Subjects: Physics >> Nuclear Physics submitted time 2024-03-08
Abstract: The Coherent Muon-to-Electron Transition (COMET) experiment is a leading experiment for the coherent
conversion of μ−N → e−N using a high-intensity pulsed muon beamline, produced using innovative slow extraction
techniques. Therefore, it is critical to measure the muon beam characteristics. We set up a muon beam
monitor (MBM), where scintillating fibers woven in a cross shape were coupled to silicon photomultipliers to
measure the spatial profile and timing structure of the extracted muon beam for the COMET. The MBM detector
was tested successfully with a proton beamline at the China Spallation Neutron Source and obtained data with
good performance in the commissioning run. The development of the MBM, including its mechanical structure,
electronic readout, and beam measurement results, are discussed.
Subjects: Nuclear Science and Technology >> Nuclear Detection Technology and Nuclear Electronics Subjects: Nuclear Science and Technology >> Nuclear Instrument and Meter submitted time 2024-02-07
Abstract: A new measurement method for the spatial distribution of neutron beam flux in boron neutron capture therapy (BNCT) is being developed based on the two-dimensional Micromegas detector. To address the issue of long processing time in traditional offline position reconstruction methods, this paper proposes an FPGA-based online position reconstruction method, grounded in the micro time projection chamber principle. This method encapsulates key technical aspects: self-adaptive serial link technique built upon the dynamical adjustment of delay chain length, fast sorting and coordinate matching technique based on the mapping between signal timestamps and random access memory (RAM) addresses, and precise start point merging technique utilizing a circular combined RAM. The performance test of the self-adaptive serial link shows the bit error rate of the link is better than 10^-12 at a confidence level of 99%, ensuring reliable data transmission. The combined experiment of the readout electronics and the Micromegas detector shows a spatial resolution of approximately 1.4 mm, surpassing the current method's resolution level of 5 mm. The beam experiment confirms that the readout electronics system can obtain the flux spatial distribution of neutron beam online, thus validating the feasibility of the position reconstruction method. The online position reconstruction method avoids traditional methods such as bubble sorting and traversal searching, simplifying the design of logic firmware and reducing the time complexity from O(n^2) to O(n). This study contributes to the advancement in measuring neutron beam flux for BNCT.
Subjects: Physics >> Nuclear Physics submitted time 2023-09-11
Abstract: A trigger system has been designed and implemented for the HIRFL-CSR external target experiment (CEE), the spectrometer for studying nuclear matter properties with heavy ion collisions in the GeV energy region. The system adopts master-slave structure and serial data transmission mode using optical fiber to deal with different types of detectors and long-distance signal transmission. The trigger logic can be accessed based on command register and controlled by a remote computer. The overall field programmable gate array (FPGA) logic can be flexibly reconfigured online to match the physical requirements of the experiment. The trigger system has been tested in beam experiment. It is demonstrated that the trigger system functions correctly and meets the physical requirements of CEE.
Peer Review Status:Awaiting Review
Subjects: Physics >> Nuclear Physics submitted time 2023-07-08
Abstract: The HIRFL-CSR external-target experiment (CEE) under construction is expected to provide novel opportunities to the studies of the thermodynamic properties, namely the equation of state of nuclear matter (nEOS) with heavy ion collisions at a few hundreds MeV/u beam energies. Based on Geant 4 packages, the fast simulations of the detector responses to the collision events generated using transport model are conducted. The overall performance of CEE, including spatial resolution of hits, momentum resolution of tracks and particle identification ability has been investigated. Various observables proposed to probe the nEOS, such as the production of light clusters, $\rm t/^3He$ yield ratio, the radial flow, $\pi^{-}/\pi^{+}$ yield ratio and the neutral kaon yields, have been reconstructed. The feasibility of studying nEOS beyond the saturation density via the aforementioned observables to be measured with CEE has been demonstrated.
