Download or read book A Theoretical and Experimental Study of Cw HF Chemical Laser Performance written by Wolfram Otto Mosebach and published by . This book was released on 1982 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental and Theoretical Study of Cw HF Chemical Laser Overtone Performance written by David Leon Carroll and published by . This book was released on 1992 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: The overtone performance of the UIUC supersonic cw HF chemical laser was characterized as a function of flow rates, cavity pressure, mode volume, mirror reflectivity and method of He injection. The overtone performance was optimized by the same set of flow rates that optimized the fundamental performance. When the absorption/scattering losses of the mirrors were taken into account, an overtone efficiency of 70-90% was achieved, which is the highest reported to date. The overtone efficiency was a strong function of media saturation. There was no significant change in overtone power and efficiency as the mode volume increased. However, there were an increase in the number of lasing lines and a shift to higher J lines. Overtone performance was as sensitive to cavity pressure as fundamental performance. There was no significant change in overtone efficiency when the method of He injection was changed. Base region absorption by ground state HF has a significant effect on fundamental and overtone performance. Even with very high degrees of saturation, approximately 10% of the total power was lost when the He purge was turned off. For a laser having an extensive data base with well characterized mirrors to firmly establish the Rigrod parameters g$sb0$ and I$sb{rm sat}$, the accuracy to which the mirror reflectivities can be deduced using measured mirror transmissivities, measured outcoupled power and Rigrod theory is approximately $pm$0.07% for high reflectivity overtone mirrors. Rigrod theory shows that a higher media saturation yields a higher overall overtone efficiency, but does not necessarily yield a higher measureable power (power in the bucket). For low absorption/scattering loss overtone mirrors and a 5% penalty in outcoupled power, the intracavity flux and hence the mirror loading can be reduced by more than a factor of two when the gain length is long enough to well saturate the media. The inclusion of HF-H$sb2$ multi-quantum VV transfer reactions in the ORNECL model significantly improved the prediction of the zero power gains for the H$sb2$ rich UI supersonic laser. The inclusion of absorption by SF$sb{rm x}$ molecules in the model significantly improved the prediction of the Fabry-Perot spectra.
Download or read book An Experimental Study of Fabry Perot and Stable Resonator CW HF Chemical Laser Performance written by Gus Tsioulos and published by . This book was released on 1985 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Experimental Study of Cw HF Chemical Laser Amplifier Performance and Zero Power Gain written by Panagiotis Theodoros Theodoropoulos and published by . This book was released on 1987 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental and Theoretical Study of Cw HF Chemical Laser Residual Fundamental Gain written by Panagiotis Theodoros Theodoropoulos and published by . This book was released on 1992 with total page 694 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Theoretical and Experimental Investigation of the Mechanisms of the Hydrogen fluoride Pulsed Chemical Laser written by Joseph J. T. Hough and published by . This book was released on 1975 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Experimental Study of Supersonic Cw HF Chemical Laser Zero Power Gain written by Thuong Xuan Nguyen and published by . This book was released on 1990 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gas Flow and Chemical Lasers written by Michele Onorato and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 750 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains eight invited papers and seventy-three contributed papers presented at the Fourth International Symposium on Gas Flow and Chemical Lasers. which was held in Stresa. Italy. from September 13 to 17. 1984. The purpose of the Symposium was to record and discuss current research developments and applications related to high power lasers. Papers were solicited from the entire spectrum of activities, includ ing basic physics, aerothermodynamics, new laser media, laser design, diagnostic techniques, laser propagation. interaction phenom ena, applications. The Symposium was an opportunity for scientists and engineers representing all these disciplines to come together to report their recent work, to exchange ideas and to provide an up-to-date account of international progress in these fields. The contributed papers were reviewed by the members of the Scientific Advisory CoEmittee. who also took responsibility for formulating the program of invited lectures. As editor I wish to express my appreciation and my gratitude to people and organizations that made this Symposium a success: the Members of the Scientific Advisory Committee, the Members of the Local Organizing Committee, the Sponsors and the Symposium Secretary. A grateful acknowledgement is expressed to Dr. M. Sandra Oggiano for assistance in the organization of the Symposium and publication of these proceedings.
