Study of soft x-ray amplification in a magnetically-confined recombining laser-produced plasma

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6608724

Kim, D E

Soft x-ray amplification based on population inversion through recombination in a magnetically confined laser-produced plasma has been studied in this thesis research. A divergence measurement of the CO{sub 2} laser-pumped C VI182 {angstrom} recombination laser has been carried out and has enabled us to estimate its output energy. The C VI 182 {angstrom}, 10-30 nsec pulse laser was found to have following characteristics: a factor of 500 amplification, 1-3 mJ pulse energy, 5 mrad beam divergence, and 10{sup {minus}5} efficiency. In a second phase of the work, the population inversion process in the Li-like ions was investigated both through experiments and through computer modelling, and in a third phase, a carbon-plasma amplifier for 182 {angstrom} radiation in C VI was developed. Population inversion between 4f and 3d levels in the Li-like ions such as Mg X, Al XI, and Si XII was investigated experimentally. Gain-length products of 1-2 for the 187.2 {angstrom}, 4f-3d transition in Mg X, 3-4 for the 154 {angstrom}, 4f-3d transition in Al XI, and 1-2 for 129 {angstrom}, 4f-3d transition in Si XII, respectively, were observed. A one-dimensional hydro-atomic code was used to model the plasma and the theoretical predictions agree well with the observations. To develop an amplifying medium, a Nd/glass laser, in a line-focus configuration, was directed at a rotatable carbon target. The maximum gain observed in the Nd/glass laser-produced carbon-plasma was 8.1 {+-} 1 cm{sup {minus}1} for the 182 {angstrom} in C VI. The gain medium was combined with the CO{sub 2} laser-pumped C VI 182 {angstrom} laser. A 19 {+-} 10% net increase of the output intensity due to amplification was observed. The C VI 182 {angstrom} recombination laser has been used to expose a biological specimen in an x-ray contact microscope.

• Research Organization: Princeton Univ., NJ (USA)
• OSTI ID: 6608724
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
426002* -- Engineering-- Lasers & Masers-- (1990-)
AMPLIFICATION
DESIGN
ELECTROMAGNETIC RADIATION
ENERGY
GAIN
GAS LASERS
IONIZING RADIATIONS
LASER-PRODUCED PLASMA
LASERS
MATHEMATICAL MODELS
PLASMA
POPULATION INVERSION
RADIATIONS
RECOMBINATION
SOFT X RADIATION
X RADIATION