Peer Review Status:Awaiting Review
Subjects: Nuclear Science and Technology >> Nuclear Detection Technology and Nuclear Electronics submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract: A compact X-ray detector based on the lutetium yttrium oxyorthosilicate scintillator (LYSO) and silicon photomultiplier (SiPM) has been designed and fabricated for the hard X-ray diagnosis on the HL_2A and HL_2M Tokamak devices. The LYSO scintillator and SiPM in small dimensions were combined in a heat shrink tube package, making the detector compact and integrative. The Monte Carlo particle transport simulation tool, Geant4, was utilized for the design of the detector for the hard X-ray from 10 keV to 200 keV and the best structure scheme was presented. Finally, the detector was used to measure the photon spectrum of a 137Cs gamma source with a pre-amplifier and a multichannel amplitude analyzer. The measured spectrum is consistent with the theoretic spectrum, it has shown that the energy resolution of the detector is less than 14.8% at an energy of 662 keV.
Subjects: Nuclear Science and Technology >> Nuclear Detection Technology and Nuclear Electronics submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract: The Dragon-I linear induction accelerator (LIA) at China Academy of Engineering Physics generates 20 MeV flash X-rays mainly for radiography applications in fluid dynamics. Its spectral information is quite important for diagnostic X-ray imaging applications, but because of its short pulse and great radiation intensity, direct measurement is impossible. In this work, we propose a new method based on transmission measurements to obtain the flash X-ray spectrum. Pure iron cylinders were used as attenuation material, and alanine dosimeters were attached on their rear bottom to record the dose after different degrees of attenuation. Iterative least square method was used to unfold the spectrum, while Geant4 Monte Carlo code was used to simulate the X-ray spectrum. The unfolded spectrum and the simulated spectrum have a high degree of consistency, with the reduced chi-square value of 0.044. This shows that the method is reliable in estimating megavoltage high-intensity X-ray spectrum.
Subjects: Nuclear Science and Technology >> Particle Accelerator submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract: A test system is developed for the BESIII ETOF/MRPC beam tests of data acquisition, environment monitoring and automatic control. The software framework is based on the CAMAC bus, VME bus and Serial Port, which are responsible for communications with the detectors. The monitor system works well in the beam test.
Subjects: Nuclear Science and Technology >> Nuclear Detection Technology and Nuclear Electronics submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract: Commercial off-the-shelf (COTS) ADCs (analog-to-digital converters) that are radiation-tolerant, high speed, high density and low power will be used in upgrading the LAr (liquid argon) calorimeter front end (FE) trigger readout electronics. Total ionization dose (TID) and single event effect (SEE) of the COTS ADCs should be characterized. In our initial TID test, 17 COTS ADCs from different manufacturers with dynamic range and sampling rate meeting requirements of the FE electronics were checked, and the ADS5272 of Texas Instruments (TI) was the best performer of all. Another interesting feature of ADS5272 is its 6.5 clock cycles latency, which is the shortest of all the 17 candidates. Based on the TID performance, we designed an SEE evaluation system for ADS5272, which allows us to further assess its radiation tolerance. In this paper, we present a detailed design of ADS5272 SEE evaluation system and show the effectiveness of this system while evaluating ADS5272 SEE characteristics in multiple irradiation tests. According to TID and SEE test results, ADS5272 was chosen to be implemented in the full-size LAr Trigger Digitizer Board (LTDB) demonstrator, which will be installed on ATLAS calorimeter during the 2014 Long Shutdown 1 (LS1).
Subjects: Nuclear Science and Technology >> Nuclear Detection Technology and Nuclear Electronics submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract: In order to realize on-line real-time measurement of dynamic and time-sharing neutron spectrum of HL-2A, a tokamak fusion neutron spectrometer based on PXI bus was developed. It consists of electronics system and eight thermal neutron detectors, namely SP9 3He proportional counter, embedded in eight polyethylene spheres in different diameters. Response function of the eight polyethylene spheres was the key to calculate the neutron spectrum accurately. In this paper, response function of the eight polyethylene spheres is simulated by adopting Geant4 code, and neutron counts from an 241Am-Be neutron source are measured by the eight detectors. The calculated spectrum of the Am-Be neutron is accurate in 0–2 MeV region, and is similar to the theoretical spectrum. The tokamak fusion neutron spectrometer was used in HL-2A device to monitor the dynamic neutron spectrum of HL-2A on-line and real-time.
