Absorption in the Region of Soft X-Rays

Energy of soft x-rays from a tungsten-coated nickel target as a function of potential from 40 to 610 v—Soft x-rays from the target were allowed to fall on a solid solution consisting of CaS${\mathrm{O}}_4$+2 percent MnS${\mathrm{O}}_4$. The square of the time of duration of the thermoluminescence produced was assumed to be proportional to the total energy of the x-rays. The results indicate that in the range 40-610 v., the total energy varies approximately as the square of the potential applied to the tube.