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Electromagnetic pulse source characteristics experiment on an underground nuclear event

Description: From EMP technical meeting; Kirtland AFB, New Mexico, USA (25 Sep 1973). Under sponsorship of the Advanced Research Projects Agency, the Lawrence Livermore Laboratory conducted an EMP experiment in conjunction with an underground nuclear event. The purpose of the overall study of which this experiment was a part was to document the characteristics of EMP signals generated by various underground nuclear events to provide checks for theoretical models under development. A major goal was to establish how a specific event configuration affects the signals generated. For this experiment, two separate EMP source mechanisms were considered: that due to an asymmetric gamma ray distribution resulting from shielding and configuration constraints in the vicinity of the device and that due to current induced on the line-of-sight pipe. The instrumentation was not ideally located to sort out the two mechanisms because of significant differences between the planned and as-fired configuration. Nevertheless, signals characteristic of the two mechanisms seem to be apparent in the data. An impulsive (10 MHz) component of the signal is probably a result of the asymmetric gamma distribution. A ringing component (1 MHz) has been attributed to currents on the line-of- sight pipe. (auth)
Date: October 22, 1973
Creator: Knapp, M.W. & Bailey, N.D.
Partner: UNT Libraries Government Documents Department

A System for Measuring Energy and Peak Power of Low-Level 1.064 [mu]m Laser Pulses

Description: From introduction: For the first time, transfer standards have been developed for measuring 1.064 Pm laser pulses of duration about 10-100 ns, peak irradiance of about 10-8-10-4 W/cm2, and fluences of about 10-16-10-11 J/cm2 . These energy and power measurement devices use PIN and APD silicon detectors, respectively, and can be used as stable transfer standards with total uncertainties (random errors computed at the 95 percent confidence level) of 10 to 15 percent. The system for calibrating these transfer standards is also described and consists of a cw Nd:YAG laser beam acousto-optically modulated to provide low-level laser pulses of known peak power and energy. A detailed evaluation of systematic and random errors is also shown.
Date: October 1982
Creator: Sanders, A. A. & Rasmussen, A. L.
Partner: UNT Libraries Government Documents Department


Description: Progress is reported in assembling available unclassified flooding data in perforated-plate pulsed extraction columns through January 1, 1963. Existing correlations are critically reviewed, and recommendations are made to develop a better flooding correlation. (auth)
Date: June 1, 1963
Creator: McAllister, R.A. & Ryon, A.D.
Partner: UNT Libraries Government Documents Department

Evolution of Rydberg states in half-cycle pulses: Classical, semiclassical, and quantum dynamics

Description: We summarize recent theoretical advances in the description of the evolution of Rydberg atoms subject to ultrashort pulses extending only a fraction of an optical cycle. We have performed classical. semiclassical and full quantum calculations in order to delineate the classical-quantum correspondence for impulsively perturbed atomic systems. We observe classical and quantum (or semiclassical) oscillations in excitation and ionization which depend on the initial state of atoms and on the strength of the perturbation. These predictions can be experimentally tested. 4 figs.
Date: December 31, 1994
Creator: Burgdoerfer, J. & Reinhold, C.
Partner: UNT Libraries Government Documents Department

Observation of ionization instability of intense laser pulses

Description: Theoretical analysis and preliminary experiment on ionization instability of intense laser pulses in ionizing plasmas are presented. The ionization instability is due to the dependence of the ionization rate on the laser intensity and scatters the laser energy off the original propagation direction.
Date: June 25, 1999
Creator: Alexeev, I; Antonsen, T M; Li, Y; Milchberg, H M & Nikitin, S
Partner: UNT Libraries Government Documents Department

A source for quantum control: generation and measurement of attosecond ultraviolet light pulses

