A comparison of enclosed confinement and outdoor nursery and growing-finishing systems of swine production

Digitized 2007 AES MoU.Includes bibliographical references (page 9)

Lifetime Measurement of the 8s Level in Francium

We measure the lifetime of the 8s level on a magneto-optically trapped sample of ^{210}Fr atoms with time-correlated single-photon counting. The 7P_{1/2} state serves as the resonant intermediate level for two-photon excitation of the 8s level completed with a 1300 nm laser. Analysis of the fluorescence decay through the the 7P_{3/2} level gives 53.30 +- 0.44 ns for the 8s level lifetime.Comment: 4 pages, 4 figure

The split-loop resonator as a superconducting heavy ion accelerating element

Ion acceleration tests utilizing a superconducting split-loop resonator at accelerating potentials above 2.7 MV/m have been made on ions up to mass 29 and charge state 12. The velocity acceptance and transit time effects were measured and found to be in good agreement with theoretical estimates. Because of the very low energy content of this resonator, the rf power dissipation at low β is less than 10% of an equivalent reentrant cavity design thus relaxing requirements on the superconducting surface resistance and on the phase stabilizing system

Lifetime Measurement of the 6s Level of Rubidium

We present a lifetime measurements of the 6s level of rubidium. We use a time-correlated single-photon counting technique on two different samples of rubidium atoms. A vapor cell with variable rubidium density and a sample of atoms confined and cooled in a magneto-optical trap. The 5P_{1/2} level serves as the resonant intermediate step for the two step excitation to the 6s level. We detect the decay of the 6s level through the cascade fluorescence of the 5P_{3/2} level at 780 nm. The two samples have different systematic effects, but we obtain consistent results that averaged give a lifetime of 45.57 +- 0.17 ns.Comment: 10 pages, 9 figure

Status of the Stony Brook Superconducting Heavy-Ion Linac

The present status of the Stony Brook Superconducting Heavy-Ion Linear Accelerator is described, with emphasis on recent operational results with a prototype unit of the accelerator. The basic LINAC elements are independently-phased lead-plated copper split-loop resonators operating at 151.7 MHz and optimized for velocities of either ß=v/c= 0.055 or ß=0.10. Resonators are grouped in units of either 4 low-ß or 3 high-ß resonators in compact cryostat modules separated by room-temperature quadrupole-doublet lenses. The LINAC consisting of 4 low-ß and 7 high-ß modules injected with heavy ions of mass A≃16-100 from the Stony Brook EN tandem will produce an additional energy gain of ~18 MeV per unit charge with a total heat dissipation at 4.5K of <300 Watts. In recent tests with low-ß prototype units, individual resonators were operated continuously at accelerating gradients in excess of 3.5 MV/m, and were phase and amplitude stabilized at 3.0 MV/ m using 175 Watts of RF power. Helium-temperature dissipation at 3.0 MV/m is ~8 Watts after helium-gas conditioning. The prototype low-ß module was used to accelerate a 30 Mev ^(16)O^(5+) beam to ~35 MeV

Status of the Stony Brook Superconducting Heavy-Ion Linac

We describe the present status of the State University of New York at Stony Brook Superconducting Heavy-Ion LINAC (SUNYLAC). The LINAC will extend at very modest cost the capabilities of the existing FN tandem Van de Graaff into the energy range 5-10 MeV/A for light heavy-ions from oxygen to bromine. The active elements are 43 lead-plated copper superconducting resonators of the split-loop type optimized for either velocity ß=v/c=0.055 or ß=0.10. Phase and amplitude of each resonator is independently set through RF-feedback controllers interfaced to an overall computer control system. Full scale construction work began in July, 1979 following the in-beam demonstration of a prototype LINAC module containing 4 low-ß resonators, and the majority of the installation work on the beam transport and refrigeration systems was completed in the summer of 1980. The project is now well into its final assembly and testing phase, with the completion of assembly scheduled in early 1982. We describe details of the design of key elements of the LINAC and the initial operating experience with the injection beam path, helium refrigerator and first production accelerator module. The progress of a continuing program aimed at optimizing crucial aspects of the LINAC is also reviewed

Polarization and relaxation of radon

Investigations of the polarization and relaxation of $^{209}$Rn by spin exchange with laser optically pumped rubidium are reported. On the order of one million atoms per shot were collected in coated and uncoated glass cells. Gamma-ray anisotropies were measured as a signal of the alignment (second order moment of the polarization) resulting from the combination of polarization and quadrupole relaxation at the cell walls. The temperature dependence over the range 130$^\circ$C to 220$^\circ$C shows the anisotropies increasing with increasing temperature as the ratio of the spin exchange polarization rate to the wall relaxation rate increases faster than the rubidium polarization decreases. Polarization relaxation rates for coated and uncoated cells are presented. In addition, improved limits on the multipole mixing ratios of some of the main gamma-ray transitions have been extracted. These results are promising for electric dipole moment measurements of octupole-deformed $^{223}$Rn and other isotopes, provided sufficient quantities of the rare isotopes can be produced.Comment: 4 pages, 4 figure