Download or read book Spatio temporally Resolved Dual Laser Plasma Photoabsorption Studies of Thorium Plasmas with Extreme UV Continuum Light Source written by J. T. Costello and published by . This book was released on 1999 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book British National Bibliography for Report Literature written by and published by . This book was released on 1999 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2676 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of the Spatial Characteristics of a Laser Plasma Extreme UV Continuum Source for Absorption Spectroscopy written by Christopher Joseph Moloney and published by . This book was released on 1998 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book XUV and VUV Photoabsorption and Emission Studies in Thorium and Other High z Laser Plasmas written by Oonagh Elizabeth Meighan and published by . This book was released on 2000 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Extreme ultraviolet Radiation Transport in Small Scale Length Laser produced Tin Plasmas written by Kevin Lamar Williams Sequoia and published by . This book was released on 2009 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: The majority of the studies on laser-produced plasmas as an efficient extreme ultraviolet (EUV) light source have focused on relatively large plasmas produced at large laser facilities. However, to develop a commercially viable light source for EUV lithography, much smaller lasers and hence much smaller plasmas must be employed. Smaller plasmas behave quite differently than large plasmas in that the temperature and density are less uniform, and lateral expansion is more important. These differences affect the energy transport and, in particular, the radiation transport. This work studies the EUV radiation transport in small scale length tin plasmas, focusing on the effects of target geometry and laser pulse duration. Both planar and spherical tin targets were irradiated with an Nd:YAG laser operating at 1.064 [Mu]m. Conversion efficiency of laser light to 13.5 nm radiation (in-band), EUV emission spectrum, two-dimensional in-band emission profile, and the plasma electron density were measured experimentally. These measurements provide insight into where the laser is absorbed, where the in-band emission is produced, and how the radiation is transmitted. The plasma evolution in these experiments were simulated with a two-dimensional radiation hydrodynamic code, while the radiation transport and atomic kinetics where modeled with a collisional radiative code. Additional experiments were conducted using planar targets where the pulse duration was varied from 0.5 ns to 16 ns to understand the effects of laser pulse duration. It was found that the optimum plasma temperature for efficient generation and transmission of in-band emission is 20 eV. This is lower than the previously reported optimum temperature of 30 eV. The use of a 1.064 [Mu]m heating laser results in overheating of the plasma in a region that is much too dense to transmit the in-band emission. This overheating is necessary for the plasma to reach the optimum temperature in the region where the density is low enough to transmit the in-band emission.
Download or read book Laser Plasma Radiation Studies for Droplet Sources in the Extreme Ultraviolet written by Reuvani D. Kamtaprasad and published by . This book was released on 2010 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: The advancement of laboratory based Extreme Ultraviolet (EUV) radiation has escalated with the desire to use EUV as a source for semiconductor device printing. Laser plasmas based on a mass-limited target concept, developed within the Laser Plasma Laboratory demonstrate a much needed versatility for satisfying rigorous source requirements. This concept produces minimal debris concerns and allows for the attainment of high repetition rates as well as the accommodation of various laser and target configurations. This work demonstrates the generation of EUV radiation by creating laser plasmas from mass-limited targets with indium, tin, and antimony doped droplets. Spectral emission from the laser plasmas is quantified using a flat-field spectrometer. COWAN code oscillator strength predications for each of the dopants were convolved with narrow Gaussian functions creating synthetic spectra for the EUV region between 10 nm - 20 nm. A preliminary comparison was made between the theoretical spectra and experimental results. From this comparison, ion stage transitions for each of the hot dense plasmas generated were assessed.
Download or read book On the Use of Vacuum Ultraviolet Absorption as a Measure of Temperature in Rare Gas Plasmas written by R. A. Rudd and published by . This book was released on 1965 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: An extension of the theory of plasma temperature measurement by vacuum ultraviolet absorption has been made which makes this technique useful in obtaining time-resolved temperatures. A survey of available photoionization cross sections is given, and improvements which lead to better time resolution are suggested. (Author).
Download or read book Space and Time Resolved Spectroscopy of Laser produced Plasmas written by Bruce Kai Fong Young and published by . This book was released on 1988 with total page 724 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Time resolved Visible and Extreme Ultraviolet Spectroscopy of Laser produced Tin Plasma written by Joseph Fred O'Shay and published by . This book was released on 2007 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the final section of this study, we investigate the radiative properties of tin ablation plasma as the laser irradiance is varied by more than an order of magnitude. The effect of increased focused laser energy is manifested in a weak scaling of radiation temperature, and a significant broadening of the emission lifetime at the highest laser intensities. It is found that the resulting radiation conversion efficiency is not a strong function of laser intensity within the parameter regime of this work. It is shown that agreement between experimental and simulated plasma conditions becomes progressively worse in the high-irradiance regime as the ionization and radiative transfer models play increasingly dominant roles in the plasma energetics.
