Accession Number : ADA200292
Title : Intense XUV Radiation Sources.
Descriptive Note : Final rept. 1 Apr 85-30 Sep 87.
Corporate Author : MARYLAND UNIV COLLEGE PARK INST FOR PHYSICAL SCIENCE AND TECHNOLOGY
PDF Url : ADA200292
Report Date : 30 Sep 1987
Pagination or Media Count : 43
Abstract : The results of the Nd:YAG laser (1.064 micron) experiments showed that the EUV output increased with laser pulse energy in a linear manner or slower. Therefore, there was no special incentive to go to higher pulse energies in the driver since increased problems of optical damage and of output saturation argued against moving in that direction. Because it was felt that higher repetition rates could translate directly into higher average outputs and published data indicated that the soft x-ray yield might be increased by use of shorter wavelengths in the laser driver, a 150 Hz excimer laser operating at 248 nm was purchased and installed as the driver for the laser plasmas. The peak pulse energy of this laser (Lambda Physik) with normal optics is 400 mj/pulse energy of 320 mj. Experiments with this system confirmed expectations and a reduction in exposure times for VUV and EUV emulsions of a factor of more than 20 when using rhe excimer rather than the Nd:YAG as a driver was observed. A major disadvantage in the use of a laser plasma light source has been the generation of large amounts of debris from the target, which coats optics and lithograph masks. A series or studies intended to minimize the amounts and effect of target debris, using the excimer laser driver were performed. Experience gained from these studies provided the basis for the new generation laser plasma light source chamber just completed in the laboratory. A paper is being prepared describing the new generation light source in detail. (rh)
Descriptors : *DAMAGE, *LIGHT SOURCES, *PULSED LASERS, *YAG LASERS, DEBRIS, EMULSIONS, ENERGY, EXPOSURE(GENERAL), FAR ULTRAVIOLET RADIATION, HIGH RATE, INTENSITY, LASERS, MOTIVATION, OPTICAL PROPERTIES, OPTICS, OUTPUT, PEAK VALUES, PLASMAS(PHYSICS), PULSES, REPETITION RATE, SATURATION, SOFT X RAYS, SOURCES, TARGETS, YIELD, YTTRIUM ALUMINUM GARNET
Subject Categories : Optics
Lasers and Masers
Distribution Statement : APPROVED FOR PUBLIC RELEASE