高功率激光装置的洁净控制技术
文献类型：学位论文
| 作者 | 李养帅 |
| 学位类别 | 博士 |
| 答辩日期 | 2015 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 朱健强 |
| 关键词 | 高功率激光装置 洁净控制 有限元分析 污染物 |
| 其他题名 | Cleanliness control technology of High Power Laser Systems |
| 中文摘要 | 激光惯性约束核聚变(Inertial Confinement Fusion，简称ICF)，是使用能量极强的激光束，均匀照射氘和氚小球，使其产生向外喷射极高能量的等离子体，然后聚变，进而释放巨大能量，是一种产生几乎无限清洁的可持续能源的方式，对于解决本世纪愈来愈严重的的能源危机有着深远的应用价值和科学研究意义，同时也可利用激光惯性约束聚变创造的条件，在实验室开展有关高能量密度物理和国防科技应用方面的研究工作，因而，是当今国际研究的前言领域。而高功率激光装置正是实现ICF研究的关键，它是一个大型的超精密光学系统，涉及成千上万个光学元器件。随着ICF研究的不断深入，需要装置的输出能力不断提高，这就要求装置中的光学元器件的负载能力不断提高。而元器件负载能力的提高除了与自身物理特性有关外，还与环境以及自身洁净度有很大关系。沉积或者粘附在光学元器件表面的污染物在高能激光通过光学元器件表面时，不但可能降低光束质量，严重时可诱发元器件的损伤。所以研究高功率激光装置的洁净控制技术对于ICF的实现具有重要意义。 高功率激光装置现有洁净控制方法可分为线下和线上洁净控制方法，元器件主要分为开放空间元器件和密闭空间元器件，因此有关高功率激光装置的洁净控制技术主要是针对开放空间和密闭空间元器件的线下和线上洁净控制技术。高功率激光装置的洁净控制是一个系统的工程，所以本文的主要研究内容如下： 首先，高功率激光装置的洁净度要求和常见污染物做了介绍和分类；分别从线下和线上两个角度介绍了洁净控制技术，其中线下洁净控制技术主要是洁净设计，洁净加工、洁净清洗，洁净加工和运输等。对线上若干洁净控制技术进行了归纳整理，提出了通过流场设计实现洁净控制的新技术，基于该技术，以传输镜和空间滤波器为开放空间和密闭空间为代表，提出了几种洁净控制方案。 其次，以传输镜代表开放空间元器件为例，对采用风刀吹扫集尘法的方案进行了研究。主要是通过边缘风刀吹扫法，以不同粒度并且分布于传输镜表面不同位置的灰尘颗粒为例，设计全试验，采用不同的吹扫工艺，即风刀与传输镜的安装位置、风刀吹扫的进气压力等，对传输镜表面进行清洁，获得了较佳的传输镜表面洁净控制工艺。 其次，利用计算流体动力学方法(Computational Fluid Dynamics 简称CFD) 对上述获得较佳的传输镜表面洁净控制工艺下的气流和污染物的运动轨迹进行了模拟，得到了气流在较佳工艺下的运动形式与状态，以及获得了不同粒度、不同类型、在传输镜表面不同分布的污染物颗粒的运动轨迹，为实现传输镜表面颗粒物的在线去除，以及为实现颗粒物的在线收集，减少吹扫过程中污染物颗粒对其他光学元器件的影响提供了重要的理论指导。 其次，针对上述对风刀吹扫气流运动形式以及污染物与颗粒的运动轨迹的模拟结果，设计了一种新的流场，通过CFD技术对该设计的新流场进行了模拟，模拟结果显示，该新流场不仅能够有效的去除传输镜表面的污染物颗粒，而且可以实现对风刀吹扫过程中污染物颗粒的在线捕捉和收集，能有效避免吹扫过程中颗粒物对其他光学元器件造成污染。并且通过试验，对该模拟结果进行了验证。 最后，以空间滤波器代表密闭空间的光学元器件，对其洁净控制技术方案进行了研究。利用CFD技术对空间滤波器内污染扩散情况进行了模拟研究。主要是以甲苯作为主要有机污染物，将空间滤波器内支撑聚焦小孔的金属支架作为污染源，设计模拟了不同情况下污染物的扩散情况，以期减少有机污染对空间滤波器两端透镜的污染。这其中不同情况主要是抽排气法，温度控制法以及两种方法的组合应用。采用抽排气法主要是研究了空间滤波器在不同抽排气位置时污染物在滤波器管道内及两端透镜处的浓度分布；温度控制法主要是通过在滤波器管道表面设置不同低温“冷井”，以期待降低污染物在空间滤波器内的扩散，最终减少减少污染物对滤波器两端透镜的污染。通过上述流场的设计和模拟，获得了较佳的控制滤波器内污染物浓度的工艺方法，也证明了抽排气法和低温法是有效的空间滤波器内污染物扩散和减少其浓度的有效方法，为实现降低空间滤波器管道内部及其端面透镜处污染物浓度提供了重要的理论指导。 总之，本文对高功率激光装置的洁净控制技术做了系统介绍和研究，主要是介绍了高功率激光装置的污染物，洁净度要求和洁净控制流程，对现有洁净控制技术进行了分类和梳理，在此基础上提出了洁净控制的新技术，并基于此技术，以传输镜和空间滤波器为高功率激光装置中的开放空间元器件和密闭空间元器件为，提出了一些洁净控制的方案。并从试验和模拟角度对若干洁净方案进行了对比验证分析，最终提高了高功率激光装置洁净控制的新认知和拓展了高功率激光装置的洁净控制技术，为高功率激光装置的洁净控制，乃至ICF的实现提供了指导作用，具有重要意义。 |
| 英文摘要 | Inertial Confinement Fusion (referred to as ICF) is relying on the strong power of laser beam to uniformly irradiate deuterium and tritium plasma ball, to drive the ball produce ejected outward high energy plasma, finally make the fusion happens and release tremendous energy. ICF provides a new way to produce sustainable energy almost infinite and clean for the world, has enormous application value and scientific research significance to the more and more serious energy crisis of this century. Meanwhile, many research work on high energy density physics and the national defense science and technology application can be done in the laboratory by using the conditions created by the laser inertial confinement fusion. So, ICF is the current international research objective field. While the High Power Laser System(referred to as HPLS) is the key to the realization of ICF. It is a huge ultra precision optical system, composing of tens of thousands of optical components.With the further studies on ICF, the output power of HPLS should be improved continuously. This requires the load capacity of optical elements in the HPLS continues to improve. Not only their own physical characteristics, but also the cleanness has association with the improvement of load capacity of the optical components. For when the high power laser through the surface of optical components, contaminants deposited or adhering to the surface of the optical components not only can degrade the beam quality, but also can cause the damage of components when serious. So that studying cleanliness control technology of HPLS has great significance for the realizing of ICF. The existing cleanliness control methods of HPLS can be divided into offline and online cleanliness control methods. The devices of HPLS are mainly components in open space and closed space. So cleanliness control technologies of HPLS are mainly the methods of offline and online to the components in open space and closed space. Cleanliness control of HPLS is a system engineering, so the main contents of this paper are as follows: First of all, cleanliness requirements and common contaminants of HPLS are made a presentation and classification. The cleanliness control methods of HPLS are introduced from the two angles of offline and online. Cleanliness control technologies are clean