Research Highlight
VIEWPOINT AND RESEARCH HIGHLIGHT
2023-03-20 14:16:49
VIEWPOINT AND RESEARCH HIGHLIGHT
2023-02-13 14:18:28
VIEWPOINT AND RESEARCH HIGHLIGHT
2023-02-13 14:18:28
Latest Articles
NUCLEAR ELECTRONICS AND INSTRUMENTATION
Design and development of multi-channel front end electronics based on dual-polarity charge-to-digital converter for SiPM detector applications
Abstract：With the development of silicon photomultiplier (SiPM) technology, front-end electronics for SiPM signal processing have been highly sought after in various fields. A compact 64-channel front-end electronics (FEE) system achieved by field-programmable gate array-based charge-to-digital converter (FPGA-QDC) technology was built and developed. The FEE consists of an analog board and FPGA board. The analog board incorporates commercial amplifiers, resistors, and capacitors. The FPGA board is composed of a low-cost FPGA. The electronics performance of the FEE was evaluated in terms of noise, linearity, and uniformity. A positron emission tomography (PET) detector with three different readout configurations was designed to validate the readout capability of the FEE for SiPM-based detectors. The PET detector was made of a 15 × 15 lutetium–yttrium oxyorthosilicate (LYSO) crystal array directly coupled with a SiPM array detector. The experimental results show that FEE can process dual-polarity charge signals from the SiPM detectors. In addition, it shows a good energy resolution for 511-keV gamma photons under the dual-end readout for the LYSO crystal array irradiated by a Na-22 source. Overall, the FEE based on FPGA-QDC shows promise for application in SiPM-based radiation detectors.NUCLEAR ENERGY SCIENCE AND ENGINEERING
Efficient and selective extraction of uranium from seawater based on a novel pulsed liquid chromatography radionuclide separation method
Abstract：The novel pulsed liquid chromatography radionuclide separation method presented here provides a new and promising strategy for the extraction of uranium from seawater. In this study, a new chromatographic separation method was proposed, and a pulsed nuclide automated separation device was developed, alongside a new chromatographic column. The length of this chromatographic column was 10 m, with an internal warp of 3 mm and a packing size of 1 mm, whilst the total separation units of the column reached 12,250. The most favorable conditions for the separation of nuclides were then obtained through optimizing the separation conditions of the device: Sample pH in the column = 2, sample injection flow rate = 5.698 mL/min, chromatographic column heating temperature = 60 ℃. Separation experiments were also carried out for uranium, europium, and sodium ions in mixed solutions; Uranium and sodium ions in water samples from the Ganjiang River; and uranium, sodium, and magnesium ions from seawater samples. The separation factors between the different nuclei were then calculated based on the experimental data, and a formula for the separation level was derived. The experimental results showed that the separation factor in the mixed solution of uranium and europium (1:1) was 1.088, whilst achieving the initial separation of uranium and europium theoretically required a 47-stage separation. Considering the separation factor of 1.50 for the uranium and sodium ions in water samples from the Ganjiang River, achieving the initial separation of uranium and sodium ions would have theoretically required at least a 21-stage separation. Furthermore, for the seawater sample separation experiments, the separation factor of uranium and sodium ions was 1.2885, therefore more than 28 stages of sample separation would be required to achieve uranium extraction from seawater. The novel pulsed liquid chromatography method proposed in this study was innovative in terms of uranium separation and enrichment, whilst expanding the possibilities of extracting uranium from seawater through chromatography.NUCLEAR ENERGY SCIENCE AND ENGINEERING
On the transient models of the VITAS code: applications to the C5G7-TD pin-resolved benchmark problem
Abstract：This article describes the transient models of the neutronics code VITAS that are used for solving time-dependent, pin-resolved neutron transport equations. VITAS uses the stiffness confinement method (SCM) for temporal discretization to transform the transient equation into the corresponding transient eigenvalue problem (TEVP). To solve the pin-resolved TEVP, VITAS uses a heterogeneous variational nodal method (VNM). The spatial flux is approximated at each Cartesian node using finite elements in the x-y plane and orthogonal polynomials along the z-axis. Angular discretization utilizes the even-parity integral approach at the nodes and spherical harmonic expansions at the interfaces. To further lower the computational cost, a predictor-corrector quasi-static SCM (PCQ-SCM) was developed. Within the VNM framework, computational models for the adjoint neutron flux and kinetic parameters are presented. The direct-SCM and PCQ-SCM were implemented in VITAS and verified using the two-dimensional (2D) and three-dimensional (3D) exercises on the OECD/NEA C5G7-TD benchmark. In the 2D and 3D problems, the discrepancy between the direct-SCM solver’s results and those reported by MPACT and PANDAS-MOC was under 0.97% and 1.57%, respectively. In addition, numerical studies comparing the PCQ-SCM solver to the direct-SCM solver demonstrated that the PCQ-SCM enabled substantially larger time steps, thereby reducing the computational cost 100-fold, without compromising numerical accuracy.NUCLEAR ENERGY SCIENCE AND ENGINEERING
