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CHARACTERIZATION OF THE COHERENT NOISE, ELECTROMAGNETIC COMPATIBILITY AND ELECTROMAGNETIC INTERFERENCE OF THE ATLAS EM CALORIMETER FRONT END BOARD (open access)

CHARACTERIZATION OF THE COHERENT NOISE, ELECTROMAGNETIC COMPATIBILITY AND ELECTROMAGNETIC INTERFERENCE OF THE ATLAS EM CALORIMETER FRONT END BOARD

The ATLAS Electromagnetic (EM) calorimeter (EMCAL) Front End Board (FEB) will be located in custom-designed enclosures solidly connected to the feedtroughs. It is a complex mixed signal board which includes the preamplifier, shaper, switched capacitor array analog memory unit (SCA), analog to digital conversion, serialization of the data and related control logic. It will be described in detail elsewhere in these proceedings. The electromagnetic interference (either pick-up from the on board digital activity, from power supply ripple or from external sources) which affects coherently large groups of channels (coherent noise) is of particular concern in calorimetry and it has been studied in detail.
Date: September 20, 1999
Creator: CHASE,B. CITTERIO,M. LANNI,F. MAKOWIECKI,D. RADEKA,S. RESCIA,S. TAKAI,H. ET AL.
System: The UNT Digital Library
Gamma-Ray Spectrometers Using a Bulk Sn Absorber Coupled to a Mo/Cu Multilayer Superconducting Transition Edge Sensor (open access)

Gamma-Ray Spectrometers Using a Bulk Sn Absorber Coupled to a Mo/Cu Multilayer Superconducting Transition Edge Sensor

We are developing gamma-ray detectors with a bulk absorber and a superconducting transition-edge sensor. The absorber is high purity Sn and the transition-edge sensor is a Mo/Cu multilayer thin film. We have characterized the detector, and will discuss x-ray and gamma-ray results.
Date: September 21, 1999
Creator: Chow, D. T.; Lindeman, M. A.; Cunningham, M. F.; Frank, M.; Barbee, T. W., Jr. & Labov, S. E.
System: The UNT Digital Library
The ARAC-RODOS-WSPEEDI Information Exchange Project (open access)

The ARAC-RODOS-WSPEEDI Information Exchange Project

Under the auspices of a US DOE-JAPAN Memorandum of Understanding JAERI and LLNL agreed to develop and evaluate a prototype information exchange protocol for nuclear accident emergency situations. This project received some interest from the US DOS and FEMA as it fits nicely under the umbrella of the G-7's GEMINI (Global Emergency Management Information Network Initiative) project. Because of LLNL/ARAC and JAERV WSPEEDI interest in nuclear accident consequence assessment and hazard prediction on all scales, to include global, we were happy to participate. Subsequent to the Spring 1997 RODOS-ARAC Workshop a Memorandum of Agreement was developed to enhance mutual collaboration on matters of emergency systems development. In the summer of 1998 the project leaders of RODOS, WSPEEDI and ARAC met at FZK and agreed to join in a triangular collaboration on the development and demonstration of an emergency information exchange protocol. JAERI and FZK are engaged in developing a formal cooperation agreement. The purpose of this project is to evaluate the prototype information protocol application for technical feasibility and mutual benefit through simulated (real) event; quick exchange of atmospheric modeling products and environmental data during emergencies, distribution of predicted results to other countries having no prediction capabilities, and utilization of …
Date: September 1, 1999
Creator: Sullivan, T J
System: The UNT Digital Library
High Energy Electrons, Positrons and Photonuclear Reactions in Petawatt Laser-Solid Experiments (open access)

High Energy Electrons, Positrons and Photonuclear Reactions in Petawatt Laser-Solid Experiments

The Petawatt laser at LLNL has opened a new regime of high-energy laser-matter interactions in which the quiver motion of plasma electrons is fully relativistic with energies extending well above the threshold for nuclear processes. We have observed that, in addition to the large flux of several MeV electrons ponderomotively expelled from the ultra-intense laser focus, there is a high energy component of electrons extending to -100 MeV, apparently from relativistic self-focusing and plasma acceleration in the underdense pre-formed plasma. The generation of hard bremsstrahlung cascade as these electrons traverse the solid target material, and the resulting photo-nuclear reactions, nuclear fission, and positron-electron pair production are described.
Date: September 9, 1999
Creator: Cowan, T. E.; Hunt, A. W.; Johnson, J.; Perry, M. D.; Fountain, W.; Hatchett, S. et al.
System: The UNT Digital Library
Hydrogen Release from Irradiated Vanadium Alloy V-4Cr-4Ti (open access)

