The magnetic moments of the ${\frac{7}{2}}^{\ensuremath{-}}$ states at 1.610 MeV in $^{37}\mathrm{Ar}$ and 1.380 MeV in $^{37}\mathrm{K}$ were measured by differential spin-precession methods. The moments, together with the remeasured halflives, are $\ensuremath{\mu}=\ensuremath{-}1.33(5){\ensuremath{\mu}}_{N}$ and ${T}_{\frac{1}{2}}=4.6(2)$ nsec for $^{37}\mathrm{Ar}$, and $\ensuremath{\mu}=+5.2(3){\ensuremath{\mu}}_{N}$ and ${T}_{\frac{1}{2}}=10.5(5)$ nsec for the $^{37}\mathrm{K}$ state. The prediction of the Sachs mirror theorem is shown to hold, and systematic trends in ${\frac{7}{2}}^{\ensuremath{-}}$-state moments of $1{f}_{\frac{7}{2}}$-shell nuclei are examined.

Within a gaseous target of a mixture of SF6 and CH4 at a total pressure of 1 atm the orientation of excited19F nuclei following the reaction19F(α, α′) is studied in terms of the anisotropy of the delayed 197 keV-γ-radiation. By observing the nuclear Larmor precession differentially in time, this anisotropy is found (i) to be constant in time from 50 to 500 nsec after excitation, and (ii) to increase from zero to 60% of the anisotropy observed in a solid CaF2 target, if the relative CH4 concentration in the target gas of constant total pressure is varied from 0 to 90%. The attenuation of the anisotropy as compared to the value in CaF2 is explained by a strong perturbation of the nuclear alignment by statistical changes of the atomic fields at the end of the recoil stopping process. The observed partial conservation is interpreted as the contribution of those recoils which have become part of the stable diamagnetic HF molecules before being desoriented. A qualitative discussion shows that the nuclear alignment survives the recoil stopping process down to residual energies of less than a few eV.

An apparatus is described which measures differentially in time the Larmor frequencies of both protons and excited nuclei in the same magnetic field with the same time to pulse height converter by transforming oscillations of the proton precession into a periodic variation of a pulse counting rate. Applied to the 198 keV 5/2+ state of 19F this method gave an accuracy of 0.2% for the ratio of the Larmor frequencies. The value for the 19F∗g-factor is g = 1.442 ±0.003.

The first two excited states of 19Ne have been populated by the reaction 19F(p, n), and the de-excitation γ-rays have been detected. The half-lives T12 have been remeasured. The gamma yield has been observed in a proton energy range from 4.4 MeV to 6.1 MeV. The g-factor of the 52+ level has been determined by the pulsed-beam DDCA method. The results are T12 = 17.7±0.7 ns, g = −0.296±0.003 for the52+ 238 keV state and T12 < 0.3 ns for the12− 275 keV state. The g-factor is compared with values predicted by various models. The mirror theorem of Sachs is applied.

The g-factor of the 7−2 state in 41K at 1.29 MeV has been measured with the spin procession method. The value found for the magnetic moment is μ = +4.41 ± 0.05 n.m.. The measured half-life is T12 = 7.3 ± 0.2 ns.

79Kr∗ nuclei (Ex = 148 keV) were produced and aligned with the reaction 79Br(p, n)79Kr. From the decay and the Larmor precession in an external field τ12 = 77.7 ± 1.5 ns and g = + 0.449 ± 0.004 were deduced. The results are discussed in order to get spin and parity for the new level.

The mirror theorem of Sachs1 ) states that most of the corrections to the single particle operator μ_ = g1 1_ + gs s_ cancel out in the mean value g¯=½ (gn+gp) of mirror states with T3= ± T. Thus the experimental values for g¯ should fit well to the respective single particle values. This simple relationship is remarkably well satisfied by the hitherto known pairs of magnetic moments2,3). Recent measurements were performed on the first excited pair of states3 ). The 7/2− states in 37Ar and 37K can possibly provide for the first time a check of the abovementioned theorem for an excited pair of f7/2 states.