Damping beam displacements through phase mixing: an illustrative model (open access)

Damping beam displacements through phase mixing: an illustrative model

We develop a simple model of a beam transported in a hard wall channel (an idealized very-high-order magnetic-multipole channel). The extremely anharmonic nature of the potential leads to damping of coherent transverse displacements of the beam via phase mixing. For the case of small uniform displacements of the beam we can write down by inspection the analytical form of the motion of the beam centroid. The same technique allows us to evaluate the effects of focussing and scattering elements in the transport channel upon the damping of the transverse motion of the beam.
Date: May 27, 1983
Creator: Barletta, W. A. & Briggs, R. J.
System: The UNT Digital Library
Experimental studies of a large heterogeneous LMFBR benchmark core, ZPPR-13A (open access)

Experimental studies of a large heterogeneous LMFBR benchmark core, ZPPR-13A

The ZPPR-13 program provides basic physics information for testing calculations of radially heterogeneous cores of about 700 MWe size. ZPPR-13 is part of the JUPITER cooperative program between Japan and the US. The results are presented of measurements and analysis for the first assembly, ZPPR-13A. These are the first data for heterogeneous cores of this size available in the US and complement results from ZPPR-9, a conventional LMFBR of similar size.
Date: May 27, 1983
Creator: Brumbach, S. B.; Collins, P. J.; Carpenter, S. G.; Suzuki, S. & Kawashima, M.
System: The UNT Digital Library
Comparison of calculated results from two analytical models with measured data from a heat-exchanger flow test (open access)

Comparison of calculated results from two analytical models with measured data from a heat-exchanger flow test

Predicted results from both a network flow model and a turbulent flow model were compared with measured results from an air flow test on a half-scale model of the auxiliary heat exchanger for a high-temperature gas-cooled reactor. Measurements of both velocity and pressure were made within the heat exchanger shell side flow field. These measurements were compared with calculated results from both a network flow model and a turbulent flow model. Both analytical models predicted early identical results which, except for some minor anomalies, compared favorably with the measured data.
Date: May 1, 1983
Creator: Carosella, D. P. & Pavlics, P. N.
System: The UNT Digital Library
Results from MAC (open access)

Results from MAC

The MAC detector has been exposed at PEP to 40 pb/sup -1/ luminosity of e/sup +/e/sup -/ collisions. The detector is described and recent results of a continuing analysis of hadronic cross section, lepton pair charge asymmetry, Bhabha process, two photon final state and radiative ..mu.. pairs are given. New results on flavor tagging of hadronic events with an inclusive ..mu.., and some searches for new particles are presented.
Date: May 1, 1983
Creator: Chadwick, George B.
System: The UNT Digital Library
Design of a high-temperature first wall/blanket for a d-d compact Reversed-Field-Pinch reactor (CRFPR) (open access)

Design of a high-temperature first wall/blanket for a d-d compact Reversed-Field-Pinch reactor (CRFPR)

A high-temperature first wall/blanket which would take full advantage of the absence of tritium breeding in a d-d reactor was designed. This design which produces steam at p = 7 MPa and T = 538/sup 0/C at the blanket exit eliminates the requirement for a separate steam generator. A steam cycle with steam-to-steam reheat yielding about 37.5 percent efficiency is compatible with this design.
Date: May 1, 1983
Creator: Dabiri, A. E. & Glancy, J. E.
System: The UNT Digital Library
Conceptual design summary for modifying Doublet III to a large dee-shaped configuration (open access)

Conceptual design summary for modifying Doublet III to a large dee-shaped configuration

The Doublet III tokamak is to be reconfigured by replacing its indented (doublet) vacuum vessel with a larger one of a dee-shaped cross section. This change will permit significantly larger elongated plasmas than is presently possible and will allow higher plasma current (up to 5 MA) and anticipated longer confinement time. Reactor relevant values of stable beta and plasma pressure are predicted. This modification, while resulting in a significant change in capability, utilizes most of the existing coils, structure, systems and facility.
Date: May 1, 1983
Creator: Davis, L. G.; Gallix, R.; Luxon, J. L.; Mahdavi, M. A.; Puhn, F. A.; Rock, P. J. et al.
System: The UNT Digital Library
Detectors for high resolution dynamic pet (open access)