Download or read book Experimental and Theoretical Study of CW Hydrogen Fluoride Chemical Laser Residual Fundamental Gain written by Panagiotis Theodoros Theodoropoulos and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A new technique that uses a multi-line probe beam to measure the gain on several lines simultaneously was developed. This new technique was used to measure the gains of the peak fundamental lines P$sb1$ (4-9) and P$sb2$(4-9) while lasing on the overtone, for three levels of media saturation. The suppression of the fundamental gains obtained at relatively high media saturation with 99.7/99.7% reflective mirrors was essentially the same as that obtained with 55% higher intracavity flux with 99.8/99.86% reflective mirrors. The gains of the low J lines P$sb1$(4-6) and P$sb2$(4-6) were suppressed 41% to 84%; the gains of the high J lines P$sb1$(7-9) and P$sb2$(7-9) were suppressed 3% to 43%. The 1 $to$ 0 lines were suppressed more than the 2 $to$ 1 lines. The maximum suppression occurred between 2 and 6 mm downstream from the nozzle exit plane, near the center of the 9 mm overtone beam. Simulation of the experiments with a rotational nonequilibrium computer model showed that the fundamental gains are determined by three independent mechanisms when lasing occurs on the overtone. First, overtone lasing decreases the gains of the P$sb1$(J) and P$sb2$(J) lines whose upper or lower levels are directly involved in P$sb{20}$(J) overtone lasing. Second, overtone lasing reduces the rate at which the low J v = 2 states are populated by rotational relaxation and increases the rate at which the low J v = 0 states are populated by rotational relaxation, resulting in suppression of the low J fundamental gains whose upper or lower levels are not directly involved in overtone lasing. Third, overtone lasing reduces the rate at which the HF(0,J) and HF(1,J) states are populated by the various collisional deactivation processes. With 10% of the original rotational relaxation rate, the computer model was in reasonable agreement with the measured zero power gain profiles. The model over predicted the fundamental gain suppression ($Deltaalpha$) for the P$sb1$(8,9) and P$sb2$(8,9) lines whose upper or lower levels were directly involved in overtone lasing, and under predicted the suppression for lines P$sb1$(4) and P$sb2$(4,5). The model predicted the suppression for lines P$sb1$(5-7) and P$sb2$(6,7) reasonably well. With the original rotational relaxation rate, the model was in reasonable agreement with the measured suppression of all P$sb1$(4-9) and P$sb2$(4-9) lines. However, with the original RR rate, the model's agreement with the experimental zero power gain profiles was not adequate.
Download or read book AFOSR Chemical Atmospheric Sciences Program Review written by United States. Air Force. Directorate of Chemical and Atmospheric Sciences and published by . This book was released on with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental CW Chemical Laser Studies written by Donald J. Spencer and published by . This book was released on 1972 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental studies of The Aerospace Corporation's continuously operating diffusion-type HF chemical lasers are presented. Nonuniform flow profiles at the laser nozzle exit are deducted by the use of pitot and total-temperature probes. The presence of shock waves and the measured flow profiles were of particular interest in the explanation of laser performance under varied flow conditions. Low-diluent-ratio flows resulted in a deterioration of laser performance partly because of thermal blockage effects. Alternate nozzles were plugged in order to provide lateral jet expansion relief, which resulted in improved laser performance. Pressure scaling was investigated up to approximately 5 atm plenum pressure and 16-Torr cavity pressure. For fixed plenum conditions, an increase in cavity pressure resulted in a decrease in laser power and axial lasing length (due to oblique shocks and nozzle separation). For fixed cavity pressure, an increase in plenum pressure resulted in an increase in power and axial lasing length (due to a reduced boundary layer). The cavity pressure for peak power corresponded quite closely to the cavity pressure predicted for matched nozzle flow. (Author).
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976 with total page 680 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies of Cw HF Chemical Laser Performance written by Anthony James Eyre and published by . This book was released on 1999 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analytical and Experimental Research on HF Chemical Lasers written by J. G. Skifstad and published by . This book was released on 1974 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The report summarizes the research activity on HF lasers. Analytical results for rotational relaxation indicated significant compromises in the performance of line selected oscillators or amplifier (MOPA) configurations with HF as contrasted with Boltzmann populations of the rotational levels. An experimental program was initiated to obtain measurements in HF/DF flow systems pertinent to chemical laser devices. The initial efforts have been concerned with development of an electrically excited HF laser for c.w. optical studies and the design of a low density flow facility for the research. (Modified author abstract).
Download or read book Theoretical Performance of an HF Chemical CW Laser written by George Emanuel and published by . This book was released on 1972 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt: A quantitative analysis of an HF cw chemical laser is presented that includes the influence of stimulated emission on the reacting medium. The numerically determined solutions encompass one-dimensional fluid mechanics, chemical kinetics, radiative de-excitation, and their mutual interaction. A comprehensive parametric study examines the effects due to changed plenum conditions, mixture ratios, and cavity parameters. Detailed discussions are presented of (1) vibration-vibration and vibration-translation energy exchange, (2) chemical efficiency, (3) mechanisms that cause lasing termination, and (4) cavity operation with a selective grating. (Author).
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1993 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lasers in Fluid Mechanics and Plasmadynamics written by Charles P. Wang and published by . This book was released on 1983 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:
