- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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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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New approach to raising the resolution of position sensitive detector with moving current-voltage characteristic
摘要： Position sensitive detectors (PSD) are widely applied for determining the coordinate of an optical signal and continuously tracking it. Currently, studies concerned with the possibility of further raising the spatial resolution of PSDs remain topical. In this paper, we present the results obtained in reaching an ultrahigh resolution for a device based on the PSD Multiscan with an integral operation principle which fundamentally differs from that of the lateral PSD. The PSD Multiscan design is based on an array of back-to-back photodiodes. Its optical signal coordinate read-out is formed via the moving current-voltage characteristic of the sensor directly on the PSD as an output potential proportional to the coordinate of the optical spot median. This measurement principle provides a continuous comparison of near-equal photocurrents, which maintains a high signal-to-noise ratio over the whole sensing area. The absence of computational operations in electronic circuits of the PSD Multiscan makes it possible to introduce a nonlinear amplifier element, which substantially improves the resolution of the device based on the sensor developed in the study (as good as 0.05 μm). It has been shown that the resolution remains high for detectors with different lengths and is independent of the position of the optical spot on the sensing area.
关键词： Analogue electronic circuits,Photon detectors for UV, visible and IR photons (solid-state) (PIN diodes, APDs, Si-PMTs, G-APDs, CCDs, EBCCDs, EMCCDs etc),Optical detector readout concepts
更新于2025-09-23 15:21:01
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Characteristics of an organic photodetector with a conjugated donor and non-fullerene acceptor for indirect X-ray detection
摘要： In this study, an organic photodetector with a small band-gap donor, PBDB-T, and a non-fullerene acceptor, ITIC, was investigated as the active element in an indirect imaging system using a scintillator of the detector for indirect X-ray imaging. Compared with the common organic photodetector with a P3HT:PC70BM active layer, higher conversion e?ciencies can be expected, because the proposed detector is advantageous for visible-light absorption and carrier transport. The absorption peak of the PBDB-T:ITIC layer was located at 640 nm and was not well-matched with the emission properties of a CsI(Tl) scintillator. Therefore, a ZnSe(Te) scintillator with an emission peak at 620 nm was also tested. Compared with the P3HT:PC70BM detector, the ZnSe(Te)-coupled detector with the PBDB-T:ITIC = 1:1 active layer was 191% higher in collected current density (CCD) and 205% higher in sensitivity. The frequency response was measured with a 520 nm green LED. The detector with the PBDB-T:ITIC layer showed the -3 dB cut-o? frequency of 31.5 kHz, which was higher than the cut-o? frequency of the P3HT:PC70BM detector.
关键词： Materials for solid-state detectors,Photon detectors for UV, visible and IR photons (solid-state) (PIN diodes, APDs, Si-PMTs, G-APDs, CCDs, EBCCDs, EMCCDs, CMOS imagers, etc),X-ray detectors
更新于2025-09-12 10:27:22
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Photon detection system designs for the Deep Underground Neutrino Experiment
摘要： The Deep Underground Neutrino Experiment (DUNE) will be a premier facility for exploring long-standing questions about the boundaries of the standard model. Acting in concert with the liquid argon time projection chambers underpinning the far detector design, the DUNE photon detection system will capture ultraviolet scintillation light in order to provide valuable timing information for event reconstruction. To maximize the active area while maintaining a small photocathode coverage, the experiment will utilize a design based on plastic light guides coated with a wavelength-shifting compound, along with silicon photomultipliers, to collect and record scintillation light from liquid argon. This report presents recent preliminary performance measurements of this baseline design and several alternative designs which promise signi?cant improvements in sensitivity to low-energy interactions.
关键词： Neutrino detectors,Photon detectors for UV, visible and IR photons (solid-state),Scintillators and scintillating ?bres and light guides,Noble liquid detectors (scintillation, ionization, double-phase)
更新于2025-09-11 14:15:04
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Design and development of in-situ temperature dependent diffuse reflectance spectroscopy setup
摘要： Recent advancements in the commercialization of In-situ temperature dependent optical spectrophotometer have shown potential not only for the recording of optical absorption spectra but also towards the exploration of physical insights and the understanding of instrument handling. Measurement on the effect of the variation of temperature onto optical properties mainly for semi-conducting oxides helps to explore the functioning and play a crucial role towards the development of optoelectronic devices. Being a non-contact, non-destructive technique temperature dependent DRS Setup can be used as a primary tool for the in-situ characterization of optical properties. This appreciation prompts us to design and develop an instrument that can add the ability of in-situ temperature dependent DRS above room temperature. The setup, developed and reported here, is able to accurately characterize the samples from room temperature to 500 K, which is most suitable range for the characterization of semiconducting materials, which is in the heard of current materials’ research. The present study provides the economical alternatives to the existing designs used for this purpose without compromising on the reliability of the obtained data. The in-house developed set up is found to be efficiently used for the analysis of various properties of the samples and will open up the instrumental development and commercialization of the temperature dependent DRS technique.
关键词： Detection of defects,Photon detectors for UV, visible and IR photons (solid-state),Overall mechanics design (support structures and materials, vibration analysis etc),Spectrometers
更新于2025-09-09 09:28:46
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Study of silicon photomultiplier performance in external electric fields
摘要： We report on the performance of silicon photomultiplier (SiPM) light sensors operating in electric field strength up to 30 kV/cm and at a temperature of 149 K, relative to their performance in the absence of an external electric field. The SiPM devices used in this study show stable gain, photon detection efficiency, and rates of correlated pulses, when exposed to external fields, within the estimated uncertainties. No visible damage to the surface of the devices was caused by the exposure.
关键词： Cryogenic detectors,Double-beta decay detectors,Photon detectors for UV, visible and IR photons (solid-state) (PIN diodes, APDs, Si-PMTs, G-APDs, CCDs, EBCCDs, EMCCDs etc),Noble liquid detectors (scintillation, ionization, double-phase)
更新于2025-09-04 15:30:14