Nuclear alignment of ytterbium 175

Abstract

Nuclear alignment of ¹⁷⁵Yb has been obtained by cooling a single crystal of ytterbium ethyl sulphate to about 0.014°K, and was detected by observing the anisotropic angular distributions of the two most energetic γ-rays. A relationship between the mixing ratios δdL(M2/E1) for these γ-rays is obtained. γ-γ angular correlation measurements for the 282 and the 114 kev γ-raye show sensibly the same value for the correlation coefficient A ₂ of +0.205±0.015 for solid and liquid sources containing ¹⁷⁵Yb. Using |δ|=0.17±0.03 for the 282 kev γ-ray determined from the angular correlation measurements the mixing ratio for the 396 kev γ-ray is found to be +0.10±0.03. The nuclear moment of ¹⁷⁶Yb is 0.15±0.04.