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Quench observation using quench antennas on RHIC IR quadrupole magnets
Quench observation using quench antennas is now being performed routinely on RHIC dipole and quadrupole magnets. Recently, a quench antenna was used on a RHIC IR magnet which is heavily instrumented with voltage taps. It was confirmed that the signals detected in the antenna coils do not contradict the voltage tap signals. The antenna also detects a sign of mechanical disturbance which could be related to a training quench. This paper summarizes signals detected in the antenna and discusses possible causes of these signals.
Date:
July 1995
Creator:
Ogitsu, T.; Terashima, A.; Tsuchiya, K.; Ganetis, G.; Muratore, J. & Wanderer, P.
Object Type:
Article
System:
The UNT Digital Library
Solar two: A molten salt power tower demonstration
A consortium of United States utility concerns led by the Southern California Edison Company (SCE) is conducting a cooperative project with the US Department of Energy (DOE), Sandia National Laboratories, and industry to convert the 10-MW Solar One Power Tower Pilot Plant to molten nitrate salt technology. The conversion involves installation of a new receiver, a new thermal storage system, and a new steam generator; it utilizes Solar One`s heliostat field and turbine generator. Successful operation of the converted plant, called Solar Two, will reduce economic risks in building initial commercial power tow projects and accelerate the commercial acceptance of this promising renewable energy technology. The estimated cost of Solar Two, including its three-year test period, is $48.5 million. The plant will begin operation in early 1996.
Date:
August 1995
Creator:
Tyner, C. E.; Sutherland, J. P. & Gould, W. R., Jr.
Object Type:
Article
System:
The UNT Digital Library
Medical imaging with coded apertures
Now algorithms were investigated for image reconstruction in emission tomography which could incorporate complex instrumental effects such as might be obtained with a coded aperture system. The investigation focused on possible uses of the wavelet transform to handle non-stationary instrumental effects and analytic continuation of the Radon transform to handle self-absorption. Neither investigation was completed during the funding period and whether such algorithms will be useful remains an open question.
Date:
June 16, 1995
Creator:
Keto, E. & Libby, S.
Object Type:
Report
System:
The UNT Digital Library
Tuning shims for high field quality in superconducting magnets
A high field quality in interaction region quadrupoles is crucial to the luminosity performance of high energy colliders such as the Relativistic Heavy Ion Collider (RHIC). The field quality in magnets is limited in part by manufacturing tolerances in the parts and assembly. A tuning shim method has been developed to reduce the relative field errors ({Delta}B/B) from {approximately}10{sup {minus}4} to {approximately}10{sup {minus}5} at 2/3 of the coil radius. Eight tuning shims having a variable thickness of iron are inserted after the construction and measurement of field harmonics in the magnet. In this paper the tuning shim technique is described for RHIC interaction region quadrupoles. The results of calculations and measurement are also presented.
Date:
August 1995
Creator:
Gupta, R.; Anerella, M. & Cozzolino, J.
Object Type:
Article
System:
The UNT Digital Library
Ultra-intense, short pulse laser-plasma interactions with applications to the fast ignitor
Due to the advent of chirped pulse amplification (CPA) as an efficient means of creating ultra-high intensity laser light (I > 5{times}10{sup 17} W/cm{sup 2}) in pulses less than a few picoseconds, new ideas for achieving ignition and gain in DT targets with less than 1 megajoule of input energy are currently being pursued. Two types of powerful lasers are employed in this scheme: (1) channeling beams and (2) ignition beams. The current state of laser-plasma interactions relating to this fusion scheme will be discussed. In particular, plasma physics issues in the ultra-intense regime are crucial to the success of this scheme. We compare simulation and experimental results in this highly nonlinear regime.
Date:
April 1, 1995
Creator:
Wilks, S. C.; Kruer, W. L.; Young, P. E.; Hammer, J. & Tabak, M.