Description: This project has pursued the possibility of producing ultra-short pulses of coherent light using harmonic conversion of a mid-infrared light source, focused into an atomic gas medium. This was a joint effort with Louis DiMauro's experimental group at Brookhaven National Laboratory and in collaboration with Ken Schafer from Louisiana State University and Mette Gaarde from Lund University on the theoretical part. High order harmonic generation (HHG) in nobel gas media using short-pulse visible and near infrared lasers has become an established method for producing coherent, short pulse radiation at wavelengths from the ultraviolet to soft x-rays. We recently proposed that this approach could lead to extremely short pulses, potentially less than one fs, provided the unavoidable frequency chirp of the highest harmonics, could be removed by compressing the pulses with a grating pair. Sources of sub-fs pulses would provide unique opportunities to study dynamical processes on time scales short compared to those associated with nuclear motion. Truly stroboscopic pictures of chemical reaction dynamics would be possible, for example. In this research project we have chosen much smaller driving frequencies than used previously in HHG studies for two reasons. First, this will allow us to measure the pulse lengths of the compressed harmonics because they will be in the vacuum ultraviolet where coincidence measurements are possible. Second, the wavelengths of these harmonics will be idea for pump-probe experiments of quantum dynamical control studies. Our theoretical effort was concentrated in two areas. We used our time-dependent quantum numerical codes to evaluate the harmonic response of alkali atoms to the mid-IR laser excitation. Results were obtained for potassium, the initial species to be used in the experiments, then sodium and rubidium to investigate the possibility of higher conversion efficiencies. In fact, rubidium was found to be significantly better than potassium, both because it ...
Date: February 19, 1999
Creator: Kulander, K C
Partner: UNT Libraries Government Documents Department


Description: Passive networks whose specified wave forms are given as a function of time are discussed. The wave forms may be periodic or a single pulse. Suggestions and techniques are presented which should enable a circuit designer with a basic knowledge of network synthesis procedures to obtain wave-forming networks for a wide variety of cases. (auth)
Date: August 1, 1961
Creator: LaPatra, J W
Partner: UNT Libraries Government Documents Department

Degenerate Four Wave Mixing of Short and Ultrashort Light Pulses

Description: This dissertation presents experimental and theoretical studies of transient degenerate four wave mixing (DFWM) in organic dyes. Chapter 1 is an introduction to DFWM. Chapter 2 describes DFWM experiments that were performed in the gain medium of a dye laser. Chapter 3 presents the theory of DFWM of short pulses in three level saturable media. Chapter 4 presents DFWM experiments of femtosecond pulses in the saturable absorber of a passively modelocked ring dye laser. Chapter 5 presents the theory of DFWM of ultrashort pulses in resonant media.
Date: August 1984
Creator: McMichael, Ian C. (Ian Charles)
Partner: UNT Libraries


Description: A series of pilot plant runs was conducted to define new cartridges for increasing the capacity in the Purex 1 Bx, 2A, lC and 2E columns and eliminate plastic cartridge failures in the HA column scrub section, the HS column and the 2A column. The most favorable designs are presented and data from the various runs are included. (J.R.D.)
Date: February 22, 1961
Creator: Jansen, G. & Richardson, G.L.
Partner: UNT Libraries Government Documents Department


Description: The papers presented at the meeting were recorded and transcripts are given along with the discussion which followed each paper. Separate abstracts were prepared for 12 of the 13 papers presented. (W.D.M.)
Date: October 31, 1960
Partner: UNT Libraries Government Documents Department

Optimal dynamic detection of explosives

Description: The detection of explosives is a notoriously difficult problem, especially at stand-off distances, due to their (generally) low vapor pressure, environmental and matrix interferences, and packaging. We are exploring optimal dynamic detection to exploit the best capabilities of recent advances in laser technology and recent discoveries in optimal shaping of laser pulses for control of molecular processes to significantly enhance the standoff detection of explosives. The core of the ODD-Ex technique is the introduction of optimally shaped laser pulses to simultaneously enhance sensitivity of explosives signatures while reducing the influence of noise and the signals from background interferents in the field (increase selectivity). These goals are being addressed by operating in an optimal nonlinear fashion, typically with a single shaped laser pulse inherently containing within it coherently locked control and probe sub-pulses. With sufficient bandwidth, the technique is capable of intrinsically providing orthogonal broad spectral information for data fusion, all from a single optimal pulse.
Date: January 1, 2009
Creator: Moore, David Steven; Mcgrane, Shawn D; Greenfield, Margo T; Scharff, R J; Rabitz, Herschel A & Roslund, J
Partner: UNT Libraries Government Documents Department