|
Review of nuclear technology in the application of COVID-19 epidemic prevention and control
Zhe WANG, Fanyu LIN, Xian SUN, Gaoyang YE, Yuexiang LU
Nuclear Techniques. 2020, 43 (12):
120001-120001.
DOI: 10.11889/j.0253-3219.2020.hjs.43.120001
In the early stage of the outbreak of COVD-19 in Wuhan city at the end of 2019, the demand for medical protective equipment increased rapidly. Many problems emerged, such as poor quality and short supply of protective masks, shortage of medical supplies caused by long sterilization cycles, difficult treatment of the medical waste and wastewater of which might cause the secondary infection. Herein, three specific applications of nuclear technology were summarized to fight against the COVID-19. The first one is the nuclear pore membrane (NPM) produced by nuclear technology. It can be used to fabricate face masks with high filtration efficiency and good reusability after simple processing. Hence the problems of poor reusability and poor filtration effects of common disposable masks can be solved by using NPM technology. The second application is the radiation sterilization technology in the process of producing medical supplies such as masks and protective clothing. The long cycle of common sterilization technology makes the demand exceed supply whereas the radiation sterilization technology can greatly shorten the production cycle and increase output, which could alleviate the shortage of medical supplies in anti-epidemic process. The third application is the use of γ-ray, X-ray or high-energy electron to sterilize medical wastewater and garbage, among which massive of surviving coronavirus are still infectious. It can treat large-volume of wastewater rapidly with a broad vision of application. Due to these unique advantages, nuclear technology has been playing an important role in this epidemic prevention and control, it possesses broader development prospects in the future.
Figures and Tables |
References |
Related Articles |
Metrics
|
|
Research on application of time-varying tune calculation algorithms on SSRF
Xing YANG,Longwei LAI,Fangzhou CHEN
Nuclear Techniques. 2020, 43 (12):
120101-120101.
DOI: 10.11889/j.0253-3219.2020.hjs.43.120101
BackgroundTune is one of the most important characteristic parameters of storage ring, it seldom changes over time, hence can be obtained by a simple harmonic analysis on the beam position data. In some particular process, tune will change with time. PurposeThis study aims to explore and optimize the time-varying tune calculation algorithms for the tune drift caused by the nonlinear effect of Lattice during the decay of the residual transverse oscillation damping, after the injection of the storage ring. MethodsFirst of all, the applicability of the wavelet algorithm and numerical analysis of fundamental frequencies (NAFF) algorithm for time-varying tune calculation was analyzed, and their performances were on above physical process of nonlinear effect of the storage ring were compared. Then the better Morlet wavelet algorithm was employed to quantitatively analyze the drift of tune during the injection of the Shanghai Synchrotron Radiation Facility (SSRF) storage ring and evaluate the nonlinear intensity changes of the SSRF during different operating period. ResultsAlgorithm comparison results show that both algorithms can realize the dynamic analysis of time-varying tune, but the wavelet method shows better performance. Evaluation results of nonlinear strength change of SSRF storage ring show that when the data analysis window is selected as 6 000 cycles, a track offset change 0.3 mm, and tune change as small as 0.000 1 can be detected. During the period of storage ring injection, the tune changes obviously. ConclusionsBy applying the morlet wavelet algorithm, the complete trajectory of the tune drift can be tracked.
Figures and Tables |
References |
Related Articles |
Metrics
|
|
The detection of synchronous radiation beam position based on position-sensitive semiconductor optoelectronic devices
Nan MENG,Jianrong ZENG,Zhongliang LI,Fenggang BIAN
Nuclear Techniques. 2020, 43 (12):
120102-120102.
DOI: 10.11889/j.0253-3219.2020.hjs.43.120102
BackgroundIn the synchrotron radiation experiment, the position of the beam and the stability of the flux seriously affect the result of experiment. Quantitative evaluation of beam stability is one of key problems in the experiment. It is essential to develop the accurate beam position measurement solution that meets the experimental requirements of the X-ray beams. PurposeThis study aims to detect beam position for synchrotron radiation X-ray experiments by using position sensitive semiconductor detector (PSD) miniature detector. MethodsPin-cushion PSD produced by Hamamatsu company of Japan was adopted for experimental test, and a rectangular beam spot of 5.9 mm×2.0 mm was taken for measurement on BL09B1 beamline of SSRF. When the X-ray beam come into the detector's sensitive region, a current was generated due to photoelectric effect collected by the four electrodes. The location of the incident X-ray beam was determined according to the value of the current given by the galvanometer. In addition, the change of the beam flux was monitored through the total current simultaneously. ResultsExperiment data show that PSD-based miniature detector can meet the needs of synchrotron radiation experiment. For a rectangular spot with a size of 5.9 mm×2.0 mm, the minimum resolution in X and Y direction are 1.5 μm and 1.4 μm, respectively. The signal/noise ratio of PSD detector for beam flux monitoring is more than 4.3×106. ConclusionsThe PSD-based miniature detector can effectively meet the monitoring requirements of spot position, spot size and luminous flux.
