Chapter 1 Introduction

1.1 Introduction

1.2 Plasma Based Acceleration

1.3 Particle-in-Cell Simulations

1.4 Motivation and Outline

Chapter 2 Phase Space Dynamics of Injected Electron Beams in Ionization Injection

2.1 Introduction

2.2 The Photoionization Process

2.3 The Residual Momentum

2.3.1 Initial Momentum from the Tunneling Ionization

2.3.2 The Momentum from the Lasers: Longitudinal Injection

2.3.3 The Momentum from the Lasers: Transverse Injection

2.3.4 The Thermal Emittance

2.4 Single Particle Motion in the Nonlinear Wake

2.5 Transverse Phase Mixing

2.5.1 Emittance Evolution: Growth and Oscillation in the Injection Stage

2.5.3 A Phenomenological Model

2.5.4 Comparisons with PIC Simulations

2.6 Longitudinal Phase Mixing

2.6.1 The Trapping Condition

2.6.2 Longitudinal Phase Mixing

2.7 Space Charge Effects

2.8 The Two-Color Ionization Injection

2.8.1 The Emittance in A Single Laser Case

2.8.2 The Two-Color Ionization Injection: Longitudinal Injection

2.8.3 The Two-Color Ionization Injection: Transverse Injection

2.9 Intrinsic Phase Space Discretization in Laser Triggered Ionization Injection

2.9.1 Single Laser Pulse Case

2.9.2 Beam Driver with a Laser Injector

2.10 Summary

3.1 Introduction

3.2 The Emittance Growth between Stages

3.2.1 Emittance Growth in Free Space Drifting

3.2.2 Emittance Growth in A Uniform Focusing Field

3.3 Theoretical Analysis of A Matching Plasma

3.3.1 How to Design the Matching Plasma?

3.3.2 The Effect of the Energy Spread

3.4 Verification by PIC Simulations

3.4.1 Matching Between Two-Stage LWFAs

3.4.2 Matching in External Injection

3.4.3 Matching between LWFAs and the Quadrupoles

Chapter 4 X-FELs Driven by Plasma Based Accelerators

4.1 Introduction

4.1.2 The Challenges and Opportunities of X-FELs Driven by plasma Based Accelerators

4.2 X-FEL Driven by A Two-Stage LWFA

4.2.2 Simulation of the Accelerator Stage

4.2.3 Simulation of the Undulator Stage

4.3 Conclusions

Chapter 5 Numerical Instability due to Relativistic Plasma Drift in EM-PIC Simulations

5.1 Introduction

5.1.1 The Boosted Frame Simulations of LWFA

5.1.2 Numerical Noise Induced by Relativistic Plasma Drift in PIC Codes

5.2 Numerical Dispersion Relation for Cold Plasma Drift

5.2.1 Derivation of Dispersion Relation

5.2.2 Elements of Dispersion Relation Tensor

5.2.3 EM Modes, and Wave-Particle Resonance

5.3 Numerica
About the Author: Xinlu Xu received his B.Sc. in engineering physics from Tsinghua University, China in 2008. He obtained his Ph.D. in nuclear science and technology from Department of Engineering Physics, Tsinghua University in Jan. 2015. His major research project in Prof. Wei Lu's group is phase space dynamics in plasma based wakefield acceleration. Subsequently, he became a post-doc fellow working with Prof. Warren B. Mori at Physics and Astronomy Department, University of California, Los Angeles, focusing on the generation, transportation of high quality electrons from plasma based wakefield accelerators and the development of high-fidelity particle-in-cell codes. Now he is working at SLAC National Accelerator Laboratory as a staff scientist to pursing high quality high energy acceleration in plasmas and study various interactions between intense beam, laser and plasmas.