Introduction to the differential geometry of quantum groups (open access)

Introduction to the differential geometry of quantum groups

An introduction to the noncommutative differential calculus on quantum groups. The invariant group average is also discussed.
Date: October 31, 1991
Creator: Zumino, B.
System: The UNT Digital Library
Introduction to the differential geometry of quantum groups (open access)

Introduction to the differential geometry of quantum groups

An introduction to the noncommutative differential calculus on quantum groups. The invariant group average is also discussed.
Date: October 31, 1991
Creator: Zumino, B.
System: The UNT Digital Library
WA80 BGO calorimetry electronics (open access)

WA80 BGO calorimetry electronics

This paper describes instrumentation designed for BGO scintillator-based calorimetry of particles covering a very wide range of energies (from less than 50 MeV to 50 GeV). The instrumentation was designed to have a measurement accuracy of 0.1% over as much of the energy range as possible so the energy resolution of BGO would be the limiting factor. Two 1.5-cm{sup 2} photodiodes were used per 2.5 cm {times} 2.5 cm {times} 25 cm BGO crystal. Both a charge-sensitive preamplifier and a pulse processor were developed specifically for the needs of the WA80 experiment. The preamplifier was designed for high detector capacitance (100 to 700 pF), low integral and differential non-linearity and low power consumption (200 mW). The pulse processor is a time-invariant shaping amplifier with integral peak-detect-and-hold and automatic gain selection circuits. The amplifier use quasi-triangular shaping with 4 {mu}s peaking time, and the hold circuit is gated with a fast first level trigger. The system has more than 20 bits of effective resolution when used with an external 12-bit ADC. Results from beam tests at CERN are presented. 6 refs., 5 figs., 1 tab.
Date: October 31, 1991
Creator: Wintenberg, A. L.; Britton, C. L., Jr.; Ericson, M. N.; Maples, R. A.; Young, G. R. & Awes, T. C.
System: The UNT Digital Library
The impact of episodic nonequilibrium fracture-matrix flow on geological repository performance (open access)

The impact of episodic nonequilibrium fracture-matrix flow on geological repository performance

Adequate representation of fracture-matrix interaction during episodic infiltration events is crucial in making valid hydrological predictions of repository performance at Yucca Mountain. Various approximations have been applied to represent fracture-matrix flow interaction, including the Equivalent Continuum Model (ECM), which assumes capillary equilibrium between fractures and matrix, and the Fracture-Matrix Model (FMM), which accounts for nonequilibrium fracture-matrix flow. We analyze the relative impact of matrix imbibition on episodic nonequilibrium fracture-matrix flow for the eight major hydrostratigraphic units in the unsaturated zone at Yucca Mountain. Comparisons are made between ECM and FMM predictions to determine the applicability of the ECM. The implications of nonequilibrium fracture-matrix flow on radionuclide transport are also discussed.
Date: October 29, 1991
Creator: Buscheck, T. A.; Nitao, J. J. & Chestnut, D. A.
System: The UNT Digital Library
Advanced Light Source beam position monitor (open access)

Advanced Light Source beam position monitor

The Advanced Light Source (ALS) is a synchrotron radiation facility nearing completion at LBL. As a third-generation machine, the ALS is designed to produce intense light from bend magnets, wigglers, and undulators (insertion devices). The facility will include a 50 MeV electron linear accelerator, a 1.5 GeV booster synchrotron, beam transport lines, a 1--2 GeV storage ring, insertion devices, and photon beam lines. Currently, the beam injection systems are being commissioned, and the storage ring is being installed. Electron beam position monitors (BPM) are installed throughout the accelerator and constitute the major part of accelerator beam diagnostics. The design of the BPM instruments is complete, and 50 units have been constructed for use in the injector systems. We are currently fabricating 100 additional instruments for the storage ring. In this paper I discuss engineering fabrication, testing and performance of the beam pickup electrodes and the BPM electronics.
Date: October 28, 1991
Creator: Hinkson, J.
System: The UNT Digital Library
Advanced Light Source Beam Position Monitor (open access)

