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open access

Adaptive Optics Control Strategies for Extremely Large Telescopes

Description: Adaptive optics for the 30-100 meter class telescopes now being considered will require an extension in almost every area of AO system component technology. In this paper, we present scaling laws and strawman error budgets for AO systems on extremely large telescopes (ELTs) and discuss the implications for component technology and computational architecture. In the component technology area, we discuss the advanced efforts being pursued at the NSF Center for Adaptive Optics (CfAO) in the develo… more
Date: July 26, 2001
Creator: Gavel, D T
open access

American Nuclear Society nuclear criticality safety division.

Description: Development of an ANSI/ANS Standard for the training and qualification of criticality safety engineers has been underway for nearly one year. The working group for this Standard is comprised of criticality safety experts from regulatory, licensee and contractor organizations. Its goal is to develop a standard that can be uniformly adopted, that covers all criticality safety engineer qualification levels, and that includes all required competencies such that most of the qualifications can be eas… more
Date: July 26, 2001
Creator: Morman, J. A. & McKamy, J.
open access

Analysis of a High-Efficiency Natural Gas-Assisted Steam Electrolyzer for Hydrogen Production

Description: This paper presents a description and analysis of a high-efficiency hydrogen production system. The main component of the system is a novel steam electrolyzer. In conventional electrolyzers, oxygen produced from electrolysis is usually released into the environment. In this design, natural gas is used to react with the oxygen produced in the electrolysis, reducing reduce the chemical potential difference across the electrolyzer, thus minimizing electricity consumption. The oxygen produced from … more
Date: June 26, 2001
Creator: Martinez-Frias, J.; Pham, A. Q. & Aceves, S. M.
open access

BaBar Superconducting Coil: Design, Construction and Test

Description: The BABAR Detector, located in the PEP-II B-Factory at the Stanford Linear Accelerator Center, includes a large 1.5 Tesla superconducting solenoid, 2.8 m bore and length 3.7 m. The two layer solenoid is wound with an aluminum stabilized conductor which is graded axially to produce a {+-} 3% field uniformity in the tracking region. This paper summarizes the 3 year design, fabrication and testing program of the superconducting solenoid. The work was carried out by an international collaboration b… more
Date: January 26, 2001
Creator: Bell, R. A.; Berndt, M.; Burgess, W.; Craddock, W.; Dormicchi, O.; Fabbricatore, P. et al.
open access

The Bbar ---> D* l nu bar form factor at zero recoil and the determination of |V{sub cb}|

Description: We summarize our lattice QCD study of the form factor at zero recoil in the decay {bar B} {yields} D*{ell}{bar {nu}}. After careful consideration of all sources of systematic uncertainty, we find, h{sub A{sub 1}}(1) = 0.913{sub -17-30}{sup +24+17}, where the first uncertainty is from statistics and fitting while the second combined uncertainty is from all other systematic effects.
Date: November 26, 2001
Creator: al., J.N. Simone et
open access

Beam-induced energy deposition issues in the Very Large Hadron Collider

Description: Energy deposition issues are extremely important in the Very Large Hadron Collider (VLHC) with huge energy stored in its 20 TeV (Stage-1) and 87.5 TeV (Stage-2) beams. The status of the VLHC design on these topics, and possible solutions of the problems are discussed. Protective measures are determined based on the operational and accidental beam loss limits for the prompt radiation dose at the surface, residual radiation dose, ground water activation, accelerator components radiation damage an… more
Date: June 26, 2001
Creator: Mokhov, Nikolai V.; Drozhdin, Alexandr I. & Foster, G. William
open access

Buildings in a Test Tube: Validation of the Short-Term Energy Monitoring (STEM) Method (Preprint)

Description: This paper is extracted from a full-length technical report that presents a detailed analysis of the differences in thermal performance between the SIP and frame units and describes the validation of the STEM method.
Date: February 26, 2001
Creator: Judkoff, R.; Balcomb, J.D. (National Renewable Energy Laboratory); Barker, G.; Hancock, E. (Mountain Energy Partnership) & Subbarao, K.
open access