Object Type:
Article
System:
The UNT Digital Library
The magnet system of the Relativistic Heavy Ion Collider (RHIC)
The Relativistic Heavy Ion Collider now under construction at Brookhaven National Laboratory (BNL) is a colliding ring accelerator to be completed in 1999. Through collisions of heavy ions it is hoped to observe the creation of matter at extremely high temperatures and densities, similar to what may have occurred in the original "Big Bang." The collider rings will consist of 1740 superconducting magnet elements. Some of elements are being manufactured by industrial partners (Northrop Grumman and Everson Electric). Others are being constructed or assembled at BNL. A description is given of the magnet designs, the plan for manufacturing and test results. In the manufacturing of the magnets, emphasis has been placed on uniformity of their performance and on quality. Results so far indicate that this emphasis has been very successful.
Date:
July 1995
Creator:
Greene, A.; Anerella, M. & Cozzolino, J.
Object Type:
Article
System:
The UNT Digital Library
Properties of a new average power Nd-doped phosphate laser glass
The Nd-doped phosphate laser glass described herein can withstand 2.3 times greater thermal loading without fracture, compared to APG-1 (commercially-available average-power glass from Schott Glass Technologies). The enhanced thermal loading capability is established on the basis of the intrinsic thermomechanical properties and by direct thermally-induced fracture experiments using Ar-ion laser heating of the samples. This Nd-doped phosphate glass (referred to as APG-t) is found to be characterized by a 29% lower gain cross section and a 25% longer low-concentration emission lifetime.
Date:
March 9, 1995
Creator:
Payne, S. A.; Marshall, C. D.; Bayramian, A. J.; Wilke, G. D. & Hayden, J. S.
Object Type:
Article
System:
The UNT Digital Library
Plasma gate switch experiment on Pegasus II
The plasma gate switch is a novel technique for producing a long conduction time vacuum opening switch. The switch consists of an aluminum foil which connects the cathode to the anode in a coaxial geometry. The foil is designed so that the maximum axial acceleration is in the center of the foil and that at the appropriate time, the center opens up and magnetic flux is carried down the gun to the load region. The switch is designed to minimize the amount of mass transported into the load region. We have completed the first experimental test of this design and present results from the test. These results indicate there were some asymmetry problems in the construction of the switch but that otherwise the switch performed as expected.
Date:
September 1995
Creator:
Wysocki, F. J.; Benage, J. F., Jr. & Shlachter, J. S.
Object Type:
Article
System:
The UNT Digital Library
Single Bunch Stability to Monopole Excitation
We study single bunch stability with respect to monopole longitudinal oscillations in electron storage rings. Our analysis is different from the standard approach based on the linearized Vlasov equation. Rather, we reduce the full nonlinear Fokker-Planck equation to a Schroedinger-like equation which is subsequently analyzed by perturbation theory. We show that the Haissinski solution [3] may become unstable with respect to monopole oscillations and derive a stability criterion in terms of the ring impedance. We then discuss this criterion and apply it to a broad band resonator impedance model.
Date:
January 19, 1999
Creator:
Podobedov, Boris
Object Type:
Report
System:
The UNT Digital Library
Neutron diffraction study of NiTi during compressive deformation and after shape-memory recovery
Neutron diffraction measurements of internal elastic strains and texture were performed during compressive deformation of martensitic NiTi deforming by twinning. Rietveld refinement of the diffraction spectrum was performed in order to obtain lattice parameter variations and preferred orientation of martensitic variants. The elastic internal strains, are proportional to the externally applied stress but strongly dependent on crystallographic orientation. Plastic deformation by matrix twinning is consistent with type I (1-1-1) twinning, whereby (100) and (011) planes tend to align perpendicular and parallel to the stress axis, respectively. The preferred orientation ratio r according to the model by March and Dollase is proportional to the macroscopic plastic strain for (100) and (011) planes for loading, unloading and shape-memory recovery. To the best of our knowledge, this is the first in situ bulk measurement of reversible twinning in NiTi. Finally, shape-memory recovery results in a marked change of NiTi cell parameters.
Date:
September 1995
Creator:
Dunand, D. C.; Mari, D.; Bourke, Mark A. M. & Goldstone, Joyce A.
