重离子冷却储存环CSR的校正及动力学孔径研究

本文对设计中的兰州重离子加速器冷却储存环CSR主环（CSRm）和实验环（CSRe）在扰动情况下（即包含各种场缺陷和元件的安装校准误差）的非线性动力学进行了较全面的研究。分析了各种误差对一阶动力学的影响，闭轨畸变及其校正，较大动量分散情况下的色散效应，以及色品和色散的校正；同时，使用李变换的方法，对一个一维的非线性加速器模型进行了数值研究，并对CSRm和CSRe在存在非线性高阶场的情况下的非线性效应以及动力学孔径进行了模拟研究，得到了定性和定量的结果。对CSR的线性耦合效应亦进行了专门的分析。 在最后确定的可容许的一阶场差和安装校准误差的情况下，20次抽样模拟的结果显示，CSRm和CSRe在校正后的闭轨畸变之最大值小于3mm，均方根值小于1mm。采用两组六极透镜对色品及色散效应校正的结果达到了预期的效果；Tune值的移动被控制在足够小的范围内，闭轨随动量散度的偏移亦很小（<3mm）。 对线性耦合的模拟研究显示了由于CSRm和CSRe工作点足够远离一阶差共振线。因此在标称的发射度下，由场缺陷和安装校准误差导致的线性耦合对一阶运动的影响较小。对冷却段的直螺线管的耦合效应进行了补偿，补偿后的耦合效应消失。 在较保守的二极磁铁和四极磁铁的高阶场分量下，较严重的非线性效应仅作用于初始粒子为大振幅的情况，因此，CSRm和CSRe均有足够大的动力学孔径。对Tune值对动力学孔径的影响进行了模拟，在有限的变化范围内，这种影响较弱。此外，对稳定 边界上粒子的混沌运动的特点及粒子的损失机制也进行了研究。

Tropical Mesoscale Convective Systems and Associated Energetics : Observational and Modeling Studies

The main purpose of the thesis is to improve the state of knowledge and understanding of the physical structure of the TMCS and its short range prediction. The present study principally addresses the fine structure, dynamics and microphysics of severe convective storms.The structure and dynamics of the Tropical cloud clusters over Indian region is not well understood. The observational cases discussed in the thesis are limited to the temperature and humidity observations. We propose a mesoscale observational network along with all the available Doppler radars and other conventional and non—conventional observations. Simultaneous observations with DWR, VHF and UHF radars of the same cloud system will provide new insight into the dynamics and microphysics of the clouds. More cases have to be studied in detail to obtain climatology of the storm type passing over tropical Indian region. These observational data sets provide wide variety of information to be assimilated to the mesoscale data assimilation system and can be used to force CSRM.The gravity wave generation and stratosphere troposphere exchange (STE) processes associated with convection gained a great deal of attention to modem science and meteorologist. Round the clock observations using VHF and UHF radars along with supplementary data sets like DWR, satellite, GPS/Radiosondes, meteorological rockets and aircrafl observations is needed to explore the role of convection and associated energetics in detail.