Showing papers by "Boris Breizman published in 2004"
TL;DR: The ongoing development of the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) involves basic physics analysis of its three major components: helicon plasma source, ion cyclotron-resonance heating module, and magnetic nozzle as mentioned in this paper.
Abstract: The ongoing development of the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) involves basic physics analysis of its three major components: helicon plasma source, ion cyclotron-resonance heating module, and magnetic nozzle. This paper presents an overview of recent theoretical efforts associated with the project. It includes (1) a first-principle model for helicon plasma source, (2) a nonlinear theory for the deposition of rf-power at the ion cyclotron frequency into plasma flow, and (3) a discussion of the plasma detachment mechanism relevant to VASIMR.
115 citations
TL;DR: In the burning fusion plasmas of next step devices such as ITER, the majority of the heating of the fusing fuel will come from the plasma self-heating by fusion born α-particles as discussed by the authors.
Abstract: In the burning fusion plasmas of next step devices such as ITER (2001 ITERFEAT Outline Design Report IAEA/ITER EDA/DS/18 (Vienna: IAEA) p 21), the majority of the heating of the fusing fuel will come from the plasma self-heating by fusion born α-particles. Recent advances in theoretical understanding, together with the development of new diagnostic techniques, make this a timely opportunity to survey the role of energetic particles in fusion plasmas and how it projects to future burning plasma devices. (Some figures in this article are in colour only in the electronic version)
78 citations
TL;DR: In this article, a model for the nonlinear response of a small cluster, with a size much smaller than the wavelength, at the third harmonic of the laser frequency is presented, which involves collective modes of a cold electron core confined within a positively charged ion background.
Abstract: A model is presented for the nonlinear response of a small cluster, with a size much smaller than the wavelength, at the third harmonic of the laser frequency. The model involves collective modes of a cold electron core confined within a positively charged ion background. The response of the electron core to the laser field is similar to that of a weakly nonlinear oscillator driven by an external force. In particular, there is a resonant enhancement of the third harmonic when the frequency of the applied field is close to one third of the core eigenfrequency. It is shown that density nonuniformity or nonspherical shape of the ion background is necessary for harmonic generation. Particle-in-cell simulations have been performed to model the time evolution of the third harmonic response as the ion density profile changes due to cluster expansion. The simulation results are consistent with the predictions of the cold electron core model. In addition, the code quantifies the role of stochastic electron heating...
45 citations
01 Jan 2004
TL;DR: In this paper, an impact thrust stand was developed to measure the force caused by a beam of charged and neutral particles impacting a target plate, which was designed to be placed in the plume of an electric thruster and has been tested and compared to the thrust measured from a Hall thruster placed on a pendulum thrust stand.
Abstract: A device has been developed to measure the force caused by a beam of charged and neutral particles impacting a target plate. This device, an impact thrust stand, was developed to allow thrusters, during early stages of development, to be quickly and easily exhausted and compared to other thrusters. Since some thruster concepts are tested using laboratory equipment that is heavy and cumbersome, measuring the momentum flux of the particles in the plume can be much simpler than placing the entire thruster on a thrust stand. Conservation of momentum requires the momentum flux measured in the plume to be related to the thrust produced by the thruster. The impact thrust stand was designed to be placed in the plume of an electric thruster and has been tested and compared to the thrust measured from a Hall thruster placed on a pendulum thrust stand. Force measurements taken at several axial locations in the magnetic nozzle region of the Variable Specific Impulse Magnetoplasma Rocket will be presented.
4 citations
Proceedings Article•
16 May 2004
TL;DR: In this paper, the third-harmonic generation from noble-gas clusters by ultrashort probe pulses is more resonantly-enhanced than linear absorption following heating by an ultra-short pump pulse.
Abstract: Third-harmonic generation from noble-gas clusters by ultrashort probe pulses is more sharply resonantly-enhanced than linear absorption following heating by an ultrashort pump pulse. Simulations of cluster expansion and collective electron dynamics reproduce the observed trends
Proceedings Article•
16 May 2004
TL;DR: In this article, the third-harmonic generation from noble gas clusters by ultrashort probe pulses is more resonantly enhanced than linear absorption following heating by an ultra-short pump pulse.
Abstract: Third-harmonic generation from noble-gas clusters by ultrashort probe pulses is more sharply resonantly-enhanced than linear absorption following heating by an ultrashort pump pulse. Simulations of cluster expansion and collective electron dynamics reproduce the observed trends.
07 Dec 2004
TL;DR: In this article, a third-harmonic generation from noble-gas clusters by ultrafast probe pulses is more sharply enhanced than linear absorption following heating by an ultrafast pump pulse, in good agreement with simulations of cluster expansion and collective electron dynamics with phase matching consideration.
Abstract: Third-harmonic generation from noble-gas clusters by ultrafast probe pulses is more sharply-enhanced than linear absorption following heating by an ultrafast pump pulse, in good agreement with simulations of cluster expansion and collective electron dynamics with phase matching consideration.