Figures and Tables |
References |
Related Articles |
Metrics
|
|
Design of beam homogenization for ground simulation of space electron environment
Changqiang WANG,Yihuai XIANG,Jinhai LI,Jinghe YANG
Nuclear Techniques. 2020, 43 (12):
120201-120201.
DOI: 10.11889/j.0253-3219.2020.hjs.43.120201
BackgroundThe effect of high-energy electrons bombardment on the integrated circuit (IC) for aerospace can be studied by the simulated space electron environment device on the ground. In the device, the high-energy electrons are provided by the electron linear accelerator, and the output beam spot is only on the order of millimeters while the experiment requires a large-area uniform electron irradiation area. PurposeThis study aims to process the beam transmission line to meet irradiation area and uniformity requirements of short beam transmission line and large irradiation area. MethodsTwo-dimensional homogenized beam expansion scheme was designed with the combination of beam expansion and scanning. According to the beam parameters output by the linear accelerator, the solenoid, α-magnet, scanning magnet, quadrupole magnets, focus sextuple magnet and other beam transmission line elements were taken into consideration simultaneously. By adjusting the element parameters through the electron beam tracking code, the electron beam with different energies of 0.5 MeV, 2.5 MeV and 5 MeV were matched with the required irradiation area and uniformity on the irradiation plane. ResultsSimulation results show that the beam uniformities in different irradiation areas for 0.5 MeV, 2.5 MeV and 5 MeV beamline are better than 90%. ConclusionsThe beam homogenization design proposed in this study for ground simulation of space electron environment meets the requirement of effect of high-energy electrons bombardment in extraterrestrial space.
Figures and Tables |
References |
Related Articles |
Metrics
|
|
Design simulation and magnetic field measurement of eddy-current type thin septum magnet for beam injection of diffraction limited storage ring
Jin TONG,Ming GU,Bo LIU,Yongfang LIU
Nuclear Techniques. 2020, 43 (12):
120202-120202.
DOI: 10.11889/j.0253-3219.2020.hjs.43.120202
BackgroundDiffraction-limited storage ring (DLSR) light source is considered to be promising candidate for future light sources within higher brightness, better transverse coherence and better stability. The challenge of DLSR design is how to achieve the ultra-low beam emittance with acceptable nonlinear performance. Short-pulse kickers such as strip-lines along with thin septum magnet could support on-axis injection of DLSR, while the traditional off-axis injection becomes inadequate. PurposeThis study aims to design and measure the magnetic field measurement of eddy-current type thin septum magnet for beam injection of diffraction limited storage ring. MethodsThe scheme of eddy-current type thin septum magnet (the thinnest thickness is 0.9 mm) was adopted, and the magnetic core was laminated silicon steel sheet. Theoretical analysis and simulation of the main field and leakage field that decayed with time were carried out by using Opera 2D/3D magnetic field analysis software. Special attention was paid to optimize the structure and processing of the septa. Point coil, long coil, integrator and oscilloscope were used to measure the magnetic field of the assembled thin septum magnet. ResultsThe experimental measurement data and 3D dynamic calculation results show that the integral peak ratio of leakage field at 3 mm away from the septa is less than 0.1% with respect to the physical requirement. ConclusionsThis study lays a foundation for injection design of future advanced light source storage ring.
Figures and Tables |
References |
Related Articles |
Metrics
|
|
Preparation of sodium alginate-based super absorbent polymer by radiation grafting and crosslinking
Feng YE,Yu GU,Fei HAN,Xiao XU,Chen HUANG,Lin MA,Renhao DING,Hongjuan MA,Jingye LI
Nuclear Techniques. 2020, 43 (12):
120301-120301.
