Search

Spatial‐variant micro/nano‐structures are widely utilized in metasurfaces to modulate optical wave‐fronts into arbitrary shapes, performing as a new generation of flat optics. To flexibly fabricate micro/nano‐structures in real time, an optical Fourier transform system modulated by a diaphragm and a binary optical element (BOE) is proposed. Theoretical analysis shows that light field at image plane is a multiple result of twice Fourier transform of diaphragm and BOE's transmission field, with its amplitude and phase distribution independently manipulated by diaphragm and BOE. Inversely, diaphragm and BOE can be designed to get customized interference fields, where four fields with different vectors are generated for instance. Utilizing these four fields for time division multiplexing exposure, fringes inside circle/ring shapes with variant orientations are produced in photoresist film. Furthermore, multiple spatial variant fields can be obtained simultaneously while more symmetric distributed apertures acted as diaphragm, which shows great potential for the fabrication of segmented or interleaved spatial‐variant micro/nano‐structures in addition. [ABSTRACT FROM AUTHOR]

Achieving the high-precision control of cable-driven parallel robots (CDPRs) is complex because of their structural properties. In this paper, a quintessential redundant CDPR is designed as the research subject, and a continuous switching sliding mode controller based on workspace vision is implemented to enhance the accuracy and stability of trajectory tracking. In addition, a virtual prototype of the CDPR with uncertainties is created in the simulation analysis software ADAMS, and co-simulation is performed with the control system designed in Simulink to validate the effectiveness of the proposed control strategy. Furthermore, a CDPR platform is established for trajectory tracking experiments using the visual-based position feedback method. The trajectory tracking performance with the three control schemes is then evaluated. The experimental results show that the continuous switching sliding mode control algorithm can significantly decrease trajectory tracking errors and exhibit superior trajectory tracking performance compared to the other control strategies. [ABSTRACT FROM AUTHOR]

Nickel‐copper‐zinc (NiCuZn) spinel ferrites have attracted intensive research owing to their unique magnetic properties and low co‐fire temperature. Combustion synthesis has been viewed as a promising protocol for the large‐scale fabrication of NiCuZn spinel ferrites. However, the spinel ferrites prepared by this method usually suffer from limited saturation magnetization and high coercivity due to their large size, which will impose detrimental harmonics on electrical equipment (e. g. transformer, motor, etc.). To address these issues, highly porous NiCuZn spinel ferrite hierarchies were prepared within several hours through a modified solution combustion method, using glucose and ammonium nitrate as the fuel and combustion enhancer, respectively. The as‐obtained NiCuZn spinel ferrite hierarchies show excellent magnetic properties with a high saturation magnetization up to 62.61 emu/g and a low coercivity of 9.6 Oe thanks to the rational distribution of cations and grain size. More importantly, this method also allows various modifications (heteroatom doping) and large‐scale applications, which may be promising for the fabrication of high‐performance soft magnets for electrical equipment. [ABSTRACT FROM AUTHOR]

Cu2O with a cubic structure was prepared by a water bath method, and then a Cu2O/Cu2S core–shell material was obtained by the redox reaction of Cu2O and Na2S with the prepared cubic Cu2O as a template and Na2S·9H2O solution as the reaction solution. At the same time, the effect of sulfidization time on the Cu2O/Cu2S structure and photohydrogen production performance was studied. The structure of the samples was further confirmed and characterized through SEM, HRTEM, XRD and XPS. The photohydrogen production properties of the Cu2O/Cu2S composites with different morphologies were tested. The flower-shaped hollow structure of Cu2O/Cu2S can be obtained by proper sulfidization, and the hydrogen production can reach 1076.95 μmol g−1 after 5 h of illumination. Then, through photocurrent response and impedance spectrum tests and DFT calculations, it is proved that the Cu2O/Cu2S heterostructure can effectively improve the photoresponse ability and carrier transport properties. It was confirmed that the interfacial charge transfer in Cu2O/Cu2S helped increase the photocatalytic hydrogen production performance. [ABSTRACT FROM AUTHOR]

In view of the high cost and low efficiency of tetracycline oxidation treatment, SiC/CdS composites were synthesized and the degradation performance of SiC/CdS for tetracycline was studied. In addition, the effects of CdS with different mass ratios and pH values on tetracycline degradation performance and the degradation mechanism were discussed. It was demonstrated that the degradation effect of SiC/CdS composites was significantly higher than that of SiC. In particular, the SiC/CdS-0.5 composite had the best degradation effect, and 78% tetracycline could be degraded within 2 h. The degradation rate constant of SiC/CdS-0.5 was 0.00969 min−1. The catalytic mechanism of SiC/CdS was evaluated by density functional calculations. In addition, the TPV relaxation curve and the free radical catalytic structure of the samples indicated that holes were the active species that played a key role in the degradation of tetracycline by SiC/CdS, while hydroxyl radicals ˙OH and superoxide radicals played a supporting role. This work provides good guidance and reference for the manufacture of efficient tetracycline degradation catalysts. [ABSTRACT FROM AUTHOR]

Fast timing detector is widely used for its picosecond (ps)-level timing resolution, such as Photek-PMT210 with about 50 ps at single-photon electron (SPE) mode. The time characteristics of these types of fast timing photodetectors include rise time, fall time, and electron transit time (TT) of the output signal. The test results of fast timing detector are affected by the light 7 source, the electronic device board, the data acquisition (DAQ) system, and so on. In this article, some comparative test results will be shown and discussed on the factors affecting the performance of fast timing detector. [ABSTRACT FROM AUTHOR]

The photomultiplier tube (PMT) and silicon photomultiplier (SiPM) of small areas have the characteristics of fast time response, suitable for the detection of fast and extremely weak light signals, and the transit time spread (TTS) can be on the picosecond scale. The test system is generally divided into two types: one is the direct acquisition of the waveform (DAW), (DAW such as the high-sampling oscilloscope), and the other is an indirect acquisition of the waveform (IDAW). In this article, both DAW and IDAW will be used to carry out the comparative test of ultra-fast photodetectors to complete the calibration of the performance of ultra-fast detectors and the study on time test systems. This will be helpful for beam experiments to be carried out in the laboratory and provide effective support for the development of domestic fast PMT. [ABSTRACT FROM AUTHOR]

