高能同步辐射光源低能束流输运线设计研究

高能同步辐射光源(HEPS)是计划在北京建造的发射度小于60 pm·rad的超低发射度光源。它由1台500 MeV直线加速器、1条500 MeV低能束流输运线、1台500 MeV～6 GeV的能量增强器、2条6 GeV的高能束流输运线、1台6 GeV的储存环以及同步辐射光束线和实验站组成。本文进行低能束流输运线的设计研究。低能束流输运线是连接直线加速器和增强器的束流传输线,在考虑建设布局限制的基础上,对两端的束流包络进行匹配,并将直线加速器产生的束流高效传输到增强器注入点。HEPS低能束流输运线设计时采用了功能分区的设计策略,设计有3个功能区,分别是消色散注入匹配区、光学参数匹配区、输出匹配区。为校正误差对束流的影响,HEPS低能束流输运线设置了8个BPM,水平和垂直各6块校正磁铁用于束流轨道校正,校正后的轨道满足束流传输要求。     

高能同步辐射光源低能束流输运线设计研究

高能同步辐射光源（HEPS）是计划在北京建造的发射度小于60 pm•rad的超低发射度光源。它由1台500 MeV直线加速器、1条500 MeV低能束流输运线、1台500 MeV～6 GeV的能量增强器、2条6 GeV的高能束流输运线、1台6 GeV的储存环以及同步辐射光束线和实验站组成。本文进行低能束流输运线的设计研究。低能束流输运线是连接直线加速器和增强器的束流传输线，在考虑建设布局限制的基础上，对两端的束流包络进行匹配，并将直线加速器产生的束流高效传输到增强器注入点。HEPS低能束流输运线设计时采用了功能分区的设计策略，设计有3个功能区，分别是消色散注入匹配区、光学参数匹配区、输出匹配区。为校正误差对束流的影响，HEPS低能束流输运线设置了8个BPM，水平和垂直各6块校正磁铁用于束流轨道校正，校正后的轨道满足束流传输要求。     

230MeV超导质子回旋加速器及治疗端研制进展

正在已建成的100 MeV强流回旋加速器技术基础上开展了230 MeV超导等时性回旋加速器关键技术研制,包括降能器设计、束流输运线技术和治疗端的前期技术研究,以研制出我国具有自主知识产权的230MeV医用超导回旋加速器及束流输运线、旋转机架、治疗头等治疗端放疗装备。     

中国散裂中子源强流质子加速器设计、研制及调试运行

中国散裂中子源（CSNS）是基于强流质子加速器的大科学装置,通过高功率质子束流轰击重金属靶产生高通量中子用于开展中子散射研究,CSNS是世界上第四台、发展中国家第一台脉冲型散裂中子源。CSNS包括高功率强流质子加速器、中子靶站和中子谱仪以及相应的配套设施等。加速器由80 MeV负氢直线加速器、1.6 GeV快循环同步加速器及相应的束流输运线组成。CSNS加速器是我国第一台中高能强流高功率质子加速器,本文将介绍CSNS加速器的设计、关键技术、设备研制以及束流调试过程和其中关键问题。     

合肥光源束流输运线线性光学参数设计研究

合肥光源由800MeV电子储存环、200MeV直线加速器和束流输运线组成。束流输运线线性光学参数是影响束流传输效率和储存环注入效率的关键因素。在分析合肥光源现束流输运线性能基础上,重新优化设计输运线聚焦结构。新设计在改善输运线与储存环之间Twiss参数和色散函数匹配基础上,更好地控制传输过程中束流包络,并减轻了开关磁铁幅度抖动对传输束流末态位置的影响。通过优化光学参数设计,束流传输效率将明显改善,同时参数匹配将有利于提高储存环注入效率。并且,新设计中的主磁铁磁场强度较低,输运线具备传输800MeV束流的能力。     

上海光源150MeV直线加速器传输波导相长度测量与调整

上海光源直线加速器加速器主体由电子枪、次谐波束聚器、基波聚束器及四台加速管组成,其功能是通过低能输运线向增强器注入150 MeV能量的电子束.直线加速器2006年12月开始安装,2007年5月出束,10月完成束流调试,向增强器供束,束流指标达到设计目标.传输波导相长度的测量与调整是微波系统及加速器建设安装过程中的的关键环节,调试结果直接关系到直线加速器的升能效果,影响到束流其它相关参数.本文阐述了上海光源直线加速器波导相长度测量与调整过程,给出了加速器束流调试的相关指标结果.     

中国原子能科学研究院紧凑型强流质子回旋加速器剥离引出技术研究

中国原子能科学研究院(CIAE)在20世纪90年代建造了一台30 MeV紧凑型强流质子回旋加速器后,经过近30年的发展,先后自主研发成功了基于剥离引出技术的能量为10 MeV、14 MeV、100 MeV、硼中子俘获治疗用14 MeV/1 mA等系列能量的紧凑型强流质子回旋加速器。建成的100 MeV紧凑型强流质子回旋加速器(CYCIAE-100),是目前国际上能量较高的一台紧凑型强流质子回旋加速器,最高流强达到520 μA,束流功率达到52 kW。建成的硼中子俘获治疗用的质子回旋加速器,也是我国首次自主研发成功的引出质子束流强达到mA量级的强流质子回旋加速器。在系列能量的紧凑型强流质子回旋加速器研发过程中,CIAE对剥离引出后的束流色散效应、剥离膜与束流夹角对引出后的束流品质的影响、单圈剥离引出技术等紧凑型强流质子回旋加速器剥离引出技术等方面展开了研究,且自主开发出了剥离引出计算程序,为紧凑型强流质子回旋加速器的应用作出了贡献。     

100 MeV强流质子回旋加速器轴向注入系统设计

100MeV强流回旋加速器要求引出质子束流强达到200μA,并计划提供脉冲束流。为达到高的平均流强,并具有提供脉冲束的能力,轴向注入系统的设计有两种方案,即对应于1#和2#注入线,如图1所示。电荷力的光学计算程序TRANSOPTR,匹配不同中性化程度的注入束流光学特性。从离子源出口到螺旋型静电偏转板出口的连续匹配计算结果表明:所设计的注入系统可有效地控制束流包络,减少束流损失,将束流注入到100MeV回旋加速器的中心区;还完成了1#线上x-y导向磁铁、螺线管透镜、聚束器和四极透镜的设计。100 MeV强流质子回旋加速器轴向注入系统设计@姚红…     

CYCIAE-100的直流流强监测器研制及实验验证

100 MeV强流质子回旋加速器（CYCIAE-100）加速H^-，引出质子束能量为75~100 MeV、最大束流强度为200 μA。为对束流输运线上的质子束流强度进行无阻挡实时监测，选择了直流流强监测器（DCCT），其在设计上考虑了空间限制、杂散磁场和外部高频干扰信号等因素对探头的影响。探头外采用了三重磁屏蔽设计，磁屏蔽外为1层黄铜的电屏蔽。采用了绝缘垫圈隔断束流输运线的直流导电性，束流输运线管壁通有冷却水以保证探头温度稳定。在绝缘垫圈处增加电容以满足探头对电容值的要求。采用高精度PLC-AI模块对DCCT的输出电压进行了读取。通过模拟束流的实验验证表明，DCCT设计合理可行，测量结果的线性度、误差等指标符合设计要求。     

600kV高压倍加器大厅内X-γ照射量率和能谱的初步测定

一、引言600 kV高压倍加器,通过T(d,n)~4He、D(d,n)~3He等核反应可产生14 MeV和2.5MeV的快中子,中子产额可达10~(11)n/s。其屏蔽设计情况,以及运行中可能产生的中子辐射场分布,在文献[1]中已有报道。在用该高压倍加器作引出质子束对光调束(质子束轰击铁靶)和离子注入等工作时,所产生的X、γ射线的照射将是主要的。测量和掌握高压倍加器上产生的快中子和X、γ     

秦山,大亚湾核电站周围地区土壤盆栽水稻对^137Cs的吸收规律

对秦山、大亚湾核电站周围地区５种水稻田土,在苗期分别施入等量（３７０Ｂｑ／ｇ土）＾１３７Ｃｓ溶液盆栽水稻,分期成熟后取样;对秦山地区的官堂水稻田土盆栽的水稻,在苗期、孕穗期和灌浆期分别施入等量（３７０Ｂｑ／ｇ土）的＾１３７Ｃｓ溶液,成熟后取样及苗期施入等量（３７０Ｂｑ／ｇ土）＾１３７Ｃｓ溶液分３个生育期取样;对相同土壤盆栽的水稻,在苗期分别施入０．３７、３．７、３７和３７０Ｂｑ／ｇ土＾１３７Ｃｓ溶     

