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In (particle, x n γ ) reactions the population of magnetic substates of a given level of spin J in the ground state quasirotational band resulting from the preceding neutrons and gammas from outside the band (i.e. side feeding) can be described by a mixture of Gaussians of various widths. The resulting angular distribution of the stretched E2 (denoted E2 ) gammas with respect to the direction of the particle beam is analysed here. It is not approximated that an E2 transition from a Gaussian distribution of substates of level J produces a Gaussian distribution for the final level J −2. The ( A 2 , A 4 ) results are discussed for a state populated by previous E2 transitions plus a single Gaussian side feeding. The results are extended to include side feeding producing substate populations of any mixture of Gaussians. A method of exact solution is given for cases where the experimental data are sufficiently accurate. The region of the ( A 2 , A 4 ) space which can result from any mixture of Gaussian side feedings is derived. The results of various assumed substate populations of side feeding are compared to experiments by Newton et al. on 182 W(α, 2n) 184 Os, 165 Ho( 11 B, 4n) 172 Hf and 159 Tb( 14 N, 5n) 168 Hf. The comparison is quite satisfactory for single Gaussian side feeding of width σ = 2.8 for each level of spin J . The qualitative differences in the angular distributions for these experimental cases are caused by different experimental intensities of side feeding. For 74 Ge(α, 2n) 76 Se a width σ = 1.6+0.1 J gives good agreement with our experimental angular distributions of the transitions 10 → 8, 8 → 6, 6 → 4, 4 → 2 and 2 → 0. The angular distribution is also derived for a case where the population of substates increases with M .

The even selenium isotopes $^{72}\mathrm{Se}$, $^{74}\mathrm{Se}$, $^{76}\mathrm{Se}$, and $^{78}\mathrm{Se}$ have been investigated by means of the $\mathrm{Ge}(\ensuremath{\alpha},2n\ensuremath{\gamma})\mathrm{Se}$ and $\mathrm{Ge}(\ensuremath{\alpha},4n\ensuremath{\gamma})\mathrm{Se}$ reactions. The $\ensuremath{\gamma}$ radiation from these nuclei was studied during the irradiation using techniques of in-beam spectroscopy. The energies of the $\ensuremath{\gamma}$ rays, their relative intensities, their angular distributions, and their time distributions relative to the 2-nsec beam bunch have been measured. Quasirotational ground-state bands were observed up to 10+ for $^{76}\mathrm{Se}$, up to 8+ for $^{74}\mathrm{Se}$ and $^{78}\mathrm{Se}$, and up to 6+ for $^{72}\mathrm{Se}$. The level energies are compared to a semiempirical formula.

The electrical potential difference between the cytoplasm and the outer medium E co and Cl − efflux have been measured simultaneously in individual cells of Acetabularia mediterranea under a light-dark regime. 1. 1. Light-dark changes of E co coincide with large, rather proportional changes of the Cl − efflux, if no action potential is triggered. 2. 2. During an action potential occurring under certain conditions after cessation of illumination, the initial small decrease of the Cl − efflux reverses after about 20 s, when the depolarisation of E co becomes steeper, into a short increase, exceeding the steady state efflux at least 3-fold. 3. 3. The measured peak efflux of about 1.7 nmoles Cl − ·cm −2 ·s −1 compares well with an inward electric current of 90 μA/cm 2 during excitation recorded under voltage clamp (Gradmann, D., (1970) Planta 93, 323–353). 4. 4. We conclude that the depolarizing inward current during the action potential of Acetabularia is carried by a Cl − efflux.