The load of a distribution transformer can be daily or seasonal fluctuant, which submits the transformer to the risk of overload through thermal stress. In this research, it is demonstrated that the aramid-enhanced cellulose in natural ester, as a high-temperature insulation system, is a solution by which the overload capability of a transformer can be improved. First, the thermal and ageing model stipulated in IEEE C57.91 Annex G, which was proposed to evaluate the Kraft and thermally upgraded Kraft, has been modified to incorporate the ageing rate benchmark derived from Arrhenius law, so the improved model can now cover various combinations of insulation systems. The top liquid temperatures, hot spot temperatures and equivalent ageing factors of transformers with aramid-enhanced cellulose in natural ester and Kraft in mineral oil under different load scenarios generated from field loading data were analyzed. The results showed that the overloading capability of the transformer with aramid-enhanced cellulose was improved, as its equivalent ageing factor was 13 percent of the equivalent ageing factor of the transformer with Kraft under the heavy overload scenario. Furthermore, an overloading test and field test were also conducted for a prototype transformer with aramid-enhanced cellulose and natural ester. The measured top liquid temperature and hot spot temperature and the calculated equivalent ageing factor after the overloading test verified that the transformer with aramid-enhanced cellulose operated well below the safety thresholds. Additionally, the results from the transformer upon installation in the field proved that the transformer also operated well under an overloading status. [ABSTRACT FROM AUTHOR]

In the past decade, a type of micro-channel-plate based photomultiplier tubes (MCP-PMT) with fast-timing resolution, also called fast-timing PMT(FPMT), has attracted considerable attention in many fields for its single-photon detection capability, good timing performance and magnetic insensitivity. The Silicon Photo-multiplier (SiPM) is another kind of newly developed photodetector with comparable performance to the FPMT. More attention was paid to the single photon time resolution of the photodetectors. However, with the improvement of the temporal performance requirements of photodetectors, the time resolution limit of photodetectors determine the limits of time performance improvement, which worth investigating. In this manuscript, a femtosecond laser is used to calibrate the time resolution limit of FPMT and SiPM. The time resolution limit of FPMT is measured to be 480.4 fs. In addition, the temporal performance of FPMT from single photon to multi-photons under femtosecond laser is also investigated. The time resolution limit of SiPM is measured to be 2.68 ps. • A femtosecond laser has been used for the first time to measure the time performance of ultrafast optoelectronic devices. • MCP-PMT achieves multi-photon time resolution on the femtosecond scale using femtosecond lasers. • The multiphoton time resolution of SiPM is less than 3 ps using femtosecond lasers. • The temporal performance of MCP-PMT under femtosecond laser is shown as a function of photon number. [ABSTRACT FROM AUTHOR]

Partial discharge acoustic detection is an important monitoring tool for power transformer diagnosis, which was traditionally performed by mounting the piezoelectric transducers on the oil tank surface. The disadvantage of partial discharge acoustic detection is its low sensitivity when partial discharge occurs inside the winding, which greatly compromises the value of partial discharge acoustic detection. Fiber optic sensors that can be deployed within power transformer are expected to be a potential solution. In this research, we used a Sagnac fiber sensor system built in lab to investigate the benefits of using fiber optic sensor for partial discharge acoustic detection. Acoustic pulses were induced in oil outside the winding and in oil duct inside the winding of a single phase 50 kV transformer. Although both fiber optic sensor and piezoelectric sensor can effectively detect the acoustic pulses outside the winding, fiber optic sensor gained a much better sensitivity over piezoelectric transducer to detect the acoustic pulses originated inside the winding. We envisage that the proposed fiber sensor can be deployed in power transformers to significantly enhance the detection performance of acoustic emission induced by partial discharge. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nickel-copper-zinc (NiCuZn) ferrites were prepared by a facile blowing-combustion method. • Variation of zinc content with temperature was investigated through inductive coupled plasma (ICP). • The effect of sintering temperatures on structural and magnetic properties of NiCuZn ferrites were investigated. We report the fabrication of nickel-copper-zinc (NiCuZn) ferrites via a facile blowing-combustion method, where the grain size and morphology can be readily controlled by adjusting the sintering temperature. The effect of sintering temperatures on the structural evolution as well as the magnetic properties of the NiCuZn ferrites was systematically studied. It's found that the Zn elemental content is highly dependent on the sintering temperature and would undergo evaporation when annealing at 800 °C, which consequently greatly affects the magnetic properties of NiCuZn ferrites. [ABSTRACT FROM AUTHOR]

Spinel ferrites have been widely used in various fields, among which nickel‐zinc (NiZn) ferrites have drawn much attention due to their high electrical resistivity as well as low eddy current loss. To accommodate highly‐integrated modern electronic devices, the preparation methods for nano/micro‐sized NiZn ferrites have been widely discussed. Nevertheless, these current synthesis routes are usually cost/time‐consuming, which hinders their large‐scale production for practical applications. Herein, we present a facile, low‐cost synthesis strategy for NiZn ferrites (NixZn1−xFe2O4, x=0, 0.25, 0.5, 0.75 and 1) through a blowing‐combustion method. The effect of Ni/Zn molar concentration on the structure, morphology as well as magnetic properties has been thoroughly investigated through X‐ray diffraction, Raman spectroscopy, scanning electron microscopy and vibrating sample magnetometer. Thanks to the synergetic effect of the pure phase and moderate Ni molar concentration, the Ni0.75Zn0.25Fe2O4 shows an enhanced saturation magnetization of 44.98 emu/g. More importantly, this blowing‐combustion method may also be commonly applied to other spinel ferrites with different stoichiometric ratios and heteroatom doping. [ABSTRACT FROM AUTHOR]

North Night Vision Tech. Ltd.(NNVT) supplied 15,000 pieces of 20-inch Microchannel plate photomultiplier tubes (MCP-PMTs) with high detective efficiency and light detection coverage for Jiangmen Underground Neutrino Observatory (JUNO) experiment for neutrino detection. The uniformity of the large-area PMT is a very important parameters, it directly affects the detective efficiency when the light illuminates on the PMT photocathode. The performances including the uniformity of the MCP-PMTs should be tested carefully before transaction and transportation in NNVT. Therefore a facility with high test efficiency and high automation is necessary to be designed and constructed to monitor the uniformity of 20-inch MCP-PMTs. In this paper, we describe and compare three development stages and methods of the uniformity scanning platform and the uniformity result of all MCP-PMTs are presented. [ABSTRACT FROM AUTHOR]

