Recent research has brought the application of microwaves from the classical fields of heating, communication, and generation of plasma discharges into the generation of compact plasmas that can be used for applications such as FIB and small plasma thrusters. However, these new applications bring with them a new set of challenges. With coverage ranging from the basics to new and emerging applications, Compact Plasma and Focused Ion Beams discusses how compact high-density microwave plasmas with dimensions smaller than the geometrical cutoff dimension can be generated and utilized for providing focused ion beams of various elements.
Starting with the fundamentals of the cutoff problem for wave propagation in waveguides and plasma diagnostics, the author goes on to explain in detail the plasma production by microwaves in a compact geometry and narrow tubes. He then thoroughly discusses wave interaction with bounded plasmas and provides a deeper understanding of the physics. The book concludes with an up-to-date account of recent research on pulsed microwaves and the application of compact microwave plasmas for multi-element FIB.
It provides a consolidated and unified description of the emerging areas in plasma science and technology utilizing wave-based plasma sources based on the author’s own work and experience. The book will be useful not only to established researchers in this area but will also serve as an excellent introduction to those interested in applying these ideas to various current and new applications.
Introduction
Plasma
Particle Interactions
Some Basic Plasma Properties
Criterion for the Definition of a Plasma
Different Types of Plasmas
Description of Plasmas
Theoretical Approaches
Microwave-Generated Plasmas
Compact Microwave Plasma Sources
Research Objective and Methods
References
Review of the Cutoff Problem
A Brief History of Earlier Work
Microwave Propagation in Waveguides
Plasma Density Cutoff
References
Plasma and Wave Diagnostics
Plasma Diagnostics with Langmuir’s Probes
Design of Electromagnetic Probes
References
Genesis of a Wave Induced Discharge: A New Perspective
Introduction
Historical Development of Breakdown Studies
Modeling of the Electron Dynamics
Development of the General Algorithm
Field-Free Case: Three-Dimensional Random Walk
Electron Transport in the Presence of an EM Field
Magnetostatically Assisted Electron Transport in the Presence of an EM Field
Electric Field Effects and the Random Walk Parameter
Linear and Circularly Polarized Waves
Summary and Conclusion
References
Plasma Production in Continuous-Mode Microwaves: Near-Circular Multicusp
Introduction
Apparatus
Multicusp Design
Waveguide Design
Experimental Results
Spatial Profiles of the Plasma
Discussion
Conclusions
References
Plasma Production in Continuous-Mode Microwaves: Rectangular Nonmulticusp Waveguide
Introduction
Experimental Procedures
Experimental Results
Discussion
Conclusions
References
Comparison of Square and Near-Circular Multicusp Waveguides
Introduction
Waveguide Design
Experimental Results
Discussion
Conclusions
Summary of Experimental Results in Continuous-Mode Microwaves
Summary of the Plasma Production Mechanisms
References
Plasma Production in Pulsed-Mode Microwaves: General Experiment
Introduction
Apparatus and Methods of the Experiment in a Circular Waveguide with a Dimension below Cutoff
Some Additional Details of the Experimental Set-Up
Probe for Measuring the Electric Field
Experimental Results
Discussion
Conclusions
References
Plasma Production in Pulsed-Mode Microwaves: Circular Multicusp Waveguide with a Dimension below Cutoff
Introduction
Experimental Setup and Procedures
Experimental Results
Discussion
Conclusions
References
Plasma Buildup by Short-Pulse, High-Power Microwaves
Introduction
Experiments
Discussion
Conclusion
References
Power Absorption and Intense Collimated Beam Production in a Pulsed High-Power Microwave Ion Source
Introduction
Ion Source Design and Experimental Setup
Experimental Results
Discussion
Conclusions
Summary in Pulsed Microwaves
References
New Experiments in Continuous-Mode Microwaves: Formation of Standing Waves and Electron Trapping
Overview of the New Experimental System
Introduction
Spatial Plasma Characteristics
Axial Wave Field Intensity Measurements
Electron Trapping in SW Minima
Model Calculation
Summary and Discussion
References
Penetration and Screening of Perpendicularly Launched Electromagnetic Waves
Introduction
Experimental Setup
Experimental Observation
Modeling
