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AC magnetic measurements of the ALS Booster Synchrotron Dipole Magnet engineering model
We made a minimal set of AC magnetic measurements of the engineering model of the ALS Booster Dipole Magnet as part of the process of qualifying its design for production. Magnetic induction integrals over paths approximating electron-beam trajectories were measured with long curved coils connected to an electronic integrator. Magnetic induction was measured with point coils and an integrator and independently with a Hall-effect Gaussmeter. These quantities, and magnet current, were displayed on a commercial digital storage oscilloscope as parametric functions of time. The displayed waveforms were stored, processed and redisplayed as representations of selected magnet parameters. A waveform representing the magnet's effective-length was created by dividing the integral waveform by the magnetic induction waveform. Waveforms of the transfer functions were produced by dividing both the integral waveform and the magnetic induction waveform by the current waveform. Pairs of matched coils, connected in series opposition, provided differential measurements of field uniformity. Quadrupole and sextupole coefficients were derived from the uniformity data. These magnet parameters were measured at 2 and 10 Hz frequencies. Together with measurements of the magnetic field at selected dc levels, the ac measurements demonstrated that the magnet design met specifications and qualified it for production. 7 refs., …
Date:
September 1, 1988
Creator:
Green, M.I.; Hoyer, E.; Keller, R. & Nelson, D.H.
Object Type:
Article
System:
The UNT Digital Library
Accelerated aging of cellulose by laser irradiation. [Development for Shroud of Turin]
We describe a new technique for studying thermally-induced chemical transformations in cellulose developed for the Shroud of Turin. The apparatus consists of a carbon dioxide laser for heating, an infrared thermometer, and an optical reflectance spectrometer for tracking the progressive discoloration of the sample. To illustrate the technique, we present measurements from a single piece of sample linen along five isotherms in the range 200-290/degree/C. The results are explained in terms of first-order chemical rate theory and a four-step model. From the measurements we derive the activation energies, Arrhenius constants, and reflectivities of the chromophoric states. 4 refs., 2 figs., 1 tab.
Date:
January 1, 1988
Creator:
Jackson, J. P.; Arthurs, E.; Schwalbe, L. A.; Sega, R. M.; Windish, D.; Long, W. H. et al.
Object Type:
Article
System:
The UNT Digital Library
Accelerating structure with linear excitation
The switched power linac (SPL) structures require a ring-shaped laser beam pulse of uniform intensity to avoid transverse field components of the accelerating field at the center. In order to also utilize the reflection of the outgoing EM wave, the switching element has to be very close to the outer edge of the structure to ensure nearly synchronous superposition at the beam hole with the original inward going wave. It is sometimes easier to produce linear (flat) laser beams, e.g., from powerful excimer lasers which have beams of rectangular cross section. Such flat beams could be used to excite linear photocathode switches or be used to produce flat electron beam pulses in electron sources. In this paper, an accelerator structure is proposed which may be considered a variant of the SPL disk structure, but could be used with linear beams. The structure utilizes a double parabolic horn. 8 refs., 9 figs.
Date:
March 1, 1988
Creator:
Fischer, J. & Srinivasan-Rao, T.
Object Type:
Article
System:
The UNT Digital Library
Accelerating Uranium in RHIC – I The Problems and Roles of an Intermediate Linac
This report is a descriptive journey of Accelerating Uranium in RHIC – I The Problems and Roles of an Intermediate Linac
Date:
March 1, 1988
Creator:
Rhoades-Brown, M. J.
Object Type:
Report
System:
The UNT Digital Library
Acceleration, current amplification and emittance in MBE-4, an experimental beam induction linear accelerator for heavy ions
We report on the implementation of a second schedule of acceleration and current amplification in MBE-4. Control of the beam current within the bunch is improved over that in the first schedule by the addition of several small amplitude induction pulsers to compensate for acceleration errors and to control the ends of the bunch. Measurements of the longitudinal and transverse emittance are presented. 5 refs., 3 figs., 1 tab.
Date:
October 1, 1988
Creator:
Warwick, A. I.; Gough, D. E.; Keefe, D. & Meuth, H.
Object Type:
Article
System:
The UNT Digital Library
Acceleration errors in MBE-4 and in a driver
Two different acceleration schedules have been implemented in MBE-4 and the resulting longitudinal emittance measured in each case. The question arises, whether this measured longitudinal emittance is small enough so that when scaled up to a driver, using induction pulsers of the same quality, the stringent constraint on {Delta}p/p at the final focus can be met.
Date:
September 1, 1988
Creator:
Warwick,A. & Lee, E.P.