Detectors for high resolution dynamic pet

This report reviews the motivation for high spatial resolution in dynamic positron emission tomography of the head and the technical problems in realizing this objective. We present recent progress in using small silicon photodiodes to measure the energy deposited by 511 keV photons in small BGO crystals with an energy resolution of 9.4% full-width at half-maximum. In conjunction with a suitable phototube coupled to a group of crystals, the photodiode signal to noise ratio is sufficient for the identification of individual crystals both for conventional and time-of-flight positron tomography.
Date: May 1, 1983
Creator: Derenzo, S.E.; Budinger, T.F. & Huesman, R.H.
System: The UNT Digital Library
e+e- collisions in the multi-TeV region (open access)

e+e- collisions in the multi-TeV region

A leading role in the elucidation of the Standard Model during the last few years has been played by e+e- colliding beam experiments. The e+e- discoveries have been made possible by the cleanliness of the experimental conditions and the ability to tune the centre-of-mass energy with precision to the desired value, thus avoiding less interesting background events. We expect history to repeat itself in the next step of elucidating physics beyond the Standard Model. Just as past e+e- machines such as SPEAR, DORIS and CESR have uncovered physics inaccessible to hadron-hadron collisions with a centre-of-mass energy several times higher, so we feel that future e+e- colliders will provide information that could not be duplicated by hadron colliders with much larger centre-of-mass energies. There is a general consensus that the next interesting energy range is likely to be in the TeV range. It is in this energy range that whatever physics provides and stabilizes the masses of the intermediate vector bosons must be revealed. Unravelling this mass generation mechanism takes us beyond the gauge principle of the Standard Model which has been so triumphantly vindicated in recent months. Therefore we discuss here the capabilities and attributes of an e+e- collider with …
Date: May 1, 1983
Creator: Ellis, J.
System: The UNT Digital Library
NATURAL CONVECTIONIN SHALLOW ENCLOSURES WITH DIFFERENTIALLY HEATED END WALLS AND NONADIABATIC HORIZONTAL WALLS (open access)

NATURAL CONVECTIONIN SHALLOW ENCLOSURES WITH DIFFERENTIALLY HEATED END WALLS AND NONADIABATIC HORIZONTAL WALLS

Numerical studies of laminar natural convection at high Ra numbers in shallow enclosures are reported. In these studies the working fluid is allowed to interact with the horizontal walls. It is shown that even a small amount of heat loss from these walls can lead to a flow structure qualitatively different from the more commonly studied situation where the horizontal walls are adiabatic. This is particularly important in applications where the mass transfer and flow structure are of interest. The results highlight the difficulty in practice of both approximating the adiabatic horizontal wall condition, and interpreting experimental data.
Date: May 1, 1983
Creator: Gadgil, A. & Shiralkar, G.
System: The UNT Digital Library
Unique portable signal acquisition/processing station (open access)

Unique portable signal acquisition/processing station

At Lawrence Livermore National Laboratory, there are experimental applications requiring digital signal acquisition as well as data reduction and analysis. A prototype Signal Acquisition/Processing Station (SAPS) has been constructed and is currently undergoing tests. The system employs an LSI-11/23 computer with Data Translation analog-to-digital hardware. SAPS is housed in a roll-around cart which has been designed to withstand most subtle EMI/RFI environments. A user-friendly menu allows a user to access powerful data acquisition packages with a minimum of training. The software architecture of SAPS involves two operating systems, each being transparent to the user. Since this is a general purpose workstation with several units being utilized, an emphasis on low cost, reliability, and maintenance was stressed during conception and design. The system is targeted for mid-range frequency data acquisition; between a data logger and a transient digitizer.
Date: May 16, 1983
Creator: Garron, R. D. & Azevedo, S. G.
System: The UNT Digital Library
Some reminiscences of the early days of californium (open access)

