Beam transfer function and Landau damping (open access)

Beam transfer function and Landau damping

This paper discusses the following topics: beam polarization; beam transfer function; weak Landau damping limit; and Landau damping and resonant energy exchange.
Date: May 1, 1989
Creator: Wang, J.M.
System: The UNT Digital Library
Channelling and related effects in electron microscopy: The current status (open access)

Channelling and related effects in electron microscopy: The current status

Channelling or Borrmann effect in electron diffraction has been developed into a versatile, high spatial resolution, crystallographic technique with demonstrated applicability in solving a variety of materials problems. In general, either the characteristic x-ray emissions or the electron energy-loss intensities are monitored as a function of the orientation of the incident beam. The technique, as formulated in the planar geometry has found wide applications in specific site occupancy and valence measurements, determination of small atomic displacements and crystal polarity studies. For site occupancy studies, the appropriate orientations in most cases can be determined by inspection and the analysis carried out according to a simple classification of the crystal structure discussed in this paper. Concentration levels as low as 0.1 wt% can be easily detected. The reciprocity principle may be used to advantage in all these studies, if electron energy-loss spectra are monitored, as both the channelling of the incoming beam and the blocking of the outgoing beam are included in the formulation and analysis. The formulation in the axial geometry is an useful alternative, particularly for monatomic crystals. Localization effects are important if, either the experiment is performed in the axial geometry or if low atomic number elements (z < …
Date: May 1, 1989
Creator: Krishnan, K.M.
System: The UNT Digital Library
The cosmological constant problem (open access)

The cosmological constant problem

A review of the cosmological term problem is presented. Baby universe model and the compensating field model are discussed. The importance of more accurate data on the Hubble constant and the Universe age is stressed. 18 refs.
Date: May 1, 1989
Creator: Dolgov, A.D.
System: The UNT Digital Library
CP violation in K decays (open access)

CP violation in K decays

Recent theoretical and experimental progress on the manifestation of CP violation in K decays, and toward understanding whether CP violation originates in a phase, or phases, in the weak mixing matrix of quarks is reviewed. 23 refs., 10 figs.
Date: May 1, 1989
Creator: Gilman, Frederick J.
System: The UNT Digital Library
Definitive design status of the SP-100 Ground Engineering System Test Site (open access)

Definitive design status of the SP-100 Ground Engineering System Test Site

The SP-100 reactor will be ground tested at the SP-100 Ground Engineering System (GES) Test Site on the US Department of Energy (DOE) Hanford Site near Richland, Washington. Project direction and the flight system design evolution have resulted in a smaller reactor size and the consequential revision to Test Site features to accommodate the design changes and reduce Test Site costs. The significant design events since the completion of the Conceptual Design are discussed in this paper.
Date: May 1, 1989
Creator: Renkey, E. J. Jr.; Bazinet, G. D.; Bitten, E. J.; Brackenbury, P. J.; Carlson, W. F.; Irwin, J. J. et al.
System: The UNT Digital Library
Design of optics for the final focus test beam at SLAC (open access)

Design of optics for the final focus test beam at SLAC

The goal of the Final Focus Test Beam experiment (FFTB) is to produce an electron beam spot of 1 ..mu..m by 60 nm in transverse dimensions. In the future linear collider of TeV region (TLC), a typical spot size of 100 nm by 1 nm at the interaction point is required to get luminosity of 1 /times/ 10/sup 34/cm/sup /minus/2/s/sup /minus/1/. This spot size is about 1/1000 of the SLC in the vertical dimension, and is demanding for an optics design, alignments, beam diagnostics, and tuning procedures. The spot size of the FFTB will be an important next step from the SLC toward the TLC. This paper describes the design of the beam optics. 11 refs., 2 figs., 1 tab.
Date: May 1, 1989
Creator: Oide, Katsunobu
System: The UNT Digital Library
Evaluation of copper, aluminum bronze, and copper-nickel for YMP [Yucca Mountain Project] container material (open access)

