Beam dynamical studies of CRYRING

Abstract

This thesis consists of two parts. Part 1 (Introduction to Accelerator Physics) gives the basis of understanding the formalism and parameters that are used in accelerator physics, especially in synchrotron theory. The text is a selected collection of relevant topics in this context and it follows closely lecture notes by K. Steffen [St85]. As an appendix of part 1 there is a short introduction to electron cooling which appears in the latter part of the thesis. Part 2 (Beam Dynamical Studies of CRYRING - Lattice Design Criteria and Operation Limits) was originally written and the work was done at the Research Institute of Physics (AFI) in Stockholm as a part of the CRYRING project. Later, after some modifications in the lattice, the text was updated and some electron cooling simulation calculations with intrabeam scattering were done at the Department of Physics, University of Jyväskylä. CRYRING is a small acceletaror and storage ring for heavy ions and it will replace the old classical 225 cm cyclotron. CRYRING will mostly be used for atomic and molecular physics but nuclear physics will not be totally forgotten. Atomic physics, which will be done inside of the ring, requires the best beam quality. Good quality in this context means small energy spread and small beam size and divergence (transverse velocity). The beam quality will be increased by using electron cooling. Nevertheless, increasing beam quality brings along some unwanted effects. If energy spread is decreased too much the beam will get into some instabilities - the most important of them here is the microwave instability. There are some competing processes to cooling. They attempt to increase the energy spread and the emittance (divergence) of the beam. These processes are residual gas scattering and intrabeam scattering. Due to very strict vacuum requirements residual gas scattering will be more or less harmless as emittance growth is concerned whereas intrabeam scattering will set the limit for beam quality where one parameter is the beam intensity. In part 2 the ion optical requirements set by the physics that will be done inside and outside of the accelerator and the operating limits as beam intensity and quality are are discussed.