Improvements in determinations using the Cu-64 annihilation gamma rays

The method of γγ coincidence counting has been applied to the determination of Cu via the 64Cu annihilation gamma rays. Preliminary experiments show that at least an order of magnitude reduction in 24Na interference may be obtained by employing the 511–511 keV coincidence peak rather than the singles 511-keV peak. The effect of the sample matrix on the yield of 24Na pair-production events was investigated by a combination of experimental measurements and Monte Carlo calculations.