8mm回旋管用超导磁体系统的研制

本文描述了一个8mm回旋管用的超导磁体系统的研制。它的主磁场线圈中心轴磁场达到2.14T,均匀区长度为14.5cm,均匀度±3.84‰,利用超导开关可以闭环运行。副磁场均匀区长度为4.5cm,均匀度±1.43‰。杜瓦具有台阶型室温通道,上端直径74mm,下端直径140mm。杜瓦是直筒型的,装有超导磁体时液氦蒸发量为4L/h。     

8mm回旋管用超导磁体系统的研制

本文描述了一个8mm回旋管用的超导磁体系统的研制。它的主磁场线圈中心轴磁场达到2.14T,均匀区长度为14.5cm,均匀度±3.84‰,利用超导开关可以闭环运行。副磁场均匀区长度为4.5cm,均匀度±1.43％。杜瓦具有台阶型室温通道,上端直径74mm,下端直径140mm。杜瓦是直筒型的,装有超导磁体时液氦蒸发量为4L/h。     

一个适用于穆斯堡尔谱学的超导磁体装置

本文叙述国内研制的第一台穆斯堡尔谱学研究用的超导磁体装置,它包括超导磁体系统、低温系统、电原和保护系统以及样品室变温和控温系统。超导磁体由主线圈和抵消线圈反接串联,最大中心场强7.5T。放射源和吸收体(样品)分别置于抵消线圈和主线圈的中心,带有超导开关的超导磁体系统工作于永久电流状态,具有良好的稳定性。磁体杜瓦用液氮屏和由蒸发的冷氦气冷却的气冷屏结构,蒸发率小于0.2 1/h,杜瓦中心具有可     

稳态超导磁镜装置工程调试进展

本文扼要地介绍了稳态超导磁镜装置的概貌。给出了在1977——1982年期间装置真空系统、电气系统、粒子束物理对中、离子注入器、碳弧中性化室和捕集室低温超导系统的局部调试和装置联合工程调试的结果。通过对装置的局部调试和联调,达到了第一期工程指标。离子源能量100keV,引出总离子流0.7A,H_2~ 束在透镜入口达120mA,注入到捕集室中心为26mA,最高注入中性束等效流强为7.2mA。捕集室超导磁体在4.2K液氦条件下实现超导9h,当磁体升流133A时,捕集室中心磁场达21.7kGs。采用了冷凝吸附抽气技术,捕集室静真空度最高达4.8×10~(-9)Torr,注束时动真空度为3.5×10~(-8)Torr。     

波振器磁场测量系统(英文)

报告了一个用于自由电子激光波振器的磁场自动测量装置,它既可以进行波振器高精度磁场测量,也可以用于加速器中的磁透镜、同轴线圈以及偏转磁铁等方面的磁场测量。系统采用高灵敏度CaAs微型霍耳探头作为磁场传感器件;采用光电编码器以及数显技术检测探头的位移;测量系统由AST/386微型计算机控制。软件内容丰富,界面友好。根据实际测试,此系统在磁场变化梯度为1.00×10~(-2)T/mm时,测量精密度△B/B_p=(0.3～1.5)×10~(-4),在磁场变化梯度为6.00×10~(-2)T/mm时,测量精密度△B/B_p=(1.5～5)×10~(-4)。     

230 MeV超导回旋加速器超导线圈系统运抵原子能院

正230 MeV超导质子回旋加速器的超导线圈系统采用液氦零挥发的冷却方式,由线圈绕组、低温恒温器、低温制冷机、液氦阀箱,以及真空系统、电源系统及失超保护系统组成。经过近一年半的艰苦攻关,超导线圈系统于2016年12月初在加工厂家完成了装配及过程中的一系列测试,超导磁体经过液氮及液氦淋浴降温,经过不到1周时间线圈降温到4.2K,如图1所示。超导线圈系统一次性成功励磁到场,并完成了不带铁芯的磁场测量与理论设计的磁场吻合。并于2017年的1月完成了源地验收。之后又进     