Subjects: Nuclear Science and Technology >> Nuclear Detection Technology and Nuclear Electronics submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract: Resistive Plate Chambers (RPCs) built from a new type of Bakelite developed at Institute of High Energy Physics (IHEP), Chinese Academy of Sciences have been used in the BESIII Muon identification system for several years without linseed oil coating, but characteristic aging performances were observed. To adapt to the RPCs in the aging state, the front-end electronics have been upgraded by enhancing the front-end protection, improving the threshold setting circuit, and separating power supplies of the comparator and the field programmable gate array (FPGA). Improvements in system stability, front-end protection and threshold consistency have been achieved. In this paper, the system upgrade and the test results are described in detail.
Subjects: Nuclear Science and Technology >> Nuclear Detection Technology and Nuclear Electronics submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract: The Dark Matter Particle Explorer (DAMPE) is being constructed as a scientific satellite to observe high energy cosmic rays in space. As a crucial detector of DAMPE, the BGO calorimeter consists of 1848 PMT dynode signals which bring difficulties in front-end electronics on the space-limited and power-limited satellite platform. To overcome the challenge, a low-noise, low-power and high-integration ASIC chip, named VA32HDR14.2, is taken into account. In order to evaluate the radiation tolerance of the chip in space radiation environment, both single event effect (SEE) and total ionizing dose (TID) tests were performed. The SEE test result shows that the effective linear energy transfer (LET) threshold of single event latch-up (SEL) of the chip is around 23.0 MeV-cm2/mg, which is relatively sensitive, thus protection methods must be taken in the electronics design. The TID test result shows that the TID performance of the chip is higher than 25 Krad(Si), which satisfies the design specification.
Subjects: Nuclear Science and Technology >> Nuclear Detection Technology and Nuclear Electronics submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract: In order to realize the on-line real-time measurement of neutron spectrum of ITER fusion, this paper presents a multi-sphere spectrometer system which consists of eight thermal neutron detectors, namely SP9 3He proportional counter, embedded in eight different diameter polyethylene spheres. The response function of eight polyethylene spheres of multi-sphere neutron spectrometer was calculated after the simulation of the neutron transport processes in multi-sphere spectrometer by adopting software Geant4. The peak of the response function is in the low energy region for smaller diameter polyethylene sphere. As the polyethylene sphere diameter increased, the peak of the response function moves to the high energy region. The experimental calibration adopts 241Am-Be neutron source. The relative error between normalized data of experiment 4π solid angle counts and normalized data of simulated detection efficiency of 4in to 8in polyethylene sphere is from 1.152% to 12.222%.The experimental results verify the response function of the simulation. All these results provide a theoretical and experimental basis for solving the on-line real-time neutron spectrum of ITER fusion.
Subjects: Nuclear Science and Technology >> Nuclear Detection Technology and Nuclear Electronics submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract: This article presents a prototype of beam position and phase measurement (BPPM) electronics designed for the LINAC in China Accelerator Driven Sub-critical system (ADS). The signals received from the Beam Position Monitor (BPM) detectors are narrow pulses with a repetition frequency of 162.5 MHz and a dynamic range more than 40 dB. Based on the high-speed high-resolution Analog-to-Digital conversion technique, the input RF signals are directly converted to In-phase and Quadrature-phase (IQ) streams through under-sampling, which simplifies both the analog and digital processing circuits. All signal processing is integrated in one single FPGA, in which real-time beam position, phase and current can be obtained. A series of simulations and tests have been conducted to evaluate the performance. Initial test results indicate that this prototype achieves a phase resolution better than 0.1 degree and a position resolution better than 20 μm over a 40 dB dynamic range with the bandwidth of 780 kHz, which is well beyond the application requirements.
Subjects: Nuclear Science and Technology >> Nuclear Detection Technology and Nuclear Electronics submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract: In this paper, a general method of data transmission system design on PXI platform is proposed. It can be used in readout system design for physical experiments. It aims at providing reusable and general interfaces for customized design of PXI while maintaining the transmission performance. It has three main features: (1)universal logic hardware interface, (2)ethernet based socket software interface, and (3)specific and simple data transmission protocol. Data transmission on PXI bus can be realized with the said two universal interfaces coordinated by this specific protocol. Test shows that this method is feasible and stable. This method can be easily reused in readout system designs for different experiments.
