Increasing the upper-limit intensity and temperature range for thermal self-focusing of a laser beam by using plasma density ramp-up

Autor:	Ali Reza Niknam, B. Bokaei
Rok vydání:	2014
Předmět:	Physics Dense plasma focus Self-focusing Plasma Atmospheric temperature range Ponderomotive force Condensed Matter Physics Laser law.invention Two-stream instability Physics::Plasma Physics law Electron temperature Atomic physics
Zdroj:	Physics of Plasmas. 21:032309
ISSN:	1089-7674 1070-664X
DOI:	10.1063/1.4869244
Popis:	This work is devoted to improving relativistic and ponderomotive thermal self-focusing of the intense laser beam in an underdense plasma. It is shown that the ponderomotive nonlinearity induces a saturation mechanism for thermal self-focusing. Therefore, in addition to the well-known lower-limit critical intensity, there is an upper-limit intensity for thermal self-focusing above which the laser beam starts to experience ponderomotive defocusing. It is indicated that the upper-limit intensity value is dependent on plasma and laser parameters such as the plasma electron temperature, plasma density, and laser spot size. Furthermore, the effect of the upward plasma density ramp profile on the thermal self-focusing is studied. Results show that by using the plasma density ramp-up, the upper-limit intensity increases and the self-focusing temperature range expands.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::b2ad102348d5fc10ae8499801a4e8459 https://doi.org/10.1063/1.4869244 Zobrazit plný text záznamu