Iron-free, dipole magnets are used extensively as steering magnets to correct for the bending, induced by extraneous magnetic fields, of particle beams that are being transported in vacuum. Generally, the dipoles are long enough that the space occupied by the end conductors is small compared to the overall magnet length. In a recent application, however, this criteria did not apply. This has motivated a reanalysis of the characteristics of a system of small aspect ratio (length/diameter) dipoles that are spaced at relatively large axial distances.

This paper describes the current design status of the plasma diagnostic system for MFTF-B. In this paper we describe the system requirement changes which have occurred as a result of the funded rescoping of the original MFTF facility into MFTF-B. We outline the diagnostic instruments which are currently planned, and present an overview of the diagnostic system.

The change of scope for MFTF from a simple mirror to a tandem mirror configuration utilizing thermal barriers has expanded the range of plasma parameters and increased the requirements of the plasma diagnostics system. The instrument set that is needed for start-up operation has been identified and conceptual design work is proceeding. This paper describes the diagnostic instrumentation as presently envisioned for start-up operation, with a summary of the detectors and data channels. Also presented is an overview of the current conceptual design for the Local Control and Data Acquisition System and the Data Processing and Display system. As more detailed design is done, the exact number and nature of instruments may change, but overall, the system described here is one expected to satisfy the requirements for start-up and be expandable to the basic set of diagnostics.

As a contribution to the required quinquennial review of American National Standard for Nuclear Criticality Safety in Operations with Fissionable Materials Outside Reactors (ANSI N16.1-1975/ANS-8.1), limits for homogeneous 233U systems have been recalculated to confirm their sub-criticality or, where there were doubts, to propose more restrictive values. In addition, other limits were calculated to be proposed for inclusion, namely, limits for aqueous solutions of UO2(NO3)2 and limits for uranium oxides. The same three methods of calculation were used as in similar work done recently for plutonium and 235U systems. The validity of each was established by correlation with the results of pertinent critical experiments. This report discusses this study.

The present aim of this program is photochemical removal of the 7 ppM concentration of DTO in D/sub 2/O that is presently found in active heavy water fission reactors (e.g., Savannah River). Though only T/D recovery is under present scrutiny at LLNL, T/H separation can also be performed using infrared laser multiple-photon dissociation (MPD). Laser-based tritium recovery from both light and heavy water may prove to be of great importance in fusion reactors. The overall cycle of the process under investigation entails initial tritiation of a fully deuterated working molecule by catalyzed chemical exchange with the contaminated heavy water, followed by isotopically-selective, room temperature, gas phase, pulsed infrared laser MPD of only the monotritiated molecules, among the transparent, majority fully deuterated specie. In the MPD interaction, the resonant molecule selectively absorbs 30 or more infrared quanta and then dissociates. The tritium-enriched photoproducts are easily removed from the reactant mainstream by physical separation means. Then the cycle continues with retritiation of the photochemically-detritiated working molecule.

The Spent Fuel Test-Climax is a test of retrievable storage in granite of spent nuclear reactor fuel. The rock has been instrumented to measure temperatures, stress changes, and displacements. Periodic tape extensometer readings provide test drift convergence data. Vertical and horizontal tape readings are made at five locations in each of two 3.4m x 3.4m (11 ft x 11 ft) drifts and six locations in a 4.6m x 6.2m (15 ft x 20.5 ft) drift. The sensitivity of the readings to temperature effects, errors in temperature corrections, change of steel tape, and change of operator has been examined. Calculated corrections for temperature-induced changes in distance range from 0.001 in. to 0.003 in.//sup 0/C. A tape changeout evidenced both a systematic error apparently due to slight changes in tape registration during punching and to nonidentical location of punched holes in the two tapes and a random error due to variability of reading and punching operations. These errors were corrected by making duplicate measurements for the tapes. Tape readings by the same operator have been repeatable within +-0.001 in. in the smaller drifts and +-0.002 in. in the larger. Different operators have been able to repeat readings to within +-0.004 in. (usually …