Hydrogen Release from Irradiated Vanadium Alloy V-4Cr-4Ti

The present work is an attempt to obtain data concerning the influence of neutron and ? irradiation upon hydrogen retention in V-4Cr-4Ti vanadium alloy. The experiments on in-pile loading of vanadium alloy specimens at the neutron flux density 1014 n/cm2s, hydrogen pressure of 80 Pa, and temperatures of 563, 613, and 773 K were carried out using the IVG.1M reactor of the Kazakhstan National Nuclear Center. A preliminary set of loading/degassing experiments with non-irradiated material has been carried out to obtain data on hydrogen interaction with vanadium alloy. The, data presented in this work are related both to non-irradiated and irradiated samples.
Date: September 1, 1999
Creator: Klepikov, A. Kh.; Romanenko, O. G.; Chikhray, E. V.; Tazhibaeva, I. L.; Shestakov, V. P. & Longhurst, Glen Reed
System: The UNT Digital Library
Demonstration of a Universal Solvent Extraction Process for the Separation of Cesium and Strontium from Actual Acidic Tank Waste at the INEEL (open access)

Demonstration of a Universal Solvent Extraction Process for the Separation of Cesium and Strontium from Actual Acidic Tank Waste at the INEEL

A universal solvent extraction process is being evaluated for the simultaneous separation of Cs, Sr, and the actinides from acidic high-activity tank waste at the Idaho National Engineering and Environmental Laboratory (INEEL) with the goal of minimizing the high-activity waste volume to be disposed in a deep geological repository. The universal solvent extraction process is being developed as a collaborative effort between the INEEL and the Khlopin Radium Institute in St. Petersburg, Russia. The process was recently demonstrated at the INEEL using actual radioactive, acidic tank waste in 24 stages of 2-cm diameter centrifugal contactors located in a shielded cell facility. With this testing, removal efficiencies of 99.95%, 99.985%, and 95.2% were obtained for 137 Cs, 90 Sr, and total alpha, respectively. This is sufficient to reduce the activities of 137 Cs and 90 Sr to below NRC Class A LLW requirements. The total alpha removal efficiency was not sufficient to reduce the activity of the tank waste to below NRC Class A non-TRU requirements. The lower than expected removal efficiency for the actinides is due to loading of the Ph2Bu2CMPO in the universal solvent exiting the actinide strip section and entering the wash section resulted in the recycle of …
Date: September 1, 1999
Creator: Law, Jack Douglas; Herbst, Ronald Scott; Todd, Terry Allen; Brewer, Ken Neal; Romanovskiy, V. N.; Esimantovskiy, V. M. et al.
System: The UNT Digital Library
Crack Growth Monitoring in Harsh Environments by Electric Potential Measurements (open access)

Crack Growth Monitoring in Harsh Environments by Electric Potential Measurements

Electric potential measurement (EPM) technology offers an attractive alternative to conventional nondestructive evaluation (NDE) for monitoring crack growth in harsh environments. Where conventional NDE methods typically require localized human interaction, the EPM technique developed at the Idaho National Engineering and Environmental Laboratory (INEEL) can be operated remotely and automatically. Once a crack-like defect is discovered via conventional means, EPM can be applied to monitor local crack size changes. This is of particular interest in situations where an identified structural defect is not immediately rejectable from a fitness-for-service viewpoint, but due to operational and environmental conditions may grow to an unsafe size with continuing operation. If the location is in a harsh environment where periodic monitoring by normal means is either too costly or not possible, a very expensive repair may be immediately mandated. However, the proposed EPM methodology may offer a unique monitoring capability that would allow for continuing service. INEEL has developed this methodology, supporting equipment, and calibration information to apply EPM in a field environment for just this purpose. Laboratory and pilot scale tests on full-size engineering structures (pressure vessels and piping) have been successfully performed. The technique applicable is many severe environments because the sensitive equipment (electronics, …
Date: September 1, 1999
Creator: Lloyd, Wilson Randolph; Reuter, Walter Graham & Weinberg, David Michael
System: The UNT Digital Library
Critical Properties of Polydisperse Fluid Mixtures From Anequation of State (open access)

