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- 摘要
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- 实验方案
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Dynamic range and resolving power of the Timepix detector to heavy charged particles
摘要： The spectrometric and particle tracking response of the Timepix detector for charged particle detection was examined for energetic (i.e. penetrating) heavy charged particles in a wide range of energies and directions. The aim of this study was to examine the detector’s resolving power including particles approaching the minimum-ionizing regime, in particular energetic protons. The per-pixel energy range, of importance namely for heavy charged particles, was also investigated. This work complements and extends the ongoing task to analyze and describe the response and resolving power of the detector in a wide range of particle types, energy (energy loss) and direction. The methodology of event discrimination in terms of these degrees of freedom was expanded and re?ned. Resolution and event classi?cation were based on analyses of cluster morphology parameters together with spectrometric, tracking and correlated derived quantities such as linear-energy-transfer (LET) and ratio cluster height to cluster path length.
关键词： Particle tracking detectors (Solid-state detectors),dE/dx detectors,Pixelated detectors and associated VLSI electronics,Heavy-ion detectors
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 16th International Conference on Group IV Photonics (GFP) - Singapore, Singapore (2019.8.28-2019.8.30)] 2019 IEEE 16th International Conference on Group IV Photonics (GFP) - Understanding the Sidewall Dependence of Loss for Ge-on-Si Waveguides in the Mid-Infrared
摘要： An empirical model for field-effect transistor (FET) based power detectors is presented. The electrical model constitutes a Volterra analysis based on a Taylor series expansion of the drain current together with a linear embedding small-signal circuit. It is fully extracted from S-parameters and IV curves. The final result are closed-form expressions for the frequency dependence of the noise equivalent power (NEP) in terms of the FET intrinsic capacitances and parasitic resistances. Excellent model agreement to measured NEP of coplanar access graphene FETs with varying channel dimensions up to 67 GHz is obtained. The influence of gate length on responsivity and NEP is theoretically and experimentally studied.
关键词： field-effect transistors (FETs),Volterra,terahertz detectors,microwave detectors,graphene,power detectors,Analytical model
更新于2025-09-23 15:21:01
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Operation and performance of microhexcavity pixel detector in gas discharge and avalanche mode
摘要： The Microhexcavity Panel (??Hex) is a novel gaseous micropattern particle detector comprised of a dense array of close-packed hexagonal pixels, each operating as an independent detection unit for ionizing radiation. It is a second generation detector derived from plasma panel detectors and microcavity detectors. The ??Hex is under development to be deployed as a scalable, fast timing (ns) and hermetically sealed gaseous tracking detector with high rate (> 100KHz∕cm2) capability. The devices reported here were fabricated as 16 × 16 pixel arrays of 2 mm edge-to-edge, 1 mm deep hexagonal cells embedded in a thin, 1.4 mm glass–ceramic wafer. Cell walls are metalized cathodes, connected to high voltage bus lines through conductive vias. Anodes are small, 457 μm diameter metal discs screen printed on the upper substrate. The detectors are filled with an operating gas to near 1 atm and then closed with a shut-off valve. They have been operated in both avalanche mode and gas discharge devices, producing mV to volt level signals with about 1 to 3 ns rise times. Operation in discharge mode is enabled by high impedance quench resistors on the high voltage bus at each pixel site. Results indicate that each individual pixel behaves as an isolated detection unit with high single pixel intrinsic efficiency to both ??s from radioactive sources and to cosmic ray muons. Continuous avalanche mode operation over several days at hit rates over 300 KHz∕cm2 with no gas flow have been observed. Measurements of pixel isolation, timing response, efficiency, hit rate and rate stability are reported.
关键词： Gas based radiation detectors,Particle detectors,Pixel detectors
更新于2025-09-23 15:21:01
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[IEEE 2020 International SAUPEC/RobMech/PRASA Conference - Cape Town, South Africa (2020.1.29-2020.1.31)] 2020 International SAUPEC/RobMech/PRASA Conference - Thin film photovoltaic module characterisation based in indoor and outdoor methods
摘要： This paper is the fifth in a series of articles on the basic physics of light yield nonproportionality in scintillators. Here, we compare and contrast the nonproportionality as registered by gamma rays and high-energy electrons. As has been noted in the past, these two types of data have different curve shapes (for plots of the light yield against electron or gamma energy). Herein, we show how the experimental gamma nonproportionality curve can be calculated from the electron response by accounting for the distribution of high energy electrons created by the gamma photon via the photoelectric interaction. Similarly, we measure and model the gamma-induced resolution as a function of energy and compare this data to predictions from our model. The utility of the model is explored using data acquired with the scintillators (Eu), GYGAG(Ce) and CsI(Na).