Vegetable oil is one of the alternatives to replace mineral oils in transformers. This paper focuses on oxidation stability assessment of a vegetable transformer oil under accelerated thermal aging at 110°C with various durations up to 2500 hours. Oil samples were aged under open condition to stimulate the oxidation process, as well as under sealed condition to provide a comparison. A number of parameters including acidity, DC conductivity, dielectric dissipation factor (DDF) and viscosity were measured to see their responses to oxidation process of the vegetable oil. The results showed that viscosity responds towards oxidation more than hydrolysis whereas acidity responds strongly to both oxidation and hydrolysis, since besides oxidation, hydrolysis of the vegetable oil also generates acid byproducts. Of more importance, oxidation stability, in the term of oxidation induction time (OIT), of thermally aged vegetable oils was investigated by using Pressure Differential Scanning Calorimetry (PDSC) method. As there was no standard on PDSC method available for vegetable oils, various measuring temperatures were tried and 130°C was found to be suitable for the investigated vegetable oil. The results showed that OIT of open samples decreases obviously with aging time until reaching the bottom plateau at 1000 hours, while OIT of sealed samples stays at a high level until the end of aging at 2500 hours. Therefore, OIT measured by using PDSC is appropriate to reflect oxidation stability of the vegetable oil. This was further confirmed by the corresponding consumption of antioxidant and generation of peroxides, dissolved decay products. [ABSTRACT FROM AUTHOR]

Abstract: This manuscript discusses a new design of large area MCP-PMT for the next generation neutrino experiments. The main motivation of the design is to improve the quantum efficiency (photo detection efficiency) of the PMT. Two sets of small MCP units, the transmission photocathode coated on the front hemisphere and the reflection photocathode coated on the rear hemisphere are assembled in the same glass envelope to form nearly 4π viewing angle to enhance the efficiency of the photoelectron detection. The photoelectrons from the 4π photocathode are collected and amplified by two sets of MCP units. Our goal is eventually to produce 20 in. diameter PMT following such an approach. We will report preliminary results of our ptoelectronic simulation and the results of a 5 in. diameter prototype PMT. Future plans and prospects are discussed at the end. [Copyright &y& Elsevier]

Abstract: The muon identification system of BESIII experiment at the IHEP is described. The muon counter (MUC) is composed of resistive plate chambers (RPCs) working in self-quenching streamer mode with the gas mixture Ar/C2F4H2/C4H10=50/42/8. The design, the construction, the mass production and the quality control result of the detectors are described in detail. The paper also presents the performance of the bare RPCs and the superlayer modules with cosmic rays. Finally, the subsystems of MUC, including the RPC superlayer modules, the gas systems, the HV and LV system and the readout electronic system, are also presented. [Copyright &y& Elsevier]

Abstract: An ionization chamber is designed to monitor the composition of the gas mixture of BESIII muon chambers, with the energy spectrum of 5.9keV X-ray of the 55Fe radioactive source. The high voltage, source strength and temperature dependence have been carefully studied to acquire stable operation of the gas monitor. [Copyright &y& Elsevier]

This manuscript reports a study of the after-pulse properties of different types of 20-inch photomultiplier tubes (PMTs), especially for the 20-inch microchannel-plate-PMTs (MCP-PMTs) for JUNO experiment. In the study, the after-pulse rate (APR) is calculated from PMT waveforms obtained by a CAEN DT5751 waveform digitizer. We tested the after-pulse characteristics of both Dynode-PMTs and MCP-PMTs and made a thorough study on the after-pulses of high quantum efficiency (HQE) MCP-PMT for JUNO experiment, including their time distribution, after-pulse rate and the causes of different after-pulse groups through flight time analysis. Based on a fast test method, individual tests on 28 HQE-MCP-PMTs on the after-pulses were conducted at the North Night Vision Tech. Ltd. (NNVT) in Nanjing in December of 2019. This paper reports the average APR under two different definitions for HQE-MCP-PMTs and the proportions of the five different after-pulse groups. [ABSTRACT FROM AUTHOR]

The large size (4 cm × 4 cm × 1 cm) Ce3+-doped high gadolinium oxyfluoride glass with density of 5.83 g/cm³ was prepared by the melt quench method at 1220 °C. The glass is colorless and transparent over the visible range. The prolonged decay time under 275 nm UV light demonstrates the energy transfer from Gd3+ ions to Ce3+ ions. The X-ray excited luminescence spectra (XEL) show the emission peak corresponds to the 5d→4f transitions of Ce3+ ion. The integral emission intensity of glass was compared with that of bismuth germanate oxide (BGO) crystals. The scintillation property of glass was studied under the γ -ray from 137Cs source and a clear energy peak was observed with light yield (LY) over 1100 ph/MeV. The scintillation decay time comprises fast and slow components. All results presented in this work indicate the appropriate potential to be high-energy rays detecting material for CEPC. [ABSTRACT FROM AUTHOR]

Eudragit L100-55-halloysite nanotubes (EL100-55, HNTs) nanocomposite microcapsules were introduced to release nattokinase (NK) and avoid the limitations of oral and systemic administration of NK while increasing the entrapment efficiency and stability of NK. The drug loading capacity, stability, and shapes of the NK microcapsules (NK@HNTs-EL) were characterized with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The maximum loading rate of NK was 82.63%, and the encapsulation efficiency of NK was 31.6%. The formulation conditions did not adversely affect the NK tertiary structure. The maximum in vitro drug release in the simulated small intestine buffer was 93.3%, and the NK@HNTs-EL exhibited pH-dependent drug release. The drug release data were analyzed with different kinetic models, which showed that the NK@HNTs-EL drug-release mechanism involved erosion and osmotic pressure on the EL100-55. After 90 days of storage, the NK@HNTs-EL maintained an enzymatic activity greater than 95%. Hemolysis analyses indicated that NK@HNTs-EL was not cytotoxic at concentrations below 500 FU/mL. These findings indicate that NK@HNTs-EL is a promising oral thrombolytic agent. [ABSTRACT FROM AUTHOR]

• A simplified model of fast timing sensor was built to simulate magnetic immunity. • We discussed gain as a function of the magnetic field for different settings. • We proposed a valid test method for evaluating magnetic immunity. • The sensors have excellent immunity and time resolution in magnetic fields. In recent years, fast timing detectors have attracted more and more attention in the fields of high-energy physics and nuclear medicine due to their advantages in magnetic immunity and time resolution. Through simulation analysis, we discussed in detail the reason why the gain of sensor changes with the magnetic field strength. To improve the test efficiency, we proposed a test scheme to evaluate the magnetic immunity through the shift of the signal pulse height with the magnetic field. The results show that when the sensor axis is parallel and perpendicular to the magnetic field direction, the magnetic field tolerance of the sensor is up to 5 T and 1.85 T, respectively. Besides, the time resolution of the sensor is not affected by the magnetic field strength under fixed conditions. [ABSTRACT FROM AUTHOR]

