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Study of neutron production and moderation for sulfur neutron capture therapy 预览
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作者 Meng Peng Guo-Zhu He +3 位作者 Qi-Wei Zhang Bin Shi Hong-Qing Tang Zu-Ying Zhou 《核技术:英文版》 SCIE CAS CSCD 2019年第1期59-66,共8页
Neutron capture therapy with Sulfur-33, similar to boron neutron capture therapy with Boron-10, is effective in treating some types of tumors including ocular melanoma. The key point in sulfur neutron capture therapy ... Neutron capture therapy with Sulfur-33, similar to boron neutron capture therapy with Boron-10, is effective in treating some types of tumors including ocular melanoma. The key point in sulfur neutron capture therapy is whether the neutron beam flux and the resonance capture cross section of 33S(n;α)30 Si reaction at 13.5 keV can achieve the requirements of radiotherapy. In this research,the authors investigated the production of 13.5 keV neutron production and moderation based on an accelerator neutron source. A lithium glass detector was used to measure the neutron flux produced via near threshold7 Li(p,n)7 Be reaction using the time-of-flight method. Furthermore, the moderation effects of different kinds of materials were investigated using Monte Carlo simulation. 展开更多
关键词 SULFUR NEUTRON CAPTURE THERAPY BORON NEUTRON CAPTURE THERAPY 33S(n α)3 Si resonance reaction 7Li(p n)^7 Be NEUTRON source
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The symmetry energy and incompressibility constrained by the observations of glitching pulsars
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作者 Yan Yan 《天文和天体物理学研究:英文版》 SCIE CAS CSCD 2019年第5期101-112,共12页
We investigate the masses of glitching pulsars in order to constrain their equation of state(EOS). The observations of glitches(sudden jumps in rotational frequency) may provide information on the interior physics of ... We investigate the masses of glitching pulsars in order to constrain their equation of state(EOS). The observations of glitches(sudden jumps in rotational frequency) may provide information on the interior physics of neutron stars. With the assumption that glitches are triggered by superfluid neutrons, the masses of glitching neutron stars can be estimated using observations of maximum glitches.Together with the observations of thermal emission from glitching pulsars Vela and J1709–4429, the slope of symmetry energy and incompressibility of nuclear matter at saturation density can be constrained.The slope of symmetry energy L should be larger than 67 MeV while the lower limit of incompressibility for symmetric nuclear matter K0 is 215 MeV. We also obtain a relationship between L and K0:6.173 MeV + 0.283 K0≤ L ≤ 7.729 MeV + 0.291 K0. The restricted EOSs are consistent with the observations of 2-solar-mass neutron stars and gravitational waves from a binary neutron star inspiral. 展开更多
关键词 NEUTRON stars:glitch NEUTRON stars:cooling NEUTRON stars:tidal DEFORMABILITY nuclear physics:symmetry ENERGY
Calculation of the wide-angle neutron spectra from the 9Be(d,xn) reaction in a thick beryllium target
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作者 韦峥 王俊润 +11 位作者 张雅玲 黄智武 马占文 张杰 丁琰琰 夏莉 李建一 卢小龙 张宇 徐大鹏 杨磊 姚泽恩 《中国物理C:英文版》 SCIE CAS CSCD 2019年第5期29-34,共6页
