configured to control biasing of the SPAD microcell structures and measure electrical characteristics of a signal provided on the output. Charge drift within the first common semiconductor substrate need not be inhibited from exciting more than one of the SPAD microcell structures of the first plurality of SPAD microcell structures by isolation barriers.

An ionizing radiation detector includes a first common semiconductor substrate and a first plurality of single-photon avalanche diode (SPAD) microcell structures disposed at a top face of the first common semiconductor substrate. Each SPAD microcell structure includes a first semiconductor junction that is reverse-biased beyond a first breakdown threshold. The ionizing radiation detector may also include common anode and cathode connections to each of the SPAD microcell structures that operate as an output. The ionizing radiation detector may also include control circuitry connected to the SPAD microcell structures. The control circuitry may be configured to control biasing of the SPAD microcell structures and measure electrical characteristics of a signal provided on the output. Charge drift within the first common semiconductor substrate need not be inhibited from exciting more than one of the SPAD microcell structures of the first plurality of SPAD microcell structures by isolation barriers.

Disclosed and described herein are embodiments and methods of use of a gamma ray spectroscope. In one aspect the gamma ray spectroscope comprises a scintillator for receiving radiation and a solid-state photomultiplier for detecting and amplifying light emitted by the scintillator in response to the received radiation, wherein an electrical output signal is provided by the photomultiplier that is proportional to the received radiation.

The radiation detector according to the present invention is always able to calculate the summation value accurately, regardless of the intensity of the fluorescent emission that is produced in the scintillator. That is, if the method for calculating the summation value set forth in the present invention is used, then the number of instantaneous intensity data d that are added together each time a fluorescent emission is produced in the scintillator will be larger the greater the intensity of the fluorescent emission. Doing this prevents the intensity of an intense fluorescent emission from being understated. Moreover, the summing portion in the present invention is able to calculate the summation value with high reliability. This is because the instantaneous intensity data used in calculating the summation value are above a threshold value a, causing the signal-to-noise ratios to be adequately high and the reliability to be high as well.

The radiation detector according to the present invention is always able to calculate the summation value accurately, regardless of the intensity of the fluorescent emission that is produced in the scintillator. That is, if the method for calculating the summation value set forth in the present invention is used, then the number of instantaneous intensity data d that are added together each time a fluorescent emission is produced in the scintillator will be larger the greater the intensity of the fluorescent emission. Doing this prevents the intensity of an intense fluorescent emission from being understated. Moreover, the summing portion in the present invention is able to calculate the summation value with high reliability. This is because the instantaneous intensity data used in calculating the summation value are above a threshold value a, causing the signal-to-noise ratios to be adequately high and the reliability to be high as well.