Recently developed ceramic and single crystal Cerium-doped gadolinium aluminum gallium garnet (GAGG:Ce) scintillators were studied. We compared their scintillation properties with samples of the same 5 × 5 × 5 mm 3 size. In photoluminescence emission spectra, ceramic and single crystal GAGG:Ce showed intense emission peak at 555 nm and 515 nm, respectively, ascribed to 5d–4f transitions of Ce 3 +. And the single crystal GAGG:Ce had a weak emission peak appearing at 380 nm. The light yield induced by 137 Cs γ -ray of ceramic was higher than that of single crystal. The afterglow of ceramic GAGG:Ce was shorter than that of single crystal after illumination. At room temperature, single crystal GAGG:Ce was more severely affected by thermoluminescence than ceramic GAGG:Ce. The primary decay time of ceramic and single crystal under γ -ray was 182.9 ns and 50.1 ns, respectively. Furthermore, the fast component of decay time was found in single crystal. This research can lay the foundation for the preparation of better GAGG:Ce scintillators in the future. • The scintillation properties of ceramic and single crystal GAGG:Ce were compared. • At room temperature, the afterglow of ceramic GAGG:Ce decreased faster. • Ceramic GAGG:Ce exhibited higher light yield and better energy resolution. • A fast decay time component was found in the single crystal GAGG:Ce. [ABSTRACT FROM AUTHOR]

The upgrade of the BESIII end cap time-of-flight (TOF) detector needs to achieve a ~40-ps time resolution level to provide high-performance reference time for beam testing. Fast silicon photomultiplier tubes (SiPMs) have excellent time characteristics and the transition time spread (TTS) can reach tens of picoseconds. Therefore, SiPMs are selected to replace the PMTs in T0 detectors. In this article, we describe that the time characteristics of a fast SiPM and T0 system were studied using a high-speed real-time oscilloscope. In order to obtain the optimal time resolution, coupling techniques of the plastic scintillators and SiPMs were studied. Single-ended coupling between a SiPM and a plastic scintillator can obtain the best time resolution. [ABSTRACT FROM AUTHOR]

A series of Mn2+ single‐doped 0.2Gd2O3‐0.2Al2O3‐0.6SiO2 (GAS: xMn2+) glasses with Si3N4 as reducing agent were prepared. The presence of [SiO4‐x] defects and Mn2+ ions was determined from the absorption and excitation spectra of the glasses. With the increase of Mn2+ concentration, the intensity of blue emission decreases, while the intensity of red emission increases. The color coordinate of GAS: 6Mn2+ glass is (0.264, 0.226). The lifetime of the glasses was tested. Under the monitoring of 440 nm, the fast components (τf) are between 17 and 85 μs, and the slow components (τs) are between 200–650 μs. The former belongs to [SiO4‐x] defects, and the latter is [4E(G), 4A1(G)]→6A1(S) transition of Mn2+ ions. Under the monitoring at 630 nm, the τf are between 110 and 300 μs, and the τs are between 680 and 1220 μs, which are due to 4T1(G)→6A1(S) transition of Mn2+ ions and Mn2+ pairs, respectively. The energy transfer mechanism of [SiO4‐x] defect→Mn2+ ions are explained. The efficient [SiO4‐x] defect →Mn2+ ions energy transfer process was demonstrated by time‐resolved photoluminescence, and the energy transfer efficiency is over 85%. The maximum photoluminescence quantum yield (PL QY) of the glasses can reach 15.87%. The thermal activation energy of the glasses was calculated. In addition, X‐ray excited red luminescence spectra and the mechanism of the glasses were investigated. [ABSTRACT FROM AUTHOR]

Compared to traditional plasma cladding technology, plasma spray melting technology is characterized by a small heat-affected zone and high processing speed, and has a high application value. However, the process still faces significant problems, such as inaccurate parameters and work points and feasibility that need to be investigated. This study discusses a two-dimensional (2D) model of the plasma spray melting process to provide a theoretical basis for determining the optimal process parameters. The spray melting process was studied in depth by considering the cooling effect of gas convection on the melting pool, as well as by the analysis of thermal cycling and thermal diffusion of the matrix. Finally, the reliability of the model was validated by a Ni60 coating with micro-metallurgical bonding characteristics, which was spray melted onto the surface of a Q235 steel matrix. Due to its characteristics of low power, fast heating, and fast cooling, plasma spray melting technology can be used to prepare various thin coatings with micro-metallurgical bonding on the die surface, so as to significantly improve the bonding strength of the coating and mitigate the influence of the heat of the spray melting process on the die, thereby improving the material performance. [ABSTRACT FROM AUTHOR]

Different B 2 O 3 content was added to Ce3+–doped Gd 2 O 3 –Al 2 O 3 –SiO 2 (xBGAS:1.1Ce3+, x = 0, 5, 10, 15) glasses to improve the photoluminescence (PL) and scintillation properties. The transmittance of 15BGAS:1.1Ce3+ glass is over 80%. The X–ray absorption near edge spectroscopy (XANES) spectra imply that Ce4+ can be effectively reduced to Ce3+ in the glasses by adding Si 3 N 4. The excitation and emission spectra show a blue shift with increase of B 2 O 3 content. The photoluminescence quantum yield (PL QY) increases with the increase of B 2 O 3 content, reached the maximum of 59.55% when x = 15. The PL decay time of the glasses exhibits typical values (44–50 ns) due to 5d→4f transition of Ce3+ ions. The PL thermal activation energy become larger, indicating that xBGAS:1.1Ce3+ glasses have better luminescent thermal stability. The integral X–ray excited luminescence (XEL) intensity of the 15BGAS:1.1Ce3+ glass is 37.38% of Bi 4 Ge 3 O 12 (BGO) crystal, and the light yield is 1267 ph/MeV with an energy resolution of 23.22% at 662 keV when exposed to γ–rays. With the increase of B 2 O 3 content, the fast component of scintillation decay time gradually becomes shorter and the slow component becomes longer. The thermally stimulated luminescence (TSL) curves were measured to investigate the trap depth and density of defects in xBGAS:1.1Ce3+ glasses. [ABSTRACT FROM AUTHOR]

We report the first study on in-situ co-growth of biphasic CsPbBr 3 and Zn-Cd-S quantum dots (QDs) in borosilicate glass, and provide explicitly evidence of their morphology and nanoscale distribution. Such biphasic QDs co-doped nano-glass composites show unique green and red dual-band emissions. By changing the thermal heating scheme, the fluorescence intensity ratio (FIR) and thus the apparent color can be widely adjusted. The FIR can be also fine-tuned simply by varying the excitation wavelength. Based on the FIR, a self-calibrated X-rays dosimeter is constructed, which also possesses a good thermal stability. Although the X-rays induced scintillation weakening occurs, it can be readily recovered by post-thermal-annealing. [ABSTRACT FROM AUTHOR]

