Experimental investigation of the Coulomb logarithm in beam-plasma interaction

In order to determine the Coulomb logarithm in the interaction between hot plasma acid ion beams, the stopping power of 350 keV protons in a laser pla sma target was measured by TOF method. The electron temperature and the ele ctron density of the target plasma was 20 eV and 10(18) cm(-3), respectivel y. The Bethe's Coulomb logarithm calculated using the measured stopping pow er of protons was 1.8 times as large as that in the beam-cold matter intera ction. The mean charge state for 350 keV/u O-16 after the interaction with the plasma was also measured by using a time-resolved magnetic spectrograph . The Coulomb logarithm of 350 keV/u O-16 was estimated by using measured m ean charge state and previously measured stopping power. The obtained Coulo mb logarithm for both projectiles are compared. (C) 2001 Elsevier Science B .V. All rights reserved.