Direct observation of the double Auger decay of a K hole

The double Auger (DA) decay of a K hole has been observed directly by detecting the two emitted electrons in coincidence. The hole was created in 37Cl following the electron-capture decay of 37Ar. The probability of DA decay, per Auger decay, with the two electrons both having an energy greater than 250 eV was found to be 3.7±0.2%. The DA probability was found to decrease exponentially as the energy partitioning between the two electrons changed from the asymmetric case (E1>E2) to the symmetric case (E1≅E2). The DA probability accounts for the bulk of the intensity of high charge states previously measured in 37Cl. copyright 1996 The American Physical Society