共查询到20条相似文献,搜索用时 46 毫秒
1.
为满足国内油田石油测井的迫切需要, 对小直径测井中子发生器进行了研发。 该发生器离子源采用微型化冷阴极Penning离子源, 离子光学采用结构简单的单极加速系统。 经实验室测试和用户现场刻度及测井表明, 研制的中子发生器具有耐高温、 产额高、 稳定性好等特点, 是目前国内研制的最小直径的工业测井中子发生器。 所测数据与其它测井方法相比较, 地质资料符合性好, 满足了用户测井要求, 现已用于油田生产测井。 A small neutron generator has been developed for meeting the need of well logging in oil fields. The miniature cold cathode Penning ion source and single electrode ion optics system are used in neutron generator. The good performance of the generator has been proved in the laboratory test and well logging in oil field. The generator has good characteristics, such as small diameter, high temperature resistant,high neutron output and good stability. At present, the neutron generator is the smallest logging generator in China, which has been used in oil field generally for conforming the geological data. 相似文献
2.
E. S. Konobeevsky L. N. Latysheva N. M. Sobolevsky 《Bulletin of the Russian Academy of Sciences: Physics》2010,74(4):443-446
The NG-430 neutron generator at the Institute for Nuclear Research, Russian Academy of Sciences, is being updated. The flux
of neutrons produced by the 3H(d,n)4He reaction can be as high as 1013 s−1. Modernization of the neutron generator involves moving it to a new accelerator hall. The generation of several extracted
neutron beams is planned. After they pass through the collimator, the neutron fluxes are calculated by the Monte-Carlo method
on the basis of the ABBN [4] neutron constants. The parameters of the biological shielding are estimated. 相似文献
3.
4.
快中子照相系统由闪烁光纤阵列和科学级可见光CCD等元件组成. 14 MeVD-T聚变中子在穿透样品后进入50 mm×50 mm闪烁光纤阵列,中子辐射转换为中心波长496 nm的绿光. 光纤阵列长100 mm,光纤截面500 μm×500 μm,100×100根闪烁体光纤组成阵列. 阵列对14 MeV中子探测效率经估算可达21.4%. CCD与光纤阵列之间采用反射镜和透镜耦合方式,使CCD避开中子源直接辐照. 综合考虑光纤尺寸、CCD记录噪声及中子源与受照样品几何关系等因素,理论上系统可获得整体分辨率1.5 mm的中子图像. 在K400直流加速器中子源上进行了初步实验,获得了中子图像. 相似文献
5.
M. L. Litvak A. A. Vostrukhin D. V. Golovin P. V. Dubasov A. O. Zontikov A. S. Kozyrev A. R. Krylov V. A. Krylov I. G. Mitrofanov M. I. Mokrousov A. N. Repkin G. N. Timoshenko K. V. Udovichenko V. N. Shvetsov 《Physics of Particles and Nuclei Letters》2017,14(4):591-601
The results of the tests of the HPGe gamma spectrometer performed with a planetary soil model and different types of pulse neutron generators are presented. All measurements have been performed at the experimental nuclear planetary science facility (Joint Institute for Nuclear Research) for the physical calibration of active gamma and neutron spectrometers. The aim of the study is to model a space experiment on determining the elemental composition of Martian planetary matter by neutron-induced gamma spectroscopy. The advantages and disadvantages of a gas-filled neutron generator in comparison with a vacuum-tube neutron generator are examined. 相似文献
6.
7.
