共查询到19条相似文献,搜索用时 234 毫秒
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《核电子学与探测技术》2015,(11)
设计了一套用于仪器中子活化分析(INAA)的新型自动换样系统。整个系统由组态王KingView6.55软件控制,其中自动进样装置每次可装载200个样品,且具有样品自动排队循环测量功能。样品转换器替换了原三叉管,并同时可为三套HPGe探测器提供传输待测样品。在传输管道关键节点上安装有光电传感器,实现了样品传输过程的实时监测,提高了样品传输的可靠性。 相似文献
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基于P89C669的反应堆样品照射控制装置设计 总被引:1,自引:0,他引:1
介绍反应堆中子活化自动辐照检测系统的设计和实现过程.系统采用PHILIPS公司具有ISP功能的单片机P89C669作为控制核心,通过气动传输装置控制样品进入反应堆和离开反应堆.安装在反应堆堆口处的光电传感器检测管道内的样品,精确控制样品的辐照时间和计算样品的冷却时间,并通过串行接口实现与计算机的通讯,实时向计算机传输样品辐照的信息,单片机驱动液晶显示器完成辐照时间、冷却时间的动态数据显示. 相似文献
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《核动力工程》2017,(Z1)
钍基熔盐堆石墨材料辐照考验目标为:中子注量为5×10~(20)cm~(-2)(±15%)(E>0.1 Me V),堆内辐照试验温度650℃(允许偏差±50℃)。为了满足辐照考验要求,在高通量工程试验反应堆(HFETR)第92-I炉的K07孔道进行辐照验证试验。该验证试验辐照装置采用分段构成的型式,主要由辅助密封段、辐照试验段、气管组件3部分构成,辐照罐外围为去离子水,辐照罐内为惰性气体用于控制辐照试验温度。使用MCNP程序对各样品中子注量进行预示计算,同时在辐照装置阳面和阴面都布置了探测器进行中子注量测量。试验表明:在辐照试验过程中,在辐照装置调气系统最佳导热模式下辐照温度略高于上限700℃;利用MCNP程序预示计算中子注量结果为5.7×10~(20)cm~(-2)(E>0.1 Me V),而中子注量测量结果为4.83×10~(20)cm~(-2)(E>0.1 Me V),基本满足石墨材料辐照考验中子注量要求。 相似文献
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建立了两套测量准确度分别达到0.5%及1%的测量系统。考察了国产BGO、CsI(Tl)、CsI(Na)和BaF_2晶体在5kGy吸收剂量下的辐照损伤效应。测量显示出两种不同掺杂的CsI晶体显著不同的辐照损伤及其自然恢复性能。发现辐照后BaF_2晶体存在逐渐衰减的强噪声,并且经天然光或日光灯光再照射后强噪声重新出现的新奇现象。 相似文献
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铒(Er)是一种适用于轻水堆(LWR)的长效可燃毒物,Er_2O_3的堆内辐照是研究中子毒物Er辐照性能的基本手段。Er_2O_3在高通量工程试验堆(HFETR)中子注量率约为2×10~(14)/(cm~2·s)的辐照孔道中辐照91.3h。采用热电离质谱法(TIMS)测定辐照前、后样品中Er同位素丰度,跳峰模式测定6个Er同位素,低丰度~(162)Er由法拉第杯检测。测定时准确控制升温测量电流,将蒸发带和电离带电流控制在1 400、5 500mA以下,可减小~(168)Yb、~(170)Yb对~(168)Er、~(170)Er的同量异位素影响。结果表明,经中子辐照后~(166)Er、~(167)Er、~(168)Er同位素丰度变化较大,丰度变化与中子吸收截面大小密切相关。 相似文献
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脉冲堆驱动线结构大多为细柔部件,且对其传动功能的要求较高。因此,首先将堆桥及整个驱动线作为一个完整的力学模型进行分析,其次分析各个子结构。并将计算结果与实验结果作了比较,表明分析的结果是可靠的,证明子结构法是一种简便实用、行之有效的分析方法。最后用响应谱法的结果对关键部位作出了初步地震安全评价。 相似文献
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为指导辐照熟食加工厂完善HACCP质量管理体系方案,本文阐述了食品危害分析和关键控制点(hazard analysis critical control point, HACCP)质量管理体系工作原理及流程、γ射线辐照灭菌原理及过程。以某熟食食品厂火腿生产工艺为例,通过鱼骨图绘制出熟食火腿在生产、辐照至出厂过程中的控制点与关键控制点,着重分析辐照灭菌部分。通过研究辐照食品的控制点及关键控制点,制定熟食辐照HACCP计划表,确定辐照食品在辐照过程中的关键控制点为辐照实施过程中剂量的控制。推广HACCP质量管理体系的建立,对食品生产厂家的可持续发展起到至关重要的作用,完善HACCP质量管理体系中关于食品进行γ射线辐照灭菌的过程体系文件,能够有效指导和监控食品辐照灭菌流程,提高食品的安全性,保障饮食安全,有必要在食品生产管理领域推广。 相似文献
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Two irradiation devices are described for the in pile measurement of tensile irradiation creep of graphite. In each machine a single sample is maintained under a controlled load by a pneumatic bellows system. Irradiation creep is measured relative to unstressed reference shells which surround the stressed sample. This differential strain is detected by linear displacement transducers, and recorded automatically by the out of pile installation. Irradiation temperatures are in the 800 to 1100°C range, and the stresses up to 60% of the U.T.S. One machine has been specifically designed for a flux change experiment, other irradiation parameters remaining fixed. Temperature control is achieved through varying gas mixtures in control gas gaps. The paper details the design principles of the machines and gives an account of the cold and hot commissioning tests, with particular reference to the accuracy of the in pile measuring system. Finally, the early irradiation experience is evaluated. 相似文献
