Plasma physics is concerned with the study of the physical characteristics, properties, and applications of plasmas. A plasma is usually defined as the "fourth state of matter." A more precise definition is that a plasma is a quasineutral gas in which many of the atoms or molecules are ionized and exhibit collective behavior. Quasineutral refers to the uniform density (n) of particles within the plasma and collective behavior means that a plasma can undergo motions which not only depend on local conditions but also on the state of the plasma in more remote regions. To be considered a plasma, a gas must satisfy the three following conditions: &lgr;<>1 and t>1. In these expressions, &lgr; is the Debye length, or the characteristic distance over which charges are shielded in a plasma, and is equal to 6.9 (T/n)½ cm; N is the number of particles contained in...