The multi-layer computing model is developed to calculate wide-angle neutron spectra, in the range from0° to 180° with a 5° step, produced by bombarding a thick beryllium target with deuterons. The doub... The multi-layer computing model is developed to calculate wide-angle neutron spectra, in the range from0° to 180° with a 5° step, produced by bombarding a thick beryllium target with deuterons. The double-differential cross-sections(DDCSs) for the 9 Be(d, xn) reaction are calculated using the TALYS-1.8 code. They are in agreement with the experimental data, and are much better than the PHITS-JQMD/GEM results at 15°, 30°, 45° and 60° neutron emission angles for deuteron energy of 10.0 MeV. In the TALYS-1.8 code, neutron contributions from direct reactions(break-up, stripping and knock-out reactions) are controlled by adjustable parameters, which describe the basic characteristics of typical direct reactions and control the relative intensity and the position of the ridgy hillock at the tail of DDCSs. It is found that the typical calculated wide-angle neutron spectra for different neutron emission angles and neutron angular distributions agree quite well with the experimental data for 13.5 MeV deuterons. The multi-layer computing model can reproduce the experimental data reasonably well by optimizing the adjustable parameters in the TALYS-1.8 code. Given the good agreement with the experimental data, the multi-layer computing model could provide better predictions of wide-angle neutron energy spectra, neutron angular distributions and neutron yields for the 9 Be(d, xn) reaction neutron source. 展开更多
关键词 NEUTRON source 9Be(d xn) REACTION THICK TARGET WIDE-ANGLE NEUTRON spectra NEUTRON angular distributions
航空电子设备大气辐射环境的危害影响分析 预览
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作者 陈宇 李明 傅耘 《装备环境工程》 CAS 2019年第9期109-112,共4页
目的调查航空电子设备在典型民用飞行高度(8 000~12 000 m)下大气辐射环境的危害影响。方法利用14 MeV高能中子源对航空电子设备用CPU、DSP、FPGA及存储器开展了辐照试验,获取了各试件的单粒子效应敏感特性,采用民航高度下大气中子注量... 目的调查航空电子设备在典型民用飞行高度(8 000~12 000 m)下大气辐射环境的危害影响。方法利用14 MeV高能中子源对航空电子设备用CPU、DSP、FPGA及存储器开展了辐照试验,获取了各试件的单粒子效应敏感特性,采用民航高度下大气中子注量率的典型值6000 n/(cm^2·s),预计典型航空电子设备在巡航高度下可能发生的软错误率。结果约900 h内,该航空电子设备会由于大气辐射单粒子效应诱发一次错误。结论在不采取针对性防护措施的前提下,大气中子诱发的单粒子效应将严重影响航空电子设备可靠性、维修性,甚至危及飞行安全。 展开更多
关键词 航空电子设备 大气辐射 中子 中子诱发的单粒子效应 软错误率
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A study of PFBR auxiliary neutron source strength activation and its variability with respect to the neutron spectrum and 123Sb capture cross section 预览
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作者 G.Pandikumar D.Sunil Kumar +4 位作者 M.M.Shanthi Bagchi Subhrojit A.John Arul D.Venkata Subramanian Rajeev Ranjan Prasad 《核技术:英文版》 SCIE CAS CSCD 2019年第8期114-122,共9页
In fast reactors, the inherent neutron source strength is often insufficient for monitoring the reactor start-up operation with ex-core detectors. To increase the subcritical neutron flux, an auxiliary neutron source ... In fast reactors, the inherent neutron source strength is often insufficient for monitoring the reactor start-up operation with ex-core detectors. To increase the subcritical neutron flux, an auxiliary neutron source subassembly(SSA) is generally used to overcome this problem. In this study, the estimated neutron source strength and detector count rate of an antimony-beryllium-based SSA are obtained using the deterministic transport code DORT and Monte Carlo calculations. Because the antimony activation rate is a critical parameter, its sensitivity to the capture cross section and neutron flux spectrum is studied. The reaction cross section sensitivity is studied by considering data from different evaluated nuclear data files.It is observed that, because of the variation in the cross sections from different evaluated nuclear data files, the values of the saturation gamma(> 1.67 MeV) activity and neutron strength predicted by ORIGEN2 lie within ±2%.The obtained antimony activation rate and sensitivity to the neutron flux are partially validated by irradiating samples of antimony in the KAMINI reactor. The average onegroup capture cross sections of bare and cadmium-covered 123Sb samples obtained by the ratio method are 4.0 and 1.78 b, respectively. The results of the calculation predicting the activated neutron source strength as a function of operating time and sensitivity to the neutron spectrum in the irradiation region are also presented. 展开更多