Catalysis of PAH Biodegradation by Humic Acid Shown in Synchrotron Infrared Studies

Description: The role of humic acid (HA) in the biodegradation of toxic polycyclic aromatic hydrocarbons (PAHs) has been the subject of controversy, particularly in unsaturated environments. By utilizing an infrared spectromicroscope and a very bright, nondestructive synchrotron photon source, we monitored in situ and, over time, the influence of HA on the progression of degradation of pyrene (a model PAH) by a bacterial colony on a magnetite surface. Our results indicate that HA dramatically shortens the o… more
Date: September 26, 2001
Creator: Holman, Hoi-Ying N.; Nieman, Karl; Sorensen, Darwin L.; Miller, Charles D.; Martin, Michael C.; Borch, Thomas et al.
open access

Charge Transfer Experiment

Description: Low energy charge transfer is an important process in plasmas where multicharged ions and neutral atoms or molecules can exist at eV/amu energies and below. At eV/amu collision energies there are no scaling laws to characterize the charge transfer cross section and both theory and experiment are difficult. The capabilities of current experimental techniques used to measure low energy total and state-selective cross sections are discussed.
Date: February 26, 2001
Creator: Havener, C. C.
open access

THE COLOR GLASS CONDENSATE.

Description: The Color Glass Condensate is a state of high density gluonic matter which controls the high energy limit of hadronic interactions. Its properties are important for the initial conditions for matter produced at RHIC.
Date: August 26, 2001
Creator: McLerran, L.
open access

Creating Ensembles of Decision Trees Through Sampling

Description: Recent work in classification indicates that significant improvements in accuracy can be obtained by growing an ensemble of classifiers and having them vote for the most popular class. This paper focuses on ensembles of decision trees that are created with a randomized procedure based on sampling. Randomization can be introduced by using random samples of the training data (as in bagging or boosting) and running a conventional tree-building algorithm, or by randomizing the induction algorithm i… more
Date: July 26, 2001
Creator: Kamath, C. & Cantu-Paz, E.
open access

Degradation of multibunch luminosity in a linear collider due to cumulative beam breakup

Description: Beam-excited transverse wakes in accelerating radiofrequency structures will influence the transverse offsets of each bunch in a multibunch train, causing the projected emittance of the bunch train to grow. An analytic theory of this phenomenon that includes the mitigating influence of a correlated energy spread across the bunch train was recently devised and applied to electron-positron linear colliders. We use the results of this theory to estimate analytically the associated degradation of m… more
Date: June 26, 2001
Creator: Bohn, Courtlandt L.; Syphers, Michael J. & Schulte, Daniel
open access

Depth-graded Multilayers as Neutron Doppler Converts At Pulsed Neutron Source

Description: A moving diffractor changes the energy of elastically diffracted neutrons by the Doppler effect. Depth-graded multilayers can diffract neutrons over a large band of energy. Using a pulsed neutron source, such a depth-graded multilayer, decelerating synchronously with the incident neutron pulse, can shift the reflected neutrons into a compressed energy window. This focusing in energy is associated with a broadening of the pulse in time, but the process does not involve a significant decrease in … more
Date: July 26, 2001
Creator: Stoica, A.D.
open access

Design and Testing of the 1.5 T Superconducting Solenoid for the BaBar Detector at Pep-II in SLAC

Description: The 1.5 Tesla superconducting solenoid is part of the BABAR Detector located in the PEP-II B-Factory machine at the Stanford Linear Accelerator Center. The solenoid has a 2.8 m bore and is 3.7 m long. The two layer solenoid is wound with an aluminum stabilized conductor which is graded axially to produce a {+-} 3% field uniformity in the tracking region. The 24 month fabrication, 3 month installation and 1 month commissioning of the solenoid were completed on time and budget. This paper summari… more
Date: January 26, 2001
Creator: O'Connor, T. G.; Shen, S.; Fabbricatore, P.; Farinon, S.; Musenich, R.; Priano, C. et al.
open access

