Other
Scientific paper
Jun 2006
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006phdt.........5a&link_type=abstract
PhD Thesis,. Proquest Dissertations And Theses 2006. Section 0769, Part 0606 196 pages; [Ph.D. dissertation].England: The Univ
Other
Laser-Produced Plasma, Pulsed Magnetic Fields
Scientific paper
This work presents an experimental investigation of the scaled simulation of high Mach number collisionless shocks found in supernovae remnants, which is part of the experimental collaboration initiated by Woolsey et al. , (Physics of Plasmas, 8, 2439, 2001). Supernovae are one of the most energetic astrophysical phenomena. They distribute new matter created inside stars throughout space and are believed to be the origin of cosmic radiation with energy below 10 15 eV. The evolution of a supernova remnant is governed by the presence of strong forward and reverse shocks and diffusive shock acceleration. Some aspects of these processes can be investigated in the laboratory using scaled experiments with laser produced plasma. The experiments explore the interaction of two rapidly expanding collisionless laser produced plasmas in a magnetic field of up to 12 tesla. The plasmas are produced by multi-beam laser irradiation of 0.1 mm thick C ~12 H ~16 plastic targets by an 80 ps pulse of wavelength 1053 nm focused to an irradiance of between 10 13 W/cm 2 and 10 14 W/cm 2 , which results in expansion velocities of up to 1.5 × 10 8 cm/s. Measurements of the plasma electron density between 10 17 cm -3 and 10 19 cm - 3 are made by interferometry of a 20 ps probe laser pulse at a wavelength of 527 nm and evidence of collisionless interaction between the plasmas is obtained using shadowgram imaging of the probe refracted by the plasmas. Two methods to produce a strong external magnetic field are investigated. In one approach, a laser-driven Helmholtz coil is used providing a magnetic field of 8 tesla in a 20 ns pulse. The field is generated by the circulation of a large return current in a Helmholtz coil. This relies on the generation of a population of hot electrons by resonance absorption of the laser. The hot and cold electron temperatures are estimated from the x-ray bremsstrahlung emission from the target, which is measured by pulse height spectroscopy using a charge coupled device image array. In another approach, a field of up to 12 tesla in a 1.5 ms pulse is generated in an electromagnet driven by a 13 kJ, 2.8 kV capacitor bank. The resulting plasma magnetisation is measured by ultraviolet spectroscopy of Zeeman splitting in the carbon V 1s2s 3 S 1 -1s2p 3 P 2,1,0 triplet at ~2270 Å and the carbon III 1s 2 2s2p 1 P 1 -1s 2 2p 2 1 D 2 line at 2296.9 Å.
No associations
LandOfFree
Experimental astrophysics with magnetised laser-produced plasma: UV/X-ray spectroscopy, interferometry and pulsed magnetic fields does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Experimental astrophysics with magnetised laser-produced plasma: UV/X-ray spectroscopy, interferometry and pulsed magnetic fields, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Experimental astrophysics with magnetised laser-produced plasma: UV/X-ray spectroscopy, interferometry and pulsed magnetic fields will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1476592