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Ion, electron and laser beams for Cultural Heritage investigations by Czech-Italian collaboration
摘要： An overview of physical investigations of cultural heritage samples using ion and laser beams performed in the frame of the international collaboration between the University of Messina (Italy) and the Nuclear Physics Institute-ASCR (Czech Republic) is presented. Solid samples are analysed in high vacuum using particle induced X-ray emission, Rutherford backscattering spectrometry, elastic recoil detection analysis, prompt γ activation analysis, nuclear reaction analysis, laser ablation, mass spectrometry, scanning electron microscopy, and many more. The elemental composition of the sample, the trace elements, the depth pro?les, the morphology and the comparison between samples and references are reported. Both electron and ion microbeams are employed to have details of the spatial distribution maps of elements of interest.
关键词： Mass spectrometers,X-ray detectors,X-ray ?uorescence (XRF) systems
更新于2025-09-23 15:21:01
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Calibration of CR-39 solid-state track detectors for study of laser-driven nuclear reactions
摘要： It is of particular interest to investigate nuclear fusion reactions generated by high-intensity lasers in plasma environments that are similar to real astrophysical conditions. We have experimentally investigated 2Hed; pT3H, one of the most crucial reactions in big bang nucleosynthesis models, at the Shenguang-II laser facility. In this work, we present a new calibration of CR-39 solid-state track detectors, which are widely employed as the main diagnostics in this type of fusion reaction experiment. We measure the dependence of the track diameter on the proton energy. It is found that the track diameters of protons with different energies are likely to be identical. We propose that in this case, the energy of the reaction products can be obtained by considering both the diameters and gray levels of these tracks. The present results would be very helpful for analyzing the 2Hed; pT3H reaction products recorded with the same batch of CR-39 solid-state track detectors.
关键词： Gray levels,Laser-driven nuclear reactions,CR-39 detectors,Big bang nucleosynthesis
更新于2025-09-23 15:21:01
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A mm <sup>3</sup> Fiber-Coupled Scintillator for In-Core Thermal Neutron Detection in CROCUS
摘要： The article presents the development, characterization and in-core testing of a miniature neutron detector for the investigation of highly localized in-core neutronics effects in the zero-power reactor CROCUS, operated at école Polytechnique fédérale de Lausanne (EPFL), Switzerland. A ZnS:6LiF screen, mixing inorganic scintillator and neutron converter, with a surface of 1 mm2 and a thickness of 0.2 mm was coupled with a silicon photomultiplier (SiPM) via a 10-m optical fiber. Analog read-out electronics were adopted in this prototype version to process the SiPM output signal. A first campaign was carried out to assess the detection system capabilities in terms of neutron detection and counting in mixed neutron-gamma radiation fields. The miniature detector was thoroughly characterized with a Pu-Be source installed in the CARROUSEL facility, and subsequently tested inside a control rod guide tube of the CROCUS reactor in different reactor conditions, i.e. at shutdown, startup and critical. The detector shows a linear response with the reactor power increase up to 6.5 W (i.e. around 108 cm-2·s-1 total neutron flux) and excellent neutron counting capabilities when compared to other localized detection systems available in CROCUS, such as miniature fission chambers and sCVD diamond detectors. In addition, the exposure of the miniature detector to a 60Co source with an activity of ～250 GBq, combined with the computation of the gamma flux in CROCUS with the Serpent 2 Monte Carlo code, confirmed the gamma insensitivity of the system in a mixed neutron-gamma field.
关键词： miniature neutron detector,CROCUS zero-power reactor,optical fiber devices,in-core neutron detectors,miniature scintillator devices
更新于2025-09-23 15:21:01
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1-D Metal-Dielectric-Metal Grating Structure as an Ultra-Narrowband Perfect Plasmonic Absorber in the Visible and Its Application in Glucose Detection
摘要： The need for an easy to fabricate perfect and narrowband light absorber in the visible range of electromagnetic (EM) spectrum has always been in demand for many scientific and device applications. Here, we propose a metal-dielectric-metal (MDM) 1-D grating plasmonic structure as a perfect narrow band light absorber in the visible and its application in glucose detection. The proposed structure consists of a 1- D grating of gold on the top of a dielectric layer on a gold film. Optimization for dielectric grating index (n), grating thickness (t), grating width (W), and grating period (P) has been done to improve the performance of plasmonic structure by calculating its quality factor and figure-of-merit (FOM). The optimized plasmonic structure behaves as a perfect narrowband light absorber. The flexibility to work at a specific wavelength is also offered by the proposed structure through an appropriate selection of the geometrical parameters and refractive index of the dielectric grating. The equivalent RC model is used to understand different components of the proposed structure on the optical response. The absorption response of the structure is invariant to the incident angle. Moreover, the calculated absorbance of the proposed plasmonic structure is ~ 100% with a narrow full-width half maxima (FWHM) of ~ 2.8 nm. We have numerically demonstrated a potential application of the proposed MDM absorber as a plasmonic glucose sensor in the visible range with detection sensitivity in the range of 140 to 195 nm/RIU.