Some reminiscences of the early days of californium

The discovery of /sup 252/Cf production in the Mike explosion is reviewed. (DLC)
Date: May 1, 1983
Creator: Ghiorso, A.
System: The UNT Digital Library
Radiation-effects limits on copper in superconducting magnets (open access)

Radiation-effects limits on copper in superconducting magnets

The determination of the response of copper stabilizers to neutron irradiation in fusion-reactor superconducting magnets requires information in four areas: (1) neutron flux and spectrum determination, (2) resistivity changes at zero field, (3) resistivity changes at field, and (4) the cyclic irradiation and annealing. Applications of our current understanding of the limits of copper stabilizers in fusion-reactor designs are explored in two examples. Recommendations for future additions to the data base are discussed.
Date: May 25, 1983
Creator: Guinan, M.W.
System: The UNT Digital Library
4. pi. data of relativistic nuclear collisions. [Plastic ball] (open access)

4. pi. data of relativistic nuclear collisions. [Plastic ball]

During the past two years, complete events of relativistic nuclear collisions are being studied with the Plastic Ball, the first electronic nonmagnetic particle-identifying 4..pi.. spectrometer. It is well suited to handle the large multiplicities in these reactions and allows collection of data at a rate sufficient to make further software selections to look at rare events. The analysis of the data follows various lines covering topics like thermalization, stopping or transparency, cluster-production mechanism (--can it tell entropy), search for collective flow through various global analyzing methods that allow determination of the scattering plane, projectile fragmentation (--is there a bounce-off), pion distribution, two-particle correlations: Hanbury-Brown Twiss, and excited nuclear states (--nucleosynthesis at the freezeout point or from chemical equilibrium). We will cover in this contribution only two subjects: stopping and thermalization and cluster production.
Date: May 1, 1983
Creator: Gutbrod, H.H.; Gustafsson, H.A. & Kolb, B.
System: The UNT Digital Library
In-situ studies of cascade defect formation at T < 10/sup 0/K (open access)

In-situ studies of cascade defect formation at T < 10/sup 0/K

Thin films of Ag and Au were ion-irradiated at temperature (T) < 10/sup 0/K and simultaneously observed using the Argonne National Laboratory high-voltage electron microscope (HVEM) ion-beam interface system. Displacement cascades were produced by Kr/sup +/ ion bombardment in the energy range 20 to 140 keV. For Ag, 20% of the 20-keV cascades and 100% of the 100-keV cascades produced observable contrast. Analysis of the observed dynamical black-white (BW)-contrast indicates that the clusters are of vacancy type. Subcascades were observed in the high-energy irradiations. The present results demonstrate that, during the evolution of displacement cascades in Ag and Au, extensive athermal rearrangement of vacancies occurs which gives rise to clustering and collapse to dislocation loops.
Date: May 1, 1983
Creator: Haga, K.; Baily, A. C.; King, W. E.; Merkle, K. L. & Meshii, M.
System: The UNT Digital Library
Nuclear-data needs for inertial-confinement fusion (ICF) (open access)

Nuclear-data needs for inertial-confinement fusion (ICF)

Our survey was limited to ICF programs in the United States. It included researchers in laser and heavy ion fusion, target design, target diagnostics, and conceptual reactor design. We asked each of these people to read the current data needs for magnetic fusion energy and to comment on additional data that they require.
Date: May 9, 1983
Creator: Haight, R. C. & Motz, H. T.
System: The UNT Digital Library
New heavy-ion-fusion accelerator research program (open access)

