摘要：2 cm电子回旋共振离子推力器具有高比冲、长寿命的特点,其应用于引力波探测的可行性已经过初步探索.然而,在探究离子源推力下限的过程中发现,在极低功率(0.5 W)和极低流量(0.1 sccm,1 sccm=1 L/min)的极限工作状态下,过度施加栅极电压可能引发离子源猝灭.采用实验手段对猝灭现象进行观测的难度很大,一方面因为猝灭现象具有随机性和瞬时性;另一方面,介入式诊断对弱放电水平的等离子体干扰很大,而光学诊断又有栅极系统阻挡.为此本文采用全粒子数值模型对离子源进行了一体化模拟,复现了猝灭现象.模拟结果表明,天线和放电室之间的双极扩散是导致离子源猝灭的最根本原因.明晰了猝灭机理后,本文提出了相应的改进措施,并用一体化模拟进行了理论验证.对猝灭机理的研究将为离子源的设计和应用提供理论依据,保障离子源安全稳定工作,满足引力波探测任务的推力需求.

摘要：诊断电子回旋共振离子源等离子体的传统方法是采用传统的单探针无发射时测量伏安曲线,并根据曲线的拐点由理论公式计算出的等离子体密度。本文设计并研制了等离子体密度的测量装置。采用单根朗缪尔探针(该探针可以用来发射电子)测量等离子体的伏安特性。在探针有发射和无发射两种状态下测量得到两条伏安曲线,根据这两条曲线的"分叉点"得到等离子体电位,然后根据该电位直接由计算机计算出电子温度、电子密度。采用该新方法,测量得到的等离子体参量空间电位约为17 V,悬浮电位约为-5 V,电子温度约为4.4 eV,离子密度为1.10×1011cm-3,与传统方法计算出的等离子体1.12×1011cm-3相比,两者相差仅1.8%,但新方法效率和精度更高。

摘要：空间推进所用的电子回旋共振离子源(ECRIS)应具有体积小、效率高的特点.本文研究的ECRIS使用永磁体环产生磁场,有效减小了体积,该离子源利用微波在磁场中加热电子,电子与中性气体发生电离碰撞产生等离子体.磁场在微波加热电子的过程中起关键作用,同时影响离子源内等离子体的约束和输运.通过比较四种磁路结构离子源的离子电流引出特性来研究磁场对10 cm ECRIS性能的影响.实验发现:在使用氩气的条件下,特定结构的离子源可引出160 mA的离子电流,最高推进剂利用率达60%,最小放电损耗为120 W·A^(-1);所有离子源均存在多个工作状态,工作状态在微波功率、气体流量、引出电压变化时会发生突变.离子源发生状态突变时的微波功率、气体流量的大小与离子源内磁体的位置有关.通过比较不同离子源的引出离子束流、放电损耗、气体利用率、工作稳定性的差异,归纳了磁场结构对此种ECRIS引出特性的影响规律,分析了其中的机理.实验结果表明:保持输入微波功率、气体流量、引出电压不变时,增大共振区的范围、减小共振区到栅极的距离,离子源能引出更大的离子电流;减小共振区到微波功率入口、气体入口的距离能降低维持离子源高状态所需的最小微波功率和最小气体流量,提高气体利用率,但会导致放电损耗增大.研究结果有助于深化对此类离子源工作过程的认识,为其设计和性能优化提供参考.

摘要：To improve the accuracy and usability of the superconducting electron cyclotron resonance ion source with advanced design in Lanzhou(SECRAL), an upgraded version of the control system was designed and tested. This paper details the architecture of the optimized control system and presents the results of its use in the long-term operation of the accelerator. The control system software, based on Visual C++, was developed following the model-view-controller architecture design pattern. The data acquisition system was based on a field-programmable gate array integrated circuit. In addition, control strategies were optimized for higher operational stability. The upgraded control system was tested with a U^(33+) ion beam at SECRAL, where it provided a data acquisition time of less than 1 ms. The fast reaction time and highprecision data processing during beam tuning verified the stability and maintainability of the control system.

摘要：LECR2 (Lanzhou Electron Cyclotron Resonance ion source No.2), which was built in 1997, has been running for more than 30 000 h and provided more than one hundred kinds of ion beams for HIRFL. This ion source was considered to be one of the best ECRISs in the world when it was under commissioning because of its