Production of highly-charged ions by nitrogen gas target irradiated with ultrashort high-intensity pulse laser

Issue title: Proceedings of the tenth International Symposium on Applied Electromagnetics and Mechanics ISEM-Tokyo

Article type: Research Article

Authors: Namba, Shinichi^{a; *} | Kawachi, Tetsuya^a | Hasegawa, Noboru^a | Nagashima, Keisuke^a | Sukegawa, Kouta^a | Kado, Masataka^a | Tanaka, Momoko^a | Daido, Hiroyuki^a | Kato, Yoshiaki^a

Affiliations: [a] Advanced Photon Research Center, Kansai Research Establishment, Japan Atomic Energy Research Institute, Umemidai 8-1, Kizu-cyo, Souraku-gun, Kyoto, 619-0215, Japan

Correspondence: [*] Corresponding author: Shinichi Namba, Tel.: +81 774 71 3348; Fax: +81 774 71 3319; E-mail: namba@hiroshima-u.ac.jp

Abstract: High-density nitrogen gas was irradiated with an ultrashort high-intensity pulse laser (pulse width: 1.5 ps, intensity: ≥ 10^{15} W/cm^{2}). It was found that highly charged ions were produced effectively as the gas density became higher. From distribution of population densities of high-lying levels of lithium like nitrogen ions, the electron temperature in a recombining phase was estimated. This electron temperature together with a calculation using a collisional-radiative model, in which doubly excited levels of beryllium like ions are included, indicated that the electron density was n_{e} = 3 × 10^{19} cm^{-3}. Moreover, the spectra also showed that population inversions between some excited states of hydrogen-, helium-, lithium like nitrogen ions were generated under this plasma conditions.

DOI: 10.3233/JAE-2002-384

Journal: International Journal of Applied Electromagnetics and Mechanics, vol. 14, no. 1-4, pp. 277-282, 2002