Industrial robots are widely used in the painting industry, such as automobile manufacturing and solid wood furniture industry. An important problem is how to improve the efficiency of robot programming, especially in the current furniture industry with multiple products, small batches and increasingly high demand for customization. In this work, we propose an outer loop adaptive control scheme, which allow users to realize the practical application of the zero-moment lead-through teaching method based on dynamic model without opening the inner torque control interface of robots. In order to accurately estimate the influence of joint friction, a friction model is established based on static, Coulomb and viscous friction characteristics, and the Sigmoid function is used to represent the transition between motion states. An identification method is used to quickly identify the dynamic parameters of the robot. The joint position/speed command of the robot's inner joint servo loop is dynamically generated based on the user-designed adaptive control law. In addition, the zero-moment lead-through teaching scheme based on the dynamic model is applied to a spray-painting robot with closed control system. In order to verify our method, CMA GR630ST is used to conduct experiments. We identified the parameters of the dynamic model and carried out the zero-moment lead-through teaching experiment to track the target trajectory. The results show that the proposed method can realize the application of modern control methods in industrial robot with closed control systems, and achieve a preliminary exploration to improve the application scenarios of spray-painting robots. [ABSTRACT FROM AUTHOR]

Highlights • A cable-driven parallel 3D printer (CDPP) is designed and developed, and the dynamics and system stiffness of the CDPP are derived. • The change laws of the system stiffness with respect to the spring stiffness constant and coordinates of the moving platform are demonstrated. • The experiments with and without executing extrusion are performed, and the experimental results verify the validity and feasibility of the CDPP. Abstract Although additive manufacturing (AM) has been developed rapidly and become an absolutely necessary tool for reducing the cycle and cost of new product development, the mechanical structures of most 3D printers based on Fused Deposition Modeling (FDM) technology are still traditional serial or parallel mechanisms with rigid components. In this paper, a novel cable-driven parallel 3D printer (CDPP) is developed. Compared with the traditional rigid mechanisms, CDPP has the advantages of larger workspace, higher payload-to-weight ratio, easier modularity and reconfigurability. A cable-driven module with three translational degrees of freedom and a follow-up tensioning module with a spring are adopted for positioning. Firstly, the inverse kinematics of the CDPP is derived considering the cable length constraint. The inverse dynamics model of the CDPP is established based on the Newton–Euler equation and the kinematics. Secondly, the system stiffness of the CDPP and stiffness along three coordinate axes are derived, respectively. The system static stiffness with respect to the stiffness constant of the spring and the coordinates of the moving platform are obtained. Finally, the experiments are performed based on numerical simulation. The results of experiments without executing extrusion demonstrate the simulation results about the static stiffness. The feasibility of the CDPP is verified via the experiments while executing extrusion. [ABSTRACT FROM AUTHOR]

Deterministic kinematic modeling and stochastic luffing angular response field prediction of the dual automobile cranes system (DACS) are studied in this paper. For the response analysis of the DACS with deterministic information, the inverse kinematics are analyzed. For the prediction of luffing angular response field of the DACS with narrowly random payload parameters, a narrowly random model is introduced. In the narrowly random model, the payload parameters with certain probability distribution are modeled as random variables. Based on the narrowly random model, the equilibrium equation of luffing angular response vector of the DACS with random parameters is derived. Then a perturbation-based random composite function method (PRCFM) is proposed. Based on the PRCFM, the first-order Neumann series expansion and the proposed random variable functional moment method, a modified hybrid random method (MHRM) for the luffing angular response field prediction of the DACS with narrowly random payload parameters is proposed. In the MHRM, the statistical characteristics of luffing angular response vector are determined. Numerical results show the feasibility and efficiency of the MHRM for solving the narrowly stochastic DACS problems compared with the Monte Carlo method. The effects of different random parameters (y, z, θ) on the DACS luffing angular response field are also investigated deeply, and numerical results indicate the impact on the variances made by the randomness in the random payload parameter y is larger than those made by random payload parameters z and θ. [ABSTRACT FROM AUTHOR]

This study investigates the three-dimensional static and dynamic stiffness analyses of the cable driven parallel robot by considering cable mass, elasticity, and mass of end-effector. According to these models, optimization of cable tensions and cable lengths using fminimax solver is performed to determine the static stiffness. Static and dynamic stiffness of the cables are obtained with simulations. Results show that analyses in three-dimension are very important to measure the actual performance of the cable driven parallel robot. This demonstrates potential for general applicability and motion of the cable driven parallel robot. [ABSTRACT FROM AUTHOR]

• A phase field model on MPB with local compositional heterogeneity is developed. • Three-phase mixture forms due to the local compositional heterogeneity. • Polarization rotation under electric fields contribute to the piezoelectricity. • d 33 coefficient decreases due to the on-average more difficult polarization rotation. In this work, the effect of local compositional heterogeneity on the domain structure and piezoelectricity at ferroelectric morphotropic phase boundary (MPB) is studied by phase field simulations. It is found that the local compositional heterogeneity leads to a unique domain structure at MPB, i.e., a mixture of tetragonal, monoclinic and rhombohedral domains. Although polarization rotation occurs for both MPB samples with and without local compositional heterogeneity, the piezoelectric d 33 coefficient becomes reduced for the sample with local compositional heterogeneity because polarization rotation becomes more difficult on average. This work unravels the effect of local compositional heterogeneity on the piezoelectric property of ferroelectric MPB. [ABSTRACT FROM AUTHOR]

• A high-performance tracking control method is proposed for surgical robot. • A non-linear hysteresis compensation algorithm is proposed. • A joint angle estimator is proposed considering the dynamic characteristics. • An external force self-sensing estimator is proposed based on the cable disturbances. Cable-pulley-driven (CPD) manipulators are widely used in minimally-invasive surgical robots and systems. However, the cable-pulley systems also bring with significant nonlinear characteristics such as the hysteresis effect and elastic creep. Moreover, it is difficult to integrate the position and force detection elements at the end of the surgical instrument. This study proposes a method of high-performance tracking control involving a self-sensing ability of external force based on the position/force estimators and non-linear hysteresis compensation (NLHC) algorithm for a CPD surgical robotic manipulator. The experiment results demonstrate that the proposed method can significantly reduce the tracking error of the joint angle and improve the position control accuracy to approximately 99% under a varying load. Additionally, the estimation resolution of the self-sensing ability of external force was approximately 0.05 N. The method proposed in this study has potential applications in the motion control and force sensing of CPD manipulators, particularly for backdrivable CPD surgical robots. [ABSTRACT FROM AUTHOR]