Advanced Light Source Beam Position Monitor

The Advanced Light Source (ALS) is a synchrotron radiation facility nearing completion at LBL. As a third-generation machine, the ALS is designed to produce intense light from bend magnets, wigglers, and undulators (insertion devices). The facility will include a 50 MeV electron linear accelerator, a 1.5 GeV booster synchrotron, beam transport lines, a 1--2 GeV storage ring, insertion devices, and photon beam lines. Currently, the beam injection systems are being commissioned, and the storage ring is being installed. Electron beam position monitors (BPM) are installed throughout the accelerator and constitute the major part of accelerator beam diagnostics. The design of the BPM instruments is complete, and 50 units have been constructed for use in the injector systems. We are currently fabricating 100 additional instruments for the storage ring. In this paper I discuss engineering fabrication, testing and performance of the beam pickup electrodes and the BPM electronics.
Date: October 28, 1991
Creator: Hinkson, J.
System: The UNT Digital Library
Thermal effects and mirror surface figure requirements for a diagnostic beamline at the Advanced Light Source (open access)

Thermal effects and mirror surface figure requirements for a diagnostic beamline at the Advanced Light Source

An imaging beamline based on a Kirkpatrick-Baez mirror configuration has been designed to image the electron beam in the ALS storage ring, to measure its size and shape. The electron beam emittance will be small ({epsilon}h = 3.4 {times} 10{sup {minus}9} m rad) and the quality of the image is extremely sensitive to surface figure distortion of the mirrors. Thermal distortions and surface temperatures have been calculated for radiatively cooled mirrors of various materials in a search for a simple design which avoids water cooling. The choice of mirror material and the thermal and mechanical design is discussed. 6 refs.
Date: October 28, 1991
Creator: Warwick, T. (Lawrence Berkeley Lab., CA (United States)) & Sharma, S. (Brookhaven National Lab., Upton, NY (United States))
System: The UNT Digital Library
Thermal effects and mirror surface figure requirements for a diagnostic beamline at the Advanced Light Source (open access)

Thermal effects and mirror surface figure requirements for a diagnostic beamline at the Advanced Light Source

An imaging beamline based on a Kirkpatrick-Baez mirror configuration has been designed to image the electron beam in the ALS storage ring, to measure its size and shape. The electron beam emittance will be small ({epsilon}h = 3.4 {times} 10{sup {minus}9} m rad) and the quality of the image is extremely sensitive to surface figure distortion of the mirrors. Thermal distortions and surface temperatures have been calculated for radiatively cooled mirrors of various materials in a search for a simple design which avoids water cooling. The choice of mirror material and the thermal and mechanical design is discussed. 6 refs.
Date: October 28, 1991
Creator: Warwick, T. & Sharma, S.
System: The UNT Digital Library
Water cooled metal optics for the Advanced Light Source (open access)

Water cooled metal optics for the Advanced Light Source

The program for providing water cooled metal optics for the Advanced Light Source at Berkeley is reviewed with respect to fabrication and metrology of the surfaces. Materials choices, surface figure and smoothness specifications, and metrology systems for measuring the plated metal surfaces are discussed. Results from prototype mirrors and grating blanks will be presented, which show exceptionally low microroughness and mid-period error. We will briefly describe out improved version of the Long Trace Profiler, and its importance to out metrology program. We have completely redesigned the mechanical, optical and computational parts of the profiler system with the cooperation of Peter Takacs of Brookhaven, Continental Optical, and Baker Manufacturing. Most important is that one of our profilers is in use at the vendor to allow testing during fabrication. Metrology from the first water cooled mirror for an ALS beamline is presented as an example. The preplating processing and grinding and polishing were done by Tucson Optical. We will show significantly better surface microroughness on electroless nickel, over large areas, than has been reported previously.
Date: October 28, 1991
Creator: McKinney, W.R.; Irick, S.C. (Lawrence Berkeley Lab., CA (United States)) & Lunt, D.L.J. (Tucson Optical Research Corp., AZ (United States))
System: The UNT Digital Library
Water cooled metal optics for the Advanced Light Source (open access)