Critical Properties of Polydisperse Fluid Mixtures From Anequation of State

Based on stability theory for plydisperse fluid mixtures, expressions have been developed for the spinodal criterion, critical criterion and various stability tests for systems containing one discrete component and one continuous homologue. Each criterion can be separated into two parts: the first part is the same in form as that for binary systems; when we assume particular mixing rules for parameters of the equation of state, that part is determined only by the average molar mass of the homologue. The second part is concerned with the distribution function that characterizes the continuous component. To illustrate results, the van der Waals equation of state is used to calculate critical properties; the composition dependences of parameters a$sup 1/2$ and b of the van der Waals equation are assumed to be linear functions of molar mass. Numerical results for the critical loci are obtained. For a discrete component i and a continuous component j, systematic variations of parameters in the distribution function for j or of the interaction parameter$sub ij$ show transitions between qualitatively different types of phase behavior.
Date: September 1, 1999
Creator: Cai, J.; Liu, H.; Hu, Y. & Prausnitz, J.M.
System: The UNT Digital Library
Preliminary Environmental Flow and Transport Modeling at the INEEL (open access)

Preliminary Environmental Flow and Transport Modeling at the INEEL

The Idaho National Engineering and Environmental Laboratory (INEEL) is located in southeastern Idaho in the USA. The primary mission since the laboratory was founded in 1949 has been nuclear reactor research. Fifty-two reactors have been built and operated on the INEEL. Other principal activities at the laboratory have been reprocessing of spent nuclear fuel. Low-level radioactive waste generated on site and mixed and transuranic waste from the Rocky Flats plutonium processing facility in Colorado has been disposed on the INEEL at the Radioactive Waste Management Complex (RWMC). Waste disposal at the RWMC began in 1952 with shallow land burial in pits and trenches. The INEEL was placed on the National Priorities List (NPL) in 1989. The resulting environmental assessments of the potential negative health impacts of disposed waste at the RWMC have required the use of predictive numerical simulations. A petroleum reservoir simulator called TETRAD was modified for use in simulating environmental flow and transport. Use of this code has allowed the complex subsurface stratigraphy to be simulated, including an extensive region of unsaturated fractured basalt. Dual continual simulation approaches have been used to assess combined aqueous- and gaseous-phase transport of volatile organic compounds as well as dissolved-phase transport of …
Date: September 1, 1999
Creator: Magnuson, Swen O; Mccarthy, James Michael & Navratil, James Dale
System: The UNT Digital Library
Installation of the Irradiation Test Vehicle in the Advanced Test Reactor (open access)

Installation of the Irradiation Test Vehicle in the Advanced Test Reactor

The Irradiation Test Vehicle (ITV) was installed in the Department of Energy’s Advanced Test Reactor (ATR) during May 1999. The ITV is capable of providing neutron spectral tailoring and individual temperature control for up to 15 experiment capsules simultaneously. The test vehicle consists of three permanently installed in-pile tubes running the length of the reactor vessel. The bores of these in-pile tubes are kept dry and test trains with integral instrumentation are inserted and removed through a transfer shield plate above the reactor vessel head. The test vehicle is designed to irradiate specimens as large as 2.2 cm in diameter, at temperatures of 250 - 800C, achieving neutron damage rates as high as 10 displacements per atom per year in Vanadium. The experiment specimen temperature control is fully automated using a Distributed Control System (DCS) to control up to 15 separate blended gas channels for the ITV. The system remains in place as a permanent ATR Experiment support system and has excess capacity to accommodate experiment program growth. The ITV was initially installed with instrumented dummy tests to allow for testing and characterization of the control system.
Date: September 1, 1999
Creator: Palmer, Alma Joseph; Hong, Bonnie Colleen; Ingram, Frederick William & Stites, David John
System: The UNT Digital Library
Multi-Detector Analysis System for Spent Nuclear Fuel Characterization (open access)