Evaluation of copper, aluminum bronze, and copper-nickel for YMP [Yucca Mountain Project] container material

In this presentation, I will discuss our evaluation of the materials copper, 7% aluminum bronze, and 70/30 copper-nickel. These are three of the six materials currently under consideration as potential waste-packaging materials. I should mention that we are also considering alternatives to these six materials. This work is part of the Yucca Mountain Project (YMP), formerly known as the Nevada Nuclear Waste Storage Investigations (NNWSI) Project. The expected-case environment in our proposed vault is quite different from that encountered at the WIPP site or that expected in a Canadian vault. Our proposed site is under a desert mountain, Yucca Mountain, in southern Nevada. The repository itself will be located approximately 700 feet above the water table and 300 to 1200 feet below the surface of the mountain. The variations in these numbers are due to the variations in mountain topography.
Date: May 1, 1989
Creator: Kass, J.N.
System: The UNT Digital Library
Event parallelism: Distributed memory parallel computing for high energy physics experiments (open access)

Event parallelism: Distributed memory parallel computing for high energy physics experiments

This paper describes the present and expected future development of distributed memory parallel computers for high energy physics experiments. It covers the use of event parallel microprocessor farms, particularly at Fermilab, including both ACP multiprocessors and farms of MicroVAXES. These systems have proven very cost effective in the past. A case is made for moving to the more open environment of UNIX and RISC processors. The 2nd Generation ACP Multiprocessor System, which is based on powerful RISC systems, is described. Given the promise of still more extraordinary increases in processor performance, a new emphasis on point to point, rather than bussed, communication will be required. Developments in this direction are described. 6 figs.
Date: May 1, 1989
Creator: Nash, T.
System: The UNT Digital Library
Exabyte helical scan devices at Fermilab (open access)

Exabyte helical scan devices at Fermilab

Exabyte 8mm helical scan storage devices are in use at Fermilab in a number of applications. These devices have the functionality of magnetic tape, but use media which is much more economical and much more dense than conventional 9 track tape. 6 refs., 3 figs.
Date: May 1, 1989
Creator: Constanta-Fanourakis, P.; Kaczar, K.; Oleynik, G.; Petravick, D.; Votava, M.; White, V. et al.
System: The UNT Digital Library
FEREAD: Front End Readout software for the Fermilab PAN-DA data acquisition system (open access)

FEREAD: Front End Readout software for the Fermilab PAN-DA data acquisition system

The FEREAD system provides a multi-tasking framework for controlling the execution of experiment specific front end readout processes. It supports initializing the front end data acquisition hardware, queueing and processing readout activation signals, cleaning up at the end of data acquisition, and transferring configuration parameters and statistical data between a ''Host'' computer and the readout processes. FEREAD is implemented as part of the PAN-DA software system and is designed to run on any Motorola 68k based processor board. It has been ported to the FASTBUS General Purpose Master (GPM) interface board and the VME MVME133A processor board using the pSOS/Microtec environment. 12 refs., 2 figs.
Date: May 1, 1989
Creator: Dorries, T.; Haire, M.; Moore, C.; Pordes, R. & Votava, M.
System: The UNT Digital Library
The Fermilab Central Computing Facility architectural model (open access)

The Fermilab Central Computing Facility architectural model

The goal of the current Central Computing Upgrade at Fermilab is to create a computing environment that maximizes total productivity, particularly for high energy physics analysis. The Computing Department and the Next Computer Acquisition Committee decided upon a model which includes five components: an interactive front end, a Large-Scale Scientific Computer (LSSC, a mainframe computing engine), a microprocessor farm system, a file server, and workstations. With the exception of the file server, all segments of this model are currently in production: a VAX/VMS Cluster interactive front end, an Amdahl VM computing engine, ACP farms, and (primarily) VMS workstations. This presentation will discuss the implementation of the Fermilab Central Computing Facility Architectural Model. Implications for Code Management in such a heterogeneous environment, including issues such as modularity and centrality, will be considered. Special emphasis will be placed on connectivity and communications between the front-end, LSSC, and workstations, as practiced at Fermilab. 2 figs.
Date: May 1, 1989
Creator: Nicholls, J.
System: The UNT Digital Library
Fermilab fixed target beams from the main injector (open access)