关键词： Gamma ray detectors,solid scintillation detectors,luminescence
更新于2025-09-23 15:21:01
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[IEEE 2019 8th International Congress on Advanced Applied Informatics (IIAI-AAI) - Toyama, Japan (2019.7.7-2019.7.11)] 2019 8th International Congress on Advanced Applied Informatics (IIAI-AAI) - Phase Type Special-Purpose Computer for Electroholography in Embedded Systems
摘要： This paper is the fifth in a series of articles on the basic physics of light yield nonproportionality in scintillators. Here, we compare and contrast the nonproportionality as registered by gamma rays and high-energy electrons. As has been noted in the past, these two types of data have different curve shapes (for plots of the light yield against electron or gamma energy). Herein, we show how the experimental gamma nonproportionality curve can be calculated from the electron response by accounting for the distribution of high energy electrons created by the gamma photon via the photoelectric interaction. Similarly, we measure and model the gamma-induced resolution as a function of energy and compare this data to predictions from our model. The utility of the model is explored using data acquired with the scintillators (Eu), GYGAG(Ce) and CsI(Na).
关键词： Gamma ray detectors,solid scintillation detectors,luminescence
更新于2025-09-23 15:21:01
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High-selectivity bandpass filter using six pairs of quarter-wavelength coupled lines
摘要： We present a 16-channel readout integrated circuit (ROIC) with nanosecond-resolution time to digital converter (TDC) for pixelated Cadmium Telluride (CdTe) gamma-ray detectors. The pixel array ROIC is the proof of concept of the pixel array readout ASIC for positron-emission tomography (PET) scanner, positron-emission mammography (PEM) scanner, and Compton gamma camera. The electronics of each individual pixel integrates an analog front-end with switchable gain, an analog to digital converter (ADC), configuration registers, and a 4-state digital controller. For every detected photon, the pixel electronics provides the energy deposited in the detector with 10-bit resolution, and a fast trigger signal for time stamp. The ASIC contains the 16-pixel matrix electronics, a digital controller, five global voltage references, a TDC, a temperature sensor, and a band-gap based current reference. The ASIC has been fabricated with TSMC m mixed-signal CMOS technology and occupies an area of mm. The TDC shows a resolution mm of 95.5 ps, a precision of 600 ps at full width half maximum W. In acquisition (FWHM), and a power consumption of mode, the total power consumption of every pixel is W. An equivalent noise charge (ENC) of at maximum gain and negative polarity conditions has been measured at room temperature.
关键词： positron emission tomography,low-power electronics,semiconductor radiation detectors,application specific integrated circuits,gamma-ray detectors,Analog-digital conversion,energy resolution
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Doped Layer Characterization Using Accurate Optical Modelling of Mid-Infrared Spectrometry
摘要： We present a 16-channel readout integrated circuit (ROIC) with nanosecond-resolution time to digital converter (TDC) for pixelated Cadmium Telluride (CdTe) gamma-ray detectors. The pixel array ROIC is the proof of concept of the pixel array readout ASIC for positron-emission tomography (PET) scanner, positron-emission mammography (PEM) scanner, and Compton gamma camera. The electronics of each individual pixel integrates an analog front-end with switchable gain, an analog to digital converter (ADC), con?guration registers, and a 4-state digital controller. For every detected photon, the pixel electronics provides the energy deposited in the detector with 10-bit resolution, and a fast trigger signal for time stamp. The ASIC contains the 16-pixel matrix electronics, a digital controller, ?ve global voltage references, a TDC, a temperature sensor, and a band-gap based current reference. The ASIC has been fabricated with TSMC m mixed-signal CMOS technology and occupies an area of mm. The TDC shows a resolution mm of 95.5 ps, a precision of 600 ps at full width half maximum W. In acquisition (FWHM), and a power consumption of mode, the total power consumption of every pixel is W. An equivalent noise charge (ENC) of at maximum gain and negative polarity conditions has been measured at room temperature.
