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Gas phase Chemistry studies of Superheavy Element Dubnium and Its Homologs
No full text本文简要叙述了超重元素的合成方法，介绍了用于研究超重元素化学性质的
气相色谱技术，总结了超重元素 Db 的气相化学研究结果，介绍了我国超重核及
超重元素化学的研究现状。
简要说明相对论效应对超重元素化学性质的影响及超重元素化合物挥发性
质的理论估计方法。根据已有的理论计算数据，对第五族元素 Db 及其同族元素
的溴化物的挥发性进行了合理的预测，得到了第五族元素溴化物的挥发性的顺序
为：DbBr5＞NbBr5＞TaBr5。
用蒙特卡罗方法模拟了易挥发化合物的气相色谱微观动力学行为,描述了化
合物随气流在固体色谱柱表面的迁移以及吸附-解吸等过程。按气相色谱微观动
力学模型编译的计算机程序模拟了超重元素化合物在等温色谱及热色谱的动力
学过程,并根据不同实验条件进行了大量计算。计算结果与实验数据较为符合。
讨论了超重元素的半衰期、吸附态的周期、载气流量以及化合物的质量密度等对
实验结果的影响及该理论模型的优点和待改进的地方。
建立并调试了用于超重元素气相化学研究的在线等温色谱装置。利用252
Cf自发裂变源产生的放射性核素101，103-108Tc，以高纯氮气中的痕量氧气作为反应气体，
研究了TcO3的挥发性，在线等温色谱的化学分离效果，半衰期对等温穿透曲线的
T50%以及化学分离效率的影响，并得到了TcO3 在石英色谱柱表面的摩尔吸附焓。
利用同位素 99Nb， 研究了Nb的溴化物和氧溴化物的挥发性。 采用HBr作为反应气体，
研究了在系统中存在痕量的氧气和水蒸气的条件下，在反应区生成 NbBr5和
NbOBr3的混合物；以及除尽氧气和水时，只生成单一产物NbBr5的可能性。通过蒙
特卡罗程序对实验结果的拟合，得到NbBr5和NbOBr3在石英表面的吸附焓分别为
92±5kJ/mol和153±5 kJ/mol。研究表明在线等温色谱装置可以很好的将101，103-108
Tc和99Nb从自发裂变碎片中分离出来
Fabrication of Rutile TiO2 Photonic Crystals by Swift Heavy Ions
No full text快重离子辐照结合化学蚀刻的方法在材料微尺度结构制备上极具潜力，这一
方法能被用于正处于研究热点的光子晶体的制备。金红石型二氧化钛单晶晶体拥
有高的折射率，因而被选为本文研究制备光子晶体的对象。
本论文使用掩膜法制备光子晶体，掩膜的作用非常关键，制备出的光子晶体
与所使用的掩膜具有相同的形貌结构。掩膜分别采用了电镜载网、自制的铜栅网
和多孔氧化铝模板。使用的掩膜孔径大小各不相同，厚度也各不相同，对辐照实
验的影响也不同。
离子辐照的各种参数也需满足一定的要求。离子辐照后二氧化钛晶体表面会
出现肿胀效应。被辐照区域能够在氢氟酸溶液中被蚀刻掉，化学蚀刻的电子能损
阈值为8.2 keV/nm，只有当辐照离子的电子能损高于这一值时，二氧化钛的辐照
区域才能被蚀刻掉。要达到饱和蚀刻深度，辐照离子的注量必须大于 1×1013
ons/cm2。当辐照注量小于 1×1013 ions/cm2时，二氧化钛的不同表面晶面开始
产生影响。本论文试图从潜径迹形成理论出发，对辐照损伤、辐照损伤对化学蚀
刻的影响作了分析和解释
多分量对偶超导理论研究
No full text本文从多分量对偶超导理论出发对强子的口袋模型做出解释。文章首先简
要地介绍对偶超导理论的物理图像，以及该理论的合理性，包括格点计算与解
析推导两方面所提供的支持。其次，分别基于Abel投影、拓扑规范势分解、联络
新参数化三种方案，讨论非Abel规范场论与对偶超导理论之间的紧密联系。
本文较为详细地探讨了多分量Ginzberg-Landau模型的动力学。特别对于二
分量超导体内的非Abrikosov涡漩解做了阐述。非Abrikosov涡漩解根据边界条
件分为D 型与N 型，拓扑类型又存在Abel与非Abel两种，磁通量子数可以是整
数亦可以是分数。通过求解运动方程，详细讨论了这些不同类型涡旋的性质。
进一步，对色磁通量字数趋向于无穷的情况予以分析，在多分量对偶超导
模型中给出了一类状似Heaviside函数的墙涡旋解。而这种墙涡旋解可以对应于
口袋模型的边界。由此，给出了QCD与口袋模型之间的直接联系。论文最后讨
论了三分量对偶超导模型，说明了在铁磁相中三分量对偶超导模型中也存在类
似的墙涡旋
BEAM-PHASE MEASUREMENT SYSTEM FOR HIRFL
No full textThe beam phase measurement system in HIRFL is<br />introduced. The system had been improved using RFsignal<br />mixing and filtering techniques and noise<br />cancellation method. Therefore, the influence of strongly<br />RF disturbing was eliminated and the signal to noise rate<br />was increased, and a stable and sensitive phase<br />measurement system was developed. The phase history of<br />the ion beam was detected by using 15 sets of capacitive<br />pick-up probes installed in the SSC cyclotron. The beam<br />phase information was necessary for tuning purposes to<br />obtain an optimized isochronous magnetic field, where<br />the beam intensity was increased and the beam quality<br />was optimized. The measurement results before and after<br />optimized isochronous magnetic field for 40Ar15+ ion and<br />12C6+ ion in SSC were given. The phase measurement<br />system was reliable by optimizing isochronous magnetic<br />field test, and the precision reached ±0.5o, the sensitivity<br />of beam signal measurement was about 10nA as well
DESIGN AND CONSTRUCTION PROGRESS OF A 7MEV/U CYCLOTRON
No full textThe 7MeV/u cyclotron accelerates carbon ions with<br />mass number 12, 5+ charges, the extraction energy of<br />carbon ions is 7MeV/u, and the beam current density is<br />designed to be 10eμA. It designed as injector for the<br />HITFiL(Heavy Ions Therapy Facility in LanZhou)<br />synchrotron, which accelerates carbon ions to the energy<br />300MeV/u for tumors treatment. Computer modeling<br />results on the axial injection, magnetic, accelerating and<br />extraction systems of the cyclotron are given. Design of<br />the main systems of the cyclotron and the results of beam<br />dynamic simulations are introduced [1], [2], [3], [4]. The<br />construction progress including the ECR ion source, the<br />axial injection beam line, the magnet, the RF system, the<br />vacuum system etc. will be described respectivel