QiuHong Wang Abdusalam Abdukerim Wei Chen Xun Chen YunHua Chen XiangYi Cui YingJie Fan DeQing Fang ChangBo Fu LiSheng Geng Karl Giboni Franco Giuliani LinHui Gu XuYuan Guo Ke Han ChangDa He Di Huang Yan Huang YanLin Huang Zhou Huang Peng Ji XiangDong Ji YongLin Ju YiHui Lai Kun Liang HuaXuan Liu JiangLai Liu WenBo Ma YuGang Ma YaJun Mao Yue Meng Parinya Namwongsa KaiXiang Ni JinHua Ning XuYang Ning XiangXiang Ren ChangSong Shang Lin Si AnDi Tan AnQing Wang HongWei Wang Meng Wang SiGuang Wang XiuLi Wang Zhou Wang MengMeng Wu ShiYong Wu JingKai Xia MengJiao Xiao PengWei Xie BinBin Yan JiJun Yang Yong Yang ChunXu Yu Jumin Yuan Dan Zhang HongGuang Zhang Tao Zhang Li Zhao QiBin Zheng JiFang Zhou Ning Zhou XiaoPeng Zhou 《中国科学:物理学 力学 天文学(英文版)》2020,(3):54-63
In dark matter direct detection experiments,neutron is a serious source of background,which can mimic the dark matter-nucleus scattering signals.In this paper,we present an improved evaluation of the neutron background in the PandaX-II dark matter experiment by a novel approach.Instead of fully relying on the Monte Carlo simulation,the overall neutron background is determined from the neutron-induced high energy signals in the data.In addition,the probability of producing a dark-matter-like background per neutron is evaluated with a complete Monte Carlo generator,where the correlated emission of neutron(s)andγ(s)in the(α,n)reactions and spontaneous fissions is taken into consideration.With this method,the neutron backgrounds in the Run 9(26-ton-day)and Run 10(28-ton-day)data sets of PandaX-II are estimated to be(0.66±0.24)and(0.47±0.25)events,respectively. 相似文献
8.
V. G. Kiptilyi A. V. Livke V. I. Nagornyi Yu. Ya. Nefedov M. V. Savin V. I. Semenov V. A. Chirkin 《Technical Physics》1998,43(4):471-472
The quality of suppression of neutrons by lithium hydride 6LiH filters for narrow and wide beams from a neutron generator incorporating deuterium and tritium targets is investigated.
The experimental data can be used for the design of measurement apparatus operating in high neutron fields.
Zh. Tekh. Fiz. 68, 136–138 (April 1998) 相似文献
9.
10.
11.
12.
13.
中子照相是一种重要的无损检测技术,它能用于火工产品、毒品和核燃料元件等的检测。基于紧凑型D-T中子发生器,完成了一个用于快中子照相的准直屏蔽体系统(BSA)的物理设计。根据D-T中子源的能谱和角分布建立了中子源模型,采用MCNP4C蒙特卡罗程序,模拟了准直屏蔽体系统中中子和γ射线的输运,准直中子束相对于单位源中子的中子注量可以达到9.30×10-6 cm-2,准直中子束中主要是能量大于10 MeV的快中子;在设置的样品平面直径14 cm的照射视野范围,准直束中子注量的不均匀度为4.30%,准直束中中子注量与γ注量的比值为17.20,中子通量和中子注量比值J/Φ为0.992,说明准直中子束有好的平行性;准直屏蔽体外的泄露中子注量率与准直束中子注量率相比降低了2个量级。所设计的准直屏蔽体能满足快中子照相的要求。Neutron radiography is an important nondestructive testing technique. It can be used to detect the explosive devices, drug and the nuclear fuel element, etc. A beam-shaping-assembly (BSA) based on a compact D-T neutron generator is designed for fast neutron radiography in this paper. D-T neutron source model is constructed based on the neutron energy spectrum and angular distribution data. The transportation of neutron and γ-ray in the BSA is simulated using MCNP4C code. The neutron fluence of the collimated neutron beam with respect to the neutron source of the unit source is 9.30×10-6 cm-2. The collimated neutron beams is mainly fast neutrons with energies greater than 10 MeV. In the irradiation field range with a diameter of 14 cm, the neutron fluence uniformity of the collimated beam is 4.3%, the ratio of the neutron fluence to the gamma fluence in the collimated beam is 17.20, and the neutron flux and the neutron fluence ratio (J/Φ) is 0.992 which indicates that the collimated neutron beam has good parallelism. The leakage neutron fluence in outside of BSA is two orders of magnitude lower than that of the collimated neutron beam. The designed BSA can meet the need of fast neutron radiography. 相似文献
14.
综述近年来在北师大低能所的国内第一台脉冲化高压倍加器上开展的快中子物理,及有关的实验和数据处理技术研究. The study on fast neutron physics and relative technique of experiment and data analysis made at a pulsed neutron generator in Beijing Normal University during recent yeras is introduced. 相似文献
15.
