Low energy range dielectronic recombination of Fluorine-like Fe~(17+) at the CSRm

The accuracy of dielectronic recombination(DR) data for astrophysics related ions plays a key role in astrophysical plasma modeling. The absolute DR rate coefficient of Fe~(17+) ions was measured at the main cooler storage ring at the Institute of Modern Physics, Lanzhou, China. The experimental electron-ion collision energy range covers the first Rydberg series up to n= 24 for the DR resonances associated with the ~2 P_(1/2)→~2 P_(3/2)△n =0 core excitations. A theoretical calculation was performed by using FAC code and compared with the measured DR rate coefficient. Overall reasonable agreement was found between the experimental results and calculations.Moreover, the plasma rate coefficient was deduced from the experimental DR rate coefficient and compared with the available results from the literature. At the low energy range, significant discrepancies were found, and the measured resonances challenge state-of-the-art theory at low collision energies.     

CSR电子冷却系统电子束空间电荷效应对电子束温度的影响

 通过求解电子冷却系统中冷却段漂移管区的强流电子束产生的空间电荷场,研究了电子束空间电荷效应对电子温升的影响。结合HIRFL CSR电子冷却系统的典型参数,得到了电子在自身空间电荷场和纵向螺线管磁场组成的交叉场作用下产生的漂移速度和由此引起的附加温度大小,并指出减小电子束空间电荷效应的方法。     

HIRFL-CSR电子冷却系统空心电子束性能研究

 电子冷却系统中冷却力的大小与电子束的温度密切相关。由于强流电子束自身产生的空间电荷场,使得电子束的速度离散,增加了电子束温度,降低了冷却效率。为了减小空间电荷效应,HIRFL CSR的电子冷却系统将首次采用空心电子束对储存环中的重离子束流进行冷却。通过分析实心电子束和空心电子束的空间电荷场,研究了其对电子束速度和温度的影响。     

N',N'-二乙基硫脲添加剂对铜微沉积工艺电化学行为的影响

为了研究N',N'-二乙基硫脲添加剂在微沉积工艺中对铜金属孔洞填充能力的影响,采用线性伏安法(LSV)、循环伏安法(CV)、SEM测量法分析比较了无添加剂、含硫脲和含N',N'-二乙基硫脲添加剂时微沉积铜工艺中的电化学行为,并借助塔菲尔方程,分析比较此三种情况下电镀反应过程中的电极动力学参数.结果显示:当铜微沉积工艺中加入N',N'-二乙基硫脲添加剂时,产生活性极化,该活性极化效应降低铜离子的放电速度,抑制孔洞边缘部分沉积较快区域的过快生长;同时活性极化提高,将导致成核点的增加,沉积膜的晶粒较小,镀膜也较平滑细致,实验测得铜离子的平滑能力比没有添加剂时提高约50%.最后通过微沉积工艺成功地将金属铜填充入宽为10 μm,深宽比为4:1的微型凹槽中,且镀层内没有空洞、空隙以及细缝等缺陷.     

HIRFL-CSRm冷却束流寿命

实验研究了HIRFL-CSRm中电子冷却装置对C6+,Ar15+两种束流寿命的影响。首先,通过对比实验的测量确定电子冷却可以有效提高束流寿命;其次,探究了电子冷却装置中的各项参数（主要是电子束密度分布、流强、能量、绝热展开因子）是如何影响束流寿命的,通过改变电子束参数,测量束流寿命的变化趋势和规律,并且结合电子冷却相关理论对实验结果给予解释,最终通过实验优化和确定最佳的冷却装置参数,使束流在HIRFL-CSRm上获得了较高的寿命,从而提高HIRFL-CSRm束流累积过程中的流强增益。     

空间辐射地面模拟装置(SESRI)同步加速器注入设计和模拟研究

国家"十二五"工程将在哈尔滨工业大学建造一台空间辐射地面模拟装置（SESRI）,该装置能够模拟空间辐照环境,对研究离子辐照材料、生命体等具有重要意义。SESRI主要由双ECR离子源,直线注入器,同步环和3个高能实验终端组成。周长为43.9 m的同步环作为装置的核心部分,能够向3个实验终端输送离子种类多、能量范围广的粒子束。为了保证环内有足够的粒子数,注入系统的设计至关重要,SESRI同步环采用多圈注入方案,并利用ACCSIM程序模拟粒子真实运动情况。结果表明,粒子的注入效率为85.5%,离子数增益可达17.1,可满足设计要求。Space Environment Simulation and Research Infrastructure (SESRI), which is one of the large-scale scientific projects proposed in National Twelfth Five-Year Plan of China, will be constructed in Harbin Institution of Technology. The SESRI project dedicated to space radiation consists of two ECR ion sources, a high intensity ion linac, a synchrotron and 3 research terminals. As the key part of the complex, a 43.9 m synchrotron can provide broadest energy range and variable ion beam for each terminal. To obtain required intensity in the synchrotron, the injection system is significant. A multi-turn injection scheme is adopted in the synchrotron and the injection process is simulated by ACCSIM with multi-particle tracking method. The results show that the injection efficiency and intensity gain factor can reach 85.5% and 17.1 respectively. The multi-turn injection system can meet the design requirement.     