Subjects: Nuclear Science and Technology >> Nuclear Detection Technology and Nuclear Electronics submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract: In this paper, a high precision vernier delay line (VDL) TDC (Time-to-Digital Convertor) in an actel flash-based Field-Programmable-Gate-Arrays A3PE1500 is implemented, achieving a resolution of 16.4-ps root mean square value or 42-ps averaged bin size. The TDC has a dead time of about 200 ns while the dynamic range is 655.36 μs. The double delay lines method is employed to cut the dead time in half to improve its performance. As the bin size of the TDC is dependent on temperature, a compensation algorithm is adopted as temperature drift correction, and the TDC shows satisfying performance in a temperature range from –5°C to +55°C.
Subjects: Nuclear Science and Technology >> Nuclear Detection Technology and Nuclear Electronics submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract: As a key part of the diagnosis system in the International Thermonuclear Experimental Reactor (ITER), the neutron flux monitor (NFM), which measures the neutron intensity of the fusion reaction, is a Counting-Campbelling system with a large dynamic counting range. A dynamic linear calibration method is proposed in this paper to solve the problem of cross-over between the different counting and Campbelling channels, and improve the accuracy of the cross-calibration for long-term operation. The experimental results show that the NFM system with the dynamic linear calibration system can obtain the neutron flux of the fusion reactor in real time and realize the seamless measurement area connection between the two channels.
Subjects: Nuclear Science and Technology >> Nuclear Detection Technology and Nuclear Electronics submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract: The experimental muon source on China Spallation Neutron Source (CSNS) is expected to be a high intensity (105 μ+/s) surface muon source with a small beam spot of 4-cm diameter. For a practical application of this muon source, we are devoting to develop the first pulsed μSR spectrometer in China. In this paper, the performance of plastic scintillators in the μSR spectrometer is studied by Monte Carlo simulation. The processes such as positron energy deposition, scintillation photons production, light propagation and photon-electron conversion are carefully considered. According to the results, an optimal dimension of the plastic scintillator is proposed using for our future spectrometer, which has a long-strip shape with the dimension variation range of 50–60 mm length, 5–8 mm height, and 10–12 mm width. Finally, we can build a spectrometer with a count rate up to 104e+/s by 100–120 forward and backward segmental detectors in total. The simulation could serve as an important guide for spectrometer construction.
Subjects: Physics >> Nuclear Physics submitted time 2016-09-14
Abstract: In order to improve the particle identification capability of the Beijing Spectrometer III (BESIII),t is proposed to upgrade the current endcap time-of-flight (ETOF) detector with multi-gap resistive plate chamber (MRPC) technology. Aiming at extending ETOF overall time resolution better than 100ps, the whole system including MRPC detectors, new-designed Front End Electronics (FEE), CLOCK module, fast control boards and time to digital modules (TDIG), was built up and operated online 3 months under the cosmic ray. The main purposes of cosmic ray test are checking the detectors' construction quality, testing the joint operation of all instruments and guaranteeing the performance of the system. The results imply MRPC time resolution better than 100ps, efficiency is about 98%燼nd the noise rate of strip is lower than 1Hz/(scm2) at normal threshold range, the details are discussed and analyzed specifically in this paper. The test indicates that the whole ETOF system would work well and satisfy the requirements of upgrade.
Peer Review Status:Awaiting Review
Subjects: Physics >> Nuclear Physics submitted time 2016-09-01
Abstract: It is proposed to upgrade the endcap time-of-flight (ETOF) of the Beijing Spectrometer III (BESIII) with multi-gap resistive plate chamber (MRPC), aiming at overall time resolution about 80 ps. After the entire electronics system is ready, some experiments, such as heat radiating, irradiation hardness and large-current beam tests,are carried out to certify the electronics' reliability and stability. The on-detector test of the electronics is also performed with the beam at BEPCII E3 line, the test results indicate that the electronics system fulfills its design requirements.
Peer Review Status:Awaiting Review