The Temperature Measurements of Polymethyl Methacrylate Under Shock Loading

The brightness temperature was measured in polymethyl methacrylate shocked to 35 GPa by means of the fast two wavelengths optical pyrometer. The calibration of the pyrometer was performed by using a standard tungsten ribbon incandescent lamp prior to each shot. The measured brightness temperature at the wavelength λ = 550 nm was Tb = (1540 ± 30) K and at the wavelength λ = 630 nm it was Tb = (1510 ± 110) K. The results were compared with the temperature calculations obtained from different polymethyl methacrylate equations of state. The absorption coefficient of the shocked polymethyl methacrylate (α = 2.5 mm–1) was determined by using the time dependences in the pyrometric signals

Evolution of the Surface Structure of CVD Tungsten During Annealing

This paper reports a study in which a rough tungsten surface was prepared by chemical vapor deposition of tungsten on a tungsten ribbon. The samples were then heated to study the smoothing behavior of the rough surface. The results show that at 1600°C the surface becomes smooth after approximately five to ten hours. At 2400°C the surface becomes smooth within 15 minutes.