Water cooled metal optics for the Advanced Light Source

The program for providing water cooled metal optics for the Advanced Light Source at Berkeley is reviewed with respect to fabrication and metrology of the surfaces. Materials choices, surface figure and smoothness specifications, and metrology systems for measuring the plated metal surfaces are discussed. Results from prototype mirrors and grating blanks will be presented, which show exceptionally low microroughness and mid-period error. We will briefly describe out improved version of the Long Trace Profiler, and its importance to out metrology program. We have completely redesigned the mechanical, optical and computational parts of the profiler system with the cooperation of Peter Takacs of Brookhaven, Continental Optical, and Baker Manufacturing. Most important is that one of our profilers is in use at the vendor to allow testing during fabrication. Metrology from the first water cooled mirror for an ALS beamline is presented as an example. The preplating processing and grinding and polishing were done by Tucson Optical. We will show significantly better surface microroughness on electroless nickel, over large areas, than has been reported previously.
Date: October 28, 1991
Creator: McKinney, W. R.; Irick, S. C. & Lunt, D. L. J.
System: The UNT Digital Library
Scintillating plastic optical fiber radiation detectors in high energy particle physics (open access)

Scintillating plastic optical fiber radiation detectors in high energy particle physics

We describe the application of scintillating optical fiber in instrumentation for high energy particle physics. The basic physics of the scintillation process in polymers is discussed first and then we outline the fundamentals of scintillating fiber technology. Fiber performance, optimization, and characterization measurements are given. Detector applications in the areas of particle tracking and particle energy determination are then described. 13 refs., 12 figs.
Date: October 26, 1991
Creator: Bross, A.D.
System: The UNT Digital Library
Scintillating plastic optical fiber radiation detectors in high energy particle physics (open access)

Scintillating plastic optical fiber radiation detectors in high energy particle physics

We describe the application of scintillating optical fiber in instrumentation for high energy particle physics. The basic physics of the scintillation process in polymers is discussed first and then we outline the fundamentals of scintillating fiber technology. Fiber performance, optimization, and characterization measurements are given. Detector applications in the areas of particle tracking and particle energy determination are then described. 13 refs., 12 figs.
Date: October 26, 1991
Creator: Bross, A. D.
System: The UNT Digital Library
The neutrinos in muon decay (open access)

The neutrinos in muon decay

We review the available information on the identity of the neutrino states emitted in muon decay, and discuss the exotic decay {mu}{sup +} {yields} e{sup +} {bar {nu}}{sub e}{nu}{sub {mu}}. 22 refs.
Date: October 21, 1991
Creator: Herczeg, P.
System: The UNT Digital Library
A summary of high-temperature electronics research and development (open access)

A summary of high-temperature electronics research and development

Current and future needs in automative, aircraft, space, military, and well logging industries require operation of electronics at higher temperatures than today's accepted limit of 395 K. Without the availability of high-temperature electronics, many systems must operate under derated conditions or must accept severe mass penalties required by coolant systems to maintain electronic temperatures below critical levels. This paper presents ongoing research and development in the electronics community to bring high-temperature electronics to commercial realization. Much of this work was recently reviewed at the First International High-Temperature Electronics Conference held 16--20 June 1991 in Albuquerque, New Mexico. 4 refs., 1 tab.
Date: October 18, 1991
Creator: Thome, F. V. & King, D. B.
System: The UNT Digital Library
Safety questions relevant to nuclear thermal propulsion (open access)

