Download or read book Investigation of Means for Generating High energy and Extremely Narrow Laser Pulses written by Anthony J. DeMaria and published by . This book was released on 1967 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: The simultaneous Q-switching and mode-locking of a 1-meter-long glass laser rod has produced a pulse having an energy content of 44 joules with a peak power of 4 gigawatts and time duration of approximately 1.5 x 10 to the -9th power sec. A 47-joule pulse has been obtained using a 45-cm-long glass rod as a simultaneous Q-switched and mode-locked oscillator and a 1-meter-long glass rod as an optical amplifier. The time duration of individual mode-locked pulses for this case was 0.75 x 10 to the 9th power sec. Use of a 16.5-cm-long oscillator and 1-meter-long amplifier resulted in generation of pulses with a peak power between 3.7 x 10 to the 10th power and 9.4 x 10 to the 10th power watts and time durations of 2 x 10 to the -11th power to 8 x 10 to the -12 power sec, respectively. These measurements are believed to represent the highest peak power pulses reported in literature to date. Experimental techniques for generating single, subnanosecond pulses having peak powers in the hundreds of megawatts range have been devised and made operative. A 600-megawatt peak power pulse of 0.4 x 10 to the -9th power sec time duration was obtained with a 45-cm-long oscillator. Using such an oscillator plus a 1-meter rod as an amplifier a single 0.5 x 10 to the -9th power sec pulse has been generated with an energy content of 1.8 joules. A Marx-Bank pulse generator was designed, constructed, and utilized in generation of these single, ultrashort optical pulses. These measurements represent the shortest single, optical pulses reported in the literature to date.
Download or read book Technical Abstract Bulletin written by Defense Documentation Center (U.S.) and published by . This book was released on 1967 with total page 784 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of Current Laser Abstracts written by and published by . This book was released on 1975 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Utilizing the Ultraintense JanUSP Laser at LLNL 99 ERD 049 Final LDRD Report written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent advances in laser and optical technologies have now enabled the current generation of high intensity, ultrashort-pulse lasers to achieve focal intensities of 102°-1021 W/cm2 in pulse durations of 100-500fs. These ultraintense laser pulses are capable of producing highly relativistic plasma states with densities, temperatures, and pressures rivaling those found in the interiors of stars and nuclear weapons. Utilizing the ultraintense 100TW JanUSP laser at LLNL we have explored the possibility of ion shock heating small micron-sized plasmas to extremely high energy densities approaching 1GJ/g on timescales of a few hundred femtoseconds. The JanUSP laser delivers 10 Joules of energy in a 100fs pulse in a near diffraction-limited beam, producing intensities on target of up to 1021W/cm2. The electric field of the laser at this intensity ionizes and accelerates electrons to relativistic MeV energies. The sudden ejection of electrons from the focal region produces tremendous electrostatic forces which in turn accelerate heavier ions to MeV energies. The predicted ion flux of 1 MJ/cm2 is sufficient to achieve thermal equilibrium conditions at high temperature in solid density targets. Our initial experiments were carried out at the available laser contrast of 10−7 (i.e. the contrast of the amplified spontaneous emission (ASE), and of the pre-pules produced in the regenerative amplifier). We used the nuclear photoactivation of Au-197 samples to measure the gamma production above 12MeV-corresponding to the threshold for the Au-197(y, n) reaction. Since the predominant mechanism for gamma production is through the bremsstrahlung emission of energetic electrons as they pass through the solid target we were able to infer a conversion yield of several percent of the incident laser energy into electrons with energies>12MeV. This result is consistent with the interaction of the main pulse with a large pre-formed plasma. The contrast of the laser was improved to the 10−1° level by the insertion of two additional pockel cells to reduce the pre-pulse intensities, and by the implementation of a pulse clean up technique based on adding an additional pre-amplifier and saturable absorber which resulted in a reduction in the ASE level by a factor of approximately 1000. In FY00/01 we performed a series of experiments to investigate the mechanisms for ion generation and acceleration in thin foil targets irradiated at incident laser intensities above 102° W/cm2, and with the laser contrast at 10−1°. Full details of this work can be found in the two accompanying papers: Energy spectrum and angular distribution of multi-MeV protons produced from ultraintense laser interactions, UCRL-JC-143112, P.K. Pate1 et al., and Enhancement of proton acceleration by hot electron re-circulation in thin foils irradiated by ultra-intense laser pulses, A.J. Mackinnon et al. UCRL-JC-145540. To obtain a more complete picture of the ion emission a range of detectors were developed and fielded including radiachromic films (measuring ion, electron, and x-ray dose), nuclear activation detectors (high energy protons), and single particle nuclear track detectors (protons and heavy ions). Significantly we found that a large fraction of the incident laser energy (greater than 1%) is coupled to highly energetic protons forming a well-collimated beam. The proton spectrum can be fit by an exponential distribution containing 1011 particles with a mean energy of 3 MeV and a high energy cutoff of 25 MeV. However, these particles appear to originate not from the interaction region at the front of the target but rather from a thin adsorption layer on the rear surface.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Review Naval Research Laboratory Washington D C written by and published by . This book was released on 1974 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Materials Under Extreme Conditions written by A. K. Tyagi and published by Elsevier. This book was released on 2017-01-13 with total page 872 pages. Available in PDF, EPUB and Kindle. Book excerpt: Materials Under Extreme Conditions: Recent Trends and Future Prospects analyzes the chemical transformation and decomposition of materials exposed to extreme conditions, such as high temperature, high pressure, hostile chemical environments, high radiation fields, high vacuum, high magnetic and electric fields, wear and abrasion related to chemical bonding, special crystallographic features, and microstructures. The materials covered in this work encompass oxides, non-oxides, alloys and intermetallics, glasses, and carbon-based materials. The book is written for researchers in academia and industry, and technologists in chemical engineering, materials chemistry, chemistry, and condensed matter physics. - Describes and analyzes the chemical transformation and decomposition of a wide range of materials exposed to extreme conditions - Brings together information currently scattered across the Internet or incoherently dispersed amongst journals and proceedings - Presents chapters on phenomena, materials synthesis, and processing, characterization and properties, and applications - Written by established researchers in the field
Download or read book Fusion Energy Update written by and published by . This book was released on 1985 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bulletin of the Atomic Scientists written by and published by . This book was released on 1980-12 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Bulletin of the Atomic Scientists is the premier public resource on scientific and technological developments that impact global security. Founded by Manhattan Project Scientists, the Bulletin's iconic "Doomsday Clock" stimulates solutions for a safer world.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 922 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ERDA Research Abstracts written by United States. Energy Research and Development Administration and published by . This book was released on 1976 with total page 1040 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AFOSR Research the Current Research Program and a Summary of Research Accomplishments written by United States. Air Force. Office of Scientific Research and published by . This book was released on 1967 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report is designed to present the research programs of the Air Force Office of Scientific Research for the information of users of Air Force research, for scientific investigators working in the same or in allied fields, and for the military, scientific and academic, and Government communities at large.
Download or read book Review written by and published by . This book was released on 1973 with total page 718 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration. Technical Information Center and published by . This book was released on 1977 with total page 1680 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book U S Government Research and Development Reports Index written by and published by . This book was released on 1969 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Vision 21 Space Travel for the Next Millennium written by and published by . This book was released on 1991 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ERDA Energy Research Abstracts written by and published by . This book was released on 1977 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt:
