上海光源储存环新注入方式

上海光源储存环的新工作模式和新装插入件会导致动力学孔径和注入效率的减小,传统的注入方式不再满足恒流注入要求。分别从改变注入方式和减小注入束流发射度两个角度解决注入对动力学孔径的需求。脉冲多极铁与凸轨相结合的注入方式可以将动力学孔径的要求降低到7 mm以下。利用斜四极铁在高能输运线上进行水平和垂直发射度互换可以将注入束流发射度降低到近1/10而降低注入点的束斑尺寸。两者都可以将注入效率提高到95%以上。二者在更小动力学孔径的情况下同时使用还可以减小脉冲多极铁的强度。     

HALS对PE辐射致色的影响

研究了受阻胺类光稳定剂（HALS）对聚乙烯（PE）辐射致色的影响，发现各种HALS均能减少PE的辐射致色，在辐照剂量低于100kGy时，添加五甲基HALS的PE的黄度比添加相应的四甲基HALS的PE的黄度略高；而在辐照剂量高于100kGy时，结果相反。并且发现，在相同的辐照剂量下，添加聚合物型HALS的PE的黄度比添加相应的黄体型HALS的PE的黄度低一些。还测定了添加HALS的PE在辐照后烷基自由基，羰基的生成。发现，在辐照剂量较大时，添加TMPM的PE的烷基自由基相对浓度大于添加PMPM的烷基自由基相对浓度，在辐照剂量较低时，含五甲基基HALS的PE薄膜的羰基指数比含四甲基HALS的PE薄膜的小，而在辐照剂量较高时，结果相反，认为HALS通过清除自由基抑制PE的辐射致色。     

武汉光源一期工程加速器系统

武汉光源一期工程计划建造一台第4代同步辐射装置,由1台1.5 GeV的低能量储存环和1台全能量直线注入器组成。储存环设计周长180 m,由8个标准混合型的7BA磁聚焦结构单元周期组成,能够储存500 mA的1.5 GeV电子。储存环自然发射度优化至222.8 pm·rad,可达到软X射线的衍射极限。为了满足用户对硬X射线的需求,每个标准单元的中心处安装了1台3-5 T的超强二极铁。同时为了提高因发射度减小造成的低寿命和动力学孔径过小造成的注入困难等问题,储存环的设计中还使用了三次谐波腔用于束团拉伸以及替换式注入系统等措施。全能量直线加速器位于储存环地下6 m处,采用S波段加速结构。本文将对武汉光源一期工程加速器系统进行更加详细的介绍。     

HALS及抗氧剂对聚丙烯辐射致色的影响

研究了在辐照条件下受阻胺光稳定剂（ＨＡＬＳ）、各种抗氧剂及ＨＡＬＳ与抗氧剂并用等对聚丙烯（ＰＰ）的黄度（ＹＩ）的影响。实验发现,添加五甲基ＨＡＬＳ的聚丙烯的黄度均小于添加相应的四甲基ＨＡＬＳ的聚丙烯的黄度。当抗氧剂Ｉｒｇａｎｏｘ１０７６和ＰＤＳ并用时,聚丙烯的黄度比单独添加１０７６或ＰＤＳ的聚丙烯的黄度都低。单独添加１０７６的聚丙烯的黄度比添加抗氧剂Ｉｒｇａｆｏｓ１６８或ＩｒｇａｎｏｘＰＳ－８０２的聚丙烯的黄度都小。当ＰＤＳ和Ｉｒｇａｎｏｘ１０７６并用时聚丙烯的黄度小于ＰＤＳ和Ｉｒｇａｆｏｓ１６８或ＩｒｇａｎｏｘＰＳ－８０２并用时的黄度。辐照后聚丙烯的黄度开始随放置时间很快降低,但随时间增加,黄度的变化逐渐减慢,最后基本保持不变。对结果进行了分析和讨论。     

紧凑型中高能同步加速器的物理设计

本文采用束流光学匹配软件优化组合磁铁布局得到一种紧凑型的同步加速器。该加速器具有周长短、磁铁孔径小、束流品质高等优点。注入和引出设计是此同步加速器的关键点,基于Matlab/AT开发了模拟软件,模拟研究注入和引出相关束流动力学问题。研究结果表明,该同步加速器束流品质优、注入效率高、引出束流损失低。该同步加速器可满足航天、材料和生物等多方面研究。     

储存环的闭合轨道畸变校正研究

在电子储存环中,弯转磁铁的场误差,转动误差和四极磁铁的横向位置偏差所科生的二极磁场分量,会导致循环电子的闭合轨道畸变（ＣＯＤ）,以ＳＳＲＦ电子储存环为例,探讨如何利用国际用加速器程序ＭＡＤ和ＲＡＣＥＴＲＡＣＫ进行第三代储存环的闭合轨道畸变校正,首先对ＳＳＲＦ电子储存环闭合轨道校正方案中的校正子和ＢＰＭ不同安放方案作了比较研究,结果表明,采用单个单元安放１０ＢＰＭ（安在六极磁铁附近）每个普通单元安装     