Fermilab fixed target beams from the main injector

This paper discusses the following topics at Fermilab: 120--150 GeV beam extraction; link to switchyard; primary beam splits and transport; and experimental facilities at 120--150 GeV.
Date: May 1, 1989
Creator: Childress, S.; Coleman, R.; Koizumi, G.; Malensek, A.; Moore, C.; Schailey, R. et al.
System: The UNT Digital Library
Gabor Lens Focusing of a Negative Ion Beam (open access)

Gabor Lens Focusing of a Negative Ion Beam

Gabor or plasma lenses have previously been used to focus intense beams of positive ions at energies from 10 keV to 5 MeV. It is the large electrostatic field of the non-neutral plasma in the Gabor lens which is responsible for the focusing. Focusing an ion beam with a given sign of charge in a Gabor lens requires a non-neutral plasma with the opposite sign of charge as the beam. A Gabor lens constructed at Fermilab has been used to focus a 30 keV proton beam with good optical quality. We discuss studies of the action of a Gabor lens on a beam of negative ions. A Gabor lens has been considered for matching an H/sup /minus// beam into an RFQ in the redesign of the low energy section of the Fermilab linac. 9 refs., 3 figs., 1 tab.
Date: May 1, 1989
Creator: Palkovic, J. A.; Mills, F. E.; Schmidt, C. & Young, D. E.
System: The UNT Digital Library
Gas flow in and out of a nuclear waste container (open access)

Gas flow in and out of a nuclear waste container

We analyze the flow of gases out of and into a high-level-waste container in the unsaturated tuff of Yucca Mountain. Containers are expected to fail eventually by localized cracks and penetrations. Even though the penetrations may be small, argon gas initially in the hot container can leak out. As the waste package cools, the pressure inside the container can become less than atmospheric, and air can leak in. {sup 14}C released from the hot fuel-cladding surface can leak out of penetrations, and air inleakage can mobilize additional {sup 14}C and other volatile radioactive species as it oxidizes the fuel cladding and the spent fuel. In an earlier paper we studied the gas flow through container penetrations occurring at the time of emplacement. Here we analyze the flow of gas for various penetration sizes occurring at 300 years. 3 refs., 2 figs.
Date: May 1, 1989
Creator: Zwahlen, E. D.; Pigford, T. H.; Chambre, P. L. & Lee, W. W. L.
System: The UNT Digital Library
Heavy ion development at the LBL (Lawrence Berkeley Laboratory) 88-inch cyclotron (open access)

Heavy ion development at the LBL (Lawrence Berkeley Laboratory) 88-inch cyclotron

The 88-Inch Cyclotron produces a wide range of ions for basic and applied research. The 6.4 GHz ECR source has completely replaced the PIG source, giving higher charge states and higher cyclotron energies. The ECR source has produced ions of 34 elements, of which 28 have been accelerated in the cyclotron, using gases, and low and high temperature ovens. A higher frequency 14.5 GHz advanced ECR is now under construction. It will further increase the charge states and energies available. A conceptual design has been done for a superconducting ECR driven by a gyrotron at 28 GHz. 8 refs., 5 figs., 1 tab.
Date: May 1, 1989
Creator: Clark, D. J. & Lyneis, C. M.
System: The UNT Digital Library
Higgs boson hunting (open access)

