- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Addressing of imperfection of a hybrid pixel sensor for X-ray detection with a circuit for charge sharing cancellation implemented
摘要： A developing trend in the design of event-driven sensors for X-ray detection are hybrid pixel detectors working in the single photon counting mode. The factors limiting detector performance, especially for small pixel sizes, include among others, mismatch of circuit components due to process variations, electronic noise and charge sharing. Charge sharing in a hybrid pixel detector occurs when the charge generated in X-ray photon interaction with a sensor is collected by more than one pixel. Charge sharing effect may significantly impair the detector energy resolution and result in counting extra events or missing some of the events. The impact of the charge sharing increases with a decrease of the pixel sizes. The small pixel size is a desired feature of a novel hybrid X-ray detector, as it allows better spatial resolution and helps to overcome the high count rate limits by accepting more photons per unit area. Therefore, the charge sharing effect must be dealt with by a dedicated readout IC or processed off-chip. Minimization of the analog parameters dispersion in the pixel matrix is crucial for the circuits designed for charge sharing cancellation. The chip’s sensitivity to the analog parameters spread and mitigation of the performance achieved with the digital correction blocks are studied. The DC offsets and gains spread can be optimized using correction circuits and dedicated trimming algorithms. Detection efficiency in case of charge sharing for the corrected and uncorrected pixel matrix is addressed. The simulation results as well as pencil beam measurements using synchrotron radiation are presented.
关键词： Front-end electronics for detector readout,Analogue electronic circuits,Digital electronic circuits
更新于2025-09-23 15:23:52
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X-ray imaging demonstration of glass GEM detector with dynamic time-over-threshold-based readout
摘要： Large-scale detection is one of the important roles for gaseous detectors to play in high-energy physics. In many cases, energy resolving multi-channel readout is required. Recent micro-pattern gaseous detectors (MPGDs) have finer pitches or pixels; hence, large-sized detectors have thousands of readout channels. In those cases, it becomes important to reduce the scale and complexity of the readout circuit while keeping its energy resolving capability. The signal processing technique called dynamic time-over-threshold (dynamic ToT, dToT) achieves both the good conversion linearity from analog to digital signal and the compact circuit scale compared with conventional analog-to-digital-converter (ADC)-based readout. In this study, we developed and demonstrated a dToT-based readout circuit for glass gas electron multiplier (glass GEM, G-GEM). The readout circuit showed better linearity than that of normal ToT. We demonstrated the readout circuit by X-ray imaging with the charge-division scheme. The good linearity of the readout circuit enabled imaging over a 100 × 100 mm2 area with small distortion. We expect that the dToT-based readout would be a promising candidate for the future readout of large-scaled MPGDs.
关键词： Digital electronic circuits,Electronic detector readout concepts (gas, liquid),Analogue electronic circuits,Micropattern gaseous detectors (MSGC, GEM, THGEM, RETHGEM, MHSP, MICROPIC, MICROMEGAS, InGrid, etc)
更新于2025-09-23 15:23:52
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Evaluation of the optical cross talk level in the SiPMs adopted in ASTRI SST-2M Cherenkov Camera using EASIROC front-end electronics
摘要： ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana), is a flagship project of the Italian Ministry of Education, University and Research whose main goal is the design and construction of an end-to-end prototype of the Small Size of Telescopes of the Cherenkov Telescope Array. The prototype, named ASTRI SST-2M, will adopt a wide field dual mirror optical system in a Schwarzschild-Couder configuration to explore the VHE range of the electromagnetic spectrum. The camera at the focal plane is based on Silicon Photo-Multipliers detectors which is an innovative solution for the detection astronomical Cherenkov light. This contribution reports some preliminary results on the evaluation of the optical cross talk level among the SiPM pixels foreseen for the ASTRI SST-2M camera.
关键词： Front-end electronics for detector readout,Gamma detectors,Cherenkov detectors,Gamma telescopes
更新于2025-09-23 15:23:52
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The LXe calorimeter and the pixelated timing counter in the MEG II experiment
摘要： The MEG experiment is to look for a lepton flavor violating μ + → e+γ decay with an unprecedented sensitivity, and we set an upper limit of the branching ratio for this decay, 5.7 × 10?13 at 90% C.L. in 2013 which is a twenty times more stringent limit than the previous experiment, MEGA. Since the sensitivity improvement was limited by the accidental background, we have considered the major detector upgrade. A proposal was submitted to PSI committee, and was approved in 2013, which aims at a sensitivity enhancement of one order of magnitude compared with the current MEG experiment. Here mainly two components of the MEG detector will be introduced, a γ-ray calorimeter with 900 L of liquid xenon (LXe), and a pixelated timing counter. The LXe detector will be improved by increasing the granularity at the incident face, by replacing the current PMTs with a larger number of smaller photosensors (MPPC) and optimizing the photosensor layout also on the lateral faces. A new highly segmented, fast timing counter array will replace the old system to allow improved timing resolution capabilities.
关键词： visible and IR photons (solid-state),HPG,Large detector systems for particle and astroparticle physics,Photon detectors for UV,CZT,Gamma detectors (scintillators,HgI etc),Timing detectors
更新于2025-09-23 15:23:52
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Development of the readout system for a time projection chamber prototype
摘要： A new GEM-TPC prototype with a laser calibration system is being designed to study the key issues of high-precision track detection whose aimed spatial resolution is better than 100 μm. Meanwhile, a readout system with scalability for the TPC is also being developed. Design of the readout system is based on the architecture of front-end ASICs and commercial ADCs for its advantages at high count rates. Given the requirement of several hundred channels, the system is composed of multiple front-end cards and DAQ boards. The DAQ boards are daisy-chained via bidirectional optical fibers, which transmit clock, trigger, data and control signals simultaneously. To achieve timing synchronization, the GigaBit Transceiver (GBT) firmware is employed to ensure fixed latency between the boards. This paper is focused on the design and setup of the DAQ system, including clock structure, trigger alignment, high-speed data acquisition, etc. The DAQ system consisting of 512 channels has been built, and tests have proved that the entire system works correctly and meets the expected requirements.