Multi-Detector Analysis System for Spent Nuclear Fuel Characterization

The Spent Nuclear Fuel (SNF) Non-Destructive Analysis (NDA) program at INEEL is developing a system to characterize SNF for fissile mass, radiation source term, and fissile isotopic content. The system is based on the integration of the Fission Assay Tomography System (FATS) and the Gamma-Neutron Analysis Technique (GNAT) developed under programs supported by the DOE Office of Non-proliferation and National Security. Both FATS and GNAT were developed as separate systems to provide information on the location of special nuclear material in weapons configuration (FATS role), and to measure isotopic ratios of fissile material to determine if the material was from a weapon (GNAT role). FATS is capable of not only determining the presence and location of fissile material but also the quantity of fissile material present to within 50%. GNAT determines the ratios of the fissile and fissionable material by coincidence methods that allow the two prompt (immediately) produced fission fragments to be identified. Therefore, from the combination of FATS and GNAT, MDAS is able to measure the fissile material, radiation source term, and fissile isotopics content.
Date: September 1, 1999
Creator: Reber, Edward Lawrence; Aryaeinejad, Rahmat; Cole, Jerald Donald; Drigert, Mark William; Jewell, James Keith; Egger, Ann Elizabeth et al.
System: The UNT Digital Library
A Simplified Shuttle Irradiation Facility for ATR (open access)

A Simplified Shuttle Irradiation Facility for ATR

During the past fifteen years there has been a steady increase in the demand for radioisotopes in nuclear medicine and a corresponding decline in the number of reactors within the U.S. capable of producing them. The Advanced Test Reactor (ATR) is the largest operating test reactor in the U.S., but its isotope production capabilities have been limited by the lack of an installed isotope shuttle irradiation system. A concept for a simple “low cost” shuttle irradiation facility for ATR has been developed. Costs were reduced (in comparison to previous ATR designs) by using a shielded trough of water installed in an occupiable cubicle as a shielding and contamination control barrier for the send and receive station. This shielding concept also allows all control valves to be operated by hand and thus the need for an automatic control system was eliminated. It was determined that 4 – 5 ft of water would be adequate to shield the isotopes of interest while shuttles are transferred to a small carrier. An additional feature of the current design is a non-isolatable by-pass line, which provides a minimum coolant flow to the test region regardless of which control valves are opened or closed. This by-pass …
Date: September 1, 1999
Creator: Palmer, Alma Joseph & Laflin, S. T.
System: The UNT Digital Library
Analysis of Pressurized Water Reactor Primary Coolant Leak Events Caused by Thermal Fatigue (open access)

Analysis of Pressurized Water Reactor Primary Coolant Leak Events Caused by Thermal Fatigue

We present statistical analyses of pressurized water reactor (PWR) primary coolant leak events caused by thermal fatigue, and discuss their safety significance. Our worldwide data contain 13 leak events (through-wall cracking) in 3509 reactor-years, all in stainless steel piping with diameter less than 25 cm. Several types of data analysis show that the frequency of leak events (events per reactor-year) is increasing with plant age, and the increase is statistically significant. When an exponential trend model is assumed, the leak frequency is estimated to double every 8 years of reactor age, although this result should not be extrapolated to plants much older than 25 years. Difficulties in arresting this increase include lack of quantitative understanding of the phenomena causing thermal fatigue, lack of understanding of crack growth, and difficulty in detecting existing cracks.
Date: September 1, 1999
Creator: Atwood, Corwin Lee; Shah, Vikram Naginbhai & Galyean, William Jospeh
System: The UNT Digital Library
Constraints on Hidden Sector Gaugino Condensation (open access)

Constraints on Hidden Sector Gaugino Condensation

This report addresses the constraints on hidden sector gaugino condensation.
Date: September 1, 1999
Creator: Gaillard, Mark K. & Nelson, Brent D.
System: The UNT Digital Library
Periodic microvariation of B416, a new luminous blue variable in M33 (open access)

Periodic microvariation of B416, a new luminous blue variable in M33

This article reports optical photometric and spectroscopic observations of the M33 star B416, establishing it as the fifth identified luminous blue variable (LBV) in that galaxy.
Date: September 2, 1999
Creator: Shemmer, Ohad; Leibowitz, E. M. & Szkody, Paula
System: The UNT Digital Library
High field solenoids for muon cooling (open access)

High field solenoids for muon cooling

The proposed cooling system for the muon collider will consist of a 200 meter long line of alternating field straight solenoids interspersed with bent solenoids. The muons are cooled in all directions using a 400 mm long section liquid hydrogen at high field. The muons are accelerated in the forward direction by about 900 mm long, 805 MHz RF cavities in a gradient field that goes from 6 T to -6 T in about 300 mm. The high field section in the channel starts out at an induction of about 2 T in the hydrogen. As the muons proceed down the cooling channel, the induction in the liquid hydrogen section increases to inductions as high as 30 T. The diameter of the liquid hydrogen section starts at 750 mm when the induction is 2 T. As the induction in the cooling section goes up, the diameter of the liquid hydrogen section decreases. When the high field induction is 30 T, the diameter of the liquid hydrogen section is about 80 mm. When the high field solenoid induction is below 8.5 T or 9T, niobium titanium coils are proposed for generating .the magnetic field. Above 8.5 T or 9 T to …
Date: September 8, 1999
Creator: Green, M. A.; Eyssa, Y.; Kenny, S.; Miller, J. R. & Prestemon, S.
System: The UNT Digital Library
Use of fish community data to evaluate restoration success of a riparian stream. (open access)

Use of fish community data to evaluate restoration success of a riparian stream.

