1. 8K conditioning (non-quench training) of a model SSC dipole (open access)

1. 8K conditioning (non-quench training) of a model SSC dipole

The accepted hypothesis is that training quenches are caused by heat generation when conductors move under Lorentz force. Afterwards no conductor motion will occur until a higher field and greater Lorentz force acts. If superior heat transfer and/or greater temperature margin is provided by operating at lower bath temperature, one might expect that the heat generated by conductor motion will not cause a runaway temperature increase, or quench. To test this hypothesis, the central dipole field in SSC model magnets was ramped at 1.8 K to 7.1 tesla without the magnets' quenching. The bath was then raised to 4.4 K and the magnets quenched at their short sample limits of 6.6 tesla or higher. Comparison with similar magnets trained in He I at 4.4 K is made and the significance of the non-quench training on system operation is discussed.
Date: September 1, 1986
Creator: Gilbert, W. S. & Hassenzahl, W. V.
System: The UNT Digital Library
5cm aperture dipole studies (open access)

5cm aperture dipole studies

The results obtained during the evolution of the design, construction, and testing program of the design ''B'' dipole are presented here. Design ''B'' is one of the original three competing designs for the Superconducting Super Collider ''SSC'' arc dipoles. The final design parameters were as follows: air cored (less than a few percent of the magnetic field derived from any iron present), aluminum collared, two layered winding, 5.5T maximum operating field, and a 5 cm cold aperture. There have been fourteen 64 cm long 5 cm aperture model dipoles cold tested (at 4.3K and less) in this program so far. There was a half length full size (6m) mechanical analog (M-10) built and tested to check the cryostat's mechanical design under ramping and quench conditions. Several deviations from the ''Tevatron'' dipole fabrication technique were incorporated, for example the use of aluminum collars instead of stainless steel. The winding technique variations explored were ''dry welding,'' a technique with the cable covered with Kapton insulation only and ''wet winding'' where the Kapton was covered with a light coat of ''B'' stage epoxy. Test data include quench currents, field quality (Fourier multipole co-efficients), coil magnetization, conductor current performance, and coil loading. Quench current, …
Date: September 30, 1986
Creator: McInturff, A.D.; Bossert, R.; Carson, J.; Fisk, H.E.; Hanft, R.; Kuchnir, M. et al.
System: The UNT Digital Library
Abstracts of Presentation: Aquatic Species Program Annual Review Meeting, Golden, Colorado, 24-25 September 1986 (open access)

Abstracts of Presentation: Aquatic Species Program Annual Review Meeting, Golden, Colorado, 24-25 September 1986

The goal of the aquatic species program is to produce gasoline and diesel fuels from microalgae grown in saline waters of the desert southwest. Microalgae are known to accumulate lipids in large quantities and can thrive in high salinity water which currently has no other use.
Date: September 1, 1986
Creator: unknown
System: The UNT Digital Library
The ACP (Advanced Computer Program) multiprocessor system at Fermilab (open access)

The ACP (Advanced Computer Program) multiprocessor system at Fermilab

The Advanced Computer Program at Fermilab has developed a multiprocessor system which is easy to use and uniquely cost effective for many high energy physics problems. The system is based on single board computers which cost under $2000 each to build including 2 Mbytes of on board memory. These standard VME modules each run experiment reconstruction code in Fortran at speeds approaching that of a VAX 11/780. Two versions have been developed: one uses Motorola's 68020 32 bit microprocessor, the other runs with AT and T's 32100. both include the corresponding floating point coprocessor chip. The first system, when fully configured, uses 70 each of the two types of processors. A 53 processor system has been operated for several months with essentially no down time by computer operators in the Fermilab Computer Center, performing at nearly the capacity of 6 CDC Cyber 175 mainframe computers. The VME crates in which the processing ''nodes'' sit are connected via a high speed ''Branch Bus'' to one or more MicroVAX computers which act as hosts handling system resource management and all I/O in offline applications. An interface from Fastbus to the Branch Bus has been developed for online use which has been tested …
Date: September 1986
Creator: Nash, T.; Areti, H.; Atac, R.; Biel, J.; Case, G.; Cook, A. et al.
System: The UNT Digital Library
ADGEN: a system for automated sensitivity analysis of predictive models (open access)