关键词： Trigger concepts and systems (hardware and software),Electronic detector readout concepts (gas, liquid),Modular electronics,Data acquisition concepts
更新于2025-09-23 15:22:29
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[IEEE 2018 18th International Symposium on Communications and Information Technologies (ISCIT) - Bangkok, Thailand (2018.9.26-2018.9.29)] 2018 18th International Symposium on Communications and Information Technologies (ISCIT) - Weapon Detector System by Using X-ray Image Processing Technique
摘要： The images in the research were obtained from the internet because there is no x-ray camera. After preparing images, the next step is to test that the evaluation used to analyze the suspicious images. The images were detected by Canny Edge Detector algorithm that consists of four steps that started by smoothing the images with a Gaussian filter to eliminate interfering signals. Then, it calculated magnitude and orientation of gradient. Non-maxima Suppression and Gradient Magnitude were used to create thinner edges. The last step is double threshold algorithm to identify edge pixels and connect the edges by optimizing image recognition technique. When detecting a suspicious object, the system would send the notification. The result of this project is that the template matching algorithm was 80% accurate.
关键词： Detector,Vehicle,X-ray,Technique,Weapon
更新于2025-09-23 15:22:29
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Study on Thallium bromide Radioactive Detector
摘要： Thallium bromide (TlBr) is a compound semiconductor material, which can be used for X-ray and gamma-ray detectors and can be used at room temperature. It has excellent physical properties, high atomic number and density, wide bandgap (B=2.68 eV), and low ionization energy. Compared with other X-ray and gamma-ray detection materials, TlBr devices have high detection efficiency and excellent energy resolution performance. So TlBr is suitable for housing in small tubes or shells, and it can be widely used in nuclear material measurement, safeguards verification, national security, space high-energy physics research and other fields. Based on the fabrication of TlBr prototype detector, this paper focuses on the device fabrication and signal acquisition technology. Gamma-ray spectrum measurements and performance tests are carried out with AM-241 radioactive source. The results show that the special photoelectric peak of 59.5 keV is clearly visible, and the optimal resolution is 4.15 keV (7%).
关键词： Compound semiconductor,Safeguards verification,TlBr detector
更新于2025-09-23 15:22:29
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Frequency shift of an optical cavity mode due to a single-atom motion
摘要： Using quantum coherence effects, we have developed a new technique of detection of motion of single atoms or ions in an optical cavity. We have theoretically demonstrated that the presence of a single atom or ion inside cavity leads to a shift in cavity frequency and phase of transmitted probe beams. It has been shown by the use of EIT technique, the change of the phase is extremely sensitive to probe detuning in the vicinity of resonance frequency and can be in the order of 10?4.
关键词： optical cavity,frequency shift,Single-atom detector,phase shift,quantum coherence
更新于2025-09-23 15:22:29
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The CMS Beam Halo Monitor electronics
摘要： The CMS Beam Halo Monitor has been successfully installed in the CMS cavern in LHC Long Shutdown 1 for measuring the machine induced background for LHC Run II. The system is based on 40 detector units composed of synthetic quartz Cherenkov radiators coupled to fast photomultiplier tubes (PMTs). The readout electronics chain uses many components developed for the Phase 1 upgrade to the CMS Hadronic Calorimeter electronics, with dedicated firmware and readout adapted to the beam monitoring requirements. The PMT signal is digitized by a charge integrating ASIC (QIE10), providing both the signal rise time, with few nanosecond resolution, and the charge integrated over one bunch crossing. The backend electronics uses microTCA technology and receives data via a high-speed 5 Gbps asynchronous link. It records histograms with sub-bunch crossing timing resolution and is read out via IPbus using the newly designed CMS data acquisition for non-event based data. The data is processed in real time and published to CMS and the LHC, providing online feedback on the beam quality. A dedicated calibration monitoring system has been designed to generate short triggered pulses of light to monitor the efficiency of the system. The electronics has been in operation since the first LHC beams of Run II and has served as the first demonstration of the new QIE10, Microsemi Igloo2 FPGA and high-speed 5 Gbps link with LHC data.
关键词： Cherenkov and transition radiation,Front-end electronics for detector readout,Beam-line instrumentation (beam position and profile monitors; beam-intensity monitors; bunch length monitors)
更新于2025-09-23 15:22:29
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PEDOT:PSS temperature sensor ink-jet printed on paper substrate
摘要： In this work we present an ink-jet printed temperature sensor consisting of PEDOT:PSS printed on paper suitable for packaging, flexible electronics and other printed applications. The substrate showed to have a large influence on both the resistance as well as the temperature sensitivity of the PEDOT:PSS ink. This effect is most likely due to NaCl content in the photo paper coating, which reacts with the PEDOT:PSS. The temperature coefficient of a prepared device of α = ?0.030 relative to room temperature (22°C) was measured, which is higher than compared to for example Silicon α = ?0.075.
关键词： Manufacturing,Detector design and construction technologies and materials
更新于2025-09-23 15:22:29