DOI: 10.11889/j.0253-3219.2020.hjs.43.120301
BackgroundSuper absorbent polymer (SAP) is a new type of polymer material. SAP is rich in hydrophilic groups, hence can absorb at least one hundred times of its own volume and swell while keeping the water from losing for a certain period of time. PurposeThis study aims to synthesize a new SAP for soil and forestry water conservation. MethodsIn this paper, sodium alginate (SA) was used as the raw material, acrylic acid (AA) was used as the monomer, and N,N-methylene bisacrylamide (MBA) was used as the crosslinking agent. SA-g-AA SAP with three-dimensional network structure was prepared by co-radiation grafting. The chemical structures and surface morphologies of the SA-g-AA SAP were characterized by fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis and scanning electron microscope (SEM). ResultsThe results showed that when the temperature was 65 ℃, the absorbed dose was 5 kGy, the mass ratio of AA to SA was 5:1, the amount of the crosslinking agent MBA was 1.25 wt%, and the AA neutralization degree was 75%, the maximum water absorption ratio of the SA-g-AA SAP reached 579.8 g?g-1. After the water absorption reused for 7 times, its water absorption ratio maintained 92.5% of the initial value. It showed that the SA-g-AA SAP had good reusability of water absorption performance; after reaching the saturated water absorption ratio, water-retaining property could be retained for up to 15 days, which showed it had good water retention performance. ConclusionsThis SAP material shows potential application in water retention and desertification control.
Figures and Tables |
References |
Related Articles |
Metrics
|
|
Simulation analysis and verification of energy response of space neutron detector
Xuan WEN,Heng AN,Shengsheng YANG,Yi WANG,Siyuan CHANG,Xin GAO,Jun WANG,Chenguang ZHANG,Zhanzu FENG
Nuclear Techniques. 2020, 43 (12):
120401-120401.
DOI: 10.11889/j.0253-3219.2020.hjs.43.120401
BackgroundSpace neutrons can cause damage to the electronic systems of orbiting spacecraft and may pose a serious threat to the lives of astronauts on mission. PurposeThis study aims to accurately analyze the characteristics of the space neutron environment to ensure the reasonable design of spacecraft's anti-radiation reinforcement and the safety of astronauts. MethodsMonte Carlo method based Fluka software was employed to simulate, analyze and design a composite structure neutron detector based on plastic scintillator. Simulation analysis from the aspects of probe size, structure position, detection efficiency, anti-coincidence structure, etc., was performed to determine the 0.5 mm, 3 mm gradient composite structure of the detector by using 14~25 MeV single energy neutrons for experimental verification. ResultsThe simulation and experimental results show that the designed detector can be used for space station cabin neutron environment and near-Earth space neutron detection. ConclusionsThis study provides theoretical and technical support for subsequent engineering load design.
Figures and Tables |
References |
Related Articles |
Metrics
|
|
Helical gamma scanning technique for activity detection of radioactive waste drum
Xinhai TANG,Weiguo GU,Hui YANG,Dezhong WANG
Nuclear Techniques. 2020, 43 (12):
120501-120501.
DOI: 10.11889/j.0253-3219.2020.hjs.43.120501
BackgroundNon-destructive assay (NDA) is a widely used method to assay the amount and categories of radioactive nuclides within the waste drum, segmented gamma scanning (SGS) is a normal method. PurposeThis study aims to evaluate the performance of helical gamma scanning (HGS) for 400-liter waste drum. MethodsBased on SGS, a new HGS detection method was proposed. The scanning mode and reconstruction algorithm were improved in SGS to realize continuous scanning measurement. Monte-Carlo method was employed to simulate the reconstruction process of three nuclides in a 400-liter waste drum filled with three different density media. Results of three point sources and three homogeneous medium materials were compared. ResultsAt low density, the root mean square error of SGS is more than 8%, while that of HGS is less than 6.5%. At medium density, the reconstruction error of SGS is more than -55%, which seriously underestimates the risk of waste drum. Compared with SGS, HGS saves at least half of the measurement time. ConclusionsHGS technology is suitable for measuring 400-liter waste drum whose density is low and medium. The measurement time of HGS is less than SGS and tomographic gamma scanning (TGS). The measurement accuracy of HGS is better than SGS.
Figures and Tables |
References |
Related Articles |
Metrics
|
|
Experimental study on the total ionizing dose effects of nonvolatile RRAM
Siyuan CHANG,Shengsheng YANG,Xuan WEN,Heng AN,Yi WANG,Zhou CAO,Hong YIN
Nuclear Techniques. 2020, 43 (12):
120502-120502.