Abstract From 1985 to 1988, stream and riparian habitats in Pen branch and Four Mile branch began recovering from deforestation caused by the previous release of hot water from nuclear reactors. The Pen branch corridor was replanted with wetland trees in 1995 to expedite recovery and restore the Pen branch ecosystem. Pen branch, Four Mile branch, and two relatively undisturbed streams were electrofished in 1995:1996 to determine how fish assemblages differed between the previously disturbed and undisturbed streams and whether such difference could be used to measure restoration success in Pen branch. Fish assemblages were analyzed using nonparametric multivariate statistical methods and the index of biotic integrity (IBI), a bioassessment method based on measurement of ecologically sensitive characteristics of fish assemblages. Many aspects of fish assemblage structure (e.g. species richness, disease incidence, taxonomic composition at the family level) did not differ between disturbed and undisturbed streams; however, the disturbed streams were characterized by higher densities of a number of species. These differences were successfully detected with the multivariate statistical methods; whereas, the IBI did not differ between most recovering and undisturbed sampling sites. Because fish assemblages are strongly influenced by instream habitat, and because instream habitat is strongly influenced by …
Date: September 1, 1999
Creator: Paller, Michael, H.; Reichert, Marcel, J.M.; Dean, John, M. & Seigle, John, C.
System: The UNT Digital Library
The design and construction of a gradient solenoid for the high powered RF cavity experiment for the muon collider (open access)

The design and construction of a gradient solenoid for the high powered RF cavity experiment for the muon collider

This report describes the construction and test of a split solenoid that has a warm bore of 440 mm and a cryostat length of 1088 mm. (A 750 mm section contains the magnetic field.) When the coils are hooked so the fields are additive, the central induction is 5.0 T at its design current. When the coils are hooked so that the fields are in opposition, the induction at the center of the solenoid is zero and the peak induction on the solenoid axis is {+-}3.7 T. The on-axis induction gradient is 25 T per meter when the coils are hooked in opposition. When the coils are operated at their design currents in opposition, the force pushing the two coils apart is about 3 MN. The force pushing the coils apart is carried by the aluminum coil mandrel and a solid aluminum sheath outside of the superconducting winding. The coil was wound as a wet lay-up coil using alumina filled epoxy (Stycast). A layer of hard aluminum wire wound on the outside of the superconducting coil carries some of the hoop forces and limits the strain so that training does not occur. At design current, at both polarities, the peak …
Date: September 5, 1999
Creator: Green, M. A.; Chen, J. Y. & Wang, S. T.
System: The UNT Digital Library
Proceedings of the 21st Seismic Research Symposium: Technologies for Monitoring The Comprehensive Nuclear Test-Ban Treaty (open access)

Proceedings of the 21st Seismic Research Symposium: Technologies for Monitoring The Comprehensive Nuclear Test-Ban Treaty

These proceedings contain papers prepared for the 21st Seismic Research Symposium: Technologies for Monitoring The Comprehensive Nuclear-Test-Ban Treaty, held 21-24 September 1999 in Las Vegas, Nevada. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Defense Threat Reduction Agency (DTRA), Air Force Technical Applications Center (AFTAC), Department of Defense (DoD), the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.
Date: September 21, 1999
Creator: Warren, N. Jill
System: The UNT Digital Library
A design for a combined function superconducting dipole for a muon collider FFAG accelerator (open access)

A design for a combined function superconducting dipole for a muon collider FFAG accelerator