Higgs boson hunting

This is the summary report of the Higgs Boson Working Group. We discuss a variety of search techniques for a Higgs boson which is lighter than the Z. The processes K /yields/ /pi/H, /eta//prime/ /yields/ /eta/H,/Upsilon/ /yields/ H/gamma/ and e/sup +/e/sup /minus// /yields/ ZH are examined with particular attention paid to theoretical uncertainties in the calculations. We also briefly examine new features of Higgs phenomenology in a model which contains Higgs triplets as well as the usual doublet of scalar fields. 33 refs., 6 figs., 1 tab.
Date: May 1, 1989
Creator: Dawson, S.; Haber, H.E. & Rindani, S.D.
System: The UNT Digital Library
High intensity hadron accelerators (open access)

High intensity hadron accelerators

This rapporteur report consists mainly of two parts. Part I is an abridged review of the status of all High Intensity Hadron Accelerator projects in the world in semi-tabulated form for quick reference and comparison. Part II is a brief discussion of the salient features of the different technologies involved. The discussion is based mainly on my personal experiences and opinions, tempered, I hope, by the discussions I participated in in the various parallel sessions of the workshop. In addition, appended at the end is my evaluation and expression of the merits of high intensity hadron accelerators as research facilities for nuclear and particle physics.
Date: May 1, 1989
Creator: Teng, L.C.
System: The UNT Digital Library
High level language memory management on parallel architectures (open access)

High level language memory management on parallel architectures

HEP memory management packages such as YBOS and ZEBRA have been implemented and are currently running on a variety of mainframe computers. These packages were originally designed to run on single CPU engines. Implementation of these packages on parallel machines, loosely or tightly coupled architectures is discussed. ZEBRA (CERN package) on ACP (Fermilab) is presented in detail. Design of memory management system for the new generation of ACP systems or similar parallel architectures are presented. The future of packages such as ZEBRA is not only linked to system architecture, but also to languages issues. We briefly mention penalties in using F77 with respect to other increasingly popular languages in HEP, such as C, on parallel systems. 9 refs.
Date: May 1, 1989
Creator: Lebrun, P. & Kreymer, A.
System: The UNT Digital Library
HREM at orthogonal projections of GaAs islands on silicon (open access)

HREM at orthogonal projections of GaAs islands on silicon

HREM studies typically examine only one projection of a structure and information in the electron beam direction is lost. In most cases, the structure in this direction is uniform and already known, but in others a second projection needs to be observed. This could involve preparing a second specimen sectioned at right angles to the first, or as described here, tilting a specimen through /plus minus/45/degree/ and observing the same volume in orthogonal projections. The specimen used here was of GaAs islands on <001> silicon, examined in the Atomic Resolution Microscope at LBL. 5 refs., 2 figs.
Date: May 1, 1989
Creator: Ponce, F.A. & Hetherington, C.J.D.
System: The UNT Digital Library
Machines for lattice gauge theory (open access)

Machines for lattice gauge theory

The most promising approach to the solution of the theory of strong interactions is large scale numerical simulation using the techniques of lattice gauge theory. At the present time, computing requirements for convincing calculations of the properties of hadrons exceed the capabilities of even the most powerful commercial supercomputers. This has led to the development of massively parallel computers dedicated to lattice gauge theory. This talk will discuss the computing requirements behind these machines, and general features of the components and architectures of the half dozen major projects now in existence. 20 refs., 1 fig.
Date: May 1, 1989
Creator: Mackenzie, P.B.
System: The UNT Digital Library
Measuring the mass and width of the Z sup 0 : The status of the energy spectrometers (open access)

Measuring the mass and width of the Z sup 0 : The status of the energy spectrometers

