<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Xianglei Mao</style></author><author><style face="normal" font="default" size="100%">Richard E. Russo</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Observation of plasma shielding by measuring transmitted and reflected laser pulse temporal profiles</style></title><secondary-title><style face="normal" font="default" size="100%">Applied Physics A-Materials Science &amp; Processing</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">ablated mass</style></keyword><keyword><style  face="normal" font="default" size="100%">ablation</style></keyword><keyword><style  face="normal" font="default" size="100%">ablation rate</style></keyword><keyword><style  face="normal" font="default" size="100%">absorption</style></keyword><keyword><style  face="normal" font="default" size="100%">aluminum</style></keyword><keyword><style  face="normal" font="default" size="100%">atomic emission-spectrometry</style></keyword><keyword><style  face="normal" font="default" size="100%">brass</style></keyword><keyword><style  face="normal" font="default" size="100%">coefficient</style></keyword><keyword><style  face="normal" font="default" size="100%">density</style></keyword><keyword><style  face="normal" font="default" size="100%">dependence</style></keyword><keyword><style  face="normal" font="default" size="100%">evaporation</style></keyword><keyword><style  face="normal" font="default" size="100%">glass</style></keyword><keyword><style  face="normal" font="default" size="100%">glasses</style></keyword><keyword><style  face="normal" font="default" size="100%">inductively-coupled plasma</style></keyword><keyword><style  face="normal" font="default" size="100%">inverse bremsstrahlung</style></keyword><keyword><style  face="normal" font="default" size="100%">laser</style></keyword><keyword><style  face="normal" font="default" size="100%">laser power density</style></keyword><keyword><style  face="normal" font="default" size="100%">laser radiation</style></keyword><keyword><style  face="normal" font="default" size="100%">light</style></keyword><keyword><style  face="normal" font="default" size="100%">mass</style></keyword><keyword><style  face="normal" font="default" size="100%">mass-spectrometry</style></keyword><keyword><style  face="normal" font="default" size="100%">model</style></keyword><keyword><style  face="normal" font="default" size="100%">plasma</style></keyword><keyword><style  face="normal" font="default" size="100%">plasma shielding</style></keyword><keyword><style  face="normal" font="default" size="100%">plume</style></keyword><keyword><style  face="normal" font="default" size="100%">power</style></keyword><keyword><style  face="normal" font="default" size="100%">profile</style></keyword><keyword><style  face="normal" font="default" size="100%">profiles</style></keyword><keyword><style  face="normal" font="default" size="100%">pulse</style></keyword><keyword><style  face="normal" font="default" size="100%">radiation</style></keyword><keyword><style  face="normal" font="default" size="100%">sample</style></keyword><keyword><style  face="normal" font="default" size="100%">samples</style></keyword><keyword><style  face="normal" font="default" size="100%">solid materials</style></keyword><keyword><style  face="normal" font="default" size="100%">surface</style></keyword><keyword><style  face="normal" font="default" size="100%">thermal</style></keyword><keyword><style  face="normal" font="default" size="100%">thermal evaporation</style></keyword><keyword><style  face="normal" font="default" size="100%">time</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1997</style></year></dates><volume><style face="normal" font="default" size="100%">64</style></volume><pages><style face="normal" font="default" size="100%">1-6</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Mass ablation rate increases with laser power density following a power law dependence and a significant change occurs at 0.3 GW/cm(2). A reflected laser temporal profile was measured from a brass sample. When the power density is greater than 0.3 GW/cm(2)+, the temporal profile changes. The transmitted laser-pulse temporal profile through a glass sample also was measured. When the power density is greater than 0.3 GW/cm(2), the later part of laser pulse becomes truncated. The power density at which the laser temporal profile changes for each case is same as the power density that the mass ablation rate coefficient changes. The ablated mass can absorb incoming laser radiation through inverse Bremsstrahlung. The mass becomes thermally ionized and opaque to the incident radiation, preventing laser light from reaching the surface. A model based on thermal evaporation and inverse Bremsstrahlung absorption was developed. Calculations show that plasma shielding occurs at approximately 0.3 GW/cm(2). The experiments and model suggest that the significant change observed in mass ablation rate coefficient is caused by plasma shielding</style></abstract><accession-num><style face="normal" font="default" size="100%">82</style></accession-num><notes><style face="normal" font="default" size="100%">NOT IN FILE</style></notes><auth-address><style face="normal" font="default" size="100%">LAWRENCE BERKELEY LAB,BERKELEY,CA 94720</style></auth-address><label><style face="normal" font="default" size="100%">Laser</style></label></record></records></xml>