A newly-available radioisotopic system, /sup 172/Hf-/sup 172/Lu, has excellent potential for tracer applications in which nuclear data acquisition must be accomplished in real time. The 6.7-day half-life of /sup 172/Lu is sufficient for a large fraction of tracer experiments, and should allow the direct incorporation of /sup 172/Lu into tests that have traditionally utilized much longer-lived radionuclides. Since /sup 172/Lu is the daughter component of a radioisotope generator, however, its effective shelf-life is determined by the half-life of its 1.9-year /sup 172/Hf parent. Consequently, the frequency of isotope procurement need not be any more extensive than investigators would normally be accustomed to. Discussion relevant to isotope production, generator operation, and nuclide acquisition is presented in this paper.

The Mirror Fusion Test Facility (MFTF-B) is a large tandem mirror device currently under construction at Lawrence Livermore National Laboratory. The completed facility will consist of a large variety of components. Specifically, the vacuum vessel that houses the magnetic coils is basically a cylindrical vessel 60 m long and 11 m in diameter. The magnetics system consists of some 28 superconducting coils, each of which is located within the main vacuum vessel. Twenty of these coils are relatively simple solenoidal coils, but the remaining eight are of a more complicated design to provide an octupole component to certain regions of the magnetic field. The vacuum system is composed of a rough vacuum chain, used to evacuate the vessel from atmospheric pressure, and a high vacuum system, used to maintain good vacuum conditions during a plasma shot. High vacuum pumping is accomplished primarily by cryogenic panels cooled to 4.5/sup 0/K. The MFTF-B coil set is shown together with typical axial profiles of magnetic field (a), electrostatic potential (b), and plasma density (c). The plasma is divided into nine regions axially, as labelled on the coil set in Figure 1. The central cell, which is completely azimuthally symmetric, contains a large volume …

Recent advances in the use of positron annihilation to study defect ensembles in and on the surfaces of metals, are pointing the way towards studies where particular positron-electron annihilation modes may be identified and studied in the presence of one another. Although a great deal is understood about the annihilation of positrons in ostensibly defect-free metals, much less is understood when the positron annihilates in complex defect systems such as liquid metals, amorphous solids, or at or near the vacuum-solid interface. In this paper the results of three experiments, all of which demonstrate means by which we can resolve various poistron annihilation channels from one another, are discussed.

The contract work was initiated by J. Epstein. The emphasis of the proposal was on (a) the continuation of DWIA calculations of the (..gamma..,..pi../sup + -/) reaction in the ..delta..(1232) region with the extension to the (..gamma..,..pi../sup 0/) reaction and (b) the application of the DWIA approach to the (..gamma..,K) reaction. The (..gamma..,..pi../sup 0/) work was intended to be in close collaboration with the experimental studies underway at Bates Linear Accelerator and the (..gamma..,K/sup + -/) calculations are relevant to proposed high duty factor electron accelerators in the 1 to 4 GeV region. DWIA calculations were carried out for coherent (..gamma..,..pi../sup 0/) reactions in /sup 12/C. Although the DWIA approach seems less fundamental than the current ..delta..-hole model calculations, we had hopes that it could be more readily applicable to incoherent reactions leaving the target nucleus in the excited state. Epstein hoped to improve the reliability of the DWIA calculations for coherent (..gamma..,..pi../sup 0/) production by better treatment of the ..delta.. propagating in the nuclear medium. In parallel with the (..gamma..,..pi../sup 0/) work, Epstein carried on an active collaboration with William Donnelly on the (..gamma..,K/sup + -/) problem. They had succeeded in a relatively complete description of the reaction for …

Thin targets of radioactive /sup 148/Gd were used to determine a precise value for the mass of /sup 147/Gd. The (p,d), (d,t), and /sup 3/He,..cap alpha..) reactions were used with high-resolution charged-particle spectrometry to determine Q-values for the /sup 148/Gd target relative to several calibration targets having known Q-values. By combining the measured Q-value with the /sup 148/Gd mass, the mass defect, ..delta..M(/sup 147/Gd) = 75356 +- 6 keV, 149 keV less than the value in the 1977 mass tabulation was obtained. 7 refs., 1 fig., 1 tab.

Abstracts of papers presented at the meeting are included. Topics discussed include: reactor engineering; space nuclear power systems; health physics and dosimetry; fusion engineering and physics; and reactor physics and theory.

Based on discussions at the Ann Arbor workshop and early work on the Reference Designs Study, we present typical parameters for a pp SSC and compare them with anti p anti p parameters similar to those presented at this workshop by T.L. collins. This comparison is summarized in the table.