Chapter 1. Introduction 1 Chapter 1. Introduction Topics or concepts to learn in Chapter 1: 1. What is plasma? 2. The two systems of units that are commonly used in the literatures of plasma physics: The Gaussian units and the SI units (Also: The basic equations, the dimension analysis, and the scale analysis) 3. What is the difference between 106 K electrons and 86 eV thermal electrons? Understand the temperature, thermal pressure, and the kinetic thermal energy of a plasma. Understand how special the 0.5 MeV electron is. 4. What is Boltzmann relation? 5. What is Debye shielding? How to determine the Debye length of a plasma? 6. What is plasma parameter? 7. What is the plasma oscillation frequency in a un-magnetized plasma? 8. What are the gyro frequency and the gyro radius (or Larmor radius) of a magnetized charge particle? 9. What is the definition of "collision" in the plasma physics