The acceleration stages for a muon collider require that the muons be accelerated within a given ring in fewer than twenty turns. One type of accelerator that appears to be attractive for a synchrotron that accelerates the muon a factor of four in energy in a few turns is the Fixed Field Alternating Gradient (FFAG) type of accelerator. As the energy of the muon beam increases, the muons move toward a higher field region of a DC combined function dipole. The following dipole and quadrupole magnet characteristics are required for a muon FFAG machine to be successful: (1) The dipole will be a fixed field dipole with an impressed quadrupole and sextupole field. There may or may not be separate quadrupoles that mayor may not have added sextupole windings. (2) The horizontal aperture of the required good field region is wider than the vertical aperture of the required good field region. (3) The magnet is relatively short, so that the conventional SSC type of superconducting dipole or quadrupole ends can not be used. The field at the end of the magnet must fall off abruptly within the distance of less than one vertical aperture. For a magnet that is 400 …
Date: September 10, 1999
Creator: Green, Michael A.
System: The UNT Digital Library
Superconducting solenoids for the Muon collider (open access)

Superconducting solenoids for the Muon collider

The muon collider is a new idea for lepton colliders. The ultimate energy of an electron ring is limited by synchrotron radiation. Mouns, which have a rest mass that is 200 times that of an electron can be stored at much higher energies before synchrotron radiation limits ring performance. The problem with muon is their short lifetime (2.1 microseconds at rest). In order to operate a muon storage ring large numbers of muon must be collected, cooled and accelerated before they decay to an electron and two neutrinos. As we see it now, high field superconducting solenoids are an integral part of a muon coUider muon production and cooling systems. This report will describe the design parameters for superconducting and hybrid solenoids that are used for pion production and collection, RF phase rotations of the pions as they decay into muons and the muon cooling (reduction of the muon emittance) before acceleration.
Date: September 23, 1999
Creator: Green, M. A.; Eyssa, Y.; Kenny, S.; Miller, J. R.; Prestemon, S. & Weggel, R. J.
System: The UNT Digital Library
Wilson loops in large N theories (open access)

Wilson loops in large N theories

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Date: September 1, 1999
Creator: Ooguri, H.
System: The UNT Digital Library
Dynamics of H abstraction from alcohols (CH3OH, C2H5OH and 2-C3H7OH) using velocity map imaging in crossed molecular beams (open access)

Dynamics of H abstraction from alcohols (CH3OH, C2H5OH and 2-C3H7OH) using velocity map imaging in crossed molecular beams

The crossed beam reactions of ground state Cl ({sup 2}P{sub 3/2}) atoms with alcohols (CH{sub 3}OH, C{sub 2}H{sub 5}OH and 2-C{sub 3}H{sub 7}OH) have been studied using the technique of velocity map imaging (VELMI). The corresponding hydroxyalkyl radical was detected via single photon ionization using 157 nm laser light. The double differential cross sections were obtained at collision energies of 8.7 kcal/mol for methanol, 6.0 and 9.7 kcal/mol for ethanol, and 11.9 kcal/mol for 2-propanol. In all cases, the scattering was predominantly in the backward-sideways direction suggesting direct rebound dynamics, with varying amounts of sideways-scattering. In the case of methanol, the angular distributions were predominantly in the sideways-backward direction with respect to the incoming alcohol beam. Scattering was into the backward hemisphere at the lower collision energy for ethanol, with enhancement of sideways scattering with an increase in collision energy. Isoropanol gave scattering predominantly in the backward direction. Coupling between the translational energy and angular distributions was particularly significant for ethanol at the lower collision energy. All of the translational energy distributions peaked at about 6 kcal/mol and on average 30-40% of the available energy was deposited into product translation for all the alcohols studied. These results are contrasted with …
Date: September 1, 1999
Creator: Ahmed, M.; Peterka, D. S. & Suits, A. G.
System: The UNT Digital Library
Design and Fabrication of a 14 T, Nb3Sn Superconducting Racetrack Dipole Magnet (open access)

Design and Fabrication of a 14 T, Nb3Sn Superconducting Racetrack Dipole Magnet

Most accelerator magnets for applications in the field range up to 10 T utilize NbTi superconductor and a cosine theta coil design. For fields above 10 T, it is necessary to use Nb{sub 3}Sn or other strain sensitive superconductors land other coil geometries that are more compatible with these materials. This paper describes our recent efforts to design a series of racetrack coil magnets that will provide experimental verification of an alternative magnet design philosophy, with the near-term goal of reaching a field level of approximately 14 T. The conductor and fabrication issues relevant to building high field, racetrack dipoles utilizing Nb{sub 3}Sn superconductor and a wind and react approach will also be discussed.
Date: September 1, 1999
Creator: Gourlay, S. A.; Bish, P.; Caspi, S.; Chow, K.; Dietderich, D. R.; Gupta, R. et al.
System: The UNT Digital Library