质子加速器注入、引出磁铁电源的纹波抑制

在国产首台质子治疗示范装置研制项目中，质子加速器的注入、引出磁铁电源采用模块电源并联方式，但注入、引出磁铁的电感量较小不利于开关电源噪声抑制。为满足项目需要，提出了一种错相设计方案，并推导了三相错相的纹波归一化量值，理论上验证了方案的可行性。在此基础上，用MOSFET以H桥结构作为基本单元，采用3单元移相120°的方式构成模块电源。经测试，3台静磁切割磁铁电源开关纹波满足设计和使用要求，同时证实了电源拓扑结构的可行性。3台电源自投入使用以来，无故障可靠稳定运行20个月以上。     

Deposition Mitigation of the First Mirrors Exposed in EAST with Metal and Carbon Mixed Wall Materials

In order to investigate the effect of aperture geometry on deposition mitigation, stainless steel （SS） first mirrors （FMs） were fixed on the holders of protective aperture geometry with different depth-diameter ratios （DDRs） and exposed in the deposition dominated environment of EAST. A baffle was used during the wall conditioning. The surface properties and reflectivity of the FMs were characterized before and after exposure. It is shown that using aperture geometry and a baffle can effectively mitigate the impurities deposition. The degradation of the surface and specular reflectivity of the FMs is reduced with the increase of DDRs in the range of 0 to 2. The main contaminated elements in a low-Z and high-Z mixed wall materials environment were still carbon and oxygen.     

HLS脉冲四极磁铁注入方法设计与研究

介绍了一种采用脉冲四极磁铁实现储存环束流注入的新方法.通过物理计算和注入过程数值模拟研究,确定了储存环上安装脉冲四极磁铁的位置和强度,并通过模拟计算评估了注入过程中注入束流存活效率和对储存束流的影响,证明了在合肥光源采用脉冲四极磁铁完成束流注入过程的可行性.     

Experimental Results of the Dichotomic Sampling in Circular Ring Positron Emission Tomograph

Experimental verification of the new dichotomic sampling scheme was attempted and applied to a circular ring PET system to improve the sampling thereby the overall system resolution and its performances. In the experiment, two different types of aperture collimators were adopted for high resolution (HR) and very high resolution (VHR) imaging. In HR mode, a resolution of 6.5 mm FWHM was obtained without appreciable degradation in overall sensitivity which represents a threefold resolution improvement over the original system. In phantom studies with HR mode a sensitivity of 4500 counts/sec/?Ci/cc was obtained for a 20 cm diameter uniform phantom filled with water. VHR mode experiment was also conducted to observe the ultimate resolution capability of DICHOTOM-I system and resolution of 4.2 mm FWHM was obtained at the expense of sensitivity reduction by a factor of four from HR mode experiment.     

The Progress of a Microbeam Facility in the Institute of Plasma Physics

The progress of a microbeam facility in the institute of Plasma Physics was discussed in this paper.This kind of equipment can supply single-particle beam which may be implanted into cells in micrometer-radius and measured by a new outstanding detector among global microbeam systems.Measurements by some plain targets showed that the highest current after the accelerator tube can be larger than 20μA ,the H2^ current before the second bending magnet is near 0.9μA ,the current after the second bending magnet is near 0.8μA,and the current of the beam line(after a 2-mm diameter aperture)is near 0.25nA which is enough for the single-particle microbeam experiment.It took scientists 3 months to do their microbeam experiment after setting up the qccelerator beam line and get the microbeam from this equipment.Two pre0collimators were installed between the 2-mm diameter aperture and the collimator to survey the beam.Tracks on the CR39 film ectched in the solution of NaOH showed that the beam can go through the collimator including a 10μm diameter aperture and the 3.5μm thick vacuum sealing film(Mylar).A new method,which is called optimization of the beam quality,was put forward in this paper,in order to get smaller diameter of beam-spot in microbeam system.     

Development of a Small-Aperture Slit System for a High Collimator Ratio at the Thermal Neutron Radiography Facility in JRR-3

A small-aperture slit system has been developed and installed to enhance the collimator ratio (“L/D”) of the thermal neutron radiography facility (TNRF) in JRR-3. The degree of unsharpness on neutron images is reduced by increasing the L/D. The small-aperture slit system increased the L/D by creating a small aperture size (“D”). Image sharpness improved when the aperture size was reduced to below 10mm by 10mm in the TNRF. On the other hand, there was almost no difference in unsharpness on images obtained above 10mm by 10mm in aperture size. These results indicate that an aperture size of less than 10mm by 10mm should be used for high-spatial-resolution imaging at the TNRF. The beam area of the small-aperture slits was relatively small in comparison with that of a conventional large collimator, though gradually increasing with increasing aperture size. Even with an aperture size of 5mm by 5 mm, the practical beam area for imaging examinations corresponded to around 25mm by 20 mm, which is enough area to carry out high-spatial-resolution imaging.     