关键词 Fast reactors NEUTRON source Coremonitoring NEUTRON and GAMMA transport Antimonyactivation Material depletion
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Measurement of the neutron total cross section of carbon at the Back-n white neutron beam of CSNS 预览
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作者 Xing-Yan Liu Yi-Wei Yang +78 位作者 Rong Liu Jie Wen Zhong-Wei Wen Zi-Jie Han Zhi-Zhou Ren Qi An Huai-Yong Bai Jie Bao Ping Cao Qi-Ping Chen Yong-Hao Chen Pin-Jing Cheng Zeng-Qi Cui Rui-Rui Fan Chang-Qing Feng Min-Hao Gu Feng-Qin Guo Chang-Cai Han Guo-Zhu He Yong-Cheng He Yue-Feng He Han-Xiong Huang Wei-Ling Huang Xi-Ru Huang Xiao-Lu Ji Xu-Yang Ji Hao-Yu Jiang Wei Jiang Han-Tao Jing Ling Kang Ming-Tao Kang Bo Li Lun Li Qiang Li Xiao Li Yang Li Shu-Bin Liu Guang-Yuan Luan Ying-Lin Ma Chang-Jun Ning Bin-Bin Qi Jie Ren Xi-Chao Ruan Zhao-Hui Song Hong Sun Xiao-Yang Sun Zhi-Jia Sun Zhi-Xin Tan Hong-Qing Tang Jing-Yu Tang Peng-Cheng Wang Qi Wang Tao-Feng Wang Yan-Feng Wang Zhao-Hui Wang Zheng Wang Qing-Biao Wu Xiao-Guang Wu Xuan Wu Li-Kun Xie Han Yi Li Yu Tao Yu Yong-Ji Yu Guo-Hui Zhang Jing Zhang Lin-Hao Zhang Li-Ying Zhang Qing-Min Zhang Qi-Wei Zhang Xian-Peng Zhang Yu-Liang Zhang Zhi-Yong Zhang Ying-Tan Zhao Liang Zhou Zu-Ying Zhou Dan-Yang Zhu Ke-Jun Zhu Peng Zhu 《核技术:英文版》 SCIE CAS CSCD 2019年第9期73-82,共10页
To verify the performance of the neutron total cross-sectional spectrometer, the neutron total cross section of carbon is initially measured in the energy range of 1 eV to 20 MeV using the time-of-flight method. The m... To verify the performance of the neutron total cross-sectional spectrometer, the neutron total cross section of carbon is initially measured in the energy range of 1 eV to 20 MeV using the time-of-flight method. The measurement is performed at the Back-n white neutron source with a 76-m time-of-flight path using the China Spallation Neutron Source. A multilayer fast fission chamber with 235U and 238U is employed as the neutron detector. The diameter and thickness of the natural graphite sample are 70 mm and 40 mm, respectively. Signal waveforms are collected using a data acquisition system. Off-line data processing was used to obtain the neutron time-of-flight spectra and transmissions. The uncertainty of the counting statistics is generally approximately 3% for each bin in the energy range of 1–20 MeV. It is determined that the results for the neutron total cross section of carbon obtained using ^235U cells are in good agreement with the results obtained using 238U cells within limits of statistical uncertainty. Moreover, the measured total cross sections show good agreement with the broadening evaluated data. 展开更多
关键词 CSNS Back-n WHITE NEUTRON source NTOX NEUTRON total cross section CARBON Multilayer fast FISSION chamber
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Activation cross-sections of titanium isotopes at neutron energies of 13.5–14.8 MeV
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作者 周丰群 宋月丽 +2 位作者 李勇 孙小军 袁书卿 《中国物理C:英文版》 SCIE CAS CSCD 2019年第9期33-45,共13页
The cross-sections for 46Ti(n,2n)45Ti,46Ti(n,p)46m+gSc+47Ti(n,d*)46m+gSc,46Ti(n,p)46m+gSc,47Ti(n,p)47Sc+48Ti(n,d*)47Sc,47Ti(n,p)47Sc,48Ti(n,p)48Sc+49Ti(n,d*)48Sc,48Ti(n,p)48Sc,and 50Ti(n,α)47Ca reactions were investi... The cross-sections for 46Ti(n,2n)45Ti,46Ti(n,p)46m+gSc+47Ti(n,d*)46m+gSc,46Ti(n,p)46m+gSc,47Ti(n,p)47Sc+48Ti(n,d*)47Sc,47Ti(n,p)47Sc,48Ti(n,p)48Sc+49Ti(n,d*)48Sc,48Ti(n,p)48Sc,and 50Ti(n,α)47Ca reactions were investigated around neutron energies of 13.5–14.8 MeV by means of the activation technique.Fast neutrons were produced by the 3H(d,n)4He reaction.Neutron energies from different directions in the measurements were obtained in advance using the method of cross-section ratios for 90Zr(n,2n)89m+gZr and 93Nb(n,2n)92mNb reactions.The results obtained are analyzed and compared with the experimental data provided by the literature and verified nuclear data in the JEFF-3.3,CENDL-3.1,ENDF/B-VIII.0 libraries,as well as results calculated by Talys-1.9 code. 展开更多
