Browsing by Subject "Carbon dioxide lasers"
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Item A New Single Mode Tunable TEA Laser(Texas Tech University, 1980-05) Dougal, Roger AdelbertA simple and inexpensive technique for producing a single mode TEA CO2 laser is explored. The method involves the use of an intracavity selective absorber. A large laser system used in the early research was observed to yield 1.1 J single longitudinal mode pulses. This amounted to 73% of the multimode pulse energy. This encouraging result led to the design of a stabilized, tunable laser system. The laser frequency is smoothly tunable over some tens of megahertz, and stepwise tunable across the entire gain bandwidth of any particular line. The system includes a frequency reference laser so that precise knowledge of the TEA laser frequency with respect to line center is possible. Both lasers are grating tunable to any of the CO^ rotational transitions in the 9 to 11 micron region. The TEA laser exhibits an output energy of 200 millijoules in a single mode pulse/ the absolute frequency of which is known within 5 MHz.Item An electron beam controlled CO2 laser(Texas Tech University, 1977-05) Jasper, Jon ShippThe engineering design and operation of a double sided cold-cathode-electron-beam controlled CO2 laser is discussed. Basic theoretical considerations are discussed, including fractional electron power transfer to the various energy levels of the CO2molecule as a function of gas mixture and E/n. Two types of cold cathode designs are investigated, and experimental results are given. Operational parameters and results for single-sided and double-sided operation are discussed.Item An experimental and numerical investigation of laser-plasma interactions(Texas Tech University, 1980-08) Druce, Robert LeeAn experiment to study the interaction of an intense CO2 laser beam with a dense, preformed, magnetically confined, hydrogen plasma has been conducted. Plasma densities considered are on the order of 10^23 m^-3 with initial temperatures of 1-3 eV. The laser is focused into the plasma in the axial direction with the vacuum focal spot positioned at the axial and radial center of the plasma. The results obtained are compared to the results of a computer code developed at Texas Tech University. Mechanisms included in the code are inverse bremsstrahlung heating of the plasma, electron-ion energy equipartition, thermal conduction in electrons and ions, and plasma fluid dynamics. A self-consistent solution of ray tracing in the plasma is also included in the code to predict the self-focusing of the laser beam. Agreement between experimental and theoretical results is generally good.