E. S. Konobeevsky L. N. Latysheva N. M. Sobolevsky R. D. Ilić 《Bulletin of the Russian Academy of Sciences: Physics》2011,75(4):449-453
Computer optimization of the collimator and shielding of the NG-430 neutron generator at the Institute for Nuclear Research,
Russian Academy of Sciences, is performed. The purpose of the optimization is to reach an acceptable value of the ratio Q between the neutron fluence in the investigated target (the signal) and the neutron fluence in the area of the detecting
equipment (the background). The fluences of fast neutrons in the target and detectors are calculated by the Monte Carlo method.
The influence of the walls of the experimental hall is taken into account. The optimal configuration of the assembly that
provides the required Q value is found. 相似文献
16.
采用束 靶机制和热核机制,利用Maxwell分布,推导了等离子体焦点装置的中子产生机制、热核反应速率、中子平均能量及中子反映速率.Using the machanism of beam target and heat nuclics, the scaling relationship between the neutron yields of denser plasma focus and the PF plasma current is induced.The results of DPF .The principle is brief discussed with denser plasma focus(DPF) as the neutron generator.We have stated that some factors that influnce the DPF discharging to produce neutron yield and some methodsthat improve stability of neutron yields on the denser plasma focus(DPF). 相似文献
17.
V. M. Bystritsky N. I. Zamyatin E. V. Zubarev V. L. Rapatsky Yu. N. Rogov I. V. Romanov A. B. Sadovsky A. V. Salamatin M. G. Sapozhnikov M. V. Safonov V. M. Slepnev A. V. Philipov 《Physics of Particles and Nuclei Letters》2013,10(5):442-446
The results of using a stationary setup for detecting and identifying explosives using the tagged neutron method (or associated particle imaging (API) method) have been presented. The source of 14.1-MeV tagged neutron beams is an ING-27 portable neutron generator made by VNIIA (Moscow). It contains an embedded 64-pixel silicon α detector with double-sided strip readout developed by the Joint Institute for Nuclear Research (JINR). The setup was tested for the identification of more than 30 explosives. 相似文献
18.
采用蒙特卡罗模拟方法研究了微结构参数、填充致密度等因素对沟槽型微结构半导体中子探测器(MSND)性能的影响规律,并开展了沟槽型MSND的优化设计研究。研究表明,随着沟槽间距的增加,MSND的探测效率呈下降趋势;当沟槽间距固定时,存在最优的沟槽宽度使得探测效率最大化;沟槽深度越大,探测效率越高。沟槽宽度和沟槽间距为15 m和5 m是一对优化的参数组合,可保证较高的探测效率和较平稳的系统甄别阈-探测效率曲线。当系统甄别阈取300 keV时,沟槽宽度、间距和深度分别为15,5 m和200 m时的MSND热中子本征探测效率可达37.77%,与平面探测器相比提高了9.2倍;对137Cs源662 keV伽马射线的中子-伽马射线甄别比可达4.1103,与平面探测器相比提高了23.7倍。本工作从理论上证明了MSND可解决传统平面型半导体中子探测器探测效率低的难题,同时可保持半导体探测器中子-伽马射线甄别容易的特点。 相似文献
19.
The applicability of the generator coordinate method as an approximation to the complete shell model diagonalization is tested in the sd shell on 24Ne. We use the quadrupole moment and the pairing energy as generator coordinates and choose as generating function a constrained Hartree-Bogoliubov solution projected on the subspace of good angular momentum and good proton and neutron number. The spectra obtained by the generator coordinate method and the complete diagonalization show good overall agreement. Also we draw some conclusions about the nature of some low-lying states in 24Ne, interpreted in terms of vibrations. 相似文献
20.
简要叙述了稠密等离子体聚焦装置作为中子发生器的工作原理,对影响稠密等离子体聚焦装置放电出中子产额及其稳定性的一些因素和改进措施进行了简单讨论.通过使用不同电极形状的场畸变开关很好地提高了焦点装置的运行,使装置输出中子的起伏得到明显的改善.通过对腔内电极的清洁,在不更换气体的条件下,聚焦装置放电出中子产额稳定.The principle of dense plasma focus(DPF) as neutron generator has been investigated in this paper. We have stated briefly some factors that mainly influnce the DPF s neutron yield and some methods improving the stability of neutron yields on the dense plasma focus. It is showed that the fluctuation of DPF output neutron becomes smaller by using different types of field-distortion elements. Over 100 consecutive shots without purging the test gas the neutron yields has no obvious change. 相似文献