The Stanford Linear Collider (SLC) located at the Stanford Linear Accelerator Center (SLAC) collides electrons and positrons produced in the linear accelerator pulse by pulse. The object is to produce collisions energetic enough to produce the heavy intermediate vector boson, the Z{sup 0}. An essential component of the SLC physics program is the precise knowledge of the center-of-mass energy of each interaction. We measure the energy of each collision by using two energy spectrometers. The spectrometers are located in extraction lines of each beam. We will measure the energy of each beam to 20 MeV or 5 parts in 10{sup 4}. We report here on the status of the energy spectrometer system. 13 refs., 7 figs., 3 tabs.
Date: May 1, 1989
Creator: Rouse, F.; Levi, M. (Lawrence Berkeley Lab., CA (United States)); Kent, J.; King, M.; Von Zanthier, C.; Watson, S. (California Univ., Santa Cruz, CA (United States)) et al.
System: The UNT Digital Library
Monitoring in future e/sup +/e/sup /minus// colliders (open access)

Monitoring in future e/sup +/e/sup /minus// colliders

Study groups throughout the world have recently been examining possible parameter choices for a TeV-class linear collider. In all cases, they have concluded that in order to achieve useful luminosity within plausible cost constraints, the opposing beams of electrons and positrons must be focused to extraordinarily small spots and steered into collision with an unprecedented degree of accuracy. Some means of monitoring these beam parameters will be essential in order to guide the focusing and steering. In this talk, examples will be presented which illustrate the nature of these new requirements, along with a discussion of the limitations of conventional techniques for monitoring such beams and some recent measurements from the SLAC Linear Collider that show how the next level of resolution in beam monitoring will be achieved. 19 refs., 12 figs., 1 tab.
Date: May 1, 1989
Creator: Erickson, R.A.
System: The UNT Digital Library
Multibunch Instability Investigations for a Tau-Charm Factory (open access)

Multibunch Instability Investigations for a Tau-Charm Factory

In the design of high-luminosity colliders for high-energy physics, it has become clear that multibunch instabilities will be one of the primary effects that limit beam intensity, and hence luminosity. This paper reports on a series of calculations of multibunch growth rates, using the LBL accelerator physics code ZAP, that illustrate the seriousness of the effect for typical design parameters of a Tau-Charm Factory. A common feature of high-luminosity machines is the requirement of a small beta function at the interaction point. To maintain the advantages of a low beta function, however, requires that the rms bunch length, {sigma}{sub {ell}}, be smaller than {beta}*. This leads, in general, to several inconvenient aspects: (1) The requirement for short bunches leads to the need for a substantial amount of RF hardware-introducing just the narrow-band (high-Q) impedance that generates multibunch instabilities in the first place. (2) The need for short bunches means that bunch lengthening from the longitudinal microwave instability must be avoided. Since the longitudinal impedance Z{sub {parallel}}/n cannot be reduced indefinitely, there is a clear benefit to using many bunches, with lower current per bunch. (3) The short bunches have a Fourier spectrum extending up to very high frequencies, thus effectively …
Date: May 1, 1989
Creator: Zisman, Michael S.
System: The UNT Digital Library
A new method of determining SIN/sup 2/ /theta//sub W/ in deep-inelastic /nu//sub mu/N scattering (open access)

A new method of determining SIN/sup 2/ /theta//sub W/ in deep-inelastic /nu//sub mu/N scattering

The value of sin /sup 2//theta//sub W/ can be determined to /plus minus/0.002 /minus/ 0.004 by using the semileptonic decays of the K/sub L/to provide a beam of /nu//sub /mu// and /bar /nu///sub /mu// and measuring the ratio R/prime/ = /sigma/(/bar /nu///sub /mu//, NC)//sigma/(/nu//sub /mu//, NC). Systematic errors which have limited the world-average of previous /nu//sub /mu//N determinations of sin/theta//sub W/ to /plus minus/0.008 are largely eliminated. This experiment will determine the radiative corrections /Delta/r in /nu//sub /mu//N scattering to /plus minus/0.007 and in combination with W,Z mass measurements will provide precise tests of the Standard Model at the tree and one-loop level. 6 refs., 1 fig., 1 tab.
Date: May 1, 1989
Creator: Bernstein, R.H.
System: The UNT Digital Library