I. H. Hutchinson

This is an excellent reference book for any researcher in plasma physics. The book does go into a nice amount of mathematical detail about many diagnostics (e.g. deriving spectral profiles for relativistic Thompson scattering, etc.) and does cover some of the more advanced diagnostics like the MSE (Motional Stark Effect) diagnostic which has become very important in many fusion experiments. Overall, I believe this to be an indispensable reference for the subject.