A Study of the Elastic Scattering of 2 to 3 MeV Neutrons by 40Ca and 32S Using an Associated Particle Time of Flight Spectrometer
An associated particle time of flight spectrometer based on the D(d,n)3He reaction has been developed using thin deuterated polythene targets. The competing D(d,p)3T was used to monitor the neutron output. The spectrometer has been used to study the elastic scattering of a 2 - 3 MeV neutrons in 40Ca and 32S; in each case the differential elastic scattering cross sections have been measured. In the angular range 20° - 100° in the laboratory frame of reference the results have been compared with an optical model analysis. Values of ¿2 per point of 3.46 and 2.84 for 40C and 32S respectively were obtained.
Nuclear Data Sheets for A=40 ☆
Abstract The experimental nuclear structure data and decay data are evaluated for the known nuclides of mass 40 (Mg, Al, Si, P, S, Cl, Ar, K, Ca, Sc, Ti). Detailed evaluated nuclear structure information is presented with the best values recommended for level energies, half-lives, γ -ray energies and intensities, decay properties (energies, intensities and placement of radiations), and other spectroscopic data. The 40 Ca and 40 K nuclides remain as the most extensively studied from many different reactions and decays; no excited states are known in 40 Mg, 40 Al, 40 P and 40 Ti. This work supersedes the earlier full evaluation of A=40 by J. Cameron and B. Singh (2004Ca38).
Intensification of Bubble Disintegration and Dispersion by Mechanical Stirring in Gas Injection Refining
Water model experiments were performed for establishing highly efficient gas injection refining processes. Mechanical stirring was applied to disintegrate the injected bubbles and to disperse them widely in the bath. The bubble disintegration and dispersion were investigated by changing rotation mode (direction of rotation), rotation speed, blade size of the impeller and gas flow rate. Forward rotation of the impeller induced a stable tangential flow and could not disperse bubbles in the bath due to formation of a vortex around the impeller shaft. The tangential flow could be suppressed by forward–interrupt rotation, which could reduce the vortex formation to some degree. However, forward–interrupt rotation could not disperse the bubbles widely in the bath. Forward–reverse rotation could prevent the vortex formation completely and create a strong shear stress field, which intensified the bubble disintegration and dispersion in the bath. Higher impeller rotation speed and larger blade length in forward–reverse rotation could enhance the bubble disintegration and make the dispersed bubbles smaller. The bubble dispersion zone became wider with larger blade length. The bubble size tended to be larger at higher gas flow rates. However, its dependence on the gas flow rate became smaller at higher impeller rotation speed.