Refractive fringe diagnostic of a ruby-laser produced plasma using a short pulse, short wavelength nitrogen laser

Abstract

An improved analysis of the refractive fringe diagnostic is developed. The assumption of a ring focus used by earlier workers is shown to be invalid. The improved technique is used to analyse shadowgrams obtained using a synchronised sub-nanosecond nitrogen laser to probe a ruby-laser-produced plasma. Electron density profiles are de-convolved.