THE CONTINUUM ABSORPTION OF ARGON, KRYPTON AND XENON DENSE-PLASMAS PRODUCED IN FLASHLAMPS

The optical thickness of dense plasma, created in linear flashtubes fi lled with noble gases, is measured over the wavelength range 466-780 n m using a cw laser beam. The electron density and temperature radial p rofiles of the plasma are determined by spectroscopic methods, infrare d laser interferometry and local thermodynamic equilibrium equations. Knowing those profiles, the absorption coefficients and consequently t he xi(fb) factors are deduced from optical thickness measurements. The se factors are compared with theoretical values of Hofsaess and with p reviously published experimental results. The dependence of xi(fb) on the wavelength and the plasma parameters (electron density in the rang e 7 x 10(17)-1.7 x 10(18) cm(-3), temperature between 10900 and 17000 K) is discussed. The effect of the interparticle interaction on the ab sorption in our dense plasmas is only sensitive to the shift of the ph otoionization thresholds of atoms.