Detailed Chemical Kinetic Reaction Mechanisms for Combustion of Isomers of Heptane

Description: Detailed chemical kinetic reaction mechanisms are developed for all nine chemical isomers of heptane (C{sub 7}H{sub 16}), following techniques and models developed previously for other smaller alkane hydrocarbon species. These reaction mechanisms are tested at high temperatures by computing shock tube ignition delay times and at lower temperatures by simulating ignition in a rapid compression machine. Although the corresponding experiments have not been reported in the literature for most of th… more
Date: March 26, 2001
Creator: Westbrook, C K; Pitz, W J; Curran, H C; Boercker, J & Kunrath, E
open access

Development of an open platform system for environmental pathway analysis.

Description: Most existing computer codes for environmental pathway modeling have been developed to satisfy a specific objective (e.g., perform analyses to demonstrate regulatory compliance). These codes were written in various computer languages and software environments over time and often are not mutually compatible. In recent years, largely driven by advancements in industrial software development, a new concept based on ''modularization'' has emerged. This approach entails the development of common ''m… more
Date: June 26, 2001
Creator: LePoire, D. J.; Arnish, J. J.; Gnanapragasam, E. & Chen, S. Y.
open access

Distributed data access and resource management in the D0 SAM system

Description: SAM (Sequential Access through Meta-data) is the data access and job management system for the D0 high energy physics experiment at Fermilab. The SAM system is being developed and used to handle the Petabyte-scale experiment data, accessed by hundreds of D0 collaborators scattered around the world. In this paper, we present solutions to some of the distributed data processing problems from the perspective of real experience dealing with mission-critical data. We concentrate on the distributed d… more
Date: June 26, 2001
Creator: Terekhov, Igor V; Pordes, Ruth & al., Victoria White et
open access

Effect of multiple and delayed jet impact and penetration on concrete target borehole diameter

Description: The effect of multiple and delayed jet impact and penetration on the borehole diameter in concrete targets is discussed in this paper. A first-order principle of shaped-charge jet penetration is that target hole volume is proportional to the energy deposited in the target by the jet. This principle is the basis for the relation that target borehole diameter at any depth along the penetration path is proportional to the jet energy deposited in the target at that location. Our current research sh… more
Date: January 26, 2001
Creator: Murphy, M J; Baum, D W; Kuklo, R M & Simonson, S C
open access

Efficiently Sorting Zoo-Mesh Data Sets

Description: The authors describe the SXMPVO algorithm for performing a visibility ordering zoo-meshed polyhedra. The algorithm runs in practice in linear time and the visibility ordering which it produces is exact.
Date: March 26, 2001
Creator: Cook, R.; Max, N.; Silva, C. & Williams, P.
open access

Electron-cloud measurements and simulations for the APS

Description: We compare experimental results with simulations of the electron cloud effect induced by a positron beam at the APS synchrotron light source at ANL, where the electron cloud effect has been observed and measured with dedicated probes. We find good agreement between simulations and measurements for reasonable values of certain secondary electron yield (SEY) parameters, most of which were extracted from recent bench measurements at SLAC.
Date: June 26, 2001
Creator: Furman, M. A.; Pivi, M.; Harkay, K. C. & Rosenberg, R. A.
open access

An Electronic Logbook for the HEP Control Room

Description: The Control Room Logbook (CRL) is designed to improve and replace the paper logbooks traditionally used in the HEP accelerator control room. Its features benefit the on-line coordinator, the shift operators, and the remote observers. This paper explains some of the most attractive features for each of these roles. The features include the ability to configure the logbook for the specific needs of a collaboration, a large variety of entry types an operator can add by simply clicking and dragging… more
Date: November 26, 2001
Creator: al., Gary Roediger et
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