Object Type:
Report
System:
The UNT Digital Library
Deep x-ray lithography for micromechanics
Extensions of the German LIGA process have brought about fabrication capability suitable for cost effective production of precision engineered components. The process attributes allow fabrication of mechanical components which are not capable of being made via conventional subtractive machining methods. Two process improvements have been responsible for this extended capability which involve the areas of thick photoresist application and planarization via precision lapping. Application of low-stress x-ray photoresist has been achieved using room temperature solvent bonding of a preformed photoresist sheet. Precision diamond lapping and polishing has provided a flexible process for the planarization of a wide variety of electroplated metals in the presence of photoresist. Exposure results from the 2.5 GeV National Synchrotron Light Source storage ring at Brookhaven National Laboratory have shown that structural heights of several millimeter and above are possible. The process capabilities are also well suited for microactuator fabrication. Linear and rotational magnetic microactuators have been constructed which use coil winding technology with LIGA fabricated coil forms. Actuator output forces of 1 milliNewton have been obtained with power dissipation on the order of milliWatts. A rotational microdynamometer system which is capable of measuring torque-speed data is also discussed.
Date:
August 1995
Creator:
Christenson, T. R. & Guckel, H.
Object Type:
Article
System:
The UNT Digital Library
Maintenance Action Work Plan for Waste Area Grouping 1 inactive tanks 3001-B, 3004-B, T-30, and 3013 at Oak Ridge National Laboratory, Oak Ridge, Tennessee. Environmental Restoration Program
This Maintenance Action Work Plan has been prepared to document the activities and procedures for the remediation of four inactive, low-level radioactive tanks at Waste Area Grouping 1, from the Category D list of tanks in the Federal Facility Agreement for the Oak Ridge Reservation (EPA et al. 1994). The four tanks to remediated are tanks 3001-B, 3004-B, T-30, and 3013. Three of the tanks (3001-B, 3004-B, and T-30) will be physically removed from the ground. Because of logistical issues associted with excavation and site access, the fourth tank (3013) will be grouted in place and permanently closed.
Date:
July 1, 1995
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
The LCLS X-Ray FEL at SLAC
The design status and R and D plan of a 1.5 Angstrom SASE-FEL at SLAC, called the Linac Coherent Light Source (LCLS), are described. The LCLS utilizes one third of the SLAC linac for the acceleration of electrons to about 15 GeV. The FEL radiation is produced in a long undulator and is directed to an experimental area for its utilization. The LCLS is designed to produce 300 fsec long radiation pulses at the wavelength of 1.5 Angstrom with 9 GW peak power. This radiation has much higher brightness and coherence, as well as shorter pulses, than present 3rd generation sources. It is shown that such leap in performance is now within reach, and is made possible by the advances in the physics and technology of photo-injectors, linear accelerators, insertion devices and free-electron lasers.
Date:
February 9, 1999
Creator:
Cornacchia, Massimo
Object Type:
Report
System:
The UNT Digital Library
Material and processing issues for the monolithic integration of microelectronics with surface-micromachined polysilicon sensors and actuators
The monolithic integration of micromechanical devices with their controlling electronics offers potential increases in performance as well as decreases in cost for these devices. Analog Devices has demonstrated the commercial viability of this integration by interleaving the micromechanical fabrication steps of an accelerometer with the microelectronic fabrication steps of its controlling electronics. Sandia`s Microelectronics Development Laboratory has integrated the micromechanical and microelectronic processing sequences in a segregated fashion. In this CMOS-first, micromechanics-last approach, conventional aluminum metallization is replaced by tungsten metallization to allow CMOS to withstand subsequent high-temperature processing during the micromechanical fabrication. This approach is a further development of an approach originally developed at UC Berkeley. Specifically, the issues of yield, repeatability, and uniformity of the tungsten/CMOS approach are addressed. Also, material issues related to the development of high-temperature diffusion barriers, adhesion layers, and low-stress films are discussed. Processing and material issues associated with alternative approaches to this integration such as micromechanics- first, CMOS-last or the interleaved process are also discussed.
Date:
August 1, 1995
Creator:
Smith, J.H.; Montague, S. & Sniegowski, J.J.
Object Type:
Article
System:
The UNT Digital Library
Using the CAVE virtual-reality environment as an aid to 3-D electromagnetic field computation
One of the major problems in three-dimensional (3-D) field computation is visualizing the resulting 3-D field distributions. A virtual-reality environment, such as the CAVE, (CAVE Automatic Virtual Environment) is helping to overcome this problem, thus making the results of computation more usable for designers and users of magnets and other electromagnetic devices. As a demonstration of the capabilities of the CAVE, the elliptical multipole wiggler (EMW), an insertion device being designed for the Advanced Photon Source (APS) now being commissioned at Argonne National Laboratory (ANL), wa made visible, along with its fields and beam orbits. Other uses of the CAVE in preprocessing and postprocessing computation for electromagnetic applications are also discussed.