DOI: 10.11889/j.0253-3219.2020.hjs.43.120502
BackgroundAs an indispensable part of spacecraft electronic systems, memory device is required to have good radiation resistance in aerospace applications . Resistive random access memory (RRAM) is a new type of non-volatile semiconductor memory with excellent performance, but little attention has been paid on its radiation effect research. PurposeThis study aims to investigate the failure mechanism of RRAM total ionizing dose effects. MethodsFirst of all, on the basis of theoretical analysis, combined with the results of 60Co γ irradiation test. The total ionizing dose effect failure mechanism of a single metal-oxide-semiconductor field-effect transistor (MOSFET) in RRAM was analyzed. Two hypotheses on the failure mechanism of the device were put forward. Then, irradiation experiments were carried out on devices with different initial data written, and the data reading function and static operating current of the memory under different cumulative doses were measured. Results & ConclusionsThe experimental results obtained by statistics verify the correctness of the hypothesis. The radiation sensitive unit of RRAM is the memory array, and the failure of the RRAM reading function is caused by the leakage current generated by the MOSFET under irradiation, which changes the level output state of the reading circuit.
Figures and Tables |
References |
Related Articles |
Metrics
|
|
Neutronic performances of small modular thorium-based molten salt reactor starting with TRUs
Chunyan ZOU,Chenggang YU,Guifeng ZHU,Wei GUO,Xiangzhou CAI,Jingen CHEN,Yang ZOU
Nuclear Techniques. 2020, 43 (12):
120601-120601.
DOI: 10.11889/j.0253-3219.2020.hjs.43.120601
BackgroundTransuranic isotopes (TRUs) in the spent fuel of pressurized water reactor (PWR) contain more than 50% of fissile fuels and can be used as a starting fissile fuel for thorium fuel cycle. PurposeThis study aims to analyze the neutronic performances of a small modular thorium-based molten salt reactor (SM-TMSR) core with TRUs as fissile fuel and Th as fertile fuel. MethodsConsidering the batch reprocessing period and the limit value of the inherent safety, proper scenarios for thorium utilization in the SM-TMSR initiated by TRUs were proposed for the evaluation of the neutronic characteristics. Reactor analysis software SCALE6.1 was employed to analyze the influences of two important parameters (fuel volume fraction and initial heavy metal mole fraction) on the characteristics of neutron spectrum, 233U production, graphite life, temperature coefficient, TRUs consumption, etc. Results & ConclusionsThe calculation results show that TRUs are an ideal fuel for starting Th-U fuel cycle of the SM-TMSR. Considering the constraints of the graphite's five-year life and the intrinsic safety (-5~-8 pcm?K-1), the core with 6% heavy metal mole fraction and 25% fuel volume fraction can obtain a preferable fuel utilization efficiency. With the thermal power of 150 MW for 5-year full-power operation, the uranium production is about 16.0 kg?a-1 and the transmutation rate of TRUs can achieve about 36.1 kg?a-1, which can effectively reduce the spent fuel containing TRUs.
Figures and Tables |
References |
Related Articles |
Metrics
|
|
Optimization of critical extrapolation for the restart of China advanced research reactor
Huaichang RAN,Jianxiao ZHEN,Jianlong LI,Yanyan GE,Yulin WANG
Nuclear Techniques. 2020, 43 (12):
120602-120602.
DOI: 10.11889/j.0253-3219.2020.hjs.43.120602
BackgroundCritical extrapolation is necessary during the restart of China advanced research reactor (CARR) after a long shutdown period. The photoneutron in the heavy water tank is not only the neutron source during the reactor restart, but also the background of the detector. During the extrapolation process, the background neutron makes the extrapolation curve "convex", and the extrapolated critical rod position is overtakes the actual critical rod position, so the extrapolation process is dangerous. PurposeThis study aims to optimize critical extrapolation by making use of neutron background value of detector. MethodsBased on the control rod grid worth curve in CARR and extrapolation formula, the background value was obtained by fitting method to improve the extrapolation process. The critical extrapolation formula of control rod was derived, and the background value was obtained by fitting with the measured neutron numbers corresponding to different rod positions in the experiment. Then, the background value was applied to the correction of extrapolated critical rod position value. ResultsThe extrapolation results show obvious improvement, and the modified extrapolated rod position basically satisfies the linear relationship between the experimental rod position and the reciprocal of detection neutron count. ConclusionsThe data fitting method can get the background value of the detector, which can significantly improve the extrapolation process.
Figures and Tables |
References |
Related Articles |
Metrics
|
|