design, clean processing, cleaning, clean processing and transportation etc.. Basing on the summarizing of some cleanliness control technologies of online, a new cleanliness control technology which is fulfilling the cleanliness control by designing flows, is put forward. On the basis of this new technology, some cleanliness control plans are proposed to transport mirrors and spatial filter which are the representatives of open space and closed components. Secondly, some studies on the idea of air knife blowing method are conducted. Transport mirrors on behalf of open space components are used as the object to be cleaned. Take dust of different sizes as the contaminants, put them evenly on the surface of transport mirror. Take the installation position and the air input pressure of the air knife as the experimental parameters,?design full experiments. By the experiments, a well cleanliness control process is obtained. Then, by using the method of computational fluid dynamics (referred to as CFD) , some simulations about motion tracks of the airflow and contaminants are done, especially in the best cleanliness control process got in the above. From the simulations, the moving tracks of contaminants are got. This provides an important theoretical guidance for the realization of contaminants removal, capture and collect online and reducing the chance that contaminating the other optical components. Then, combing the above simulation results, a new flow field is designed which not only can remove pollutant particle away from the transport mirror surface effectively, but also can realize online capture and collection of contaminant particles in the process of air knife blowing. It can effectively avoid the particles contaminate the other optical components. The feasibility of the process is verified from simulation of CFD and experiment. Lastly, spatial filter are taken as the representative of confined space optical components, some conceives of cleanliness control technology on it are researched through CFD technology. This part mainly design flow fields to find a good way of reducing the effect of the organic contaminant on the lens on both end of the spatial filter. Toluene and the metal stent which support the con-focal pinhole, are respectively viewed as organic contaminant and contaminant source. Several methods are used to design flow field, just as pumping method, temperature control method and a mixture of the both methods. The pumping method are mainly pumping gas containing contaminant out of the spatial filter to reduce the density distribution of the toluene in the pipeline and on the lens nearby. Contaminant removal effects using the pumping method in different positions of pumping are researched. Temperature control method is mainly by setting different cold necks in the filter pipe surface, to look forward to reduce the pollutant diffusion in the space within the filter, finally reduce contaminant on both lens in the ends of the filter. Through the design and simulation on the flow filed, a good process of controlling contaminant density are gained. It also proved that the pumping method and the temperature control method are both the effective ways of controlling the contaminant density in the spatial filter. The simulation of contaminant diffusion in the filter provides an important theoretical guidance for the implementation of reduce contaminant density in spatial filter pipe and its lens in the end of the spatial filter. In all, this paper systematically introduced and did some research on the cleanliness control technologies of HPLS. Basing on the classifying and summarizing of cleanliness control methods of nowadays existing, a new cleanliness control technology is raised. On the basis of this new technology, some cleanliness control plans are proposed to transport mirrors and spatial filter which are the representatives of open space and closed components. A few cleanliness control plans are verified by experimental and theoretical analysis. Ultimately a new cognitive to the cleanliness control technologies of HPLS is improved and the cleanliness technologies are expanded. It also plays a important role on keeping the cleanliness of HPLS and has a great significance on the realization of ICF. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15932]  |
| 专题 | 上海光学精密机械研究所_学位论文 |
| 推荐引用方式 GB/T 7714 | 李养帅. 高功率激光装置的洁净控制技术[D]. 中国科学院上海光学精密机械研究所. 2015. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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