Recent US target-physics-related research in heavy-ion inertial fusion: simulations for tamped targets and for disk experiments in accelerator test facilities (open access)

Recent US target-physics-related research in heavy-ion inertial fusion: simulations for tamped targets and for disk experiments in accelerator test facilities

Within the last few years, there have also appeared in the Heavy-Ion Fusion literature several studies of targets which have outer tampers. One-dimensional simulations indicate higher target gains with a judicious amount of tamping. But for these targets, a full investigation has not been carried through in regards to conservative criteria for fluid instabilities as well as reasonable imperfections in target fabrication and illumination symmetry which all affect target ignition and burn. Comparisons of these results with the gain survey of Part I would have to be performed with care. These calculations suggest that experiments relating to high temperature disk heating, as well as beam deposition, focusing and transport can be performed within the context of current design proposals for accelerator test-facilities. Since the test-facilities have lower ion kinetic energy and beam pulse power as compared to reactor drivers, we achieve high-beam intensities at the focal spot by using short focal distance and properly designed beam optics.
Date: June 24, 1982
Creator: Mark, J.W.K.
Object Type: Article
System: The UNT Digital Library
Mathematical models and illustrative results for the RINGBEARER II monopole/dipole beam-propagation code (open access)

Mathematical models and illustrative results for the RINGBEARER II monopole/dipole beam-propagation code

RINGBEARER II is a linearized monopole/dipole particle simulation code for studying intense relativistic electron beam propagation in gas. In this report the mathematical models utilized for beam particle dynamics and pinch field computation are delineated. Difficulties encountered in code operations and some remedies are discussed. Sample output is presented detailing the diagnostics and the methods of display and analysis utilized.
Date: May 24, 1982
Creator: Chambers, F.W.; Masamitsu, J.A. & Lee, E.P.
Object Type: Report
System: The UNT Digital Library
Evaluation of soil damping techniques used in soil structure interaction analysis of a nuclear power plant (open access)

Evaluation of soil damping techniques used in soil structure interaction analysis of a nuclear power plant

A prediction of dynamic soil properties at the site of a nuclear power plant plays a very important role in the seismic analysis of the facility. Conventional modal analysis procedures can accommodate virtually any range of equivalent elastic soil stiffness which is used to characterize the site. However, high radiation damping associated with energy dissipation in the soil half-space is difficult to accommodate in an elastic modal solution to the dynamic problem. Several methods are available to combine the soil damping with the structural damping in a composite modal damping coefficient. However, even with this convenient representation, the resulting large fractions of critical damping can make modal solutions to the problems suspect. This paper is based on experience gained in this area during studies performed for the Nuclear Regulatory Commission involving seismic analyses of power plants.
Date: February 24, 1982
Creator: Nelson, T.A.
Object Type: Article
System: The UNT Digital Library
Nuclear interactions of heavy ions (open access)

Nuclear interactions of heavy ions

A possible source of preheat for heavy ion driven inertial fusion targets is the production of fast precursors by nuclear interactions between the incident heavy ions and the outer parts of the target. A model has been developed which roughly describes these interactions for all beam-target combinations for all incident energies. This interaction model has been applied to a specific capsule design. The resultant preheat is an order of magnitude below the level which could impair target performance.
Date: February 24, 1982
Creator: Tabak, M. & Bangerter, R.
Object Type: Article
System: The UNT Digital Library
Graph-theoretic algorithm for hierarchial decomposition of dynamic systems (open access)

Graph-theoretic algorithm for hierarchial decomposition of dynamic systems

A graph-theoretic scheme is proposed for partitioning of dynamic systems into hierarchially ordered subsystems having independent inputs and outputs. The resulting subsystems are input-output reachable as well as structurally controllable and observable, so that a piece-by-piece design of estimators and controllers can be accomplished for systems with large dimensions without excessive computer requirements.
Date: March 24, 1982
Creator: Pichai, V.; Sezer, M.E. & Siljak, D.D.
Object Type: Report
System: The UNT Digital Library
Finite-element stress and deflection analysis of CDF yoke and end plug (open access)

Finite-element stress and deflection analysis of CDF yoke and end plug

A large detector is being designed to study anti pp collisions at center-of-mass energies of up to 2000 GeV as part of the Fermilab Collider Detector Facility (CDF). The central detector of this facility consists of a solenoid, calorimeter yoke, and a variety of particle measurement devices. The yoke will be a large steel structure that will provide the magnetic flux return path as well as support structure for calorimetry and other instrumentation. It must resist both electromagnetic and gravitational loads while exhibiting only small elastic deformations. The instrumented endplugs of the yoke are subjected to large electromagnetic loads. Moreover, due to the presence of wire chambers within these plugs, they must also be particularly stiff. The purpose of this paper is to present the results of a finite element stress and deflection analysis of these structures under various anticipated load conditions. The PATRAN-G finite element modeling program, installed on a CDF-VAX 11/780 and operating from a Ramtek 6212 colorgraphics terminal, was used to generate the analysis models. The actual finite element analysis was performed by the ANSYS general purpose finite element program, installed on the Fermilab Cyber 175's.
Date: May 24, 1982
Creator: Wands, R.; Grimson, J.; Kephart, R. & Theriot, D.
Object Type: Report
System: The UNT Digital Library
Fastbus backplane impedance (open access)

Fastbus backplane impedance

None
Date: November 24, 1982
Creator: Haldeman, M.
Object Type: Report
System: The UNT Digital Library
Diagnostics in the Hostile Environments of a Prototype Fusion Reactor (open access)