关键词 TITANIUM NEUTRON reaction cross section D-T NEUTRON ACTIVATION technique
Studies on unfolding energy spectra of neutrons using maximumlikelihood expectation–maximization method 预览
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作者 Mehrdad Shahmohammadi Beni D.Krstic +1 位作者 D.Nikezic K.N.Yu 《核技术:英文版》 SCIE CAS CSCD 2019年第9期24-33,共10页
Energy spectra of neutrons are important for identification of unknown neutron sources and for determination of the equivalent dose. Although standard energy spectra of neutrons are available in some situations, e.g.,... Energy spectra of neutrons are important for identification of unknown neutron sources and for determination of the equivalent dose. Although standard energy spectra of neutrons are available in some situations, e.g., for some radiotherapy treatment machines, they are unknown in other cases, e.g., for photoneutrons created in radiotherapy rooms and neutrons generated in nuclear reactors. In situations where neutron energy spectra need to be determined, unfolding the required neutron energy spectra using the Bonner sphere spectrometer (BSS) and nested neutron spectrometer (NNS) has been found promising. However, without any prior knowledge on the spectra, the unfolding process has remained a tedious task. In this work, a standalone numerical tool named ‘‘NRUunfold’’ was developed which could satisfactorily unfold neutron spectra for BSS or NNS, or any other systems using similar detection methodology. A generic and versatile algorithm based on maximum-likelihood expectation– maximization method was developed and benchmarked against the widely used STAY’SL algorithm which was based on the least squares method. The present method could output decent results in the absence of precisely calculated initial guess, although it was also remarked that employment of exceptionally bizarre initial spectra could lead to some unreasonable output spectra. The neutron count rates computed using the manufacturer’s response functions were used for sensitivity studies. The present NRUunfold code could be useful for neutron energy spectrum unfolding for BSS or NNS applications in the absence of a precisely calculated initial guess. 展开更多
关键词 NEUTRON spectrometry MAXIMUM-LIKELIHOOD expectation–maximization Nested NEUTRON spectrometer
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Nucleonic ^1S0 Superfluidity Induced by a Soft Pion in Neutron Star Matter with Antikaon Condensations
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作者 许妍 支启军 +4 位作者 王夷博 黄修林 丁文波 喻孜 刘承志 《中国物理快报:英文版》 SCIE CAS CSCD 2019年第6期12-16,共5页
The nucleonic 1S0 superfluidity is investigated by solving the gap equation for the Reid soft-core potential as the nucleon-nucleon interaction in neutron star(NS) matter which is considered to be made up of p, e,μ a... The nucleonic 1S0 superfluidity is investigated by solving the gap equation for the Reid soft-core potential as the nucleon-nucleon interaction in neutron star(NS) matter which is considered to be made up of p, e,μ and condensed antikaon matter. We mainly study the influence of the soft pion-induced potential on the nucleonic1S0 pairing gaps in the above NS matter. It is found that the intensities of the nucleonic 1S0 pairing gaps including the soft pion-induced potential are smaller than those calculated in the case of not including the soft pion-induced potential. Furthermore, the nucleonic 1S0 pairing gaps with the soft pion-induced potential fall into decline with the deepening of the optical potential of antikaons in the above NS matter, whereas they increase with the parameter η for the fixed optical potential of antikaons. Due to the appearance of the soft pion-induced potential, the maximum values of nucleonic 1S0 pairing gaps at parameter η= 0.20,0.55 are suppressed by1.7%-6.8% with respect to the case without soft pion-induced potential in the above NS matter. 展开更多
