The Measurement of X-Ray Absorption Coefficients by the Use of the FP-54 Pliotron

The FP-54 pliotron has been used to measure the ionization currents produced in the determination of x-ray absorption coefficients. When careful shielding was made and proper insulation provided it was found to be extremely stable in the measurement of currents of the order of magnitude 3×${10}^{-15\mathrm{}}$ amperes. The x-ray absorption coefficients of copper and aluminum were determined over a range from 0.25A to 0.6A. They were found to agree quite well with those obtained by other observers and led to a value of 2.7, in the wave-length range 0.25A to 0.6A, for the constant $n$ in the absorption equation, $\frac{\mu }{\rho }=C{N}^4{\lambda }^n+\frac{\sigma }{\rho }$.