Sub-picosecond laser-produced plasmas

Miscellaneous · Sun Jan 01 00:00:00 EST 1989

OSTI ID:6105910

Murnane, M M

This thesis research consisted of the development of a high power femtosecond dye laser system and its use in the investigation of high temperature, high density, x-ray emitting plasmas. Experimental results have been obtained which demonstrate that plasmas produced on sub-picosecond time scales access a new plasma regime previously unattainable using conventional laser plasmas and are useful as a source of ultrafast (picosecond) x-ray pulses. The results agree with initial theoretical predictions, published as a proposal before the experimental work was initiated. These investigations are of current scientific interest, in particular for the fields of high-intensity laser-matter interaction and x-ray lasers. The project involved: (1) Construction of a high-power, short-pulse dye laser system, which is the most powerful of its kind available to date. This system has been duplicated in part by a number of laboratories in the U.S. since being built at Berkeley. (2) Reflectivity measurements using the high-intensity laser, which demonstrate absorption of the ultrashort-pulse laser at near solid densities, before any significant plasma expansion occurs. (3) X-ray pulsewidth measurements, which have been used to demonstrate that the x-ray pulsewidth from the plasma is less than 1.5 psec in duration. This measurement was instrument limited and represents an order of magnitude improvement over previously available time-resolution in the x-ray region. A series of experiments have been performed in order to determine the plasma conditions under which short duration x-ray pulses can be obtained. (4) Plasma spectroscopy diagnostics, which have been used to show that the x-ray emission spectra from low atomic number targets are characteristic of a high-density plasma in LTE.

• Research Organization: California Univ., Berkeley, CA (USA)
• OSTI ID: 6105910
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
DYE LASERS
X-RAY LASERS
RESEARCH PROGRAMS
CONSTRUCTION
ELECTRON DENSITY
ELECTRON TEMPERATURE
EMISSION SPECTRA
INTERACTIONS
LASER RADIATION
LASER-PRODUCED PLASMA
LTE
MATTER
PLASMA DENSITY
PLASMA DIAGNOSTICS
PLASMA EXPANSION
PLASMA PRODUCTION
PULSES
REFLECTIVITY
USES
X RADIATION
ELECTROMAGNETIC RADIATION
EQUILIBRIUM
EXPANSION
IONIZING RADIATIONS
LASERS
LIQUID LASERS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
PLASMA
RADIATIONS
SPECTRA
SURFACE PROPERTIES
426002* - Engineering- Lasers & Masers- (1990-)