Thermodynamic Calculation on the Vaporization of Fission-Produced Noble Metal System in Vacuum and Oxidative Atmosphere at High Temperatures

The vaporization behavior of fission-produced noble metal system (Mo-Ru-Pd, Mo-Ru-Rh and Mo-Tc-Pd) in vacuum and oxidative atmosphere at high temperatures was investigated by the thermodynamic calculation on the basis of the regular solution model and the available experimental data. The palladium and rhodium in the allyoys, and molybdenum and ruthenium in the alloys vaporize preferentially at high temperature in vacuum and in ari, respectively. At low temperature below 385K in air, ruthenium and technetium in the alloys vaporize predominantly by oxidation.     

~(131)I在甲状腺中活性和剂量的分布

众所周知,~(131)I 是核爆炸后早期落下灰中对人体危害较大的一种核素~[1,2],同时也是临床医学应用最广泛的一种放射性同位素~[8]。过去,在放射性碘的生物效应研究中,对甲状腺受照剂量的估算,是基于放射性碘在腺体中呈均匀分布,根据有关参数采用经典剂显公式计算的。这种方法计算的剂量与实际受照剂量有多大差别,还不十分清楚。为此,本文研究了~(131)I 在狗甲状腺中活性的分布情况,用 LiF 剂量元件测量了~(131)I 均匀分布的甲状腺水模型(以下简称甲状腺模型)中的剂量和狗食入~(131)I 后甲状腺的受照剂量,通过数学处理和分析,找出~(131)I 在狗甲状腺中的分布特点,建立了~(131)I 在甲状腺模型中的剂量分布函数,以描述剂量的空间分布,导出了计算甲状腺实际受照剂量的公式和甲状腺体的等剂量曲面方程,为~(131)I 的剂量与效应的研究提供参考性资料。     

Numerical analyses on liquid-metal magnetohydrodynamic flow in sudden channel contraction

Three-dimensional numerical calculations have been performed on the magnetohydrodynamic (MHD) flows through a rectangular channel with sudden contraction, particularly in order to estimate the pressure drop through the sudden contraction. The sudden contraction is in the directions both perpendicular and parallel to the applied magnetic field. The Hartmann number, the Reynolds number, and the magnetic Reynolds number were set to ～100, ～1000, and ～0.001, respectively, in simulating laboratory conditions. The continuity equation, the momentum equation, and the induction equation were solved numerically. In the sudden contraction in the direction perpendicular to applied magnetic field, the loss coefficient takes a positive value in all the cases performed in this study, contrary to the expectation. This result is in contrast to that in the sudden expansion in the direction perpendicular to applied magnetic field, where the loss coefficient generally takes a negative value due to the MHD effect. In the sudden contraction in the direction of applied magnetic field, the loss coefficient takes a positive and large value in all the cases performed in this study. The loss coefficient generally becomes larger than that in the case of corresponding channel expansion in the direction of applied magnetic field.     

Reactions between SiC and SrO at High Temperatures

A mixture of SiC and SrO was heated in air, in Ar and in vacuum, and the reaction products were determined by powder X-ray diffraction. The reaction began above 1,000°C and the products varied, depending on the oxygen content in the heating atmosphere. For example, in the case of a mixture of 1:1 in atomic ratio, SrO·SiO₂ formed in air, while in oxygen-free atomsphere, SrC₂ and Sr were produced besides SrO·SiO₂. It was also found that the powder X-ray diffraction pattern of SrO·SiO₂ obtained in the present experiment differed in part from O'Daniel's data. It is concluded that study of the microstructural changes in the SiC coating layer at high temperatures should be most important for assuring the retainment of the fission products Sr and Ba in coated particle fuels.     

铀尾矿废渣回填治理区植物中铀放射性水平调查

为了解北方某铀矿尾渣回填区内放射性核素铀在植物体中富集情况,为进一步探讨利用植物修复技术对铀矿区进行土壤修复的可行性,以及寻找放射性核素污染土壤治理的方法提供理论依据,采集矿区内堆浸工位与矿区外尾渣回填治理区常见植物样本,采用ICP-MS测定植物和土壤中放射性铀水平,针对植物对铀的耐受性和富集能力进行评估,筛选出富集能力较强的植物,进一步探索利用植物修复技术对放射性废物治理。结果表明,经对采集的植物中铀含量检测发现植物的地下部分铀含量高于地上部分,铀主要集中在根部,植物各部位铀含量由高到低分别为根、叶、茎。矿区内堆浸工位处的大籽蒿根部铀活度为 64.26 Bq/kg;在矿区外尾渣回填区同一植物根部铀活度为0.86 Bq/kg。所调查的北方某铀矿尾渣回填区内所采集的植物中铀含量极低,远小于矿区内堆浸工位所采植物样品中铀含量。深埋回填铀矿尾渣是切实有效可行的。     