Object Type:
Report
System:
The UNT Digital Library
Accelerator and Fusion Research Division: 1987 summary of activities
An overview of the design and the initial studies for the Advanced Light Source is given. The research efforts for the Center for X-Ray Optics include x-ray imaging, multilayer mirror technology, x-ray sources and detectors, spectroscopy and scattering, and synchrotron radiation projects. The Accelerator Operations highlights include the research by users in nuclear physics, biology and medicine. The upgrade of the Bevalac is also discussed. The High Energy Physics Technology review includes the development of superconducting magnets and superconducting cables. A review of the Heavy-Ion Fusion Accelerator Research is also presented. The Magnetic Fusion Energy research included the development of ion sources, accelerators for negative ions, diagnostics, and theoretical plasma physics. (WRF)
Date:
April 1, 1988
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
The accelerator automation application toolkit workshop presentations
Over the past 18 months on the GTA project at Los Alamos, we have been developing tools for building control systems for accelerators. The first tool developed has already demonstrated greatly reduced requirements for conventional computer programming in applying control systems to an accelerator. Even in the early stages, this work has received considerable attention and the system is currently being investigated or used at several other institutes. Further tools are either in the conceptual design, design, or implementation phase. Over the same period, a group at CERN has been developing the ideas and design for a generic software kit for the application of a control system to accelerators. The CERN software kit also addresses the technical management and documentation aspects of control systems. The purpose of the AT Division effort and the CERN kit is to greatly simplify the implementation and lifetime maintenance of an accelerator control system. Experience has shown that accelerator control systems are also applicable to other experimental physics machines. The purpose of the workshop was to explore these ideas and developments as well as other relevant developments in the field, to verify the viability of the concepts, and to develop further the written specifications for …
Date:
January 1, 1988
Creator:
Howell, J. A.; Bjorklund, E. A.; Clout, P. N.; Dalesio, L. R.; Kozubal, A. J.; Mottershead, C. T. et al.
Object Type:
Article
System:
The UNT Digital Library
Accelerator physics in RHIC (Relativistic Heavy Ion Collider)
RHIC (for Relativistic Heavy Ion Collider) is a colliding beam facility to be built at BNL in the tunnel system that was constructed for the defunct ISABELLE/CBA project. It is intended for the study of collisions between fully stripped ions of the same or different species with magnetic rigidities of up to at least 839.5 Tm, corresponding with an energy of 100 GeV/amu (amu for atomic mass unit) for particles with A/Z = 2.5, and 251 GeV for protons. There are six potential crossing regions, each with, initially, time average luminosities of up to a few times 10/sup 26/ cm/sup -2/ sec/sup -1/ for Au, with luminosity life-times of 10 hours for Au, and longer for the lighter ions. The initial proton-proton luminosity will be about 10/sup 31/ cm/sup -2/ sec/sup -1/. The rms length of the interaction diamond is 0.2 m when the beams collide colinearly, it is determined by the lengths of the colliding bunches. The diamond length can be reduced by having the beams cross at an angle, but this reduces the luminosity. The magnitude of the crossing angle is restricted geometrically in dependence of the energies and species of the interacting ions and possibly also by …
Date:
January 1, 1988
Creator:
Claus, J.
Object Type:
Article
System:
The UNT Digital Library
Accelerator research on MBE-4, an experimental multi-beam induction linac
The multiple beam accelerator MBE-4 is a device for research toward a heavy ion driver for inertial confinement fusion, based on the induction linac concept. Its main goal is proof of the principle of current amplification by acceleration and controlled self-similar beam pulse compression. Into the 16-m long device four beams, each with an initial current of 10 mA are injected from a Marx-driven diode at 200 keV. The current amplification is up to nine-fold, with a final beam energy of about 800 keV in the middle of the bunch. Now that all the apparatus' accelerator sections have been completed, installed and aligned, and its unaccelerated transport properties have been studied, our experimental research has reached the crucial phase of implementing appropriate accelerator schedules that approximate self-similar current-pulse compression. These schedules are established through a close interplay of computations using a one-dimensional simulation code and a manual empirical tuning procedure. In a first approach, with a rather vigorous schedule that uses most of the accelerator modules to their voltage limits, we have determined the limits of our capability for controlled pulse compression, mainly due to waveform shaping of the driving pulse-forming networks. We shall report on these results. In the …
Date:
June 1, 1988
Creator:
Meuth, H.; Fessenden, T. J.; Keefe, D. & Warwick, A. I.