ADGEN: a system for automated sensitivity analysis of predictive models

A system that can automatically enhance computer codes with a sensitivity calculation capability is presented. With this new system, named ADGEN, rapid and cost-effective calculation of sensitivities can be performed in any FORTRAN code for all input data or parameters. The resulting sensitivities can be used in performance assessment studies related to licensing or interactions with the public to systematically and quantitatively prove the relative importance of each of the system parameters in calculating the final performance results. A general procedure calling for the systematic use of sensitivities in assessment studies is presented. The procedure can be used in modelling and model validation studies to avoid ''over modelling,'' in site characterization planning to avoid ''over collection of data,'' and in performance assessment to determine the uncertainties on the final calculated results. The added capability to formally perform the inverse problem, i.e., to determine the input data or parameters on which to focus additional research or analysis effort in order to improve the uncertainty of the final results, is also discussed.
Date: September 1, 1986
Creator: Pin, F. G.; Horwedel, J. E.; Oblow, E. M. & Lucius, J. L.
System: The UNT Digital Library
The analog processing system for the Liquid Argon Calorimeter for SLD at SLAC (open access)

The analog processing system for the Liquid Argon Calorimeter for SLD at SLAC

The analog processing system for the Liquid Argon Calorimeter for the SLD project at SLAC is described. Amplification, storage of the analog information, and multiplexing is realized on specially developed hybrids, which will be mounted directly on the detector. This leads to a substantial reduction of the cable plant. Test results for the amplifier and for the sampling and multiplexing hybrid (CDU hybrid) are presented. The latter hybird contains a custom monolithic device, the Calorimeter Data Unit (CDU).
Date: September 1, 1986
Creator: Haller, G. M.; Nelson, D. & Freytag, D. R.
System: The UNT Digital Library
Analysis of fissionable material using delayed gamma rays from photofission (open access)

Analysis of fissionable material using delayed gamma rays from photofission

The energetic gamma-ray spectra from the fission products of photofission have been investigated to determine whether photofission can identify heavily shielded fissionable material. Target samples of natural thorium, 93% enriched /sup 235/U, natural uranium, and 93% enriched /sup 239/Pu were irradiated with bremsstrahlung gamma rays produced by 10-MeV electrons from a small linear accelerator. The gamma-ray spectra for each of the four isotopes studied reveals a distinctive intensity distribution. For example, the intensity ratio of the pair of gamma rays at 1436 keV (/sup 138/Cs) and 1428 keV (/sup 94/Sr) is 1.9 for /sup 235/U, 2.4 for /sup 238/U, 1.7 for /sup 232/Th and 1.4 for /sup 239/Pu. 6 refs., 2 figs., 1 tab.
Date: September 1, 1986
Creator: Hollas, C. L.; Close, D. A. & Moss, C. E.
System: The UNT Digital Library
Analysis of the human electroencephalogram with methods from nonlinear dynamics (open access)

Analysis of the human electroencephalogram with methods from nonlinear dynamics

We apply several different methods from nonlinear dynamical systems to the analysis of the degree of temporal disorder in data from human EEG. Among these are methods of geometrical reconstruction, dimensional complexity, mutual information content, and two different approaches for estimating Lyapunov characteristic exponents. We show how the naive interpretation of numerical results can lead to a considerable underestimation of the dimensional complexity. This is true even when the errors from least squares fits are small. We present more realistic error estimates and show that they seem to contain additional, important information. By applying independent methods of analysis to the same data sets for a given lead, we find that the degree of temporal disorder is minimal in a ''resting awake'' state and increases in sleep as well as in fluroxene induced general anesthesia. At the same time the statistical errors appear to decrease, which can be interpretated as a transition to a more uniform dynamical state. 29 refs., 10 figs.
Date: September 8, 1986
Creator: Mayer-Kress, G. & Holzfuss, J.
System: The UNT Digital Library
Antiproton proton searches for quark-gluon plasma at the Fermilab collider (open access)

Antiproton proton searches for quark-gluon plasma at the Fermilab collider

The Fermilab Tevatron antiproton-proton collider will begin operation late 1986. A brief description of experiments with the capability for detecting the formation of quark-gluon plasma is presented.
Date: September 1, 1986
Creator: Hojvat, C.
System: The UNT Digital Library
Application of atomic vapor laser isotope separation to the enrichment of mercury (open access)

Application of atomic vapor laser isotope separation to the enrichment of mercury