关键词 NEUTRON star(NS) Antikaon CONDENSATIONS SOFT PION
Insight-HXMT observations of the Crab pulsar
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作者 You-Li Tuo Ming-Yu Ge +3 位作者 Li-Ming Song Lin-Li Yan Qing-Cui Bu Jin-Lu Qu 《天文和天体物理学研究:英文版》 SCIE CAS CSCD 2019年第6期109-116,共8页
We report on X-ray emission properties of the Crab pulsar(PSR B0531+21) using observations by Insight-HXMT during its first year after launch. We obtained high signal-to-noise profiles in the X-ray energy band 11–250... We report on X-ray emission properties of the Crab pulsar(PSR B0531+21) using observations by Insight-HXMT during its first year after launch. We obtained high signal-to-noise profiles in the X-ray energy band 11–250 keV. We have confirmed an increase in the flux ratio of the second peak over the main peak with increasing energy, consistent with other missions. The separation of the two peaks shows no significant trend with increasing energy. The phase-averaged spectrum, fitted by a logpar model, and the phase-resolved spectra of the Crab pulsar, fitted by a powerlaw in the different energy bands of HXMT, are consistent with RXTE and NuSTAR in that photon indices evolve as a function of phase as well as a function of energy, contributing to a broadband modeling. 展开更多
关键词 STARS NEUTRON star-pulsars individual(Crab)-X-rays
Pulsar giant pulse: Coherent instability near light cylinder
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作者 WeiYang Wang JiGuang Lu +3 位作者 SongBo Zhang XueLei Chen Rui Luo RenXin Xu 《中国科学:物理学、力学、天文学英文版》 SCIE EI CAS CSCD 2019年第7期113-122,共10页
Giant pulses(GPs) are extremely bright individual pulses of radio pulsar. In microbursts of Crab pulsar, which is an active GP emitter, zebra-pattern-like spectral structures are observed, which are reminiscent of the... Giant pulses(GPs) are extremely bright individual pulses of radio pulsar. In microbursts of Crab pulsar, which is an active GP emitter, zebra-pattern-like spectral structures are observed, which are reminiscent of the 'zebra bands' that are observed in type Ⅳ solar radio flares. However, band spacing linearly increases with the band center frequency of ~5-30 GHz. In this study, we propose that the Crab pulsar GP can originate from the coherent instability of plasma near a light cylinder. Further, the growth of coherent instability can be attributed to the resonance observed between the cyclotron-resonant-excited wave and the background plasma oscillation. The particles can be injected into the closed-field line regions owing to magnetic reconnection near a light cylinder. These particles introduce a large amount of free energy that further causes cyclotron-resonant instability, which grows and amplifies radiative waves at frequencies close to the electron cyclotron harmonics that exhibit zebra-pattern-like spectral band structures. Further, these structures can be modulated by the resonance between the cyclotron-resonant-excited wave and the background plasma oscillation. In this scenario, the band structures of the Crab pulsar can be well fitted by a coherent instability model, where the plasma density of a light cylinder should be ~1013-15 cm-3, with an estimated gradient of >5.5 × 105 cm-4. This process may be accompanied by high-energy emissions. Similar phenomena are expected to be detected in other types of GP sources that have magnetic fields of ? 106 G in a light cylinder. 展开更多
关键词 NEUTRON star pulsar radiation mechanisms INSTABILITIES in PLASMAS
