An Experimental Approach to Simulations of the CLIC Interaction Point
J. Esberg · 2012
Since this thesis covers a relatively wide range of topics, the abstract is best split into sections that describe the scope of each chapter: The chapter on future colliders gives an introduction to key concepts of future high-energy, high-luminosity linear collider experiments. The chapter revolves around the CLIC baseline design and focuses on the dynamics of the interaction points with an introduction to constraints set by various machine components. The chapter on ultra-relativistic particles in crystals gives a brief theoretical introduction to key concepts of particles penetrating crystalline matter. The 6th chapter briefly introduces basic theoretical aspects that are natural for understanding the processes occurring at the interaction points of a future collider and in fixed target experiments. It is the purpose of this chapter to give basic formulas but also to give the reader an understanding of definitions of processes and quantities that will be used throughout the rest of the thesis. The 7th chapter focuses on the parts of my work that is related to experiment. The main topic is the NA63 Trident experiment which will be discussed in detail. Results of the crystalline undulator experiments conducted at MAMI will be presented. Furthermore the chapter discusses the performance of new CMOS based detectors to be used in future experiments by the NA63 collaboration. The chapter on collider simulations introduces the beam-beam simulation codes GUINEA-PIG and GUINEA-PIG++, their methods of operation and their features. The characteristics of the simulated particles are presented and a comparison between the outputs of these codes with those from CAIN. \item In the chapter on tridents, the implementation of the direct trident process in GUINEA-PIG++ is described. The results are compared to theoretical ones, and simulations are applied to the 3 TeV CLIC scenario. Here, experimentally based conclusions on the applicability of the theory for strong field production of pairs will be made. In the chapter on depolarization, simulations of the beam-beam depolarization will be presented. The chapter describes the details of the depolarization algorithm and the strong-field modifications to the theory. New results on the energy dependence of the luminosity weighted depolarization are presented. Here, possible schemes for spin measurements are presented and the relevance of these measurements with respect to the luminosity weighted depolarization is discussed. In the chapter on muons, the implementation of the production of incoherent muons in GUINEA-PIG++ will be discussed. Comments on the correctness and completeness of the implementation of muon production will be presented. The chapter on additional collider simulations addresses two main subjects: The implementation of the generation of synchrotron radiation from incoherent pairs (tertiary photons), and their characteristics. Here, it is proposed to investigate the possibility of utilizing these photons as a luminosity signal. The second subject is a scheme for achieving ultra high energies by mixing beams of opposite charges.