Temperature dependence of the absorptivity of aluminum targets at the 10.6 μ wavelength

The temperature dependence of the absorptivity A(T) of aluminum targets was determined experimentally at the 10.6μ wavelength in the temperature range 20≤T≤780°C. An abrupt change in A(T) was observed on passing through the melting point. It is found that when the initial value of A(T) (at room temperature), which depended on the state of the surface, decreased, the slope dA/dT also decreased. The experimental data were compared with calculations of A(T) allowing for a slightly anomalous skin effect for aluminum under these conditions.