Unifying neutron star sub-populations in the supernova fallback accretion model
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作者 Bai-Sheng Liu Xiang-Dong Li 《天文和天体物理学研究:英文版》 SCIE CAS CSCD 2019年第3期111-122,共12页
We employ the supernova fallback disk model to simulate the spin evolution of isolated young neutron stars(NSs).We consider the submergence of the NS magnetic fields during the supercritical accretion stage and its su... We employ the supernova fallback disk model to simulate the spin evolution of isolated young neutron stars(NSs).We consider the submergence of the NS magnetic fields during the supercritical accretion stage and its succeeding reemergence.It is shown that the evolution of the spin periods and the magnetic fields in this model is able to account for the relatively weak magnetic fields of central compact objects and the measured braking indices of young pulsars.For a range of initial parameters,evolutionary links can be established among various kinds of NS sub-populations including magnetars,central compact objects and young pulsars.Thus,the diversity of young NSs could be unified in the framework of the supernova fallback accretion model. 展开更多
关键词 accretion accretion disks一stars neutron evolution rotation magnetic field magnetars一pulsars general
Suitable resolution of EOS tables for neutron star investigations
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作者 陈厚源 文德华 张娜 《中国物理C:英文版》 SCIE CAS CSCD 2019年第5期93-98,共6页
Inasmuch as the hydrostatic structure of the interior of neutron stars uniquely depends on the equation of state(EOS), the inverse constraints on EOS from astrophysical observations have been an important method for r... Inasmuch as the hydrostatic structure of the interior of neutron stars uniquely depends on the equation of state(EOS), the inverse constraints on EOS from astrophysical observations have been an important method for revealing the properties of high density matter. Currently, most EOS for neutron star matter are given in tabular form,but these numerical tables can have quite different resolution. To guarantee both the accuracy and efficiency in computing the Tolman-Oppenheimer-Volkoff equations, a concise standard for generating EOS tables with suitable resolution is investigated. It is shown that EOS tables with 50 points logarithmic-uniformly distributed in the supra-nuclear density segment [ρ0, 10ρ0], where ρ0 is the nuclear saturation density, correspond to the interpolation induced errors of ~0.02% for the gravitational mass M and ~0.2% for the tidal deformability ∧. 展开更多
关键词 NEUTRON star equation of state TOV equations
Novel Cancer Treatment Using Targeted Delivery of Short-Lived Radiologically Activated Nanoparticles 预览
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作者 P.L.Andrade J.B.Leao 《健康科学:英文版》 2019年第1期43-47,共5页
The goal of our preliminary study is to show that a minimal of overall body toxicity while maximizing the cancer tumor treatment may be achieved in a novel approach where minute amounts of coated nanoparticles may be ... The goal of our preliminary study is to show that a minimal of overall body toxicity while maximizing the cancer tumor treatment may be achieved in a novel approach where minute amounts of coated nanoparticles may be radiologically activated prior to treatment and“coerce”tumor cells into readily absorb these nanoparticles.This targeted intracytoplasmic delivery of short-lived radiologically activated nanoparticles could provide less“whole-body”radiation dose while delivering a short lived potent tumor localized dose,along with their low toxicity may prove to be another tool in the treatment of diverse cancers. 展开更多
关键词 NANOPARTICLES NEUTRON activation IRRADIATION cancer metabolism WARBURG effect GLUTAMINE GLUCOSE
