Research with High-Power Short-Wavelength Lasers

• Published in: Science (American Association for the Advancement of Science) 1985-09, Vol.229 (4718), p.1045-1051
• Main Authors: Holzrichter, J. F., Campbell, E. M., Lindl, J. D., Storm, E.
• Format: Article
• Language: English
• Subjects: Density; Electrons; Energy; Exact sciences and technology; High power lasers; High temperature plasmas; Laser beams; Laser plasma interactions; Lasers; Lasers in plasma research; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; Plasma (Ionized gases); Plasma density; Plasma lengths; Plasma production and heating; Plasmas (Ionized gases); Wavelengths; X-rays
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.229.4718.1045

Three high-temperature, high-density experiments were conducted recently with the 10-terawatt, short-wavelength Novette laser system at the Lawrence Livermore National Laboratory. The experiments demonstrated successful solutions to problems that arose during previous laser-plasma interaction experiments with long-wavelength (greater than 1 micrometer) lasers: (i) large-scale plasmas, with dimensions approaching those needed for high-gain inertial fusion targets, were produced in which potentially deleterious laser-plasma instabilities were collisionally damped; (ii) deuterium-tritium fuel was imploded to a density of 20 grams per cubic centimeter and a pressure of 10$^{10}$ atmospheres under the improved laser conditions, and compression conditions (preheating and pressure) were consistent with code calculations that predict efficient (high-gain) burn of a large thermonuclear fuel mass when driven with a large, short-wavelength laser; and (iii) soft x-rays were amplified by a factor of 700 by stimulated emission at 206 and 209 angstroms (62 electron volts) from selenium ions in a laser-generated plasma. These small, short-pulse x-ray sources are 10$^{10}$ to 10$^{11}$ times brighter than the most powerful x-ray generators and synchrotron sources available today. The plasma conditions for these experiments were made possible by advances in Nd:glass laser technology, in techniques to generate efficiently its short-wavelength harmonics at 0.53, 0.35, and 0.26 micrometers, and in diagnostic and computational modeling.