Download or read book Laser generated Plasma as a Spectroscopic Light Source written by and published by . This book was released on 1970 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polarisation Resolved Spectroscopy of Laser Produced Plasmas written by Getasew Admasu Wubetu and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The degree of polarisation of the light emitted from laser produced plasmas has been studied using time-resolved imaging along with time- and polarisation-resolved spectroscopy in the visible spectral range. A Q-switched Nd: YAG laser (wavelength = 1064 nm, pulse width = 14 ns) was used to ablate the target. Optical spectra were obtained using a Czerny-Turner spectrometer equipped with an intensified charge-coupled device (ICCD) readout. A Wollaston prism split the emitted radiation into orthogonally polarised states for simultaneous spectral acquisition. Polarisation anisotropy in line emission is the result of a non-statistical distribution of population amongst the available magnetic sublevels in the upper state of the transition of interest. The origin of the non-statistical distribution lies in an anisotropy in the electron velocity distribution function (EVDF) which is the most often described by a bi-Maxwellian function. For the continuum emission, it is found that the main contributor is recombination radiation and once again an EVDF anisotropy is the origin. In this case the partially preferred direction of motion of the recombining electrons is transferred into a partially preferred polarisation direction. The imaging results reveal stronger plasma emission polarisation in air than in vacuo. They also showed stronger polarisation of the continuum emission compared to line emission at higher pressure for Al (at 396.15 nm) and Al+ (466.3 nm) features. In vacuo, the degree of polarisation (P) of all charge states studied oscillates with time. It is suggested that this oscillation is a result of self-generated magnetic fields which cause the plasma itself to undergo compression and rarefraction cycles. In this case the EVDF will also oscillate and hence the degree of polarisation will do so. The magnetic field itself is thought to arise from a Rayleigh-Taylor (RT) instability. The effects of target geometry and incident laser polarisation on the emission were also studied. A greater effect was observed for continuum radiation compared to line emission. It is also observed that the laser polarisation has the greatest effect for oblique incidence on the target.
Download or read book A Laser Produced Plasma as a Pulsed Source of Continuum Infrared Radiation for Time Resolved Absorption Spectroscopy written by Arthur W. Adamson and published by . This book was released on 1983 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focussed beam from the 20 ns pulse of an amplified Nd glass laser produces a high temperature plasma in air or other media. Such plasmas, while well known as phenomena, seem not to have been investigated as a source of infrared radiation. We find the emission in the chemical infrared region, 2100-1700/CM, to be a continuum or white, and at least twenty five times more intense than that from a typical glow bar used in conventional infrared absorption spectroscopy. Emission from the plasma formed in air decays with a wavelength dependent lifetime, about 150 ns for the visible portion, and 2 microsecond for the infrared portion. When formed in argon, the plasma emission is more intense, and the decay time of the infrared emission rises to 4 microsec. Use of this source is demonstrated in a measurement of the carbonyl stretching absorption for W(C0)6 and plans are to apply the method to the determination of infrared absorption spectra of thermally equilibrated excited states of organic molecules and of coordination compounds.
Download or read book Laser Drive Relativistic Plasmas Applied for Science Industry and Medicine written by Sergei V. Bulanov and published by American Institute of Physics. This book was released on 2008-07-03 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: These Proceedings are devoted to the studies of intense laser-plasma interactions and its applications, especially in medicine, such as hadron therapy. They address the laser driven accelerators of charged particles and the laser driven coherent and incoherent x-ray sources. In relation to quantum field physics and astrophysics, special attention is paid to the generation of super intense electromagnetic waves and super strong static magnetic fields in high power laser-matter interactions.
Download or read book Space and Time Resolved Spectroscopy of Laser produced Plasmas written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The determination of level populations and detailed population mechanisms in dense plasmas has become an increasingly important problem in atomic physics. In this work, the density variation of line intensities and level populations in aluminum K-shell and molybdenum and silver L-shell emission spectra have been measured from high-powered, laser-produced plasmas. For each case, the density dependence of the observed line emission is due to the effect of high frequency electron-ion collisions on metastable levels. The density dependent line intensities vary greatly in laser-produced plasmas and can be used to extract detailed information concerning the population kinetics and level populations of the ions. The laser-plasmas had to be fully characterized in order to clearly compare the observed density dependence with atomic theory predictions. This has been achieved through the combined use of new diagnostic instruments and microdot targets which provided simultaneously space, time, and spectrally resolved data. The plasma temperatures were determined from the slope of the hydrogen-like recombination continuum. The time resolved electron density profiles were measured using multiple frame holographic interferometry. Thus, the density dependence of K-shell spectral lines could be clearly examined, independent of assumptions concerning the dynamics of the plasma. In aluminum, the electron density dependence of various helium-like line intensity ratios were measured. Standard collisional radiative equilibrium models fail to account for the observed density dependence measured for the ''He/sub .cap alpha.//IC'' ratio. Instead, a quasi-steady state atomic model based on a purely recombining plasma is shown to accurately predict the measured density dependence. This same recombining plasma calculation successfully models the density dependence of the high-n ''He/sub .gamma.//He/sub .beta./'' and ''He/sub delta//He/sub .beta./'' helium-like resonance line intensity ratios.
Download or read book Laser Driven Relativistic Plasmas Applied to Science Energy Industry and Medicine written by Sergei V. Bulanov and published by American Institute of Physics. This book was released on 2012-09-19 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of the Symposium is to address studies of basic science problems associated with laser-plasma interactions, as well as industrial applications and applications to medical diagnostics and hadron therapy. We address special topics, related to the laser driven accelerators of charged particles and the laser driven coherent and incoherent x-ray sources with their applications. As it relates to basic research in quantum field physics and astrophysics, special attention will be paid to the generation of super intense electromagnetic waves and to super intense static magnetic fields in high power laser - matter interactions.
Download or read book Proton Radiography of Laser Plasma Interactions with Picosecond Time Resolution written by T. H. Phillips and published by . This book was released on 2005 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radiography of laser-produced plasmas with MeV protons has the potential to provide new information on plasma conditions in extreme states of matter. Protons with energies up to many hundreds MeV, produced by large scale accelerators have been recently been used to obtain mass density radiographs of the behavior of large samples which have been shocked on microsecond timescales with approximately mm spatial resolution. The recent discovery of laminar proton beams accelerated to multi-MeV energies by picosecond duration laser beams has provided the opportunity to probe dense plasmas with hitherto unparalleled temporal and spatial resolution.
