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Effects of electron irradiation on p-type germanium at liquid helium temperatures using ac hopping conductivity (open access)

Effects of electron irradiation on p-type germanium at liquid helium temperatures using ac hopping conductivity

P-type germanium single crystals (8 x 10/sup 14/Ga/cm/sup 3/ and 6 x l0/ sup 1 Ga/cm/sup 3) were irradiated with 1.1-Mev electrons at pumped liquid helium temperatures and defect production and annealing studied using ac hopping conductivity. Production rates obtained from measurements at 1.5 deg K and 10/ sup 4/ Hz were 0.6 cm/sup -10/ for samples doped 6 x 10/sup 15/ Ga/cm/sup 3/ and 0.11 cm/sup -10/ for samples doped 8 x 10/ sup 14/ Ga/cm/sup 3/. Above 10/sup 14/ e,/cm/sup 2/ fluence the production rates for the higher doped samples decreased to approximately 0.06 cm/sup -1/ at 10/sup 15/ e/cm/sup 2/ fluence except for one sample which was anomalous. No such long irradiation of the low doped samples was made. The apparent inconsistency between these results and production rates of less than 3 x 10/sup -4/ cm/sup -1/ observed by previous workers was resolved by introducing a donor level for the defect produced by irradiation near the chemical acceptor level, so that the defect would be neutral at temperatures near 30 deg K and charged + 1 at l.5 deg K. Surface effects were observed which did not affect production rate measurements at 1.5 deg K more than …
Date: October 1, 1973
Creator: Roop, Raymond Marvin
System: The UNT Digital Library
Two-nucleon transfer reactions induced by polarized protons (open access)

Two-nucleon transfer reactions induced by polarized protons

None
Date: October 1, 1973
Creator: Macdonald, J.A.
System: The UNT Digital Library
Translocation Dynamics of 239-Plutonium (open access)

Translocation Dynamics of 239-Plutonium

>Thesis. The translocation dynamics of /sup 239/Pu(NO/sub 3/)/sub 4/ and /sup 239/PuO/sub 2/ from ulated puncture wounds in the paws of beagle dogs were studied. The difference between the more soluble Pu(NO/sub 3/)/sub 4/ form the insoluble high fired PuO/sub 2 particles was assumed to bring about highly differing translocation dynamics from the wound site, through lymphatic channels into the system's circulation and to organs of deposition and of excretion. There was rapid movement of Pu from the paw to the first major lymph node with a resulting buildup and regression pattern for activity within the node. Differential translocation, concentration, retention, and excretion of Pu and Am were demonstrated with both chemical forms. The effectiveness of DTPA administration for Pu removal from the body was dependent on the chemical form of the Pu contaminant. ( CH)
Date: October 1, 1973
Creator: Bistline, R.W.
System: The UNT Digital Library
K-matrix fits to $pi$N $Yields$ N$pi$ and N$pi$$pi$ in the resonance region $Root$s = 1.3 to 2.0 GeV (open access)

K-matrix fits to $pi$N $Yields$ N$pi$ and N$pi$$pi$ in the resonance region $Root$s = 1.3 to 2.0 GeV

Thesis. Starting with partial wave amplitudes for pi N yields N pi and pi N yields several isobar model states of N pi pi , one can apply the constraint of unitarity (using the K-matrix). This permits the removal of the overall phase ambiguity of the isobar amplitudes at each energy. The K-matrix fits generated a smooth prescription for the T-matrix amplitudes, enabling one to search the complex energy plane for poles. The uniqueness of these poles was demonstrated by doing Breit-Wigner refits to the fitted T-matrix amplitudes. The success of the results and the obvious interpretation justified a simple determination of coupling signs for which there can be checks with theory. This thesis corresponds closely to a forthcoming paper submitted to Physical Review except that here the K-matrix is based on a 1972 solution A'' isobar-model fits to N pi pi data, and in the final paper solution B'' is used. (auth)
Date: October 1, 1973
Creator: Longacre, R. S.
System: The UNT Digital Library
Stimulated Brillouin and backward Raman light scattering (open access)

Stimulated Brillouin and backward Raman light scattering

Thesis. The definition, production, and properties of brillouin and Raman scattering using lasers are discussed. (JFP)
Date: October 1, 1973
Creator: Bonnett, D.
System: The UNT Digital Library