Construction of fault diagnosis system for control rod drive mechanism based on knowledge graph and bayesian inference
Abstract：Knowledge graph technology has distinct advantages in terms of fault diagnosis. In this study, the control rod drive mechanism (CRDM) of the liquid fuel thorium molten salt reactor (TMSR-LF1) was taken as the research object, and a fault diagnosis system was proposed based on knowledge graph. The Subject-Relation-Object triples are defined based on CRDM unstructured data, including design specification, operation and maintenance manual, alarm list, and other forms of expert experience. In this study, we constructed a fault event ontology model to label the entity and relationship involved in the corpus of CRDM fault events. A three-layer robustly optimized bidirectional encoder representation from transformers (RBT3) pretraining approach combined with a text convolutional neural network (TextCNN) was introduced to facilitate the application of the constructed CRDM fault diagnosis graph database for fault query. The RBT3-TextCNN model along with the Jieba tool is proposed for extracting entities and recognizing the fault query intent simultaneously. Experiments on the dataset collected from TMSR-LF1 CRDM fault diagnosis unstructured data demonstrate that this model has the potential to improve the effect of intent recognition and entity extraction. Additionally, a fault alarm monitoring module was developed based on WebSocket protocol to deliver detailed information about the appeared fault to the operator automatically. Furthermore, the Bayesian inference method combined with the variable elimination algorithm was proposed to enable the development of a relatively intelligent and reliable fault diagnosis system. Finally, a CRDM fault diagnosis Web interface integrated with graph data visualization was constructed, making the CRDM fault diagnosis process intuitive and effective.VIEWPOINT AND RESEARCH HIGHLIGHT
ACCELERATOR, RAY TECHNOLOGY AND APPLICATIONS
On-chip stackable dielectric laser accelerator
Abstract：In this paper, we propose a novel stacked laser dielectric acceleration structure. This structure is based on the inverse Cherenkov effect and represented by a parametric design formulation. Compared to existing dielectric laser accelerators relying on the inverse Smith–Purcell effect, the proposed structure provides an extended-duration synchronous acceleration field without requiring the pulse front tilting technique. This advantage significantly reduces the required pulse duration. In addition, the easy-to-integrate layered structure facilitates cascade acceleration, and simulations have shown that low-energy electron beams can be cascaded through high gradients over extended distances. These practical advantages demonstrate the potential of this new structure for future chip accelerators.
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- THE MEASUREMENT OF SLIGHT WEAR OF ENGINEERING PLASTIC COMPOSITES USING NEUTRON ACTIVATION ANALYSIS
- Therapeutic safety evaluation of sodium glycididazole combined with 131I radiotherapy for differentiated thyroid carcinoma
- STUDY OF HYDROGEN IN ANNEALED AMORPHOUS SILICON AND IMPLANTED AMORPHOUS CARBON
- Single neutron hole entropy in 105Cd and 111Cd
- DEPTH PROFILING OF 1H AND/OR 4He IN SOLIDS BY ERD WITH 19F IONS
- Phase changes of the ZrO2-12 wt%Y2O3 film with Ar+ irradiation
- Magnetic flux leakage analysis and compensation of high-frequency planar insulated core transformer
- Re-estimation of absolute gamma ray intensities of 56Mn using
k 0-standardization - TOTAL AND METHYL MERCURY LEVELS IN HUMAN SCALP HAIRS
- First commissioning results of the coherent scattering and imaging endstation at the Shanghai soft X-ray Free-Electron Laser facility
- Commissioning the photocathode radio frequency gun: a candidate electron source for Hefei Advanced Light Facility
- A high fidelity general purpose 3-D Monte Carlo particle transport program JMCT3.0
- Analysis and simulation of the tune ripple effect on beam spill ripple in RF-KO slow extraction
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Accurate Prediction of Cross-section of Extremely Rare Isotope
Announcement 28 Feb 2023
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State-of-the-Art CEPC 650 MHz Superconducting Radio-Frequency Cavity
Announcement 11 Jan 2023 -
Mature Software for 3D Bunch Position & Charge Measurement
Announcement 22 Nov 2022 -
Nuclear System Design via JMCT3.0 Particle Transport Program
Announcement 22 Nov 2022 -
State-of-the-art Commercial 600 MWe HTGR Nuclear Power Plant
Announcement 12 Oct 2022 -
New SSRF Facility: Laser Electron Gamma Beamline SLEGS
Announcement 20 Spt 2022 -
Low-background Neutron Detector for Precise Measurement of Reaction Cross-Section
Announcement 3 Aug 2022
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