同步辐射加速器超导Wiggler磁体系统低温恒温器

介绍了低温恒温器的设计和制造特点。Wiggler磁体是同步辐射装置的重要部件。合肥国家同步辐射加速器的一周期超导Wiggler磁体,最大中心磁场为5T。低温恒温器为超导磁体提供4.2K的工作环境,用液氮套屏蔽辐射热。超导磁体用8根不锈钢管悬挂在低温恒温器的外壳上。8块采用双面敷铜印刷线路板制作,并经过表面处理的防辐射屏,用于减少颈管顶法兰的辐射热。低温恒温器提供了20×40mm椭圆形截面的束流通道。     

同步辐射加速器超导Wiggler磁体系统低温恒温器

介绍了低温恒温器的设计和制造特点。Wiggler磁体是同步辐射装置的重要部件。合肥国家同步辐射加速器的一周期超导Wiggler磁体,最大中心磁场为5T。低温恒温器为超导磁体提供4.2K的工作环境,用液氮套屏蔽辐射热。超导磁体用8根不锈钢管悬挂在低温恒温器的外壳上。8块采用双面敷铜印刷线路板制作,并经过表面处理的防辐射屏,用于减少颈管顶法兰的辐射热。低温恒温器提供了20mm×40mm椭圆形截面的束流通道。     

串列加速器升级工程低温恒温柜设备验收工作介绍

1情况简介 串列升级工程中的超导增能器主要由4个QWR铜铌溅射超导腔构成。低温恒温柜用于给QWR铜铌溅射超导腔提供4．2K的低温环境。为达到4．2K的低温,恒温柜的核心部分将利用液氦冷却;同时为了降低液氦的热负载,恒温柜的外围真空容器与核心部分间还将设置1个利用液氮冷却的冷屏。低温恒温柜总的设计指标为：常温下从大气状态抽真空到6×10^-5Pa所需的时间小于48h;静态热损耗小于10W;射频功率热损耗小于28W。     

CFETR纵场超导磁体CICC导体低温冷却设计与分析

纵场磁体中导体低温超导性对整个托卡马克装置磁体系统的稳定具有重要作用。对纵场磁体的低温冷却系统进行热分析,确定线圈排布匝数、纵场磁体中心冷却孔以及盒壁内侧冷却孔的质量流速,并计算液氦在导体中心冷却孔流动时的沿程压降。分析结果表明:同种工况不同线圈排布磁体组件温差值各不相同,经过对比分析,纵场磁体选用154匝线圈排布方案。为确保纵场线圈盒体温度与导体铠甲的温度分别在20 K与5 K范围之内,线圈盒内侧壁面冷却孔质量流速为3.6 g?s~(-1),纵场磁体线圈导体内中心冷却孔质量流速为9.5 g?s~(-1),液氦流动沿程压降为1.72×10~5Pa。     

医源性电离辐射损伤及其生物医学防护

随着核与辐射技术在医学检查、诊断和治疗领域运用的增加,世界范围受照人群不断增多,医源性辐射已成为人类最主要的人工辐射来源之一。医疗机构和个人在选择利用放射手段获取诊断和治疗利益的同时,需要注意和防护伴随的辐射损伤效应。本文介绍了医源性辐射及其危害、机体组织的辐射损伤特性和类型、辐射生物效应分子及效应调节研究的进展,简要概述目前临床已经使用或最具应用潜力的辐射防护策略。     

Distribution and Fixation of Cesium and Strontium in Zeolite A and Chabazite

The selective removal and fixation of Cs and Sr have been studied in zeolite A and chabazite. Cesium ion was preferentially distributed into chabazite with a high distribution coefficient (K _Cs>10³ cm³·g^?1) in the presence of NaCl (10^?1 mol·dm^?3). The K _Sr values for zeolite A attained about 10³ cm³·g^?1 in the pH range of 8～10, and they gradually decreased with an decrease in pH.

The initial rate of Cs adsorption was fairly fast in chabazite, and the adsorption ratio reached almost 100% within a few hours. The adsorption ratio of Sr in binderless A zeolite reached almost 100% after 15 h. The adsorption of Cs and Sr on these zeolites was followed by Langmuir-type isotherm. Cesium forms of these zeolites recrystallized to pollucite (CsAlSi₂O₆) above 900°C for zeolite A and above 1,200°C for chabazite. As for Sr forms, these zeolites changed to SrAl₂Si₂O₆ above 900°C.

