Time-resolved measurements of quartz erosion are carried out to determine the density of the energy flux incident onto the sample surface. These data are needed to create a reliable code describing the interaction of a thermonuclear plasma with a solid surface. Experiments were performed in the 2MK-200 facility under the program of modeling heat loads on divertor plates during disruptions in tokamaks. A 10-mm-thick plate of fused quartz was exposed to a high-temperature deuterium-plasma stream with the temperature T-i + T-e less than or equal to 1 keV, density (5-10) x 10(15) cm(-3), beta = 0.25, energy density up to 200 J/cm(2), and power density similar to 10 MW/cm(2). It is shown that the quartz erosion begins almost immediately after the stream reaches the surface. The eroded material shields the quartz surface from further destruction. Under the given experimental conditions, the integral shielding factor (the ratio of the stream energy to the energy reaching the surface) was rather high (about seventeen). As a result, at a stream energy density of similar to 150 J/cm(2), the total erosion depth was about 0.75 mum over 35 mus. Based on the measured time dependence of the erosion depth and the reference data on the thennal conductivity of the fused quartz, the power density incident onto the quartz sample was numerically calculated. (C) 2001 MAIK " Nauka/Interperiodica ".