Date:
August 1995
Creator:
Turner, L. R.; Levine, D.; Huang, M.; Papka, M. & Kettunen, L.
Object Type:
Article
System:
The UNT Digital Library
Superlattice Photocathodes for Accelerator-Based Polarized Electron Source Applications
A major improvement in the performance of the SLC was achieved with the introduction of thin strained-layer semiconductor crystals. After some optimization, polarizations of 75-85% became standard with lifetimes that were equal to or better than that of thick unstrained crystals. Other accelerators of polarized electrons, generally operating with a much higher duty factor, have now successfully utilized similar photocathodes. For future colliders, the principal remaining problem is the limit on the total charge that can be extracted in a time scale of 10 to 100 ns. In addition, higher polarization is critical for exploring new physics, especially supersymmetry. However, it appears that strained-layer crystals have reached the limit of their optimization. Today strained superlattice crystals are the most promising candidates for better performance. The individual layers of the superlattice can be designed to be below the critical thickness for strain relaxation, thus in principle improving the polarization. Thin layers also promote high electron conduction to the surface. In addition the potential barriers at the surface for both emission of conduction-band electrons to vacuum and for tunneling of valence-band holes to the surface can be significantly less than for single strained-layer crystals, thus enhancing both the yield at any intensity …
Date:
March 22, 1999
Creator:
Clendenin, James E
Object Type:
Report
System:
The UNT Digital Library
Results of design calculations. Specification of a prototype zone plate for focusing hard x-rays
A zone plate capable of focusing hard x-rays to less than 1 {mu}m spot size is designed and specified. This design is based on the state-of-art fabrication technology available today. This zone plate consists of Cu/Al layers sputtered alternatively on a round stainless steel core. Parameters of this zone plate are given. The focal length f is given for 8Kev x-rays and the thickness is optimized for focusing efficiency of the same x-ray energy.
Date:
January 1991
Creator:
Yun, W. B.; Chrzas, J. & Viccaro, P. J.
Object Type:
Report
System:
The UNT Digital Library
Solid Waste Assurance Program Implementation Plan
On June 6, 1995, a waiver to Hanford Site Solid Waste Acceptance Criteria, was approved by the US Department of Energy Richland Operations Office (RL) to replace the low-level, mixed, and transuranic (TRU) generator assessment programs with the Solid Waste Assurance Program (SWAP). This is associated with a waiver that was approved on March 16, 1995 to replace the Storage/Disposal Approval Record (SDAR) requirements with the Waste Specification System (WSS). This implementation plan and the SWAP applies to Solid Waste Disposal (SWD) functions, facilities, and personnel who perform waste acceptance, verification, receipt, and management functions of dangerous, radioactive, and mixed waste from on- and off-site generators who ship to or within the Hanford Site for treatment, storage, and/or disposal (TSD) at SWD TSD facilities.
Date:
June 19, 1995
Creator:
Irons, L.G.
Object Type:
Report
System:
The UNT Digital Library
Preliminary design and estimate of capital and operating costs for a production scale application of laser decontamination technology
The application of laser ablation technology to the decontamination of radioactive metals, particularly the surfaces of equipment, is discussed. Included is information related to the design, capital and operating costs, and effectiveness of laser ablation technology, based on commercial excimer and Nd:YAG lasers, for the decontamination of production scale equipment.
Date:
August 6, 1994
Creator:
Pang, Ho-ming & Edelson, M. C.
Object Type:
Report
System:
The UNT Digital Library
Functional design criteria for the self-installing liquid observation well
This document presents the functional design criteria for installing liquid observation wells (LOWs) into single-shell tanks containing ferrocyanide wastes. The LOWs will be designed to accommodate the deployment of gamma, neutron, and electromagnetic induction probes and to interface with the existing tank structure and environment.
Date:
June 16, 1995
Creator:
Parra, S.A.
