An experiment was performed to measure the total impulse transferred to a surface by a high-power pulsed 10.6-μ laser under atmospheric conditions, and also to determine the degree to which the observed plasma decouples the laser energy from the surface. Specific interest was directed toward conditions under which a ``radiation-driven detonation wave'' may form due to the presence of a surface. The momentum transferred in dyn sec/J decreases with an increase in the ratio of incident energy to spot area since a larger fraction of the energy is decoupled from the surface.
The optical quality of a pulsed atmospheric CO(2) electric laser is investigated. The density disturbances in the optical cavity are caused by edge waves originating at the anode and cathode. Volumetric heating effects associated with a nonuniform electric discharge are shown to be negligible. The disturbance propagating from the cathode results from a discontinuity in the spatial heating and the cathode fall. The wave emanating from the anode is associated with the presence of a solid surface that prevents the gas from expanding. As a result, lasers have to be designed with pulse durations much less than the acoustic transit time across the cavity.
Articles you may be interested inAbsolute calibration method for laser megajoule neutron yield measurement by activation diagnostics Rev. Sci. Instrum. 82, 073501 (2011); 10.1063/1.3605485Quartz crystal microbalance measurements of absolute laser photodeposition rates: Application to 257nm deposition from W(CO)6In the energy meter described here the CO 2 laser radiation is almost completely absorbed by an Al 2 0 3 surface on an aluminum plate. The high absorption of the surface (z9S%) eliminates the need for calibration and the laser energy is computed by measuring the temperature rise of a plate with known thermal capacity. Experimentally we find that the calorimeter noise level corresponds to an energy density of about 2 mJ/cm 2 • Calculations indicate that the instrument is capable of measuring the energy of a single pulse that is 1 nsec wide, provided the pulse contains an average energy density of 10 mJ/cm 2 • We have estimated the radiation and convection losses and found them to be negligible. The calorimeter is good for radiation between 8.5 and 11 !J.; however, with modifications the bandwidth could easily be increased.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.