scispace - formally typeset
Search or ask a question

Showing papers on "Power density published in 1969"



Journal ArticleDOI
TL;DR: It is shown that the peak power density increases in a circuit with low inductance and high capacitor voltage and that the energy density has an optimum at a fill pressure of ~28 Torr.
Abstract: The laser power density and its time history from a pulsed molecular nitrogen laser are calculated. Their dependence on the fill pressure and on various parameters of an electric circuit, in which the nitrogen gas acts as a variable resistor, is illustrated. It is shown that the peak power density increases in a circuit with low inductance and high capacitor voltage and that the energy density has an optimum at a fill pressure of ~28 Torr. Based on these and the gain calculations, some design considerations are also discussed.

34 citations


Journal ArticleDOI
TL;DR: In this article, the authors describe a practical solid-state phase and frequency converter, where three-phase input power is converted to single-phase power of higher variable frequency output power, without the use of a dc link.
Abstract: The paper describes a practical solid-state phase and frequency converter. Three-phase input power is converted to single-phase power of higher variable frequency output power, without the use of a dc link. A brief description of the circuit is given, followed by simplified theoretical considerations and actual experimental results.

21 citations


Journal ArticleDOI
01 Jun 1969-Nature
TL;DR: In this article, the formation and arrangement of microcraters produced by an unfocused pulse of power density ∼ 100 MW/cm2 was discussed, where the pulses, of width 1.0 × 10−8 s, were generated by a ruby laser, Q-switched by vanadyl phthalocyanine.
Abstract: Q-SWITCHED laser pulses focused on to a metal cause microcraters at the surface1,2. This communication deals with the formation and arrangement of microcraters produced by an unfocused pulse of power density ∼ 100 MW/cm2. The pulses, of width 1.0 × 10−8 s, were generated by a ruby laser, Q-switched by vanadyl phthalocyanine.

17 citations


Journal ArticleDOI
TL;DR: In this article, the three nonlinear coupled differential equations for a three-frequency backward-traveling-wave parametric interaction in a lossless dielectric were solved for the power density in the three fields as a function of position in the crystal.
Abstract: The three nonlinear coupled differential equations for a three‐frequency backward‐traveling‐wave parametric interaction in a lossless dielectric are solved for the power density in the three fields as a function of position in the crystal. When the theory is applied to a single‐pass oscillator, it predicts the existence and magnitude of a threshold pump power even for lossless media. The theoretical curves showing the power outputs in the signal and idler waves for the single‐pass oscillator as a function of pump power and crystal parameters are given.

16 citations


Journal ArticleDOI
TL;DR: In this paper, the angular power distribution at angles between 0.01° and 1° from the beam axis was measured by scanning with a narrow slit and a linear structure function was calculated for coherence lengths between 20 microns and 1 millimeter, assuming isotropic surface statistics.
Abstract: Most of the light scattered from high-reflectivity dielectric mirrors is radiated into directions close to the reflected beam. We measured the angular power distribution at angles between 0.01° and 1° from the beam axis by scanning with a narrow slit. From this a linear structure function is calculated for coherence lengths between 20 microns and 1 millimeter, assuming isotropic surface statistics. The corresponding power density decreases with the third power of the scattering angle. The power outside a given radius and the power density is plotted for various wavelengths and distances.

13 citations


Patent
23 Jul 1969
TL;DR: In this paper, the power output of a boiling liquid reactor was increased by providing means for forming a vortex within the boiling zone of coolant channels, which is called vortex vortex formation.
Abstract: The power output of a boiling liquid reactor is increased by providing means for forming a vortex within the boiling zone of coolant channels.

11 citations


Journal ArticleDOI
TL;DR: The efficiency of krypton, xenon, and tungsten-iodine lamps for pumping Nd: YAG are compared both spectroscopically and by laser pumping to determine the best over-all efficiency.
Abstract: The efficiency of krypton, xenon, and tungsten–iodine lamps for pumping Nd:YAG are compared both spectroscopically and by laser pumping. The relative pumping efficiencies of xenon and tungsten to krypton are 0.86 and 1.1, respectively. However, because the tungsten filament uses a higher percentage of its power in overcoming the laser threshold, the krypton lamp with its larger power density yielded the best over-all efficiency. An output power of 105 W was obtained at an input power of 3610 W for an over-all efficiency of 2.9%.

10 citations



Journal ArticleDOI
TL;DR: A beam collimator and shutter assembly has been designed and fabricated to define and interrupt the high maximum areal power density (30 kW/cm2) external beam anticipated for the Princeton A. V. F. Cyclotron as mentioned in this paper.
Abstract: A beam collimator and shutter assembly has been designed and fabricated to define and interrupt the high maximum areal power density (30 kW/cm2) external beam anticipated for the Princeton A. V. F. Cyclotron. Pairs of graphite cylinders which rotate at 300 r/min about parallel axes a precisely adjustable distance apart, define the beam in each of the horizontal and vertical directions. A similar rotating graphite cylinder which is raised and lowered by an air cylinder operating in a fail-safe mode functions as the beam shutter. The power of the beam incident of these cylinders is dissipated by thermal radiation to surrounding water-cooled structures. Tests with an electron gun have shown that the slit cylinders can successfully dissipate a beam power of 2.2 kW with an areal density power of 10 kW/cm2 with no indication of deterioration or overheating of critical components. Calculations indicate power levels up to 5.0 kW with 50kW/cm2 areal density may be tolerated by these slits.