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中国原子能科学研究院建立了一台DZ-12/4多能量档电子直线加速器,该装置主要用作辐射加工级电子束辐照实验平台。为了检测该电子束辐照实验平台辐照工艺控制参数,本文利用中国原子能科学研究院FJL-02型辐射变色薄膜剂量计对DZ-12/4多能量档电子直线加速器关键参数能量进行了测量,并对研制的束流监测系统法拉第筒的可靠性进行了验证。结果表明,DZ-12/4多能量档电子直线加速器能量在4~12 MeV范围可调,运行参数准确可靠;日常运行中,加速器运行人员通过监测设备和调节加速器参数可有效控制并估计辐照剂量,具有非常好的实用性和简便性。 相似文献
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A sealed-tube type 14 MeV neutron generator with maximum neutron output of 1011 n/sec, incorporating a pneumatic sample transfer system of single-tube type and with a single rotation of the sample during neutron irradiation, is used to develop a method for determining oxygen content in steel in the ppm range with the best precision, and at the same time, to make the process suitable for routine work in industrial applications. The pneumatic sample transfer system is made to incline at an angle of about 20° towards the horizontal at the irradiation station. Together with a constant pressure gas reservoir for providing a constant optimum gas pressure in the transfer tube, the system gives a result of nearly perfect reproducibility in the operation.A pulse shape analyser system incorporating an organic scintillation detector is used for monitoring neutron flux level during the neutron irradiation of the sample. The percentage standard deviation of the neutron counts by the present monitoring system ranges from 0.9 to 2.7% with 0.5% as the percentage statistical deviation alone.Polyethylene, of oxygen content 163 ppm determined by comparison with lucite, is used as the steel sample carrier. A 3 × 3 in. NaI(Tl) crystal is used with a single channel analyser to count the 6.1 and 7.1 MeV gamma rays emitted from 16N as a result of the reaction 16O(n, p)16N. An optimum combination for the time of irradiation, delay and counting of the induced activity; of 30, 0.1 and 30 sec, respectively, is chosen in the present experiment. Thus, for a 100 g steel sample with an oxygen concentration of 170 ppm, the percentage standard deviation is about 4.4% which is, in fact, the counting statistic itself, resulting from a neutron flux level of 1.3 × 108 n/sec cm2 at the sample. As the present activation analysis makes use of the comparison method, a steel-mylar standard made of layered steel and mylar discs is prepared and a calibration curve constructed. A method of correcting the oxygen contribution in the polyethylene sample carrier is devised and the content of oxygen in the steel standard is determined.A survey of neutron flux distribution is also attempted and it is found that nearly symmetrical distribution of the flux, about the centre of the sample carrier which is placed with its axis in parallel to the plane of the disc-shaped target of the neutron-generating tube, is far from being flat. 相似文献
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针对不同样品的分析需求,本文设计了几种不同类型的微束X射线荧光谱仪。用高精度激光位移传感器实时校正样品表面被测量点与毛细管透镜出端之间的距离,以减少形状不规则的古陶瓷样品测量时带来的误差;利用毛细管X光透镜传输能量高于25 keV的X射线效率低的特点,将其应用于高铅釉瓷器彩料的无损分析中;采用大功率X射线源,扫描分析了大米中K、Ca等元素分布;以人民币5角硬币为例,研究了能量色散的微束X射线衍射方法。研究结果表明,本文研发的微束X射线荧光谱仪在生物样品和文物样品的分析研究中有广泛的应用前景。 相似文献