New heavy-ion-fusion accelerator research program

This paper will briefly summarize the concepts of Heavy Ion Fusion (HIF), especially those aspects that are important to its potential for generating electrical power. It will also note highlights of the various HIF programs throughout the world. Especially significant is that the US Department of Energy (DOE) plans a program, beginning in 1984, aimed at determining the feasibility of using heavy ion accelerators as drivers for Inertial Confinement Fusion (ICF). The new program concentrates on the aspects of accelerator design that are important to ICF, and for this reason is called HIF Accelerator Research.
Date: May 1, 1983
Creator: Herrmannsfeldt, W.B.
System: The UNT Digital Library
NOVANET: communications network for a control system (open access)

NOVANET: communications network for a control system

NOVANET is a control system oriented fiber optic local area network that was designed to meet the unique and often conflicting requirements of the Nova laser control system which will begin operation in 1984. The computers and data acquisition devices that form the distributed control system for a large laser fusion research facility need reliable, high speed communications. Both control/status messages and experimental data must be handled. A subset of NOVANET is currently operating on the two beam Novette laser system.
Date: May 23, 1983
Creator: Hill, J.R.; Severyn, J.R. & VanArsdall, P.J.
System: The UNT Digital Library
Intense positron beams: linacs - preworkshop copy (open access)

Intense positron beams: linacs - preworkshop copy

Beams of monoenergetic positrons with energies of a few eV to many keV have been used in experiments in atomic physics, solid-state physics and materials science. The production of positron beams from a new source, an electron linac, is described. Intense, pulsed beams of low-energy positrons have been produced by a high-energy beam from an electron linac. The production efficiency, moderator geometry, beam spot size and other positron beam parameters have been determined for electrons with energies from 60 to 120 MeV. Low-energy positron beams produced with a high-energy electron linac can be of much higher intensity than those beams currently derived from radioactive sources. These higher-intensity beams will make possible positron experiments previously infeasible.
Date: May 1, 1983
Creator: Howell, R. H.; Alvarez, R. A.; Woodle, K. A.; Dhawan, S.; Egan, P. O.; Hughes, V. W. et al.
System: The UNT Digital Library
Critical look at studies of radionuclide migration in fractured granite cores (open access)

Critical look at studies of radionuclide migration in fractured granite cores

A series of laboratory experiments studying radionuclide migration were conducted on eleven fractured granite cores from the Climax Stock at the Nevada Test Site. Failor et al (1982) discuss the equipment used, the preparation of the core, the experimental procedure, the data reduction, and the experimental results. They give estimates of the average fracture apertures, retardation values of /sup 85/Sr, /sup 95m/Tc, and /sup 137/Cs relative to /sup 3/H, and the percentage of each radionuclide retained in the core after each run. To determine the effect of fracture fill material and solution composition on radionuclide migration, they studied both natural and artificial fractures using either natural Climax ground water or distilled water. The results are summarized below along with a discussion of the problems inherent in the experiments and suggestions to minimize these problems.
Date: May 1, 1983
Creator: Isherwood, D. & Failor, R.
System: The UNT Digital Library
Measured versus predicted performance of the SERI test house: a validation study (open access)

Measured versus predicted performance of the SERI test house: a validation study

For the past several years the United States Department of Energy (DOE) Passive and Hybrid Solar Division has sponsored work to improve the reliability of computerized building energy analysis simulations. Under the auspices of what has come to be called the Class A Monitoring and Validation program, the Solar Energy Research Institute (SERI) has engaged in several areas of research that includes: (1) developing a validation methodology; (2) developing a performance monitoring methodology designed to meet the specific data needs for validating analysis/design tools; (3) constructing and monitoring a 1000-ft/sup 2/, multizone, skin-load-dominated test building; (4) constructing and monitoring a two-zone test cell; and (5) making sample validation studies using the DOE-2.1, BLAST-3.0, and SERIRES-1.0 computer programs. This paper reports the results obtained in comparing the measured thermal performance of the building to the performance calculated by the building energy analysis simulations. It also describes the validation methodology and the class A data acquisition capabilities at SERI.
Date: May 1, 1983
Creator: Judkoff, R.; Wortman, D. & Burch, J.
System: The UNT Digital Library
BNL AGS - a context for kaon factories (open access)