Safety questions relevant to nuclear thermal propulsion

Nuclear propulsion is necessary for successful Mars exploration to enhance crew safety and reduce mission costs. Safety concerns are considered by some to be an implements to the use of nuclear thermal rockets for these missions. Therefore, an assessment was made of the various types of possible accident conditions that might occur and whether design or operational solutions exist. With the previous work on the NERVA nuclear rocket, most of the issues have been addressed in some detail. Thus, a large data base exist to use in an agreement. The assessment includes evaluating both ground, launch, space operations and disposal conditions. The conclusion is that design and operational solutions do exist for the safe use of nuclear thermal rockets and that both the environment and crews be protected against harmful radiation. Further, it is concluded that the use of nuclear thermal propulsion will reduce the radiation and mission risks to the Mars crews.
Date: October 15, 1991
Creator: Buden, D.
System: The UNT Digital Library
Safety questions relevant to nuclear thermal propulsion (open access)

Safety questions relevant to nuclear thermal propulsion

Nuclear propulsion is necessary for successful Mars exploration to enhance crew safety and reduce mission costs. Safety concerns are considered by some to be an implements to the use of nuclear thermal rockets for these missions. Therefore, an assessment was made of the various types of possible accident conditions that might occur and whether design or operational solutions exist. With the previous work on the NERVA nuclear rocket, most of the issues have been addressed in some detail. Thus, a large data base exist to use in an agreement. The assessment includes evaluating both ground, launch, space operations and disposal conditions. The conclusion is that design and operational solutions do exist for the safe use of nuclear thermal rockets and that both the environment and crews be protected against harmful radiation. Further, it is concluded that the use of nuclear thermal propulsion will reduce the radiation and mission risks to the Mars crews.
Date: October 15, 1991
Creator: Buden, D.
System: The UNT Digital Library
Space nuclear power requirements for ozone layer modification (open access)

Space nuclear power requirements for ozone layer modification

This work estimates the power requirements for using photochemical processes driven by space nuclear power to counteract the Earth's ozone layer depletion. The total quantity of ozone (O{sub 3}) in the Earth's atmosphere is estimated to be about 4.7 {times} 10{sup 37} molecules. The ozone production and destruction rates in the stratosphere are both on the order of 4.9 {times} 10{sup 31} molecules/s, differing by a small fraction so that the net depletion rate is about 0.16 to 0.26% per year. The delivered optical power requirement for offsetting this depletion is estimated to be on the order of 3 GW. If the power were produced by satellite reactors at 800 km altitude (orbit decay time {approximately} 300 years), some means of efficient power beaming would be needed to deliver the power to stratospheric levels (10--50 km). Ultraviolet radiation at 140--150 nm could have higher absorption rates in O{sub 2} (leading to production of atomic oxygen, which can combine with O{sub 2} to form O{sub 3}) than in ozone (leading to photodissociation of O{sub 3}). Potential radiation sources include H{sub 2} lasers and direct nuclear pumping of ultraviolet fluorescers. 5 refs.
Date: October 15, 1991
Creator: Dolan, T.J.
System: The UNT Digital Library
Recent results from the Crystal Barrel experiment (open access)

Recent results from the Crystal Barrel experiment

The Crystal Barrel experiment has been constructed and installed at the Low Energy Antiproton Ring (LEAR) at CERN. It has been fully operational since late 1989. In this talk, recent results of meson spectroscopy in p[bar p]-annihilations are presented. The main emphasis is on all-neutral annihilations, the study of the strange quark content of the proton, and the investigation of the decay mode of il particles. A 2[sup ++] resonance decaying into [pi][degrees][pi][degrees]at a mass of 1515 [plus minus] 10 MeV with a width of 120 [plus minus] 10 MeV has been seen in a 3[pi][degrees] final state.
Date: October 9, 1991
Creator: unknown
System: The UNT Digital Library
Recent results from the Crystal Barrel experiment (open access)

