Abstract Details
Bow Shocks Formed by the Collision of Plasmas in Laser-Irradiated Cylindrical Cavities
Author: Jorge Filevich
Requested Type: Poster Only
Submitted: 2009-04-21 22:48:16
Co-authors: M.A.Purvis, J.Grava, D.P.Ryan, J.Dunn, S.J.Moon, V.N.Shlyaptsev, J.J.Rocca
Contact Info:
Colorado State University
1320 Campus Delivery ERC rmB30
Fort Collins, CO 80523
USA
Abstract Text:
The formation of long lasting bow shocks that emit extreme ultraviolet radiation was observed to form outside laser-irradiated semi-cylindrical grooves. The plasmas were created by the irradiation of semi-cylindrical targets of several different materials at an intensity of 1×10^12 W/cm^2 with 120 ps duration laser pulses. The plasma evolution was studied with laser interferometry and with hydrodynamic simulations conducted with the code HYDRA. The shocks were observed to emit extreme ultraviolet radiation along a narrow arc that develops outside the cavity. The combination of optical and SXR interferometry allowed the mapping of the plasma electron density in the range of 5×10^17 cm^-3 to ~1 ×10^20 cm^-3. The interferograms show that the plasma expands off the target surface and converges in a focal region, where the electron density build-up is measured to exceed 1×10^20 cm^-3. Subsequently, this central plasma expands mainly away from the semi-cylindrical groove but also laterally. The shock is formed when this laterally expanding central plasma collides with plasma that originates from the flat target walls surrounding the groove. Simulations agree well with measurements in describing the shock formation and evolution in C, Al, Cu, and Ag plasmas.
Comments:
Please place this near the poster by Michael Purvis entitled, "Collimation of dense laboratory plasma jets studied with soft x-ray laser interferometry"