低剂量X射线照射对小鼠脾淋巴细胞丝裂原反应的影响

本实验观察了低剂量 X 射线整体和离体照射后对小鼠脾淋巴细胞丝裂原反应的影响。结果表明,X 射线全身照射后小鼠脾脏 T、B 淋巴细胞对刀豆蛋白-A(Con A)和细菌脂多糖(LPS)的反应较对照组增强,尤以75 mGy 组最为明显。在离体照射后,脾淋巴细胞对 Con A 的反应未见明显改变,而对 LPS 反应则低于对照组。提示低剂量 X 射线照射可刺激 T 细胞反应增强。     

Analysis of Experiment on Temperature Coefficient of Reactivity in Light-Water-Moderated and Heavy- Water-Reflected Cylindrical Core Loaded with Highly-Enriched-Uranium or Medium-Enriched-Uranium Fuel

An analysis was performed for the temperature coefficient of reactivity measured in the six types of light-water-moderated and heavy-water-reflected cylindrical cores containing highly-enriched-uranium (HEU) or medium-enriched-uranium (MEU) fuel, which was constructed in the Kyoto University Critical Assembly (KUCA). The purpose of the present analysis was to reveal a mechanism why a light-water region existed in the core contributes to a large positive temperature effect on reactivity. Therefore, based on the assessment of the computational method to calculate the temperature coefficient of reactivity in a multi-region type core, studies were carried out to examine each effect of three physical processes (Doppler broadening, thermal expansion and thermal neutron spectral shift) on the temperature coefficient and to separate each contribution of the multi-regions to this physical quantity. The measured temperature coefficients were approximately simulated by the calculations using the SRAC code system. The Doppler broadening caused a slightly negative effect in the MEU cores and the thermal expansion a negative effect in all the cores, whereas the thermal neutron spectral shift caused a large positive effect in all the cores. The temperature effect on reactivity in the fuel region was negative, while that in the light-water region existed in the core was positive because of the decrease in neutron absorption due to the thermal expansion and the spectral shift effects, and it became positive in the present core where large light-water regions existed in the core.     

Neutron Transport Benchmark Calculations, (I)

Five benchmark problems were selected as standards for the evaluation of calculations on neutron penetration. For three of these problems there were available reliable experimental results obtained in absolute intensities of the neutron angular spectrum in graphite and in water and of the neutron reaction rate in a two-dimensional water shield. The two remaining problems were based on PALLAS transport calculations in graphite and in water in plane geometry. For the first three problems, comparisons were made between the results of PALLAS calculations using ENDF/B-I cross sections and those obtained by experiment. It is concluded that the PALLAS calculations result in fairly good agreement with experiment, except at certain spatial meshes in two-dimensional geometry, due to ray effect. Comparisons are also made of the angular flux spectrum in graphite between calculations using ENDF/B-I and B-III data, as well of the scalar flux spectrum in water between those by PALLAS and by ANISN codes.     

Measurement of Local Power Peaking Factors in Heavy-Water Moderated Plutonium Lattices

Local power peaking factors (LPF) in the heavy-water moderated plutonium lattices were measured by a new method of γ-scanning of fuel pins using the calculated power correction factor of which accuracy was evaluated with the aid of foil activation method. Accuracy in measurement of the LPF was evaluated to be within 1%.

By this measurement, behaviors of the LPF have been made clear concerning the differences in fuel materials, coolant materials and arrangement in fuel enrichments. Depression of the thermal power in the fuel cluster makes LPF in the plutonium fuel lattice larger than in the uranium lattice. This tendency is more remarkable in air coolant lattice than in H₂O coolant lattice. The value of LPF for the plutonium fuel cluster of different enrichments is smaller than that of a uniformly enriched fuel cluster. The reduction of LPF is smaller in H₂O coolant than in air coolant lattice.

The values of LPF by WIMS-D code based on the transport theory and by METHUSELAH-II code based on the diffusion theory are in agreement with the measured ones, within 1.5 and 2.4% respectively.