Recent results from the Crystal Barrel experiment

The Crystal Barrel experiment has been constructed and installed at the Low Energy Antiproton Ring (LEAR) at CERN. It has been fully operational since late 1989. In this talk, recent results of meson spectroscopy in p{bar p}-annihilations are presented. The main emphasis is on all-neutral annihilations, the study of the strange quark content of the proton, and the investigation of the decay mode of il particles. A 2{sup ++} resonance decaying into {pi}{degrees}{pi}{degrees}at a mass of 1515 {plus_minus} 10 MeV with a width of 120 {plus_minus} 10 MeV has been seen in a 3{pi}{degrees} final state.
Date: October 9, 1991
Creator: The Crystal Barrel Collaboration
System: The UNT Digital Library
MCNP neutron benchmarks (open access)

MCNP neutron benchmarks

Over 50 neutron benchmark calculations have recently been completed as part of an ongoing program to validate the MCNP Monte Carlo radiation transport code. The new and significant aspects of this work are as follows: These calculations are the first attempt at a validation program for MCNP and the first official benchmarking of version 4 of the code. We believe the chosen set of benchmarks is a comprehensive set that may be useful for benchmarking other radiation transport codes and data libraries. These calculations provide insight into how well neutron transport calculations can be expected to model a wide variety of problems.
Date: October 8, 1991
Creator: Hendricks, John S.; Whalen, Daniel J.; Cardon, David A. & Uhle, Jennifer L.
System: The UNT Digital Library
Hadron collider physics (open access)

Hadron collider physics

An introduction to the techniques of analysis of hadron collider events is presented in the context of the quark-parton model. Production and decay of W and Z intermediate vector bosons are used as examples. The structure of the Electroweak theory is outlined. Three simple FORTRAN programs are introduced, to illustrate Monte Carlo calculation techniques. 25 refs.
Date: October 3, 1991
Creator: Pondrom, L.
System: The UNT Digital Library
The LLNL computer control system (open access)

The LLNL computer control system

Lawrence Livermore National Laboratory (LLNL) has implemented a computer control system for operation of an FN tandem accelerator. The control software utilized is the Thaumaturgic Automated Control Logic (TACL) written by the Continuous Electron Beam Accelerator Facility and co-developed with LLNL. Details of the design philosophy, hardware configuration, control software, and special control algorithms will be presented. 2 refs., 4 figs.
Date: October 3, 1991
Creator: Roberts, M. L.
System: The UNT Digital Library
Small Inertial Fusion Energy (IFE) demonstration reactors (open access)

Small Inertial Fusion Energy (IFE) demonstration reactors

ICF target design studies done for the Nova Upgrade have identified conditions under which the target ignition ``cliff`` is shifted to much lower drive energy albeit with the penalty that the gain achieved at a given energy is also smaller. These targets would repeatedly produce the output and spectra of a higher gain targets at low yield. They should, thus, allow building much smaller R&D reactors with full thermonuclear effects. Demonstration reactor at the 1 to 100 MW{sub e} level appear to be feasible with driver energies of 0.5 to 2.0 MJ per pulse. These smaller, less expensive test and demonstration facilities should result in lower IFE development cost. If the U.S. government builds a driver and target factory, it is also conceivable that commercial organizations could build their own scaled concepts of IFE reactors using the beams and targets supplied by the government`s facilities.
Date: October 3, 1991
Creator: Hogan, W.J.
System: The UNT Digital Library
A 2-GHz Rectangular Corrugated Horn (open access)

A 2-GHz Rectangular Corrugated Horn

We have designed, constructed and tested a large, rectangular horn antenna with a center frequency of 2.0 GHz, corrugated on the E-plane walls, made out of aluminum sheet. A new technique has been developed to solder thin aluminum strips onto the back plane to form the corrugations. The radiation beam pattern shows half-power beamwidths of 12{sup 0} and 14{sup 0} in the H and E planes respectively, and side lobe response below -40 dB at angles greater than 50{sup 0} from horn axis. The measured return loss is less than -20 dB (VSWR < 1.22) between 1.7 and 2.3 GHz; insertion loss is less than 0.15 dB.
Date: October 1, 1991
Creator: Bersanelli, M.; Bensadoun, M.; De Amici, Giovanni; Limon, M.; Smoot, George F.; Tanaka, S. et al.
System: The UNT Digital Library