Modeling Results
Discussion and Summary
References
Wave Birefringence in Perpendicular Propagation
Introduction
Polar Plasma Characteristics
Polar Wave Field Intensity Measurements
Modeling of the Wave Birefringence
Discussion and Summary
References
Electron Localization and Trapping Physics Revisited
Introduction
Experimental Setup
Experimental Results
Modeling
Modeling Results
Summary and Discussion
References
New Experiments in Pulsed Microwaves: Quasisteady-State Interpulse Plasmas
Introduction
Experiment
Experimental Results
Model Calculation
Discussion and Conclusion
References
Electron Plasma Waves Inside Large-Amplitude Electromagnetic Pulses
Introduction
Experimental Setup
Experimental Results
Time–Frequency Analysis
Model
Summary
References
Transition from Interpulse to Afterglow Plasmas
Introduction
Experimental Setup
Results
Summary
References
Introduction to Focused Ion Beams
Focused Ion Beams
References
Experimental Setup for Basic Plasma Studies
Introduction
Basic Plasma Experiments
Measurement of Plasma Parameters
Sub-Cutoff Dimensional Plasma Sources
Conclusion
References
Basic Beam Studies: Extraction and Ion Energy Distribution
Introduction
Experiment
Results and Discussion
Conclusion
References
Multielement Focused Ion Beam
Introduction
Beam Column of MEFIB
Beam Simulation Codes
Results and Discussion
Tolerance Studies
Conclusion
References
Focused Ion Beam Experiments
Introduction
Results and Discussion
Conclusion
References
Summary and Future Prospects
Index
Biography
Sudeep Bhattacharjee
"In his book, Professor Bhattacharjee has shown how compact and overdense plasmas in the microwave regime can be generated and sustained using multicusp magnetic fields. Detailed investigations of the physics of wave interactions with such bounded plasmas have been carried out and elaborated in the book, including adequate theoretical treatments and modeling. … The book reports several new findings in this class of plasmas … the latter half of the book is devoted to generation of multi-element focused ion beams (FIB) from these compact plasmas to widen the scope of research and applications of present day FIB systems. … The book will also be useful to graduate students or researchers wanting to learn experimental plasma physics in general and or entering the research area of wave-assisted plasmas."
—Hiroshi Amemiya, RIKEN Expert Corps Research and Development Inc. (Rec-Rd Inc.), Wako, Saitama, Japan"… valuable treatise on compact plasma production and its applications … The book will be useful not only to researchers in this area but will also serve as an excellent introduction to those contemplating to apply these ideas to various current and new applications. My congratulations to the author on this excellent contribution."
—Abhijit Sen, Institute for Plasma Research, India"This book addresses one of the popular methods used to create dense plasmas: microwave sources. It is addressed to those wishing to have a more profound understanding of the physics of microwave plasma generation in small sources and the details of the extraction of kilovolt ion beams from such a source. I can recommend this book to all who wish to enter this new area of technological development."
—Rod Boswell, Australian National University, Canberra"The book is rich in knowledge on physics of wave interaction with plasmas sustained in compact geometries in multicusp magnetic fields and, furthermore, suggests a novel application of ion beams obtained from these plasmas. I am confident that the readers will benefit much from this book. The author is congratulated on completing this outstanding piece of work."
—Takahide Nakagawa, RIKEN Nishina Center for Accelerator-Based Science, Japan"The book provides a timely account of this emerging and exciting field of microwave plasmas, and it is written by an author who has worked in the frontier of the field for nearly two decades. The text is clear and concise. No print is wasted on lengthy expansions of basic textbook introductions to plasma physics. Instead, the focus turns immediately to the most relevant topics necessary to understand this particular type of plasma production. … a thorough discussion on wave interaction with bounded plasmas provides a deeper understanding of the physics. … This important book is a must for graduate students and researchers in experimental plasma physics who want to get up to speed with the latest research in compact microwave plasmas!"
—Ashild Fredriksen, University of Tromso, Norway