Directional Correlation of the Gamma Rays ofLa140andCe140

Abstract

The directional correlation of coincident gamma rays in ${\mathrm{La}}^{140}$ and ${\mathrm{Ce}}^{140}$ has been reinvestigated. Using a coincidence circuit having a resolving time of $\tau =10\mathrm{}$ nsec, the gamma rays in coincidence with a given gamma ray, as seen by a single counter, were displayed on a multichannel analyzer. Analysis of the intensity of the lines in the coincidence spectrum was made with the help of many calibration lines and a least-squares reduction technique using an electronic computer. In ${\mathrm{Ce}}^{140}$ the following coincidences have been investigated: 923-1597, 815-1597, 487-1597, 329-1597, and 329-487 keV. In ${\mathrm{La}}^{140}$ the coincidence 162-304 keV was investigated. A discussion of the data in light of the disintegration schemes is given.