HIAF-BRing中极化质子加速研究

为了更深入地研究核子性质,中国科学院近代物理研究所将在强流重离子加速器装置（HIAF）上利用极化质子束开展实验。HIAF增强器BRing能够提供最大能量9.3 GeV/u的极化质子束,在加速过程中极化束流会遇到多次退极化共振,需要特殊设计才能使束流保持较高的极化度。利用退极化共振强度模拟程序DEPOL,研究了BRing加速过程中不同退极化共振对束流极化度的影响。结果表明,加速过程遇到的两种退极化共振将会使束流完全退极化;在BRing电子冷却段加入Full Siberian Snake可以使质子束在加速时保持较高的极化度。In order to explore the nucleon properties in details, the polarized proton will be used for some special experiments at HIAF project in Institute of Modern Physics, Chinese Academy of Sciences (IMP,CAS). The maximum energy of 9.3 GeV/u for Polarized protons will be provided in the Booster Ring(BRing) at HIAF. The polarized beam experiences depolarizing resonances many times during acceleration process, so it's necessary to suppress those resonances to keep polarizability well by special design. In this paper, the code DEPOL is used to simulate the influence of depolarizing resonances process in BRing. According to the results, the beam's polarization has been destroyed completely by the depolarizing resonances in the acceleration process. And the Full Siberian Snake is chosen in the Electron Cooler part of BRing to preserve the beam's polarization during the acceleration, and its strength and location of the Siberian Snake are also presented here.     

双馈感应风力发电机的H_∞鲁棒控制

研究了变速恒频双馈感应风力发电系统的鲁棒控制问题.利用基于定子磁场定向的矢量变换技术,建立了同步旋转坐标系下双馈感应发电机的状态空间模型,为了降低控制器的阶数以利于工程实现,对该动态数学模型进行了合理简化.针对最大功率点跟踪控制中建模误差、外部干扰等不确定性的影响,应用H∞鲁棒控制理论,设计了具有鲁棒干扰抑制作用的电机转子电压控制器.仿真结果表明,即使在参数变化、未建模动态等不确定因素以及风速突变干扰下,所设计的控制器仍可保证电机转速很好地跟踪指令值,使风力发电系统最大效率地吸收风能.     

低温等离子体脱硝技术研究进展

低温等离子体技术(non-thermal plasma,NTP)作为极具发展潜力的污染物脱除技术之一,已被广泛应用于氮氧化物脱除工艺。首先介绍低温等离子体技术的工作原理、影响因素和工业应用,其次综述低温等离子体脱硝技术的研究进展,详细阐述反应器电极形状尺寸、放电间隙、能量密度、气流速度、反应气氛、氧化还原剂及催化剂等因素对该技术脱除效率的影响作用,最后简要介绍了低温等离子体技术的工业试点及应用项目;并对低温等离子体技术的发展方向进行了展望。     

CSRe储存环动力学孔径研究(英文)

动力学孔径对环形加速器, 尤其是现代的储存环, 起着越来越重要的作用。采用MAD程序研究了兰州重离子加速器实验环（CSRe）的动力学孔径。通过对比几种情况下的模拟结果, 发现六极铁和二极铁的高阶场对束流的动力学孔径影响较大, 使CSRe的动力学孔径减小, 但减小后的动力学孔径也远大于该环的物理孔径。因此, 束流可以长期、 稳定的存在。Dynamic aperture(DA) is playing a more and more important role in circular accelerators, especially in the modern storage rings. In this paper, the DA of CSRe is analyzed by MAD program. Comparing the DA under various assumptions, we find that the multipole errors in dipoles or quadrupoles, and the sextupoles which bring strong non linearities, and limit the DA of CSRe. Fortunately, the DA is larger than the physical aperture in all the cases, and that is large enough to satisfy the high precision physical experimental request.