REVIEW OF HIGH-POWER CYCLOTRONS FOR HEAVY-ION BEAMS
No full textAbstract<br />Since the development of heavy ion cyclotrons in the<br />1980s for use in the field of radioactive beam physics<br />considerable effort has been made to upgrade these<br />cyclotrons in terms of beam intensity and beam energy.<br />This paper presents an overview of cyclotrons that<br />provide heavy-ion beams with powers in the range of<br />several hundred W and above. Some technological issues<br />related to high-power heavy-ion beams are also discussed<br />on the basis of the experiences of those cyclotrons
CONSTRUCTION OF NEW INJECTOR LINAC AT RIBF
No full textA new injector linac called RILAC2 has been constructed<br />in order to enable the independent operation of<br />the RIBF experiments and super-heavy element synthesis.<br />Construction of the RILAC2 started at the end of FY2008.<br />The RFQ linac and three DTL tanks were installed in the<br />AVF-cyclotron vault and the excitation of rated voltage<br />have succeeded. Two rebunchers are in fabrication and<br />alignments of LEBT and HEBT are performed now. We<br />plan to start the beam commissioning in December 2010.IMP;Chinese Academy of Science
CENTRAL REGION DESIGN OF A BABY CYCLOTRON
No full textBaby cyclotrons are widely used in short lived β+<br />radioactive isotope production. A 11 MeV baby cyclotron<br />for PET isotope production was designed and is in<br />construction in CAEP now. Central region design is one<br />of the most important parts of cyclotron design work. In<br />this paper, central region design of the 11 MeV baby<br />cyclotron, including design processes and design results,<br />is reported.IMP;Chinese Academy of Science
TOWARDS QUANTITATIVE PREDICTIONS OF HIGH POWER CYCLOTRONS *
No full textThe large and complex structure of cyclotrons poses<br />great challenges in the precise simulation of high power<br />beams. However, such simulation capabilities are<br />mandatory in the design and operation of the next<br />generation high power proton drivers. The powerful tool<br />OPAL enables us to do large scale simulations including<br />3D space charge and particle matter interactions. We<br />describe a large scale simulation effort, which leads to a<br />better quantitative understanding of the existing PSI high<br />power proton cyclotron facility and predicts the beam<br />behaviour of CYCIAE-100 under construction at CIAEIMP;Chinese Academy of Science
DESIGN AND PRIMARY TEST OF FULL SCALE CAVITY OF CYCIAE-100
No full textThe engineering of the RF cavity for cyclotron concerns
several aspects, including the vacuum, cooling,
mechanical support etc. Sometimes it is even more
complex than RF design itself. Given the space limit in a
compact cyclotron, to have a voltage distribution of 60kV
in central orbit and 120kV for outer orbit, a double stem
double gap lambda by 2 cavity has been designed for
CYCIAE-100[1]. The RF resonance of the cavity is
simulated [1] by finite integral codes, while the thermal
analysis and mechanical tolerance is studied using other
approaches[2-3]. The mechanical design and fabrications
is then carried out under these directions, resulting in a
full scale testing cavity. The simulations and mechanical
design will be reported in this paper, followed with low
level measurement results of quality factor, shunt
impedance curve along accelerating gap etc. After surface
polishing, the measurement yields an unloaded Q value of
9300, which matches well with the simulation with a
neglectable difference of several hundreds. The high
power test of the cavity and will be presented in a separate
paper of this conference.IMP;Chinese Academy of Science