These recrystallized phases were suitable hosts for the immobilization of Cs and Sr in the nuclear waste solutions.     

全国核与辐射安全监管信息系统的研究和建议

文章简要介绍了全国核与辐射安全监管信息系统的前期规划建设情况,包括基本建设内容、系统总体架构、以及工作中发现的影响和制约工作开展的主要问题,并提出了建议。     

Development and diversity and defense-in-depth application of ABWR feedwater pump and controller model

This work developed an advanced boiling water reactor (ABWR) feedwater pump and controller model, which was incorporated into Personal Computer Transient Analyzer (PCTran)-ABWR, a nuclear power plant simulation code. The feedwater pump model includes three turbine-driven feedwater pumps and one motor-driven feedwater pump. The feedwater controller includes a one-element/three-element water level controller and a specific feedwater speed controller for each feedwater pump. The performance tests, including step change of dome pressure, feedwater pumps transfer, inadvertent closure of all turbine control valves, and one feedwater pump trip at 100% power, demonstrate the feasibility of dynamic response of stand-alone model and incorporated model. Furthermore, a diversity and defense-in-depth analysis is performed to demonstrate the feasibility for motor-driven feedwater pump as an emergency core cooling system (ECCS) automatic diverse back-up. In Lungmen nuclear power plant (NPP), a diverse manual initiation means for the high pressure core flooder (HPCF) loop C is designed as the back-up of digitalized engineered safety features actuation system (ESFAS). If the motor-driven feedwater pump (MDFWP) can be an automatic digital diverse back-up for ESFAS, Lungmen NPP would be more robust to defend against software common-cause failure (CCF).     

清洁解控和退役若干动向与新发展

对国际辐射防护协会第 1 0届大会 ( IRPA-1 0 )涉及的清洁解控和退役问题作了论述 ,包括排除、豁免、清洁解控和废物最少化 ;退役工程技术的发展 ,包括去污技术、切割解体技术、探测技术 ;介绍了一个研究堆退役例子和加速器退役 ;最后 ,还论及了退役中受关注的一些问题 ,如 :石墨废物、混凝土废物、重水堆退役的氚防护、退役时间和退役废物量等。     

核与辐射风险的认知与沟通

面对公众对核与辐射风险极度敏感的现象,本文阐述了对风险的认知及影响认知程度的因素,介绍了风险沟通的发展阶段和四种类型,并给出了若干有效的风险沟通策略建议。     

Thermophysical and mechanical properties of CrB and FeB

ABSTRACT

Fuel debris in the Fukushima Daiichi nuclear power plant is thought to contain borides that are generated from B₄C control material. In order to successfully devise methods to effectively remove the debris material, characterization of the properties of the fuel debris is essential. This paper presents some of the thermophysical and mechanical properties of two types of borides, FeB and CrB, and compares them with those of Fe₂B and ZrB₂. These are the representative borides that might have been generated in the Fukushima Daiichi (1F) nuclear power plant accident. We observed that the thermal conductivity values of both CrB and FeB are much lower than that of ZrB₂, and are similar to that of Fe₂B. Moreover, the Vickers hardness and fracture toughness of FeB and CrB are almost identical to each other, and similar to those of ZrB₂ and Fe₂B.     

Sorption methods of separating barium and radium,aluminum and gallum,and zirconium and hafnium

Chromatographic methods of separating elements with very similar properties have now been developed. However, a number of these methods are difficult to use industrially as their throughput is low. The efficiency of chromatographic separation methods could be increased considerably by using appropriate complex formers, which decrease the effective concentration of the ions being separated, and,in the first approximation, this is equivalent to a decrease in the amount of elements being separated. The difference in the formation constants of the complex compounds increases the separation coefficient. By investigating chromatographic separation with the use of various complex formers, we found the optimal conditions for separating barium and radium, zirconium and hafnium, and aluminum and gallium. The throughput of these methods, with respect to the macroelement was 15–60 kg/hr per m² of column cross section.     

测温热电偶拔出回收技术及回收处理装置

核电站反应堆测温热电偶回收装置是堆芯热电偶检修、更换、回收的专用设备。本文结合３００ＭＷ反应堆型，介绍了一种结构简单、操作方便、使用安全可靠的热电偶拔出回收技术及回收处理装置。