Panofsky magnet for the beam extraction from the synchrotron using a fast Q-magnet and RF-knockout

The fast control of the beam spill extracted from a synchrotron is a key function for the spot scanning irradiation in cancer therapy application. The authors propose an extraction method which uses the quadruple field of fast response, as well as the RF-knockout. A Panofsky magnet was developed as a quadruple magnet, with a frequency response of around 10 kHz. The Panofsky magnet has a rectangular beam aperture and plate coils attached to the pole face. A model magnet has been manufactured with ferrite, and static and dynamic magnetic fields were measured. From the measurement we observed that the effects of eddy current in the plate coils were large and the uniformity of the magnetic field gradient in the beam aperture was worse than ±5% with a plate thickness of 0.02 cm and a frequency of current of 10 kHz. For the future, in a detailed design the eddy current effects have to be taken into account.     

Two-plane painting injection scheme for BRing of HIAF

The high-intensity heavy-ion accelerator facility(HIAF)is under design at the Institute of Modern Physics(IMP)and will provide an intense ion beam for nuclear physics,atomic mass measurement research,and other applications.As the main ring of HIAF,the BRing accumulates beams to high intensity and accelerates them to high energy.To achieve high intensities up to 1×10~(11)(~(238)U~(34+)),the injection gain of the BRing must be as high as 88.However,multiple multiturn injection supported by the electron cooling system takes a long time,causing substantial beam loss under a strong space charge effect.Hence,a two-plane painting injection scheme is proposed for beam accumulation in the BRing.This scheme uses a tilted injection septum and horizontal and vertical bump magnets to paint the beam into horizontal and vertical phase space simultaneously.In this paper,the two-plane painting injection parameters are optimized,and the resulting injection process is simulated using the Objective Ring Beam Injection and Tracking(ORBIT)code.An injection gain of up to 110.3 with a loss rate of 2:3%is achieved,meeting the requirements of BRing.     

小型堆破口失水事故初步研究

为验证中国广核集团小型堆方案设计,尤其是其中非能动安全注入系统的初步设计,基于RELAP/SCDAPSIM程序,建立了小型堆的一、二回路系统和非能动安全注入系统模型,模拟计算了冷管段0.04 m等效直径破口、冷管段0.2 m等效直径破口、直接注入管道双端断裂、自动卸压系统误启动等LOCA工况。计算结果表明,一回路可实现有效的冷却和降压,堆芯不会过热,验证了其非能动安全注入系统的设计合理性和反应堆系统的安全性。     

CIAE强流ECR离子源研制

本文介绍了研制的一台强流ECR微波离子源,其能从7 mm直径的圆孔引出大于150 mA的氢离子束(75 keV),质子比达90%。该离子源采用独特的结构提高了离子源寿命。离子源在75 keV、110 mA束流条件下连续工作超过220 h,束流中断2次,不间断工作时间超过150 h。     

Texture, residual strain, and plastic deformation around scratches in alloy 600 using synchrotron X-ray Laue micro-diffraction

Deformation around two scratches in Alloy 600 (A600) was studied nondestructively using synchrotron Laue differential aperture X-ray microscopy. The orientation of grains and elastic strain distribution around the scratches were measured. A complex residual deviatoric elastic strain state was found to exist around the scratches. Heavy plastic deformation was observed up to a distance of 20 μm from the scratches. In the region 20-30 μm from the scratches the diffraction spots were heavily streaked and split indicating misoriented dislocation cell structures.     

辐射制备热敏性水凝胶及控制释放

通过在空气中预辐射聚丙烯，将单体Ｎ－异丙基丙烯酰胺接枝到聚丙烯多孔膜的表面上，得到一种新型的具有良好的热敏性及机械性能的水凝胶。研究了各种因素对接枝后应的影响，考察了其热敏性能及表面形貌，通过变温度可改变多孔膜孔膜大小，并产针其用于托马斯亮蓝分子的渗透及控释过程。     

陶瓷真空室研制及其阻抗的研究

介绍了电子储存环注入凸轨击磁铁及春真空室常采用的几种技术方案。合肥电子储存环新凸轨注入系统选择了铁氧体磁铁内置陶瓷真空室的方式。为了同时满足脉冲磁场穿透性能及束流耦合阻抗的要求，陶瓷真空室的内壁须镀１层金属薄膜。     

微波离子源聚焦离子束光学系统的研究

设计了一种微波离子源的聚焦离子束光学系统,分析计算了光学系统的束径。并数值模拟了由空间电荷作用造成的束径增宽效应,找出了影响束斑大小的主要因素和减小束径的方法。测试结果表明,在束能在２５ｋｅＶ时,束流为１４８ｎＡ,束径约为２０μｍ左右。