R.A. Warner

High-spin level systematics in 177–182W: Yrast band anomaly in 180W☆

Abstract High-spin levels in 177–182W have been populated in (α,χnγ) reactions. Backbending-type behavior appears most prominently in 180W. The role of i 13 2 neutrons and h 9 2 protons in the 180W yrast behavior is examined. A strongly-coupled Kπ = 10+ band structure is identified in 182W, the first seniority-two i 13 2 configuration to be characterized in a deformed nucleus.

Ultra-fast chemical separations (“plasma chemistry”) with a helium-jet recoil-transport system

Abstract The transport efficiency through a long-capillary He-jet recoil-transport system can be changed for different elements by altering the nature and/or the concentration of the impurities in the He. Thus, it appears that a form of “plasma chemistry” is taking place in the formation of the “macromolecules” that transport the radioactive recoils through the system and the attachment of the recoils to chemically specific sites on these macromolecules. We describe some experimental results and point out the advantages of such a system; also, we note that it is possible to obtain information about the Z of a nuclide from these experiments.

Spurious peaks produced by compton scattering in Ge(Li)-Ge(Li) coincidence gamma-ray spectrometer systems

We present results from our investigations of Compton scattering between Ge(Li) γ-ray detectors in coincidence experiments. Such scattering can generate false peaks that can be mistaken for photopeaks. The effects of varying gate position, gate width, background subtraction, and angle between detectors are discussed, and suggestions an: made for recognizing and minimizing spurious effects.

A He-jet chopper for measuring half-lives of short-lived nuclei☆

Abstract A He-jet chopper has been built to enable one to measure the half-lives of nuclear species from several seconds to as short as several tens of milliseconds. The chopper has been used to measure some of the mirror beta decays in the f 7 2 shell.