Über kooperatives Verhalten äußerer Nukleonen im Oszillator-Modell mit Quadrupolwechselwirkung

The question is discussed whether the ELLIOTT model nucleus can be interpreted as a rotating one. The classical interpretation of the quadrupole interaction explains the prolate deformation of the nucleus and yields a pure rotation of the classical system of orbits. The quantum mechanical treatment shows that the states of the ELLIOTT model which are analogous to the rotating states of the rotational model are rotating states, too. This involves the existence of a (positive) intrinsic quadrupole moment.

THE GAMMA-NEUTRON CROSS SECTION FOR F19

The F19(γ,n)F18 reaction has been studied by irradiating teflon samples in the X-ray beam of a 25-Mev betatron and detecting the annihilation radiation emitted during the decay of the residual nuclei. The cross section shows maxima at 10.6 (very small), 12.4, 14.0, 16.1, 17.2, and 19.3 Mev. The peak at 12.4 Mev is possibly due to excitation of the last neutron in F19 with only a small disturbance of the core nucleons. The peaks at 14.0 and 19.1 Mev are interpreted as the components of a split giant resonance, indicating an intrinsic quadrupole moment, Q0, of approximately 0.30 × 10−21 cm2 for F19.

THE PHOTODISINTEGRATION OF MANGANESE AND RHODIUM

The cross section for the production of photoneutrons from Mn55 and Rh103 has been found by irradiating these elements in the X-ray beam of a 24-Mev betatron. For Mn55, the giant resonance shows two distinct peaks and the intrinsic quadrupole moment is estimated to be 0.73 ± 0.14 barn; for Rh103, two peaks cannot be resolved, but the shape of the giant resonance curve is consistent with an intrinsic quadrupole moment of approximately 2.1 barns.