Diagnostics in the Hostile Environments of a Prototype Fusion Reactor

The first lecture begins by reviewing the various facets of a thermonuclear-type plasma that will likely require special considerations or hardening of the applied diagnostic instrumentation. Several factors are necessary to adopt relatively standard plasma diagnostic techniques to function satisfactorily in the more hostile environment of a thermonuclear-type plasma. This lecture contains a listing of the various types of expected hardening requirements for a representative set of diagnostic instrumentation, including both on-line diagnostic instrumentation requirements for satisfactory operation and considerations to reduce integrated radiation damage sufficiently for a reasonable diagnostic lifetime. The second lecture in this series concerns several new diagnostics aimed specifically at measuring the plasma characteristics most appropriate to a thermonuclear-reactor-type plasma. This includes instrumentation needed to make quantitative energy-flow measurements during long-term operation with the expected high-input power sources, and locally very-high-wall power loadings. The second part of this lecture broadens diagnostics to include materials damage measurements needed for engineering design studies. This includes needed diagnostic instrumentation to assess first-wall damage, sputtering erosion at the walls (and high-power beam dumps), and radiation damage to components such as insulators.
Date: September 24, 1982
Creator: Osher, John E.
Object Type: Article
System: The UNT Digital Library
Recent US target-physics-related research in heavy-ion inertial fusion: depostion physics and other discussions (open access)

Recent US target-physics-related research in heavy-ion inertial fusion: depostion physics and other discussions

Theoretical work on heavy-ion deposition physics continues at several US laboratories. For example, simulations of charge-state evolution during initial phases of beam-target interactions are suggestive that equilibrium charge is reached only after a substantial fraction of the ion range. Thus we expect reduced interactions and energy loss to the blow-off plasma and also to the tampers in the case of tamped targets. Studies of plasma effects of beam-target interactions are still relevant. But recent result of high current density experiments (250 kA/cm/sup 2/) with a deuteron beam at the Naval Research Laboratory are indicative of classical deposition for finite temperature plasmas. Moreover, presently we expect heavy-ion beams to have even more stable beam-target interactions than deuterons. Further experimental and accompanying theoretical studies would be very useful.
Date: June 24, 1982
Creator: Mark, J.W.K.
Object Type: Article
System: The UNT Digital Library
General formalism for the study of activation: application to radiochemical detectors (open access)

General formalism for the study of activation: application to radiochemical detectors

This paper develops mathematical techniques required for the study of neutron-induced activation of importance to fission and fusion devices - reactors, nuclear weapons, etc. The formalism is presented as a guide for examining the dependence of activation products on flux time history, spatial gradients and the sensitivity to the assumed reactions and cross sections. Exact solutions in powers of the neutron fluence are presented and examined in various limits. As an example, radiochemical threshold (n,2n) detectors used to diagnose thermonuclear explosions are studied using approximations to these solutions. In particular, approximate formulas for the sensitivity of the radiochemical products to different cross sections are derived.
Date: September 24, 1982
Creator: Poppe, C.H.
Object Type: Report
System: The UNT Digital Library
TMX-Upgrade (TMX-U) operation in the sloshing-ion mode (open access)

TMX-Upgrade (TMX-U) operation in the sloshing-ion mode

This report summarizes initial results from TMX-U carried out from June through August 1982. In these successful experiments we operated TMX-U in the sloshing-ion mode. We generated sloshing ions, measured improved energy confinement, and observed improved microstability compared to TMX. The experiments operated about as we expected and we are pleased with the results. During this period many additional achievements were also recorded. The magnetically confined sloshing ions constitute one of the two ingredients needed to build a thermal barrier. The second ingredient consists of magnetically confined electrons, which will be studied in the next series of TMX-U experiments using microwave heating of the electrons. Later, the hot ions and electrons will be combined to form thermal barriers.
Date: September 24, 1982
Creator: Simonen, T. C.; Allen, S. L. & Casper, T. A.
Object Type: Report
System: The UNT Digital Library
Diagnostics in the Hostile Environments of a Prototype Fusion Reactor (open access)

Diagnostics in the Hostile Environments of a Prototype Fusion Reactor

Various facets of a thermonuclear type plasma that will likely require special considerations or hardening of applied diagnostic instrumentation are reviewed. The discussion will include both on-line diagnostic instrumentation requirements for satisfactory operation and considerations to reduce integrated radiation damage sufficiently for a reasonable diagnostic lifetime. Several new diagnostics aimed specifically at measurements of the plasma characteristics most appropriate to a thermonculear reactor type plasma are discussed. This will include instrumentation needed to make quantitative energy flow measurements during long term operation with the expected high input power sources, and locally very high wall power loadings. The second part of this lecture will broaden diagnostics to include materials damage measurements needed for engineering design studies. This will include needed diagnostic instrumentation to assess first wall damage, sputtering erosion at walls (and high power beam dumps), and radiation damage to components such as insulators.
Date: August 24, 1982
Creator: Osher, J. E.
Object Type: Article
System: The UNT Digital Library
TeVatron I Small-Aperture Quad lamination analysis (open access)

TeVatron I Small-Aperture Quad lamination analysis

Stacking, compression, and welding of the laminations for the TeV I Small Aperture Quad results in a deformation due to springback which is unacceptable due to magnetic field requirements. ANSYS has been used to analyze a solution to this problem.
Date: September 24, 1982
Creator: Leininger, M.
Object Type: Report
System: The UNT Digital Library