Ce3+‐doped 20Gd2O3–20Al2O3–60SiO2 (GAS:xCe3+) glasses (x = 0.3, 0.7, 1.1, 1.5, 1.9 mol%) with Si3N4 as a reducing agent were prepared. The density of the glasses is around 4.2 g/cm3. With the increase in the Ce3+ concentration, both the photoluminescence (PL) and PL excitation peaks of GAS:xCe3+ glasses show a redshift because the 4f–5d energy levels of Ce3+ ions are narrowed. PL quantum yield and PL decay time of GAS:xCe3+ glasses are 28.32–50.59% and 43–64 ns, respectively. In addition, they both first increases and then decreases with the Ce3+ concentration increasing, reached the maximum when x = 1.1 mol%. The integrated X‐ray excited luminescence (XEL) intensity of the GAS:1.1Ce3+ glass is 23.86% of that of Bi4Ge3O12 (BGO) crystal, and the light yield reaches 1200 ph/MeV with an energy resolution of 22.98% at 662 keV when exposed to γ‐rays. The PL and XEL thermal activation energies of GAS:xCe3+ glasses are independent of Ce3+ ions concentration. Scintillating decay time of the glasses exhibits two components consisting of nanosecond and microsecond levels, and the scintillating decay time gradually decreases with the Ce3+ concentration increasing. The difference between PL and scintillating decay time is discussed regarding the different luminescent mechanisms. [ABSTRACT FROM AUTHOR]

This paper discusses the electron optical system of an 8-in. spherical MCP-PMT. The MCP assembly, the supporting pole and the supply voltages are carefully designed to optimize the photoelectron collection efficiency and the transit time spread. Coating the MCP nickel-chromium electrode with an additional high secondary emission material is employed to make a breakthrough on the collection efficiency. With the simulation software CST, the Finite Integration method and the Monte Carlo method are combined to evaluate the collection efficiency, the time properties and the Earth's magnetic field effects. Simulation results show that the photocathode active solid angle is over 3.5 πsr, the average collection efficiency can exceed 95% with the coated MCP and the mean transit time spread is 2.2 ns for a typical electric potential of 500 V applied between the photocathode and the MCP input facet. The prototype and the measured single photoelectron spectrum are also presented. [ABSTRACT FROM AUTHOR]

The High Energy Cosmic Radiation Detection (HERD) facility will be installed on the China space station, and the critical sub-detector is the homogeneous, isotropic, and finely segmented 3D calorimeter (CALO), composed of 7500 LYSO cubes. In this paper, GEANT4 was used to simulate the optical photon propagation inside a single LYSO crystal including the Wavelength Shifting Fiber (WLSF) and photodiode (PD) and compared with experimental results. The results show that only a tiny fraction of the photons produced in the LYSO can be collected through the WLSF and PD, and the light output can be enhanced by increasing the number of rough surfaces. Additionally, the variability in WLSF and PD light output when particles entered the LYSO crystal from varying positions, known as non-uniformity, was examined through simulation. The simulated non-uniformity using thin X-ray beams is compatible within the experimental errors and can be improved at higher light output. Finally, the non-uniformity is highly sensitive to the polishing condition of the crystal surface, and better polishing conditions are preferred. [ABSTRACT FROM AUTHOR]

The use of time-of-flight (TOF) technology in positron emission tomography (PET) is expected to enhance the performance of clinical tasks such as lesion detection and disease staging. One critical requirement for TOF-PET is achieving lower Coincidence Time Resolution (CTR). In this manuscript, we developed a kind of multi-anode micro channel plate photomultiplier tube (MCP-PMT) specifically designed for TOF-PET applications. The direct use of Cherenkov radiator as the optical window eliminate the optical interface between the radiator and the detector, and the multi-anode structure enables a great positional resolution. Using the fast analog-to-digital converters (FADCs) technology to record the entire waveforms of the signals, the CTR measured by a pair of MCP-PMTs was analyzed offline, and the best CTR of 40. 9 ± 12. 9 ps Full Width at Half Maximum (FWHM), which is equivalent to a position resolution of 6. 1 ± 1. 9 mm line of response (LOR) was obtained. [ABSTRACT FROM AUTHOR]

The Circular Electron Positron Collider (CEPC) is a large international scientific facility proposed by the Chinese particle physics community. For the particle flow algorithms (PFA) oriented HCAL of the CEPC, an analog read-out option (AHCAL) is chosen in this regard. The proposal of silicon photomultiplier (SiPM) coupling with the glass scintillator as the detection unit HCAL is a new solution for the next generation calorimeter. The optical and scintilation characteristics of the aluminoborosilicate glass scintillator have been measured. When the wavelength is longer than 450 nm, the transmittance of the aluminoborosilicate glass is higher than 65%. In X-ray excited luminescence spectra, the integral intensity of the glass is 25.5% that of Bi 4 Ge 3 O 12 (BGO) crystal. The energy resolution of the glass is approximately 27%. Moreover, the light yield of the glass is greater than 800 ph/MeV. The scintillating decay time of the fast and slow components is 262.10 ns (18%) and 1234.83 ns (82%), respectively. The difference between the scintillating and fluorescence decay time of the glass is explained by the luminescent mechanism. In addition, the afterglow of the glass was tested. • A new solution for coupling a silicon photomultiplier (SiPM) to a glass scintillator as a hadron calorimeter of CEPC is proposed. • Optical and scintillation properties of the aluminoborosilicate glass were evaluated. • The scintillation light yield is higher than 800 ph/MeV, and the energy resolution is 26.77%. [ABSTRACT FROM AUTHOR]

In collaboration with the North Night Vision Science and Technology (Nanjing) Research Institute Co. Ltd, researchers at the Institute of High Energy of Physics in China have successfully developed the 20-inch micro-channel-plate photomultiplier tube (MCP-PMT) that exhibits high detection efficiency (DE) for use in the Jiangmen Underground Neutrino Observatory (JUNO). Due to the long drift path of electrons from photocathode to MCP, the 20-inch MCP-PMT has a time resolution on the order of nanoseconds. Recently, the team has made advancements in ultra-fast MCP-PMTs (FPMTs), achieving picosecond-level time resolution with both 1-inch and 2-inch types. By now, prototypes featuring single-anode, 2 × 2 anodes, 4 × 4 anodes, and 8 × 8 anodes have been successfully manufactured and tested. The 8 × 8 anode FPMT, in particular, demonstrates a transit time spread (TTS) of 36 ps (Sigma) in single photon mode, thanks to its meticulously engineered structure. To assess the FPMT's time performance under beam conditions, two beam tests were conducted at Fermi Lab and CERN. In these tests, the 8 × 8 pixel arrays of four distinct radiators, including LYSO, BGO, Pb glass and quartz glass, were paired with the 8 × 8 anodes FPMT. This setup involved the use of two radiator-coupled FPMT detectors for particle detection. The best coincidence time resolution recorded was 64 ps (Sigma) with a 120 GeV proton beam and 56 ps (Sigma) with a 108 GeV muon beam. [ABSTRACT FROM AUTHOR]

