【作者】 周正；

【导师】 饶波；

【作者基本信息】 华中科技大学 ， 电气工程， 2019， 硕士

【摘要】 可控核聚变能源是人类目前已知的解决未来能源危机的终极能源,它从原理上满足人类对能源安全、高效、清洁以及可持续的追求。时至今日,磁约束与惯性约束两种可控核聚变技术途径的理论已经取得了很大的进步,然而由于它们的实验装置建设成本过高,有越来越多的研究人员开始探索经济小型的技术路径,以场反位形为代表的磁惯性约束技术在这方面具有很大的优势。为了开展相关研究,华中科技大学也开始了磁压缩场反位形等离子体装置的研究。磁压缩场反位形等离子体装置主要由位于两端的FRC等离子体形成区以及处于中心的对碰融合区组成,其中,FRC等离子体首先在形成区产生,然后向中心区域对碰融合以产生参数更高的等离子体,在该过程中,装置内中性气体的分布非常重要。首先,装置形成区内FRC等离子体通过θ-箍缩产生,有相关研究表明,在其预电离阶段,靠近真空室壁面的气体最容易也是最先被电离,因此,如果能对注入中性气体的径向分布加以控制,使更多的气体分布在靠近壁面的位置,可能会提高θ-箍缩预电离阶段的效率。此外,中心区域的中性气体会冷却喷入的等离子体,这可能会导致新形成等离子体参数降低,因此,如果注气时对气体在轴向上的分布加以控制,使对碰融合前装置中心区域的中性气体尽可能减少,可能会有效提升对碰融合所产生的FRC等离子体的质量。本文主要内容是场反等离子体装置注气策略的设计与测试。由于仿真工作存在非常大的困难,因此本文主要通过实验开展相关研究。首先,我们对实验所需的真空计进行了选型,并对所选的DL5热阴极电离真空计进行了改造,使其能够满足毫秒级气压快速测量的要求。此外,我们为装置的注气阀门进行了选型与测试,最终选择了响应快速(<100μs)、注气量足(>1000 Pa·L)的009-1669-900脉冲电磁阀。最后,本文搭建了气体注气测试平台,对轴向注气与斜向注气策略进行了测试,对比实验结果后选择了更容易实现气体径向分布的轴向注气策略用于装置注气系统。更多还原

【Abstract】 Controllable nuclear fusion energy is the ultimate energy source known to mankind to solve the future energy crisis.It fundamentally meets human pursuits of energy‘s security,efficiency,cleanliness and sustainability.Up to now,the theory of magnetic confinement and inertial confinement,which are two mainstream controllable fusion approaches,has made great progress.However,due to the high construction cost of their reactor,more and more researchers have begun to explore economic approaches to realize fusion.Represented by the field-reversed configuration(FRC),the magnetic inertial confinement has great advantages in this respect.In order to carry out related research,Huazhong University of Science and Technology has also begun the development of magnetic compression field-reversed configuration(MCFRC)plasma device.MCFRC device is mainly composed of three parts.There are two FRC plasma forming region on the both sides of the device,and a collision fusion region in the center.The FRC plasma is first generated in the formation region,and then merged into the central region.In order to improve the plasma’s quality,the distribution of neutral gas in the device is very important.The FRC plasma in the device formation region is generated by θ-pinch.Related studies have shown that in its pre-ionization,the gas near the wall of the vacuum chamber is the easiest and the first to be ionized.Therefore,if radial gas distribution is controlled to make more gas distributed near the wall than near the axis,the efficiency of the pre-ionization may be increased.In addition,the neutral gas in the central region can cool the injected plasma,which may result in a parameter decrease in the plasma.Therefore,if the distribution of the gas in the axial direction is controlled during gas injection,so that he neutral gas in the central region is reduced as much as possible,and then the quality of the FRC plasma generated by the collision-merging may be improved effectively.In summary,the design of the gas injection strategy is related to the results of the FRC plasma experiment,therefore,it must be carefully considered during the design phase of the device.The design and test of gas injection strategy for FRC plasma device is described in this paper.Due to the difficulty in simulation work,the paper conducts relevant research through experiments.The time from the initial injection to the pre-ionization is only a few milliseconds,so the hot cathode ionization gauge is utilized to monitor the gas pressure change during experiment.In addition,a pulse solenoid valve with fast response time(<200 μs)and sufficient gas injection volume(>1000 Pa·L)is adopted to inject sufficient gas into the forming region before the neutral gas diffuses to the central region.To further study the influence of gas injection position on gas distribution,an experimental gas injection test platform was fabricated.Gas pressure distribution results under two gas injection strategies,i.e.axis injection and radial injection,are measured and discussed in detail.The consistency and reliability of results demonstrates the axis gas injection strategy can meet the requirements of gas injection system of FRC device更多还原