Title :
Dynamics of high-radiance visible-laser beam interaction with metals
Author :
Chang, Jen-Yuan James ; Warner, B.E.
Author_Institution :
Lawrence Livermore Nat. Lab., CA, USA
Abstract :
Summary form only given. We have investigated laser-material coupling, laser-plasma interaction, and material removing mechanisms with high-power copper vapor lasers (CVL). It is found that material coupling with high-radiance visible laser light improves quickly as material undergoes rapid temperature and phase changes during the 50 to 70 ns laser pulse. The measurements of vapor expansion on aluminum and steel reveal that strong plasma-absorption-induced ignition starts at a laser intensity of 1-2 GW/cm/sup 2/. This plasma ignition induces a detonation wave that travels with a speed of a few tens of km/s. Hydrodynamic relations indicate that the vapor density at the end of a laser pulse is 3(10/sup 10/)-1(10/sup 11/) cm/sup -3/ with a pressure of a few thousand atmosphere near the target surface.
Keywords :
aluminium; hydrodynamics; laser ablation; laser beam effects; plasma production by laser; plasma shock waves; steel; 50 to 70 ns; Al; Cu; detonation wave; high-power Cu vapor lasers; high-radiance visible-laser beam interaction; hydrodynamic relations; interaction dynamics; laser intensity; laser pulse; laser-material coupling; laser-plasma interaction; material coupling; material removing mechanisms; metals; phase changes; plasma ignition; pressure; rapid temperature changes; steel; strong plasma-absorption-induced ignition; vapor density; vapor expansion; Laser transitions; Optical coupling; Optical materials; Optical pulses; Phase change materials; Plasma density; Plasma materials processing; Plasma measurements; Plasma temperature; Plasma waves;
Conference_Titel :
Lasers and Electro-Optics, 1996. CLEO '96., Summaries of papers presented at the Conference on
Conference_Location :
Anaheim, CA, USA
Print_ISBN :
1-55752-443-2
