Fine Structure of the Scattered Radiation from Graphite

This analysis of the "undisplaced" scattered radiation was made with double x-ray spectrometer previously described. (Davis and Purks, Proc. Nat. Acad. Vol. 13, No. 6, June 1927, Vol. 14, No. 2, Feb. 1928. ) A special double target (Mo) x-ray tube was used with a block of graphite between the targets as the scattering element. The crystals were placed for reflection at first order. Four lines were observed: (a) an undisplaced line at position of Mo K₁; (b) a line displaced 80'' (0. 0012A) from K₁ position; (c) a line displaced 140'' (0. 002A) from K₁; (d) a line displaced 780'' (0. 0113A) from K₁. These are all on the long wave-length side of Mo K₁. The undisplaced line (a) is scattered from whole atom. The line displaced (0. 0113A) closely agrees with h^'=h-Ve, where Ve is the energy level (287 volts) of the carbon atom. The line (b) is displaced (0. 0012A). This is equivalent to 29 volts which does not agree with the L₁₁₁ level of carbon (11. 2 volts). The line (c) is displaced (0. 002A). This is equivalent to 50 volts, and does not agree with the L₁ level of carbon which is 34 volts. In the case of these two lines the relation h^'=h-Ve does not hold. A search was made for scattered radiation on the short wave-length side of the Mo K₁ position, corresponding to the relation h^'=h+Ve. No positive results were obtained.