The excellent jet energy resolution is crucial for the precise measurement of the Higgs properties at future e + e − Higgs factories, such as the Circular Electron Positron Collider (CEPC). For this purpose, a novel design of the particle flow oriented hadronic calorimeter based on glass scintillators (GSHCAL) is proposed. Compared with the designs based on gas or plastic scintillators, the GSHCAL can achieve a higher sampling fraction and more compact structure in a cost-effective way, benefiting from the high density and low cost of glass scintillators. In order to explore the physics potential of the GSHCAL, its intrinsic energy resolution and the contribution to the measurement of the hadronic system was investigated by Monte Carlo simulations. Preliminary results show that the stochastic term of hadronic energy resolution can reach around 24% and the Boson Mass Resolution (BMR) can reach around 3.38% when the GSHCAL is applied. Besides, the key technical R&D of high-performance glass scintillator tiles is also introduced. [ABSTRACT FROM AUTHOR]

Background: Menaquinone (MK-7) is a highly valuable vitamin K2 produced by Bacillus subtilis. Common static metabolic engineering approaches for promoting the production of MK-7 have been studied previously. However, these approaches caused an accumulation of toxic substances and reduced product yield. Hence, dynamic regulation by the quorum sensing (QS) system is a promising method for achieving a balance between product synthesis and cell growth. Results: In this study, the QS transcriptional regulator SinR, which plays a significant role in biofilm formation and MK production simultaneously, was selected, and its site-directed mutants were constructed. Among these mutants, sinR knock out strain (KO-SinR) increased the biofilm biomass by 2.8-fold compared to the wild-type. SinRquad maximized the yield of MK-7 (102.56 ± 2.84 mg/L). To decipher the mechanism of how this mutant regulates MK-7 synthesis and to find additional potential regulators that enhance MK-7 synthesis, RNA-seq was used to analyze expression changes in the QS system, biofilm formation, and MK-7 synthesis pathway. The results showed that the expressions of tapA, tasA and epsE were up-regulated 9.79-, 0.95-, and 4.42-fold, respectively. Therefore, SinRquad formed more wrinkly and smoother biofilms than BS168. The upregulated expressions of glpF, glpk, and glpD in this biofilm morphology facilitated the flow of glycerol through the biofilm. In addition, NADH dehydrogenases especially sdhA, sdhB, sdhC and glpD, increased 1.01-, 3.93-, 1.87-, and 1.11-fold, respectively. The increased expression levels of NADH dehydrogenases indicated that more electrons were produced for the electron transport system. Electrical hyperpolarization stimulated the synthesis of the electron transport chain components, such as cytochrome c and MK, to ensure the efficiency of electron transfer. Wrinkly and smooth biofilms formed a network of interconnected channels with a low resistance to liquid flow, which was beneficial for the uptake of glycerol, and facilitated the metabolic flux of four modules of the MK-7 synthesis pathway. Conclusions: In this study, we report for the first time that SinRquad has significant effects on MK-7 synthesis by forming wrinkly and smooth biofilms, upregulating the expression level of most NADH dehydrogenases, and providing higher membrane potential to stimulate the accumulation of the components in the electron transport system. [ABSTRACT FROM AUTHOR]

To realize neutron-gamma discrimination of piled-up pulses in high counting rate circumstances, the discrimination performance of the charge comparison method and three neural network models to actual piled-up pulses was studied in this paper. The neural network models, including a residual neural network (ResNet), a convolutional neural network (CNN) and a fully connected neural network (FCNN), were trained and tested by seven kinds of actual experimental data sets, which included the background signals (bg), non-piled-up neutron (n) and gamma (g) pulses as well as piled-up neutron + neutron (n + n), neutron + gamma (n + g), gamma + neutron (g + n), and gamma + gamma (g + g) pulses. The labels of the seven data sets were provided after discriminating by the charge comparison method. The results showed that the charge comparison method could be applied to discriminate piled-up neutron-gamma pulses with the Figure of Merit (FoM) value of 1.0. The integration length has been optimized to be different for piled-up and non-piled-up pulses, but follow the same criterion for neutron and gamma discrimination. The FoM values are worse than that of non-piled-up signals because the baseline fluctuation is very large under high counting rate conditions, which gives lots of interference to pulse shape discrimination. The ResNet model has the highest total prediction accuracy (93.85%) for the seven signal types, and through the comparison and analysis of the inconsistent events discriminated by the charge comparison method and the ResNet model, it is concluded that the discrimination result of the ResNet model is more accurate. These results indicate that both the charge comparison method and residual neural network can be used for complicated n/ γ discrimination under high counting rate conditions, and the residual neural network works better. [ABSTRACT FROM AUTHOR]

The performance of two 6Li enriched elpasolite scintillators Cs 2 LiYCl 6 : Ce 3 + (CLYC) and Cs 2 LiLaBr 6 : Ce 3 + (CLLB) were investigated using mono-energetic fast neutrons generated by a 3 MV tandem accelerator. The Pulse Shape Discrimination (PSD) ability, response and energy resolution to fast neutrons and scattered slow neutrons were studied. The 6Li enriched CLYC had excellent discrimination ability between neutron and gamma rays with the Figure of Merit (FOM) value better than 2.4. An Artificial neural network (ANN) model could discriminate fast neutrons and scattered slow neutrons effectively with an accuracy of 97%, which render the Li-6 enriched CLYC capable to detect thermal neutrons with high efficiency and the energy spectrum of fast neutrons simultaneously. The quenching factors are calculated to be 0.92 and 0.48 for the 35Cl(n, p)35S and 35Cl (n, α)32P reaction, while the detection efficiency is about 0.1%–0.75% for fast neutrons within the energy range of 0.9–5.2 MeV. Unlike CLYC, CLLB was only sensitive to slow neutrons, and the discrimination ability between neutrons and gamma rays is worse than CLYC, while the ANN model exhibit better performance which has an accuracy of 97%. [ABSTRACT FROM AUTHOR]

