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Yanqiu Wei,Baozhi Yang,Yunlong Li,Yongcheng Duan,Deyu Tian,Baoxiang He,Chuangfu Chen,Wenjun Liu,Limin Yang 대한수의학회 2020 Journal of Veterinary Science Vol.21 No.4
A fluorescent microsphere-based immunochromatographic strip test (FICT) was developed for the rapid, sensitive, and quantitative detection of porcine reproductive and respiratory syndrome virus (PRRSV) antibodies at the pen-side. The assay was based on the formation of a sandwich immune-complex (anti-pig IgG-PRRSV antibodies-NSP7/N), which was validated by a comparison with IDEXX-ELISA using 3325 clinical specimens. The diagnostic specificity, sensitivity, and accuracy of FICT were 97.28, 93.41, and 94.95%, respectively. FICT showed a good correlation with the virus neutralization assay. Overall, a promising pen-side diagnostic tool was developed for the rapid and quantitative detection of PRRSV antibodies within 15 min.
Measurement of TOF of fast neutrons with <sup>238</sup>U target
Li, Meng,Guan, Yuanfan,Lu, Chengui,Zhang, Junwei,Yuan, Xiaohua,Duan, Limin,Yang, Herun,Hu, Rongjiang,He, Zhiyong,Wei, Xianglun,Ma, Peng,Gan, Zaiguo,Yang, Chunli,Zhang, Hongbin,Chen, Liang,Qiu, Tianli Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.6
We developed a Dual-PPACs detector for fast neutron measurements that consists of two sets of PPAC: conventional PPAC and fission PPAC. A<sup>238</sup>U(U<sub>3</sub>O<sub>8</sub>) coating is placed in the fission PPAC's anode, which is used as the neutrons conversion layer. An experiment was performed to measure neutron time-of-flight (TOF) in which <sup>252</sup>Cf spontaneous fission source was used. An excellent time resolution of 164ps has been observed at 6 mbar in isobutene gas. With the excellent time resolution of Dual-PPACs detector, exact neutron energy can be extracted from the timing measurement. The experimental detection efficiency was 1.9 × 10<sup>-7</sup>, consistent with the efficiency of 2.5 × 10<sup>-7</sup> given by a Geant4 simulation. Ultimately, the results show that the Dual-PPACs detector is a suitable candidate for measuring fast neutrons in the future CiADS system.
The investigation of a new fast timing system based on DRS4 waveform sampling system
Jinda Chen,Chengming Du,Jinda Chen,Herun Yang,Jie kong,Haibo Yang,Peng Ma,Guozhu Shi,limin Duan,Zhengguo Hu 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.2
In the study of nuclear structure, the fast timing technique can be used to measure the lifetime of excitedstates. In the paper, we have developed a new fast timing system, which is made up of two LaBr3:Cedetectors and a set of waveform sampling system. The sampling system based on domino ring samplerversion 4 chip (DRS4) can digitize and store the waveform information of detector signal, with a smallervolume and higher timing accuracy, and the waveform data are performed by means of digital waveformanalysis methods. The coincidence time resolution of the fast timing system for two annihilation 511 keVg photon is 200ps (FWHM), the energy resolution is 3.5%@511 keV, and the energy linear response in thelarge dynamic range is perfect. Meanwhile, to verify the fast timing performance of the system, the152Gd-21þ state form bþ decay of 152Eu source is measured. The measured lifetime is 45.3(±5.0)ps, veryclose to the value of the National Nuclear Data Center (NNDC: 46.2((±3.9)ps). The experimental resultsindicate that the fast timing system is capable of measuring the lifetime of dozens of ps. Therefore, thesystem can be widely used in the research of the fast timing technology.
Power control of CiADS core with the intensity of the proton beam
Kai Yin,Wenjing Ma,Wenjuan Cui,Zhiyong He,Xinxin Li,Shiwu Dang,Feng Yang,Yuhui Guo,Limin Duan,Meng Li,Yikai Hou 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.4
This paper reports the control method for the core power of the China initiative Accelerator DrivenSystem (CiADS) facility. In the CiADS facility, an intense external neutron source provided by a protonaccelerator coupled to a spallation target is used to drive a sub-critical reactor. Without any control rodinside the sub-critical reactor, the core power is controlled by adjusting the proton beam intensity. Inorder to continuously change the beam intensity, an adjustable aperture is considered to be used at theLow Energy Beam Transport (LEBT) line of the accelerator. The aperture size is adjusted based on theProportional Integral Derivative (PID) controllers, by comparing either the setting beam intensity or thesetting core power with the measured value. To evaluate the proposed control method, a CiADS coremodel is built based on the point reactor kinetics model with six delayed neutron groups. The simulations based on the CiADS core model have indicated that the core power can be controlled stably byadjusting the aperture size. The response time in the adjustment of the core power depends mainly onthe adjustment time of the beam intensity
Development of Parallel Plate Avalanche Counter for heavy ion collision in radioactive ion beam
Wei, Xianglun,Guan, Fenhai,Yang, Herun,Wang, Yijie,Zhang, Junwei,Ma, Peng,Diao, Xinyue,Lu, Chengui,Li, Meng,Guan, Yuanfan,Duan, Limin,Hu, Rongjiang,Zhang, Xiuling,Xiao, Zhigang Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.3
We have developed a position-sensitive Parallel Plate Avalanche Counter (PPAC) to detect the fission fragments and reconstruct the fission reaction plane in the experiment of studying nuclear equation of state (nEOS) by means of heavy ion collision (HIC). This experiment put forward high requirements for the performances of PPAC, such as the time resolution, efficiency and position resolution. According to these requirements we designed the PPAC with an active area of 240 mm × 280 mm working at low gas pressure. The results show that time resolution could be less than 300 ps. Position resolution is consistent with the theoretical calculation about 1.35 mm. Detection efficiency could be approaching 100% gradually with the voltage increasing in different gas pressures. The performances of PPAC have also been verified in beam experiment. Each set of anode wires can be accurately separated in the position spectrum. In the beam experiment, we also got the back-to-back correlation of fission fragments which is one of the direct signals characterizing binary decay.