Workers at GTE/Sylvania have shown that the efficiency of fluorescent lighting may be markedly improved using mercury that has been enriched in the /sup 196/Hg isotope. A 5% improvement in the efficiency of fluorescent lighting in the United States could provide a savings of approx. 1 billion dollars in the corresponding reduction of electrical power consumption. We will discuss the results of recent work done at our laboratory to develop a process for enriching mercury. The discussion will center around the results of spectroscopic measurements of excited state lifetimes, photoionization cross sections and isotope shifts. In addition, we will discuss the mercury separator and supporting laser mesurements of the flow properties of mercury vapor. We will describe the laser system which will provide the photoionization and finally discuss the economic details of producing enriched mercury at a cost that would be attractive to the lighting industry.
Date: September 1, 1986
Creator: Crane, J. K.; Erbert, G. V.; Paisner, J. A.; Chen, H. L.; Chiba, Z.; Beeler, R.G. et al.
System: The UNT Digital Library
Application of atomic vapor laser isotope separation to the enrichment of mercury (open access)

Application of atomic vapor laser isotope separation to the enrichment of mercury

Workers at GTE/Sylvania have shown that the efficiency of fluorescent lighting may be markedly improved using mercury that has been enriched in the /sup 196/Hg isotope. A 5% improvement in the efficiency of fluorescent lighting in the United States could provide a savings of $450 million dollars in the corresponding reduction of electrical power consumption. We discuss the results of recent work done at our laboratory to develop a process for enriching mercury. The discussion centers around the results of spectroscopic measurements of excited-state lifetimes, photoionization cross sections, and isotope shifts.
Date: September 1, 1986
Creator: Crane, J.; Erbert, G.; Paisner, J.; Chen, H.; Chiba, Z.; Beeler, R. et al.
System: The UNT Digital Library
Approaching maximal performance of longitudinal beam compression in induction accelerator drivers (open access)

Approaching maximal performance of longitudinal beam compression in induction accelerator drivers

Longitudinal beam compression occurs before final focus and fusion chamber beam transport and is a key process determining initial conditions for final focus hardware. Determining the limits for maximal performance of key accelerator components is an essential element of the effort to reduce driver costs. Studies directed towards defining the limits of final beam compression including considerations such as maximal available compression, effects of longitudinal dispersion and beam emittance, combining pulse-shaping with beam compression to reduce the total number of beam manipulators, etc., are given. Several possible techniques are illustrated for utilizing the beam compression process to provide the pulse shapes required by a number of targets. Without such capabilities to shape the pulse, an additional factor of two or so of beam energy would be required by the targets.
Date: September 24, 1986
Creator: Mark, J. W. K.; Ho, D. D. M.; Brandon, S. T.; Chang, C. L.; Drobot, A. T.; Faltens, A. et al.
System: The UNT Digital Library
ASTROMAG: A superconducting particle astrophysics magnet facility for the space station (open access)

ASTROMAG: A superconducting particle astrophysics magnet facility for the space station

This paper describes a superconducting magnet system which is the heart of a particle astrophysics facility to be mounted on a portion of the proposed NASA space station. This facility will complete the studies done by the electromagnetic observatories now under development and construction by NASA. The paper outlines the selection process of the type of magnet to be used to analyze the energy and momentum of charged particles from deep space. The ASTROMAG superconducting magnet must meet all the criteria for a shuttle launch and landing, and it must meet safety standards for use in or near a manned environment such as the space station. The magnet facility must have a particle gathering aperture of at least 1 square meter steradian and the facility should be capable of resolving heavy nuclei with a total energy of 10 Tev or more. 4 refs., 3 figs.
Date: September 1, 1986
Creator: Green, M. A.; Smoot, G. F.; Golden, R. L.; Israel, M. H.; Kephart, R.; Niemann, R. et al.
System: The UNT Digital Library
Atomic-defect mechanisms for diffusion in refractory bcc metals (open access)

Atomic-defect mechanisms for diffusion in refractory bcc metals

Despite a number of recent investigations into the nature and properties of equilibrium atomic defects in the refractory bcc metals, the mechanisms responsible for the high-temperature mass transport in these materials are not clear. The observed strong high-temperature enhancement in self-diffusion appears to be unexplainable in terms of divacancies, but might result from the presence of small equilibrium concentrations of highly-mobile self-interstitials. Recent vacancy formation measurements in Cr appear to support this view. However, recent studies of diffusion in Nb(W) alloys and high-temperature vacancy migration in W have raised new issues to be considered.
Date: September 1, 1986
Creator: Siegel, R. W.; Mundy, J. N. & Smedskjaer, L. C.
System: The UNT Digital Library
Atomic vapor laser isotope separation using resonance ionization (open access)