Object Type:
Article
System:
The UNT Digital Library
Accelerator Technology Program: Status report, October 1985--March 1986: Volume 1
This report presents highlights of the major projects in the Accelerator Technology (AT) Division of the Los Alamos National Laboratory. The first section details progress associated with the accelerator test stand. Following sections cover achievements in accelerator theory and simulation, LAMPF II accomplishments, and updates on BEAR, beam dynamics, the rf laboratory, p-bar gravity experiment, University of Illinois racetrack microtron, and NBS microtron. Also included are results from the Proton Storage Ring commissioning, developments in very high microwave systems, and advances in the Fusion Materials Irradiation Test rf technology. In addition, the Phoenix Project and the Krypton Fluoride Project are discussed. The report concludes with a listing of papers published by AT-Division personnel during this reporting period. 42 figs., 5 tabs.
Date:
July 1, 1988
Creator:
Jameson, R. A. & Schriber, S. O.
Object Type:
Report
System:
The UNT Digital Library
Accident analysis of railway transportation of low-level radioactive and hazardous chemical wastes: Application of the /open quotes/Maximum Credible Accident/close quotes/ concept
The maximum credible accident (MCA) approach to accident analysis places an upper bound on the potential adverse effects of a proposed action by using conservative but simplifying assumptions. It is often used when data are lacking to support a more realistic scenario or when MCA calculations result in acceptable consequences. The MCA approach can also be combined with realistic scenarios to assess potential adverse effects. This report presents a guide for the preparation of transportation accident analyses based on the use of the MCA concept. Rail transportation of contaminated wastes is used as an example. The example is the analysis of the environmental impact of the potential derailment of a train transporting a large shipment of wastes. The shipment is assumed to be contaminated with polychlorinated biphenyls and low-level radioactivities of uranium and technetium. The train is assumed to plunge into a river used as a source of drinking water. The conclusions from the example accident analysis are based on the calculation of the number of foreseeable premature cancer deaths the might result as a consequence of this accident. These calculations are presented, and the reference material forming the basis for all assumptions and calculations is also provided.
Date:
September 1, 1988
Creator:
Ricci, E. & McLean, R.B.
Object Type:
Report
System:
The UNT Digital Library
Accident Management for Severe Accidents
The management of severe accidents in light water reactors is receiving much attention in several countries. The reduction of risk by measures and/or actions that would affect the behavior of a severe accident is discussed. The research program that is being conducted by the US Nuclear Regulatory Commission focuses on both in-vessel accident management and containment and release accident management. The key issues and approaches taken in this program are summarized. 6 refs.
Date:
January 1, 1988
Creator:
Bari, R. A.; Pratt, W. T.; Lehner, J.; Leonard, M.; Disalvo, R. & Sheron, B.
Object Type:
Article
System:
The UNT Digital Library
Accomplishments of Long-Term Research and Development
Technological breakthroughs cannot be penciled on the calendar in advance. The rate of new technological discovery, while highly uncertain, depends on a base of knowledge acquired earlier. In the economic environment of 1980, progress in basic research, which builds the technology base that will underpin future energy development by Government and industry, was being slowed as cost increases due to inflation grew faster than funding increase.
Date:
July 1, 1988
Creator:
Jordy, George Y.
Object Type:
Report
System:
The UNT Digital Library
Accumulated surface damage on ZnS crystals produced by closely spaced pairs of picosecond laser pulses
Excitation of a transparent ZnS crystal by repetitive picosecond dye laser pulses causes an accumulated surface modification leading to optical damage. The onset of the damage is detected by an abrupt increase in the emission of neutral Zn (and possibly S/sub 2/) from the surface. Comparison of the neutral emission thresholds with pulse-pair and single-pulse excitation shows that linear absorption is the dominant laser-surface interaction. In general, this measurement technique shows considerable promise for investigating the possible influence of nonlinear absorption or excitation processes on damage mechanisms. The data suggest that heating of small absorbing regions produces the surface modification that leads to the observed surface ablation. The nature of the damage observed at fluences above the threshold suggests that it is caused by heating of a relatively large (/approximately/10 - 100 ..mu..m) surface region that has been modified by the accumulation pulses. 3 refs., 5 figs.
Date:
December 1, 1988
Creator:
Chase, L. L. & Lee, H. W. H.
Object Type:
Article
System:
The UNT Digital Library
ACE: AMY CDC (Central Drift Chamber) Fast Track Finder
The central drift chamber (CDC) of the AMY detector at the TRISTAN e/sup /+//e/sup /-// collider features its fine granularity and multi-band structure. The tracking software named ACE which makes the most of these features shows an excellent performance for reconstruction of high multiplicity events with highly collimated jets. The obtained reconstruction efficiency is 97% for the particles coming from within 5 cm of the primary vertex with p/sub t/ /approx gt/ 500 MeVc in the simulated hadronic events. The processing time is on average less than 300 ms per hadronic event (simulated or real) on a FACOM M-382 computer. 3 refs., 5 figs.
