Cadmium Target Research Articles

Complete Fusion induced by Krypton Ions: Indications for Synthesis of Superheavy Nuclei

COMPLETE nuclear fusion has been produced by bombarding targets of germanium, cadmium and thorium with 450 MeV Kr23+ and 500 MeV Kr24+ obtained from the Orsay accelerator ALICE1. Recoiling synthesized nuclei were slowed down in helium gas, transferred through a capillary tube and deposited on a steel rod in an evacuated enclosure2. An annular silicon semiconductor counter around the capillary tube detected the alpha particles produced by the decaying nuclei. Typical bombardment times were of the order of 10 h with 108 Kr ions s−1, and the background was shown to be insignificant by bombarding for 24 h without a target in place. Further tests also showed that secondary neutrons and gamma rays did not induce nuclear reactions in the detector.

Untersuchungen an Kratern von Mikroprojektilen im Geschwindigkeitsbereich von 0,5 bis 10 km/sec

Abstract Iron spheres of μ-size were accelerated by a modified 2 MV Van de Graaff accelerator to velocities from 0.5 to 10 km/sec. With these particles craters were produced in metal targets. The dimensions of the craters were measured by an electron microscope (Stereoscan). Systematical measurements were made for lead, cadmium, silver, copper and aluminum targets. The dependence of the crater diameter, depth and volume as function of the mass and the velocity of the projectile and of the target material is described.

The Production of High Specific Activities of Tin

Abstract The production of high specific activities of tin, 113Sn and 117mSn, with a cyclotron had been studied. Thick target yields for the reactions (A) 113In(d,2n)113Sn, (B) 115In(α,pn)-117mSn and (C) 110Cd(α,n)113Sn+111Cd(α,2n)-113Sn+ 114Cd(α,n)117mSn were determined for several incident particle energies. The reactions A and B are available for the production of the single tin activity. Reaction C is preferable to the others in the total yields of tin activities for the energy range studied, i. e., up to the energy of about 5 MeV. per nucleon of the incident particle. A thick target yield for reaction B has also been obtained from the excitation function up to the alpha particle energy of 40 MeV. The procedures for the carrier-free isolation of the tin activity from indium and cadmium targets by coprecipitation and ion exchange have also been described.

Coulomb Excitation Studies Using Inelastically Scattered Particles

Targets of samarium, terbium, and cadmium were bombarded with protons, and in one case with deuterons, of up to 7.0 Mev and the inelastically scattered particles were observed. In the rare earths, samarium and terbium, four previously known levels were studied: the 58- and 139-kev levels in Tb/sup 159/ the 80-kev level in Sm/sup 154/ and the 123-kev level in Sm/sup 152/. The excitation process was determined to be primarily Coulomb excitation up to 7.0 Mev, and the reduced transition probabilities were measured with a precision of approximately 10%. A test of the collective model was made by measurement of the ratios of the reduced transition probabilities to two excited states in the same nucleus, Tb/sup 159/. Eight levels were observed in cadmium. Two of them, at 585 and 641 kev, have not been previously reported. The absolute cross sections of the eight levels were determined with various angles of observation, incident energy, and type of bombarding particle. It was concluded that Coulomb excitation is a major contributor to the cross section at 6.0 Mev, and reduced transition probabiiities were measured at this energy. (auth)