The results of recent numerical simulations of supernova explosions are presented and a variety of topics discussed. Particular emphasis is given to (i) the nucleosynthesis expected from intermediate mass (10sub solar less than or equal to M less than or equal to 100 Msub solar) Type II supernovae and detonating white dwarf models for Type I supernovae, (ii) a realistic estimate of the ..gamma..-line fluxes expected from this nucleosynthesis, (iii) the continued evolution, in one and two dimensions, of intermediate mass stars wherein iron core collapse does not lead to a strong, mass-ejecting shock wave, and (iv) the evolution and explosion of vary massive stars (M greater than or equal to 100 Msub solar of both Population I and III. In one dimension, nuclear burning following a failed core bounce does not appear likely to lead to a supernova explosion although, in two dimensions, a combination of rotation and nuclear burning may do so. Near solar proportions of elements from neon to calcium and very brilliant optical displays may be created by hypernovae, the explosions of stars in the mass range 100 M/sub solar/ to 300 M/sub solar/. Above approx. 300 M/sub solar/ a black hole is created by stellar …

The Spent Fuel Test in the Climax granitic stock at the DOE Nevada Test Site is a test of the feasibility of storage and retrieval of spent nuclear reactor fuel in a deep geologic environment. Eleven spent fuel elements, together with six thermally identical electrical resistance heaters and 20 peripheral guard heaters, are emplaced 420 m below surface in a three-drift test array. This array was designed to simulate the near-field effects of thousands of canisters of nuclear waste and to evaluate the effects of heat alone, and heat plus ionizing radiation on the rock. Thermal calculations and measurements are conducted to determine thermal transport from the spent fuel and electrical resistance heaters. Calculations associated with the as-built Spent Fuel Test geometry and thermal source histories are presented and compared with thermocouple measurements made throughout the test array. Comparisons in space begin at the spent fuel canister and include the first few metres outside the test array. Comparisons in time begin at emplacement and progress through the first year of thermal loading in this multi-year test.

Calculations of the high pressure equation of state of selected materials are reviewed, in order to illustrate general trends which occur in the evolution of electronic structure with compression, and the consequences of these trends for material properties.

With the use of a particle simulation code we have investigated the ballistic transport of heavy ion beams through a gas-filled reactor for inertial confinement fusion. The background gas pressure has been taken to be 10/sup -4/ torr - 10/sup -3/ torr of Lithium vapor as is appropriate to the HYLIFE reactor concept. During transport to the pellet, Coulomb collisions of beam particles with the background gas will convert a fraction of the beam to charges states higher than the initial value. Collisons will also produce an associated swarm of knock-on electrons. As the beam approaches the pellet, anharmonic components of the space charges forces will lead to a distortion of the phase space of the beam and a consequent degradation of the focal properties of the beam. This degradation can be described in terms of an increase in the rms emittance of the beam. The degree of emittance growth depends sensitivity upon the initial spatial distribution of particles in the beam. For this study we have modified a single-disk particle simulation code, DESTIN (2), to follow two species of particles, the number of which varies in a prescribed fashion dependent upon reactor temperature as the beam converges toward the …

The grain size and strain dependence of work hardening in Type 304L stainless steel were analyzed between 200 and 250 K where hydrogen damage is greatest. Tensile data were obtained for specimens of several grain sizes, both with and without prior exposure to hydrogen gas at 69 MPa pressure. The analysis suggests that hydrogen has little influence on lattice friction stress but has a large effect on dislocation interaction and the back stress of dislocation pileups. This report discusses this study.

Hydrogen solubility was directly measured in specimens of Types 304L, 21-6-9, and modified A-286 austenitic stainless steels saturated with hydrogen at 69 MPa pressure at 470 K. Nitrogen in Type 21-6-9 stainless steel and precipitate morphology in the modified Type A-286 stainless steel altered the hydrogen solubility. Cold work and surface treatment had only minor effects on hydrogen solubility in the three stainless steels. This reports discusses this study.