We want to make clear at the outset what this book is NOT. It is not a polished, comprehensive textbook on plasma processing, such as that by Lieberman and Lichtenberg. Rather, it is an informal set of lecture notes written for a nine-week course offered every two years at UCLA. It is intended for seniors and graduate students, especially chemical engineers, who have had no previous exposure to plasma physics. A broad range of topics is covered, but only a few can be discussed in enough depth to give students a glimpse of forefront research. Since plasmas seem strange to most chemical engineers, plasma concepts are introduced as painlessly as possible. Detailed proofs are omitted, and only the essential elements of plasma physics are given. One of these is the concept of sheaths and quasineutrality. Sheaths are dominant in plasma reactors, and it is important to develop a physical feel for their behavior. Good textbooks do exist. Two of these, to which we make page references in these notes for those who want to dig deeper, are the following: M.A. Lieberman and A.J. Lichtenberg, Principles of Plasma Discharges and Materials Processing (John Wiley, New York, 1994).