关键词： Metal-dielectric-metal,Plasmons,Glucose detection,Optical sensors,Optical detectors,LC equivalent circuit
更新于2025-09-23 15:21:01
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A hydrothermally synthesized MoS <sub/>2(1a??x)</sub> Se <sub/>2x</sub> alloy with deep-shallow level conversion for enhanced performance of photodetectors
摘要： Photoelectric detectors based on binary transition metal chalcogenides have attracted widespread attention in recent years. However, due to the high-temperature synthesis of binary TMD, high-density deep-level defect states may be generated, leading to poor responsiveness or a long response time. Besides, the addition of an alloy will change the DLDSs from deep to shallow energy levels caused by S vacancies. In this paper, MoS2(1?x)Se2x nanostructures were synthesized by a hydrothermal method, and a novel type of photodetector was fabricated by using the synthesized material as a light sensitive material. The MoSSe-based photodetector not only has a high photocurrent, but also exhibits a wide spectral response in the range of 405 nm to 808 nm. At the same time, it can achieve a responsivity of 1.753 mA W?1 under 660 nm laser irradiation of 1.75 mW mm?2. Therefore, this work can be considered as a method of constructing a new type of photodetector with a simple process and low cost.
关键词： MoS2(1?x)Se2x,photoelectric detectors,photodetector,transition metal chalcogenides,hydrothermal synthesis
更新于2025-09-23 15:21:01
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Large Angle Optical Access in a Sub-Kelvin Cryostat
摘要： The development of lens-antenna-coupled aluminum-based microwave kinetic inductance detectors (MKIDs) and on-chip spectrometers needs a dedicated cryogenic setup to measure the beam patterns of the lens-antenna system over a large angular throughput and broad frequency range. This requires a careful design since the MKID has to be cooled to temperatures below 300 mK to operate effectively. We developed such a cryostat with a large opening angle θ = ± 37.8? and an optical access with a low-pass edge at 950 GHz. The system is based upon a commercial pulse tube cooled 3 K system with a 4He–3He sorption cooler to allow base temperatures below 300 mK. A careful study of the spectral and geometric throughput was performed to minimize thermal loading on the cold stage, allowing a base temperature of 265 mK. Radio-transparent multi-layer-insulation was employed as a recent development in ?lter technology to ef?ciently block near-infrared radiation.
关键词： Lens-antenna,Kinetic inductance detectors,Cryogenic optics,Cryostat
更新于2025-09-23 15:21:01
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Simulation of 3D-Silicon sensors for the TIMESPOT project
摘要： The experimental conditions in future High Luminosity LHC experiments require new detector systems with increased performances compared to the current state of the art. In this context, increasing spacial resolution and including time measurement with a resolution of less than 50 ps for particle tracking systems can avoid false track reconstruction due to event pileup. For this kind of future tracking detectors the 3D silicon sensor technology appears as a good option. In this context the TIMESPOT initiative was launched. Concerning the development of the sensor, different geometrical solutions have been explored and simulated to optimize the timing response of the single pixel sensor using Sentaurus TCAD. The configuration with the best electric field characteristics for timing was selected for signal simulation. In order to compensate the very time-consuming behavior of TCAD simulations, a faster charge transport simulator with TCAD and Geant4 support is under development. Further sensor configurations, including a first primitive capacitive and resistive load, were also simulated and evaluated. This paper shows a general overview of the project with particular attention to the silicon sensor development. First results are presented.
关键词： Fast timing tracking,3D silicon sensors,Tracking detectors,sensor simulation,TCAD
更新于2025-09-23 15:21:01
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First experience with Belle II Aerogel RICH detector
摘要： The Aerogel Ring-Imaging Cherenkov (ARICH) detector provides particle identification information in the forward endcap part of Belle II. It efficiently separates charged kaons from pions for momenta between 0.5 GeV/c and 4.0 GeV/c. Optical photons are emitted in a double layer aerogel radiator and detected by Hybrid Avalanche PhotoDetectors. ARICH was installed in Belle II at the end of 2017, the first phase of a complex detector calibration of electronic signals and preparation for physics signals calibration has been successfully concluded. Cherenkov rings, created by cosmic rays as well as by charged particles from beam collisions, have been observed. The kaon identification efficiency using D±? decays has been studied and its calibration is expected by the end of the commissioning phase when sufficient data is available.
关键词： Cherenkov detectors,Calibration,Particle identification,Optical photons,Beam collisions
更新于2025-09-23 15:21:01
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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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Macro Pixel ASIC (MPA): the readout ASIC for the pixel-strip (PS) module of the CMS outer tracker at HL-LHC
摘要： The CMS tracker at HL-LHC is required to provide prompt information on particles with high transverse momentum to the central Level 1 trigger. For this purpose, the innermost part of the outer tracker is based on a combination of a pixelated sensor with a short strip sensor, the so-called Pixel-Strip module (PS). The readout of these sensors is carried out by distinct ASICs, the Strip Sensor ASIC (SSA), for the strip layer, and the Macro Pixel ASIC (MPA) for the pixel layer. The processing of the data directly on the front-end module represents a design challenge due to the large data volume (30720 pixels and 1920 strips per module) and the limited power budget. This is the reason why several studies have been carried out to ?nd the best compromise between ASICs performance and power consumption. This paper describes the current status of the MPA ASIC development where the logic for generating prompt information on particles with high transverse momentum is implemented. An overview of the readout method is presented with particular attention on the cluster reduction, position encoding and momentum discrimination logic. Concerning the architectural studies, a software test bench capable of reading physics Monte-Carlo generated events has been developed and used to validate the MPA design and to evaluate the MPA performance. The MPA-Light is scheduled to be submitted for fabrication this year and will include the full analog functions and a part of the digital logic of the ?nal version in order to qualify the chosen VLSI technology for the analog front-end, the module assembly and the low voltage digital supply.
关键词： Digital electronic circuits,Data reduction methods,Pixelated detectors and associated VLSI electronics
更新于2025-09-23 15:21:01