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依托tap/tun设备分析openstack中的网络虚拟化 预览
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作者 陈金莲 《黄冈职业技术学院学报》 2019年第4期146-147,共2页
云计算是重要的网络新技术,openstack是云计算的事实标准,学习openstack是每一个云计算工程师的必经之路。Openstack的架构非常庞大和复杂,到目前为止,包含九大核心组件,并且组件还在不断增加。架构中的neutron组件,更是异常生涩,而它... 云计算是重要的网络新技术,openstack是云计算的事实标准,学习openstack是每一个云计算工程师的必经之路。Openstack的架构非常庞大和复杂,到目前为止,包含九大核心组件,并且组件还在不断增加。架构中的neutron组件,更是异常生涩,而它的基础便是Linux下的网络虚拟化。通过分析Linux下的网络虚拟化设备之一—tap/tun,解析openstack架构中的网络虚拟化,让学习者能更好地理解neutron组件。 展开更多
关键词 云计算 OPENSTACK 网络虚拟化 虚拟网络设备 NEUTRON
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Measurement of the prompt neutron spectrum from thermalneutron- induced fission in U-235 using the recoil proton meth 预览
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作者 Tie He Pu Zheng Jun Xiao 《核技术:英文版》 SCIE CAS CSCD 2019年第7期68-76,共9页
A measurement of the ^235U prompt fission neutron spectrum (PFNS) by the recoil proton method was performed at the Institute of Nuclear Physics and Chemistry, China. Details of the method, which include the calculatio... A measurement of the ^235U prompt fission neutron spectrum (PFNS) by the recoil proton method was performed at the Institute of Nuclear Physics and Chemistry, China. Details of the method, which include the calculation and validation of the response matrix, are presented. The PFNS for ^235U in the energy range 1–12 MeV, induced by thermal neutrons, was obtained. The measured spectrum in the low-energy region was in good agreement with previous work and the ENDF/B-VII library, except for minor differences. In the high-energy region, however, the relative height of the measured spectrum was greater, and an analysis of the experiment indicated uncertainties of 13% at 10 MeV and 24% at 12 MeV. Experimental results showed that the recoil proton method could be used to measure prompt fission neutron spectra. Some directions for future work are included. 展开更多
关键词 PROMPT FISSION NEUTRON spectra RECOIL PROTON method Response matrix U-235
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Analysis of Dimer Impurity in Polyamidoamine Dendrimer Solutions by Small-angle Neutron Scattering
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作者 Tian-Fu Li Yi-Yun Cheng +11 位作者 Yu Wang Hui Wang Dong-Feng Chen Yun-Tao Liu Li Zhang Wen-Ze Han Rong-Deng Liu Zi-Jun Wang Chun-Ming Yang Charl J. Jafta Daniel Clemens Uwe Keiderling 《高分子科学:英文版》 SCIE CAS CSCD 2019年第8期827-833,共7页
Dimer impurity in the solution of a generation five(G5) polyamidoamine(PAMAM) dendrimer has been investigated by small-angle neutron scattering(SANS). The existence of dimer impurity in dendrimer solution was evidence... Dimer impurity in the solution of a generation five(G5) polyamidoamine(PAMAM) dendrimer has been investigated by small-angle neutron scattering(SANS). The existence of dimer impurity in dendrimer solution was evidenced by indirect Fourier transform(IFT) analysis of the SANS data, in which the maximum dimension of particles in solution was found to be about twice the diameter of G5 dendrimer. We then developed an analytical model which accounts for the scattering contribution from both dendrimer monomer and dimer. The experimental data were well fitted by using the established model. The results showed that the amount of dimer impurities is significant for the measured three batches of G5 PAMAM dendrimers. 展开更多
关键词 PAMAM DENDRIMER DIMER IMPURITY SMALL-ANGLE neutron SCATTERING SCATTERING model
Comparison of the dark signal degradation induced by Gamma ray, proton, and neutron radiation in pinned photodiode CMOS image sensors
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作者 Zujun WANG Yuanyuan XUE +8 位作者 Wei CHEN Rui XU Hao NING Baoping HE Zhibin YAO Minbo LIU Jiangkun SHENG Wuying MA Guantao DONG 《中国科学:信息科学(英文版)》 SCIE EI CSCD 2019年第6期174-176,共3页