Atomic vapor laser isotope separation using resonance ionization

Atomic vapor laser isotope separation (AVLIS) is a general and powerful technique. A major present application to the enrichment of uranium for light-water power-reactor fuel has been under development for over 10 years. In June 1985, the Department of Energy announced the selection of AVLIS as the technology to meet the nation's future need for enriched uranium. Resonance photoionization is the heart of the AVLIS process. We discuss those fundamental atomic parameters that are necessary for describing isotope-selective resonant multistep photoionization along with the measurement techniques that we use. We illustrate the methodology adopted with examples of other elements that are under study in our program.
Date: September 1, 1986
Creator: Comaskey, B.; Crane, J.; Erbert, G.; Haynam, C.; Johnson, M.; Morris, J. et al.
System: The UNT Digital Library
Availability of enriched stable isotopes: present status and future prospects (open access)

Availability of enriched stable isotopes: present status and future prospects

The Electromagnetic Isotope Enrichment Facility (EMIEF) is currently used to produce 225 enriched stable isotopes of 50 elements. Among these are included most of the known elements with stable isotopes except for the noble gases, certain light elements, monisotopic elements, etc. The EMIEF can also be used to produce enriched samples of radioactive species, most notably the isotopes of uranium and plutonium. These enriched materials are placed in either the Sales Inventory of in the Research Materials Collection (RMC). The materials in the Sales Inventory are for sale to anyone on a first come, first served basis. Prices in the most recent catalog range from $0.05/mg for 99.8% /sup 140/Ce to $1,267/mg for 98.5% /sup 176/Lu. The materials in the RMC are made available to US researchers (or groups that include a US investigator) on a loan basis for use in non-destructive experiments and applications. In addition, certain samples have been provided to European investigators for cross-section studies through the auspices of EURATOM and the European-American Nuclear Data Committee. The status of the enriched isotopes included in the Sales Inventory is tabulated where isotopes are listed that are either not available or are in insufficient quantity or quality to meet …
Date: September 18, 1986
Creator: Hoff, R.W.
System: The UNT Digital Library
Beam foil spectroscopy of N = 3 to N = 2 transitions in highly stripped heavy ions. Revision 1 (open access)

Beam foil spectroscopy of N = 3 to N = 2 transitions in highly stripped heavy ions. Revision 1

The spectroscopy of very highly ionized atoms provides an important testing ground for multi-electron atomic theory. We report preliminary experimental results on the n = 3 ..-->.. 2 spectra of Bi/sup +73/ and A/sup +69/ obtained at the GSI UNILAC accelerator. 19 refs., 4 figs.
Date: September 1, 1986
Creator: Dietrich, D.D.; Chandler, G.A.; Egan, P.O.; Ziock, K.P.; Mokler, P.H.; Reusch, S. et al.
System: The UNT Digital Library
Bending and focusing effects in an FEL oscillator. I. Simple models (open access)

Bending and focusing effects in an FEL oscillator. I. Simple models

The combination of wiggler, electron beam, and optical beam produces not only gain, but also refractive effects. These effects have been modeled for an oscillator configuration with a simple prism and lens. An instability is found to occur whenever the focal strength of the electron beam is sufficiently large. An estimate has been made of the magnitude of these effects and we present a discussion of the likely consequences.
Date: September 1, 1986
Creator: Warren, R.W. & McVey, B.D.
System: The UNT Digital Library
Bending and focusing effects in an FEL oscillator. II. Numerical simulations (open access)

Bending and focusing effects in an FEL oscillator. II. Numerical simulations

Bending and focusing of the optical beam by the electron beam is investigated for an FEL oscillator configuration. Numerical calculations are performed with the simulation code, FELEX.
Date: September 1, 1986
Creator: McVey, B.D. & Warren, R.W.
System: The UNT Digital Library
Calculations and measurements for the SLAC SLC positron return quadrupole magnet (open access)