关键词： positron emission tomography,low-power electronics,application speci?c integrated circuits,semiconductor radiation detectors,gamma-ray detectors,Analog-digital conversion,energy resolution
更新于2025-09-23 15:21:01
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Characterization of Si and SiC detectors for laser-generated plasma monitoring in short wavelength range
摘要： Silicon carbide detectors were employed to characterize the plasma produced by laser interaction with a double stream gas-pu? target source. A 10 Hz repetition rate Nd:YAG laser (1064 nm wavelength, 0.69 J pulse energy and 3 ns pulse duration) was employed to irradiate di?erent gas-pu? targets (Argon, Xenon and Sulfur hexa?uoride), at di?erent pressures (1–10 bar), emitting plasma radiation in di?erent wavelength ranges (ultraviolet, extreme ultraviolet and soft X-rays). The emission produced by the laser radiation was properly ?ltered (employing Titanium, Aluminium, Zirconium and Calcium ?uoride ?lters), to narrow down the broad-band emission of the generated plasma. The SiC detectors’ signals were compared with a calibrated traditional silicon detector evaluating their di?erences, i.e. taking into account the plasma stability, the time trace pro?le and the characteristics of the gas-pu? target source. The obtained results, which will be presented and discussed, allow to improve the geometry and con?guration of the SiC detectors avoiding saturation and charge recombination e?ects and getting a better proportionality to the energy and ?uence of the detected radiations.
关键词： X-ray detectors,Radiation monitoring,Detectors for UV, visible and IR photons,Plasma generation (laser-produced, RF, x ray-produced)
更新于2025-09-23 15:21:01
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Timepix in LEO Orbit onboard the VZLUSAT-1 Nanosatellite: 1-year of Space Radiation Dosimetry Measurements
摘要： The VZLUSAT-1 satellite, the first Czech CubeSat, was successfully launched on June 23, 2017, to a 510 km Sun-synchronous low-Earth orbit. It carries several scientific payloads including a Timepix detector as focal plane imager for the X-Ray telescope onboard. The Timepix detector contributes significantly to the satellite data collection, with more than 25 000 sampling acquisitions in the first year of deployment. Despite limitations of the satellite attitude control system, necessary for capturing X-Ray images of the Sun, the Timepix detector allows measuring the space radiation environment along the satellite orbit. As of September 2018, we conducted 33 whole-Earth mappings, recording radiation doses around the planet. Further, we show data from scans of the South Atlantic Anomaly and polar radiation horns, where the location and acquisition time were tailored to minimize event pile-up and particle track overlap. Since October 2017, the optics segment of the onboard X-Ray telescope was deployed, which exposed the Timepix detector unshielded to free open space. This change produced entirely new observations namely of low energy charged particles and a significant increase of measured particle flux. We also registered the effects of exposing the sensor to direct intense sunlight. We will summarize on the actual performance of the custom readout interface, which exceeds expectations in the constrained environment of the low-cost and low-powered CubeSat nanosatellite.
关键词： Particle detectors,On-board space electronics,X-ray detectors and telescopes,Space instrumentation
更新于2025-09-23 15:21:01
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Recent progress in high-performance photo-detectors enabled by the pulsed laser deposition technology
摘要： In the past decade, photo-detectors have been demonstrated to have very important applications in image sensing, optical communication, fire detection, environmental monitoring, space exploration, safety detection, and many other scientific research and industrial technology fields and are regarded as the key components of wearable devices. Compared to traditional fabrication approaches, pulsed-laser deposition (PLD)-grown materials for photo-detectors offer several merits. First, PLD is a clean physical vapor deposition approach. A stoichiometric amount of atoms can be transferred from the target to the substrate, avoiding complicated and potentially dangerous chemical reactions. Furthermore, the PLD process is carried out in a high-vacuum environment. Therefore, almost no contaminants, such as catalysts, precursors, surfactants and by-products, will be introduced. Also, the thickness of the films can be controlled by simply manipulating the energy and pulse number of the pulsed laser. Furthermore, the fabrication temperature is relatively low, which is available to deposit materials on various substrates, even flexible ones. Most importantly, PLD is a deposition technology with large area coverage, which can produce centimeter-scale thin films, the planar geometry of which has significant potential for compact device integration with modern semiconductor techniques. Consequently, this review introduces the recent advances on the materials, fabrication, and application of pulsed-laser deposition for a variety of high-performance photo-detectors from an overall perspective. Moreover, the challenges and future development trends are discussed.
关键词： wearable devices,fabrication,optoelectronics,applications,photo-detectors,PLD,pulsed-laser deposition,high-performance,materials
更新于2025-09-23 15:21:01