Object Type:
Report
System:
The UNT Digital Library
Multidimensional DDT modeling of energetic materials
To model the shock-induced behavior of porous or damaged energetic materials, a nonequilibrium mixture theory has been developed and incorporated into the shock physics code, CTH. The foundation for this multiphase model is based on a continuum mixture formulation given by Baer and Nunziato. This multiphase mixture model provides a thermodynamic and mathematically-consistent description of the self-accelerated combustion processes associated with deflagration-to-detonation and delayed detonation behavior which are key modeling issues in safety assessment of energetic systems. An operator-splitting method is used in the implementation of this model, whereby phase diffusion effects are incorporated using a high resolution transport method. Internal state variables, forming the basis for phase interaction quantities, are resolved during the Lagrangian step requiring the use of a stiff matrix-free solver. Benchmark calculations are presented which simulate low-velocity piston impact on a propellant porous bed and experimentally-measured wave features are well replicated with this model. This mixture model introduces micromechanical models for the initiation and growth of reactive multicomponent flow that are key features to describe shock initiation and self-accelerated deflagration-to-detonation combustion behavior. To complement one-dimensional simulation, two-dimensional numerical calculations are presented which indicate wave curvature effects due to the loss of wall confinement. This study is …
Date:
July 1, 1995
Creator:
Baer, M. R.; Hertel, E. S. & Bell, R. L.
Object Type:
Report
System:
The UNT Digital Library
Multidimensional DDT modeling of energetic materials
A nonequilibrium continuum mixture model has been incorporated into the CTH shock physics code to describe deflagration-to-detonation transition in granular energetic materials. This approach treats multiple thermodynamic and mechanics fields including the effects of relative material motion, rate-dependent compaction and interphase exchange of mass, momentum and energy. A finite volume description is formulated and internal state variables are solved using an operator-splitting method. Numerical simulations of low-velocity impact on a weakly-confined porous propellant bed are presented which display lateral wall release leading to curved compaction and reaction wave behavior.
Date:
August 1, 1995
Creator:
Baer, M. R.; Hertel, E. S. & Bell, R. L.
Object Type:
Article
System:
The UNT Digital Library
Technical evaluation report for the demonstration of radio frequency soil decontamination at Site S-1
The Air Force`s Armstrong Laboratory at Tyndall Air Force Base, Florida, has supported the research and development of Radio Frequency Soil Decontamination. Radio frequency soil decontamination is essentially a heat-assisted soil vapor extraction process. Site S-1 at Kelly Air Force Base, San Antonio, Texas, was selected for the demonstration of two patented techniques. The site is a former sump that collected spills and surface run-off from a waste petroleum, oils, and lubricants and solvent storage and transfer area. In 1993, a technique developed by the IIT Research Institute using an array of electrodes placed in the soil was demonstrated. In 1994, a technique developed by KAI Technologies, Inc. using a single applicator placed in a vertical borehole was demonstrated. Approximately 120 tons of soil were heated during each demonstration to a temperature of about 150 degrees Celsius.
Date:
April 1, 1995
Creator:
Lyon, Chesley R.; Blanchard, Clifton F. & Whitt, Laura H.
Object Type:
Report
System:
The UNT Digital Library
Geomorphology of plutonium in the Northern Rio Grande
Nearly all of the plutonium in the natural environment of the Northern Rio Grande is associated with soils and sediment, and river processes account for most of the mobility of these materials. A composite regional budget for plutonium based on multi-decadal averages for sediment and plutonium movement shows that 90 percent of the plutonium moving into the system is from atmospheric fallout. The remaining 10 percent is from releases at Los Alamos. Annual variation in plutonium flux and storage exceeds 100 percent. The contribution to the plutonium budget from Los Alamos is associated with relatively coarse sediment which often behaves as bedload in the Rio Grande. Infusion of these materials into the main stream were largest in 1951, 1952, 1957, and 1968. Because of the schedule of delivery of plutonium to Los Alamos for experimentation and weapons manufacturing, the latter two years are probably the most important. Although the Los Alamos contribution to the entire plutonium budget was relatively small, in these four critical years it constituted 71--86 percent of the plutonium in bedload immediately downstream from Otowi.
Date:
March 1, 1993
Creator:
Graf, William L.
Object Type:
Report
System:
The UNT Digital Library