Calculations and measurements for the SLAC SLC positron return quadrupole magnet

The three-dimensional magnetostatic computer program TOSCA, running on the NMFECC CRAY X-MP computer, was used to compute the integral of gradient length for the SLC type QT4 positron return line quadrupole magnet. Since the bore diameter of the magnet is 12.7 centimeters, and the length is only 10.16 centimeters, three dimensional effects are important. POISSON calculations were done on a two-dimensional model to obtain magnetic shimming which assured enough positive twelve pole to offset end effects, while TOSCA was used to estimate the effective length of the quadrupole. No corrections were required on the magnet as built. Measurements showed that the required integrated gradient was achieved for the given current, and that integrated higher harmonics were generally less than 0.1% of the quadrupole component.
Date: September 1, 1986
Creator: Early, R.A. & Cobb, J.K.
System: The UNT Digital Library
The CEBAF Superconducting Accelerator Cryomodule (open access)

The CEBAF Superconducting Accelerator Cryomodule

The design and fabrication of the cavity enclosure and calculation to support the 2*K operating temperature, and techniques for minimizing operating heat loads and cryostat loads are discussed. The integrating of the Cryogen fluid distribution system into the cavity cryostat will be presented.Integration of the cavity designing into cavity fabrication and maintenance program, with emphasis on system reliability and flexibility, is included.
Date: September 1, 1986
Creator: Rode, Claus & Biallas, George
System: The UNT Digital Library
Chemical characteristics of material released during Source Term Experiments Project (STEP) in-pile tests: Part 1 (open access)

Chemical characteristics of material released during Source Term Experiments Project (STEP) in-pile tests: Part 1

A series of four experiments aimed at characterizing the radiological source term associated with postulated severe light water reactor (LWR) accidents has been conducted at Argonne's Transient Reactor Test Facility (TREAT). The STEP tests drove fuel elements to the point of severe cladding disruption in steam environments by fission heating and oxidation of the Zircaloy cladding. The released fission products and volatile cladding constituents entrained in the steam/hydrogen flows were captured by the test vehicles' sampling systems and analyzed by SEM/EDX. The principal constituents of the deposits were fission product cesium, molybdenum and rubidium, and tin from the cladding. Iodine was generally seen collocated with cesium, although lone iodine deposits were observed indicating that the iodine was not completely transported as CsI. Structural material was also observed. The composition information in conjunction with counted particle distributions were used to determine the particle loading of that portion of the material released during the first test that was transported in aerosol form.
Date: September 1, 1986
Creator: Schlenger, B. J.; Dunn, P. F.; Herceg, J. E.; Simms, R.; Horton, E. L.; Baker, L., Jr. et al.
System: The UNT Digital Library
Comments on the impedances of the SSC shielded bellows at low frequencies due to the truncation of the wake fields (open access)

Comments on the impedances of the SSC shielded bellows at low frequencies due to the truncation of the wake fields

The behavior of the longitudinal impedance of the SSC shielded bellow at low frequencies depends very much on the length of the wake field used in the Fourier transformation. We show analytically and numerically that, regardless of the difference, single-bunch effects are independent of the actual shape of the impedance when the length of the wake used is bigger than the bunch length.
Date: September 1, 1986
Creator: Ng, King-Yuen
System: The UNT Digital Library
Commissioning of the SLC injector (open access)

Commissioning of the SLC injector

For every cycle of the SLC, the injector is required to launch two electron bunches and a single positron bunch into their respective emittance damping rings. Each bunch is to have a population of 7.5 x 10/sup 10/ particles/bunch, an energy of 1.21 GeV, and a full width energy spread of less than 2%. The electron beams are produced from a thermionic cathode, bunched, and accelerated to about 200 MeV. Positrons are injected after electrons at the 200 MeV point. The three bunches, spaced by approximately 60 ns, are subsequently accelerated to the damping ring energy within a single RF pulse. As of September 1986, all of the injector hardware had been installed and tested. Single electron bunches were being produced, stabilized with respect to energy characteristics, and injected into the damping rings. Commissioning of two electron bunch operation is currently in progress. Three bunch running should be commissioned by early 1987 and the SLC injector is expected to be operational by April 1987. This paper will report on the hardware and software developments necessary for the injector. The operational status of the entire system will be discussed.
Date: September 1, 1986
Creator: Sheppard, J. C.; Bambade, P. S.; Clendenin, J. E.; Gearhart, R. A.; Miller, R. H. & Sodja, J.
System: The UNT Digital Library