Jinping Neutrino Experiment plans to deploy a new type of 8-inch MCP-PMT with high photon detection efficiency for MeV-scale neutrino measurements. This work studies the performance of the MCP-PMTs, including the photon detection efficiency, the charge resolution of the single photoelectron, the transition time spread, single photoelectron response, rates of dark counts and after pulses. We find a long tail in the charge distribution, and combined with the high photon detection efficiency, the overall energy resolution sees substantial improvements. Those results will be provided as the inputs to detector simulation and design. Our results show that the new PMT satisfies all the requirements of the Jinping Neutrino Experiment. [ABSTRACT FROM AUTHOR]

In this work, Cs 2 LiLaBr 6 :1%Ce (CLLB:Ce) single crystal with the size of Ф26 mm × 80 mm were successfully grown by the Bridgman method. The optimal conditions of application were presented by coupling with R6231-100 PMT. The pulse spectra are recorded by the 4-channel digital converter DT5751 at a sampling rate of 1 GS/s. The energy spectra of the CLLB:Ce crystal were recorded under different PMT gain voltage. The best energy resolution is obtained (up to 3.8%) when the gain voltage of PMT is 3.65V. The non-proportionality of CLLB:Ce crystal was measured under varied radioactive sources while the background radioactive was discussed. Besides, the energy spectra of CLLB:Ce crystal were recorded when the temperature was varied from −30 °C to 50 °C. Finally, the discriminating ability of neutron and gamma was evaluated under 252Cf source and AmBe source, the FOM value is 1.4 and 1.2, respectively, which has a greatly potential application in the nuclear radiation detection. • Cs 2 LiLaBr 6 :1%Ce single crystal with the size of Ф26mm × 50 mm were successfully grown. • Cs 2 LiLaBr 6 :1%Ce has a good non-proportionality (3%). • CLLB:Ce crystal has a best scintillation properties at the temperature of 30 °C. • The FOM value of CLLB:Ce crystal is estimated about 1.4 under 252Cf source. [ABSTRACT FROM AUTHOR]

For inner-hole parts, the main positions bearing load are their inner walls, which are prone to strain, wear, corrosion and other damages during use. Aluminum‑silicon (Al Si) coating (Al 25Si) with excellent properties can be prepared through inner-hole supersonic atmospheric plasma spraying (SAPS) technology to provide reliable protection for inner-hole parts. In this paper, a study was conducted to find out how spray gas parameters, spray electrical parameters, and spray distances influence the temperature and velocity of flying particles during the process of preparing Al 25Si coatings through inner-hole SAPS. Meanwhile, the coating preparation process was also optimized in this study. Through analysis and experimental verification, the optimal process parameters for preparing the coatings are as follows: The total gas flow is 115 L/min, the hydrogen (H 2) content is 7.5 %, and the spray voltage, spray current, and spray distance remain at 86 V, 430 A, and 90 mm. Under these spray parameters, the particle temperature and flight velocity are 2698.7 °C and 473.9 m/s, respectively, while the porosity and microhardness of the coating are 0.79 % ± 0.56 % and 267.09 ± 14.85 HV 0.2 , respectively. [ABSTRACT FROM AUTHOR]

• A serial of Eu2+-doped CLLB single crystals were successfully grown. • The Eu2+ activated CLLB matrix strategy increases the Stokes shift. • The light yields of CLLB: 2% Eu is 18700ph/MeV under 137Cs source at 662 keV. • CLLB: Eu crystal has the application potential of long afterglow X-ray imaging. In this work, a novel single crystal scintillator, Eu2+-doped Cs 2 LiLaBr 6 (CLLB: Eu) with Ф12 mm × 50 mm, was successfully grown by the Bridgman method. The effects of substitution amount of europium ions on the crystal structure, luminescent properties and scintillation properties were systematically studied by fluorescence spectroscopy, XEL, decay kinetics, and temperature-dependent emission spectra. The Cs 2 LiLaBr 6 :2%Eu sample presents the highest light yield under X-ray excitation, which is about 235 times that of commercial BGO single crystals. The nanosecond decay lifetime of Eu2+ was observed in Cs 2 LiLaBr 6 :Eu crystal. The afterglow result indicates that the Cs 2 LiLaBr 6 : Eu crystal has a long afterglow and the afterglow mechanism of Cs 2 LiLaBr 6 : Eu crystal was proposed and constructed. It has a potent application in nuclear radiation detection and imaging as a scintillation long afterglow material. [ABSTRACT FROM AUTHOR]

Abstract This paper describes the design of the 8-inch and 20-inch photomultiplier tubes based on microchannel plates (MCP-PMT). In the large area MCP-PMT, the small MCPs replace the bulky dynode chain in the traditional large PMTs. Photoelectrons are electrostatically focused on MCPs. The MCP assembly, focusing electrodes as well as the supply voltages are carefully optimized to achieve a wide photosensitive area, high photon detection efficiency and good timing resolution. Highlights • The electron-optics design of the large-area spherical MCP-PMT and the elliptical MCP-PMT is described. • The effect of the photoelectron angle of incidence on the first MCP on the collection efficiency are discussed. • The Earths magnetic field effects on the 20-inch MCP-PMT are studied. • The method employed to design the large-area MCP-PMT can be also used in optimizing other large format photon detectors. [ABSTRACT FROM AUTHOR]

Three series of Dy3+-, Tb3+-doped and Tb3+/Dy3+ co-doped 40TeO 2 -20(Gd,Lu) 2 O 3 –40WO 3 glasses with density of about 6.75 g/cm3 were successfully prepared by high temperature melt-quenching method. The luminescence properties of these rare earth ions doped 40TeO 2 -20(Gd,Lu) 2 O 3 –40WO 3 glass were systematically studied by transmittance, photoluminescence (excitation and emission spectra), time-resolved emission spectra (TRES) and X-ray excited luminescence (XEL) spectra, together with the luminescence decay curves. The optimal doping concentration of Dy3+ and Tb3+ ions in 40TeO 2 -20(Gd,Lu) 2 O 3 –40WO 3 glasses was determined under UV and X-ray excitation, respectively. It is found there is an efficient energy transfer from Dy3+ to Tb3+ ions in 40TeO 2 -20(Gd,Lu) 2 O 3 –40WO 3 glass in photoluminescence spectra. However, it is not true under X-ray excitation due to the complicated physical process. • The density of Dy3+-, Tb3+-doped and Tb3+/Dy3+ codoped 40TeO 2 -20(Gd,Lu) 2 O 3 –40WO 3 scintillation glasses is up to 6.75 g/cm3. • The energy transfer process of Dy3+.→Tb3+ was confirmed through photoluminescence spectra, luminescence decay curves and TRES spectra. • The energy transfer efficiency of Dy3+ ions to Tb3+ ions is up to 97.6%. • The difference of energy transfer effect between XEL and PL process was explored. [ABSTRACT FROM AUTHOR]