| Inertial confinement fusion (ICF) is one of important science domains which are developed significantly quickly and studied by so many researchers in the present world. The capsule is employed as the thermonuclear reaction fuel container and as the center on which all drive energy focused. The geometry status characteristics of the capsules surface, especially surface perturbations with a bigger wave length, are considered as the leading factors which result in possible hydrodynamic instabilities (such as Rayleigh-Taylor instability, etc.) during the implosion acceleration. This instability will determine the results of ICF ignition experiments: success or fail. Therefore, precision measurements of capsules surface circumferential characteristics can not only provide important data for numerical simulations and theoretical analysis of laser ignition experimental process, but also contribute great significance to laser target physics and capsule manufacture technology.In present, the sphere profilometer which is developed and improved continuously by Lawrence Livermore National Laboratory of U.S.A and General Atomics Corporation is considered as the most valuable and effective instrument. Based on this instrument, the capsule topography measurement can be realized and the power spectrum versus full-range mode number can be achieved. Due to lack of key technologies and instruments, there is no precision instrument to measure the circumferential topography of capsule surface and related character evaluation theory in China up to now.In this thesis, based on an atomic force microscope (AFM), a measure instrument is established to perform measurement of the whole capsule spherical face with an orthogonal biaxial system. Evaluation methods of spherical surface characterization of capsule and measurement methods are also studied. The main content of this thesis includes the following parts:Evaluation methods of micro capsules surface are discussed. Capsule surface is one kind of micro spherical face. Therefore, it can be evaluated by a series of characteristic parameters, such as surface roughness, waveness, roundness, sphericity and so on. Simultaneously, the capsule, which is different from the ordinary ball, is the centre of ignition experiments. A special evaluation parameter: surface power spectrum versus mode number characteristic curve is needed.Effects of ICF capsule surface perturbations with different mode-numbers and different initial amplitudes on Rayleigh-Taylor instability are analyzed. The algorithm of power spectrum versus mode number based on Fast Fourier Transforms and data-processing methods of partial surface defections are discussed. According to national standards of China and NIF standards curve of U.S.A, the definition methods of capsule profile surface roughness, waveness, roundness are developed. The mode-number range is defined as follows: roundness: 2~10, waveness: 11~100, roughness: 101 to maximal mode-number. The relationship between power spectrum versus mode number curve and evaluation parameters of common spherical surface is presented.As for whole topography measurements of micro capsule, a new type of capsule surface geometry status measurement system is developed according to spherical face measurement method. Additional orthogonal biaxial system is integrated with existing AFM to realize arbitrary circumferential trace measurement scheme of spherical face. In addition, the precision rotating air-bearing spindle, auxiliary transform rotary spindle are designed. An electric controller and related software are also developed for the system.In order to obtain the accuracy indices of the ICF capsule surface geometry status measurement system, both measurement accuracy of the system and positioning errors resulted from spindle and auxiliary shafts are analyzed based on plenty of experiments and theoretical discussions. On the one hand, measurement precision is the key factor which assures obtaining accuracy data of capsule topography. Conversion error of A/D, static noise amplitude, spindle error and the uncertainty of synthesis measurement are determined through measurement tests. On the other hand, positioning error of biaxial system operating capsule is discussed. Selection and design principles of micro-tube mouth parameters are presented. High quality micro-tube is made. Adsorption reliability is discussed. The effects of parameters on positioning errors are analyzed during operating capsule process when the axial cords of spindle and auxiliary transform rotary are not perpendicular to each other or when spacial position deviation arises. The mathematic models of related parameters mentioned above are developed and their availabilities of improving ICF capsule positioning precision are verified by experiments.Based on the ICF capsule surface geometry status measurement system, characteristic parameters of capsule surface are obtained from synthetical experimental investigations which include partial surface measurement, orthogonal great circle measurement, equiangular longitude method and so on. In order to achieve the total coverage of capsule surface, the longitude-latitude traces method is proposed. The coverage percentage of different project of longitude number and latitude offset distance is analyzed. The time efficiency of total surface measurement is also discussed.In addition, patterning on capsule surface is carried out by a diamond tip. Contrast measurement tests for surface topography of before and after experiments are made. The expected surface micro-structures are obtained. The experiments show that there are obvious changes at the wanted mode number in surface power spectrum versus mode number after patterning. The results verify the feasibility of capsule surface topography pattern through mechanical machining. Simultaneously, beneficial attempts are also made in aspects of three dimensional topography modification and changing the laser fusion ignition experimental performances.
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