The Absorption ofNa24Gamma-Radiation in Lead, Copper, and Aluminum

Abstract

The absorption of sodium (24) gamma-radiation has been measured with a Geiger-Müller counter out to 16 cm of lead, 22 cm of copper, and 61.5 cm of aluminum. Each of the curves obtained can be analyzed into two components. These give absorption coefficients 0.454±0.004 ${\mathrm{cm}}^{-1\mathrm{}}$ and 0.62±0.01 ${\mathrm{cm}}^{-1\mathrm{}}$ for lead, 0.311±0.005 ${\mathrm{cm}}^{-1\mathrm{}}$ and 0.46±0.01 ${\mathrm{cm}}^{-1\mathrm{}}$ for copper, and 0.088±0.001 ${\mathrm{cm}}^{-1\mathrm{}}$ and 0.144±0.005 ${\mathrm{cm}}^{-1\mathrm{}}$ for aluminum. All of these are in agreement with theoretical values as obtained from Heitler's curves for the sodium gamma-rays of energies 2.76 Mev and 1.38 Mev, respectively.