Date:
January 1, 1988
Creator:
Mori, T.
Object Type:
Article
System:
The UNT Digital Library
Achromatic beam combiner and bend system for ILSE (Induction Linac System Experiment)
The lattice configuration of the beam combiner and bend system of the proposed Induction Linac System Experiment (ILSE) is described. These subsystems must transport high current ion beams with large momentum variations within a single pulse (..delta..P/P/sub 0/ less than or equal to +-.1), with minimal beam loss or emittance growth. Configurations which are achromatic through first order, including the effect of image fields have been developed. Calculations of the beam envelope and centroid motion are made with beam dynamics code HICURB, which includes strong space charge effects and chromatic effects through all orders. 5 refs., 5 figs.
Date:
June 1, 1988
Creator:
Lee, Edward P.
Object Type:
Article
System:
The UNT Digital Library
Achromatic lattice comparison for light sources
The next generation of synchrotron light sources are being designed to support a large number of undulators and require long dispersion-free insertion regions. With less demand for radiation from the dipole magnets, the storage ring cost per undulator beam can be reduced by decreasing the number of dipole magnets and increasing the number of dispersion free straight sections. The two simplest achromatic lattices are the Chasman-Green or double-bend achromatic (DBA) and the three-bend achromat (TBA). The DBA in its simplest form consists of a single horizontally-focussing quadrupole between the two dipole magnets. Since this quadrupole strength is fixed by the achromatic condition, the natural emittance (/var epsilon//sub n/) may vary as the beta functions in the insertion region (IR) are varied. The expanded Chasman-Green (also DBA) uses multiple quadrupoles in the dispersive section to provide emittance control independent of the beta functions in the IR. Although this provides flexibility in the ID beta functions, the horizontal phase advance is constrained to /phi/ /approx equal/ 180/degree/ between approximately the centers of the dipole magnets. If small /var epsilon//sub n/ is required, the horizontal phase advance between the dipoles will be near one and the lattice properties will be dominated by this …
Date:
January 1, 1988
Creator:
Kramer, S. L.; Crosbie, E. A. & Cho, Y.
Object Type:
Article
System:
The UNT Digital Library
Acoustic emission in a fluid saturated heterogeneous porous layer with application to hydraulic fracture
A theoretical model for acoustic emission in a vertically heterogeneous porous layer bounded by semi-infinite solid regions is developed using linearized equations of motion for a fluid/solid mixture and a reflectivity method. Green's functions are derived for both point loads and moments. Numerically integrated propagators represent solutions for intermediate heterogeneous layers in the porous region. These are substituted into a global matrix for solution by Gaussian elimination and back-substitution. Fluid partial stress and seismic responses to dislocations associated with fracturing of a layer of rock with a hydraulically conductive fracture network are computed with the model. A constitutive model is developed for representing the fractured rock layer as a porous material, using commonly accepted relationships for moduli. Derivations of density, tortuosity, and sinuosity are provided. The main results of the model application are the prediction of a substantial fluid partial stress response related to a second mode wave for the porous material. The response is observable for relatively large distances, on the order of several tens of meters. The visco-dynamic transition frequency associated with parabolic versus planar fluid velocity distributions across micro-crack apertures is in the low audio or seismic range, in contrast to materials with small pore size, such …
Date:
November 1, 1988
Creator:
Nelson, J.T. (California Univ., Berkeley, CA (USA). Dept. of Mechanical Engineering Lawrence Berkeley Lab., CA (USA))
Object Type:
Report
System:
The UNT Digital Library
Acoustical properties of drill strings
The recovery of petrochemical and geothermal resources requires extensive drilling of wells to increasingly greater depths. Real-time collection and telemetry of data about the drilling process while it occurs thousands of feet below the surface is an effective way of improving the efficiency of drilling operations. Unfortunately, due to hostile down-hole environments, telemetry of this data is an extremely difficult problem. Currently, commercial systems transmit data to the surface by producing pressure pulses within the portion of the drilling mud enclosed in the hollow steel drill string. Transmission rates are between two and four data bits per second. Any system capable of raising data rates without increasing the complexity of the drilling process will have significant economic impact. One alternative system is based upon acoustical carrier waves generated within the drill string itself. If developed, this method would accommodate data rates up to 100 bits per second. Unfortunately, the drill string is a periodic structure of pipe and threaded tool joints, the transmission characteristics are very complex and exhibit a banded and dispersive structure. Over the past forty years, attempts to field systems based upon this transmission method have resulted in little success. This paper examines this acoustical transmission problem …
Date:
August 1, 1988
Creator:
Drumheller, D.S.