BNL AGS - a context for kaon factories

Figure 1 shows the Brookhaven site with the AGS-CBA complex highlighted. In this photograph the AGS is dwarfed by CBA and indeed during the past few years future plans for particle physics at BNL have been dominated by this enormous project. However, very recently interest in future physics use of the AGS has undergone a strong revival. Indeed, since the beginning of this year, two projects for augmenting the AGS have been proposed. Such projects could keep the AGS viable as a research machine for many years to come. In general such schemes will also improve the performance and increase the versatility of the CBA, and so are doubly valuable. It should be kept in mind that in spite of the fact the AGS has been perhaps the most fruitful machine in the history of high energy physics, its full capacities have never been exploited. Even without improvements at least one generation of rare K decay experiments beyond those currently launched seems feasible. Beyond that a major effort at any of the experiments discussed above could take it to the point where it would be limited by intrinsic physics background. To pursue a full program of physics at this level …
Date: May 1, 1983
Creator: Littenberg, L. S.
System: The UNT Digital Library
Experiments to study the feasibility of making an x-ray laser at the Novette laser facility (open access)

Experiments to study the feasibility of making an x-ray laser at the Novette laser facility

We will discuss a set of experiments which are designed to study approaches to and search for the existence of amplified spontaneous emission at photon energies of 42.3, 53.6, 119.0, and 153.0 eV. The schemes utilize pumping from the Novette laser operated with cylindrical optics at 5 TW/beam and 100 psec.
Date: May 17, 1983
Creator: Matthews, D.L.; Hagelstein, P. & Kauffman, R.
System: The UNT Digital Library
Ultra-relativistic heavy ions and cosmic rays (open access)

Ultra-relativistic heavy ions and cosmic rays

The collisions of ultra-relativistic heavy ions, E/sub /N/ greater than or equal to 1 TeV/nucleon are most interesting, since, at these energies, matter is produced at sufficiently high energy density that a quark-gluon plasma has a good chance to form. Very heavy ions are also most interesting since the matter forms in a larger volume than for light ions, and the matter is at a somewhat higher energy density. At very high energies with very heavy ions there is great flexibility in the experimental signals which might be studied, as well as the nature of the matter which is produced. The fragmentation region and central region provide different environments where a plasma might form. The former is baryon rich while the central region is high temperature with low baryon number density and is not accessible except at very high energies.
Date: May 1, 1983
Creator: McLerran, L.
System: The UNT Digital Library
Multigamma-ray calibration sources (open access)

Multigamma-ray calibration sources

We have calibrated a self-consistent set of multigamma-ray standards using the automated multi-spectrometry ..gamma..-ray counting facility at LLNL's Nuclear Chemistry Division. Pure sources of long-lived activity were produced by mass separation and/or chemical purification. The sources were counted individually and in combination on several different calibrated spectrometer systems. These systems utilize various detectors ranging from small (x-ray) detectors to large volume high-purity Ge detectors. This has allowed the use of the most ideal individual detector-efficiency characteristics for the determination of the relative ..gamma..-ray intensities. Precise energy measurements, reported earlier (Meyer, 1976) have been performed by an independent method. Both the energy and ..gamma..-ray-emission probabilities determined compare well with independently established values such as the recent ICRM intercomparison of /sup 152/Eu. We discuss our investigations aimed at resolving the shape of the efficiency response function up to 10 MeV for large volume Ge(Li) and high-purity Ge detectors. Recent results on the ..gamma..-ray-emission probabilities per decay for /sup 149/Gd and /sup 168/Tm multigamma-ray sources are discussed. For /sup 168/Tm, we deduce a 0.01% ..beta../sup -/ branch to the 87.73-keV level in /sup 168/Yb rather than the previous value which was a factor of 200 greater. In addition, we describe current cooperative efforts …
Date: May 1, 1983
Creator: Meyer, R. A. & Massey, T. N.
System: The UNT Digital Library