Dear editor,CMOS image sensors (CISs) present numerous advantages and have become feasible alternatives for CCDs (charge coupled devices) in satellite imaging system, nuclear industry, and particle detection (1–3)How... Dear editor,CMOS image sensors (CISs) present numerous advantages and have become feasible alternatives for CCDs (charge coupled devices) in satellite imaging system, nuclear industry, and particle detection (1–3)However, CISs used in these applications are often operated under harsh radiation environments and are susceptible to total ionizing dose (TID) and displacement damage. 展开更多
关键词 PROTON Figure COMPARISON of the DARK SIGNAL DEGRADATION induced by Gamma ray and neutron radiation in pinned PHOTODIODE CMOS image sensors
First polar direct-drive exploding-pusher target experiments on the ShenGuang laser facility
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作者 余波 杨家敏 +20 位作者 黄天晅 王鹏 尚万里 乔秀梅 邓学伟 张占文 宋仔峰 唐琦 彭晓世 陈家斌 理玉龙 蒋炜 蒲昱东 晏骥 陈忠靖 董云松 郑无敌 王峰 江少恩 丁永坤 郑坚 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第9期288-294,共7页
Low density and low convergence implosion occurs in the exploding-pusher target experiment, and generates neutrons isotropically to develop a high yield platform.In order to validate the performance of ShenGuang(SG) l... Low density and low convergence implosion occurs in the exploding-pusher target experiment, and generates neutrons isotropically to develop a high yield platform.In order to validate the performance of ShenGuang(SG) laser facility and test nuclear diagnostics, all 48-beam lasers with an on-target energy of 48 kJ were firstly used to drive room-temperature, DT gas-filled glass targets.The optimization has been carried out and optimal drive uniformity was obtained by the combination of beam repointing and target.The final irradiation uniformity of less than 5% on polar direct-drive capsules of 540 μm in diameter was achieved, and the highest thermonuclear yield of the polar direct-drive DT fuel implosion at the SG was 1.04 × 10~(13).The experiment results show neutron yields severely depend on the irradiation uniformity and laser timing,and decrease with the increase of the diameter and fuel pressure of the target.The thin CH ablator does not impact the implosion performance, but the laser drive uniformity is important.The simulated results validate that the cos γ distribution laser design is reasonable and can achieve a symmetric pressure distribution.Further optimization will focus on measuring the symmetry of the hot spot by self-emission imaging, increasing the diameter, and decreasing the fuel pressure. 展开更多
关键词 POLAR DIRECT-DRIVE exploding-pusher TARGET NEUTRON yield irradiation UNIFORMITY
Effects of deuteration on the structure of NH4H2PO4 crystals characterized by neutron diffraction
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作者 刘宝安 朱丽丽 +6 位作者 刘发付 孙洵 陈喜平 谢雷 夏元华 孙光爱 巨新 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第1期484-489,共6页
A series of deuterated ammonium dihydrogen phosphate(DADP) crystals were grown and their structures were investigated by using powder neutron diffraction method. In the entire composition range, the deuterated level i... A series of deuterated ammonium dihydrogen phosphate(DADP) crystals were grown and their structures were investigated by using powder neutron diffraction method. In the entire composition range, the deuterated level in the crystals is lower compared with the aqueous growth solution. The deuterium segregation coefficient in the crystals decreases with increasing deuterium content of the solution. The deuterium content in the NH4+ group is higher than that in H2PO4- group.In addition, the variations of lattice parameters are shown here. 展开更多
关键词 DADP CRYSTAL NEUTRON DIFFRACTION DEUTERATION LEVEL
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