Measurement of intense magnetic fields associated with laser−produced plasmas

Abstract

Measurements have been made with subnanosecond resolution of the azimuthal magnetic field spontaneously associated with plasmas produced by high-intensity (1012–1014 W/cm2) 1-nsec-duration CO2 laser pulses. In addition to a distinct dependence on background argon gas pressure, it is found that the magnetic field displays a 1/r2 radial dependence, and its onset is synchronous with the initial formation of the plasma.

Phase-selective laser-induced breakdown spectroscopy of metal-oxide nanoparticle aerosols with secondary resonant excitation during flame synthesis

“…Moreover, the exact temporal evolution of the magnetic eld may not be the same as that for the laser pulse under this condition. The generated magnetic eld depends strongly on the laser-matter-plasma interactions; 59,65,66 and especially in the present case, the mass of the nanoparticles will be reduced quickly within the rst several nanoseconds, 24 which will Fig. 7 Temporal evolution of the emission spectrum from 2.5 to 32.5 ns relative delay time for 355 nm laser irradiance of 2.4 GW cm À2 .…”

Review on spontaneous magnetic fields in laser-produced plasmas: Phenomena and measurements

“…Later induction probe studies (Edwards et al 1977) also showed, as earlier (Case & Schwirzke 1975), that the magnetic field expanding from a metallic target has a fast component traveling with the front velocity. Probes with a subnanosecond response have shown that the rise of the magnetic field is synchronous with the initial formation of the plasma (Serov & Richardson 1976). A systematic magnetic probe study of the magnetic fields produced for a solid target in vacuum (Nakano & Sekiguchi 1979) was made and compared with a computer simulation.…”

“…It was recognized (Stamper 1972) that a linearly polarized laser beam would produce, at high irradiance, enhanced heating along the laser electric field and that the resulting pressure anisotropy would generate a nonazimuthal magnetic field. Kinetic theory, with ponderomotive modifications (Shkarofsky 1980;Mora & Pellat 1981a), has provided a basis for radiation pressure effects (Section 4) as well as the laser-induced tensor character of the electron pressure.…”

Laser-Processed Nanosilicon: A Multifunctional Nanomaterial for Energy and Healthcare

“…Because almost all radiation energy is absorbed in the front of the plasma shock wave moving toward the lens, a laser spark plasma can accumulate a huge amount of energy. Therefore, nanoclusters ablated from the target by LSP find themselves in a hot plasma with temperatures higher than 10 4 K and intense electromagnetic fields, − which can lead to modification of their properties. The clusters then return to the focal spot due to hydrodynamic processes in the laser plasma to form a crystalline nanostructured film.…”