Object Type:
Report
System:
The UNT Digital Library
ACRR (Annular Core Research Reactor) fission product release tests: ST-1 and ST-2
Two experiments (ST-1 and ST-2) have been performed in the Annular Core Research Reactor (ACER) at Sandia National Laboratories (SNLA) to obtain time-resolved data on the release of fission products from irradiated fuels under light water reactor (LWR) severe accident conditions. Both experiments were conducted in a highly reducing environment at maximum fuel temperatures of greater than 2400 K. These experiments were designed specifically to investigate the effect of increased total pressure on fission product release; ST-1 was performed at approximately 0.16 MPa and ST-2 was run at 1.9 MPa, whereas other parameters were matched as closely as possible. Release rate data were measured for Cs, I, Ba, Sr, Eu, Te, and U. The release rates were higher than predicted by existing codes for Ba, Sr, Eu, and U. Te release was very low, but Te did not appear to be sequestered by the zircaloy cladding; it was evenly distributed in the fuel. In addition, in posttest analysis a unique fuel morphology (fuel swelling) was observed which may have enhanced fission product release, especially in the high pressure test (ST-2). These data are compared with analytical results from the CORSOR correlation and the VICTORIA computer model. 8 refs., 8 figs., …
Date:
January 1, 1988
Creator:
Allen, M. D.; Stockman, H. W.; Reil, K. O.; Grimley, A. J. & Camp, W. J.
Object Type:
Article
System:
The UNT Digital Library
Activation characteristics of different steel alloys proposed for near-term fusion reactors
Analyses have been made for different structural alloys proposed for the International Thermonuclear Experimental Reactor (ITER). Candidate alloys include austenitic steels stabilized with nickel (NiSS) or manganese (MnSS). The radioactivity, the decay heat, and the waste disposal rating of each alloy have been calculated for the inboard shield of the ITER design option utilizing water cooled solid breeder blanket. The results show, for the 55 cm inboard shield and after 3 MW.yr/m2 fluence, that the long term activation problems, e.g., radioactive waste, of the MnSS are much less than that of the NiSS. All the MnSS alloys considered are qualified as Class C or better low level waste. Most of the NiSS alloys are not qualified for near surface burial. However, the short term decay heat generation rate for the MnSS is much higher than that of the NiSS. 6 refs., 8 figs., 2 tabs.
Date:
August 1, 1988
Creator:
Attaya, H.; Gohar, Y.; Smith, D. & Baker, C. C.
Object Type:
Article
System:
The UNT Digital Library
Active Cooling for Downhole Instrumentation: Preliminary Analysis and System Selection
A feasibility study and a series of preliminary designs and analyses were done to identify candidate processes or cycles for use in active cooling systems for downhole electronic instruments. A matrix of energy types and their possible combinations was developed and the energy conversion process for each pari was identified. The feasibility study revealed conventional as well as unconventional processes and possible refrigerants and identified parameters needing further clarifications. A conceptual design or series od oesigns for each system was formulated and a preliminary analysis of each design was completed. The resulting coefficient of performance for each system was compared with the Carnot COP and all systems were ranked by decreasing COP. The system showing the best combination of COP, exchangeability to other operating conditions, failure mode, and system serviceability is chosen for use as a downhole refrigerator. 85 refs., 48 figs., 33 tabs.
Date:
March 1, 1988
Creator:
Bennett, G. A.
Object Type:
Report
System:
The UNT Digital Library
Activity report: A report of research activity in fiscal years 1986 and 1987
This report summarizes the last elements of work conducted in this program prior to its termination at the end of FY 87. The work was primarily an analysis of a fuel cell electrocatalyst using electron microscopy. The catalyst was a three component system containing Pt-Co-Ni (3:2:2 atomic ratios) dispersed on an amorphous carbon support in unknown phases, supplied to us by Giner Inc. (designated as their sample no. G82-5-19). The preparation of this catalyst is proprietary, (patent pending). Our objective was to analyze the catalyst by a variety of techniques to determine, to the greatest extent possible, the distribution of the three elements on the carbon support along with identification of their chemical states and phases.
Date:
January 1, 1988
Creator:
Ross, P.N.; Beard, B. & Sattler, M.
Object Type:
Report
System:
The UNT Digital Library