Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics (open access)

Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics

The Large Hadron Collider (LHC) at CERN promises a major step forward in the understanding of the fundamental nature of matter. The ATLAS experiment is a general-purpose detector for the LHC, whose design was guided by the need to accommodate the wide spectrum of possible physics signatures. The major remit of the ATLAS experiment is the exploration of the TeV mass scale where groundbreaking discoveries are expected. In the focus are the investigation of the electroweak symmetry breaking and linked to this the search for the Higgs boson as well as the search for Physics beyond the Standard Model. In this report a detailed examination of the expected performance of the ATLAS detector is provided, with a major aim being to investigate the experimental sensitivity to a wide range of measurements and potential observations of new physical processes. An earlier summary of the expected capabilities of ATLAS was compiled in 1999 [1]. A survey of physics capabilities of the CMS detector was published in [2]. The design of the ATLAS detector has now been finalised, and its construction and installation have been completed [3]. An extensive test-beam programme was undertaken. Furthermore, the simulation and reconstruction software code and frameworks have …
Date: November 28, 2011
Creator: Aad, G.; Abat, E.; Abbott, B.; Abdallah, J.; Abdelalim, A. A.; Abdesselam, A. et al.
Object Type: Article
System: The UNT Digital Library
TRISO Fuel Performance: Modeling, Integration into Mainstream Design Studies, and Application to a Thorium-fueled Fusion-Fission Hybrid Blanket (open access)

TRISO Fuel Performance: Modeling, Integration into Mainstream Design Studies, and Application to a Thorium-fueled Fusion-Fission Hybrid Blanket

This study focused on creating a new tristructural isotropic (TRISO) coated particle fuel performance model and demonstrating the integration of this model into an existing system of neutronics and heat transfer codes, creating a user-friendly option for including fuel performance analysis within system design optimization and system-level trade-off studies. The end product enables both a deeper understanding and better overall system performance of nuclear energy systems limited or greatly impacted by TRISO fuel performance. A thorium-fueled hybrid fusion-fission Laser Inertial Fusion Energy (LIFE) blanket design was used for illustrating the application of this new capability and demonstrated both the importance of integrating fuel performance calculations into mainstream design studies and the impact that this new integrated analysis had on system-level design decisions. A new TRISO fuel performance model named TRIUNE was developed and verified and validated during this work with a novel methodology established for simulating the actual lifetime of a TRISO particle during repeated passes through a pebble bed. In addition, integrated self-consistent calculations were performed for neutronics depletion analysis, heat transfer calculations, and then fuel performance modeling for a full parametric study that encompassed over 80 different design options that went through all three phases of analysis. Lastly, …
Date: November 28, 2011
Creator: Powers, J J
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Suppressed Charmed B Decay (open access)

Suppressed Charmed B Decay

This thesis describes the measurement of the branching fractions of the suppressed charmed B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decays and the non-resonant B{sup 0} {yields} D{sup (*)-} {eta}{pi}{sup +} decays in approximately 230 million {Upsilon}(4S) {yields} B{bar B} events. The data have been collected with the BABAR detector at the PEP-II B factory at the Stanford Linear Accelerator Center in California. Theoretical predictions of the branching fraction of the B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decays show large QCD model dependent uncertainties. Non-factorizing terms, in the naive factorization model, that can be calculated by QCD factorizing models have a large impact on the branching fraction of these decay modes. The predictions of the branching fractions are of the order of 10{sup -6}. The measurement of the branching fraction gives more insight into the theoretical models. In general a better understanding of QCD models will be necessary to conduct weak interaction physics at the next level. The presence of CP violation in electroweak interactions allows the differentiation between matter and antimatter in the laws of physics. In the Standard Model, CP violation is incorporated in the CKM matrix that describes the weak interaction between quarks. Relations …
Date: November 28, 2011
Creator: Snoek, Hella Leonie & /Vrije U., Amsterdam
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Design and Factory Test of the E /E- Frascati Linear Accelerator for DAFNE (open access)

Design and Factory Test of the E /E- Frascati Linear Accelerator for DAFNE

The electron-positron accelerator for the DAFNE project has been built and is in test at Titan Beta in Dublin, CA. This S-Band RF linac system utilizes four 45 MW sledded klystrons and 16-3 m accelerating structures to achieve the required performance. It delivers a 4 ampere electron beam to the positron converter and accelerates the resulting positrons to 550 MeV. The converter design uses a 4.3T pulsed tapered flux compressor along with a pseudo-adiabatic tapered field to a 5 KG solenoid over the first two positron accelerating sections. Quadrupole focusing is used after 100 MeV. The system performance is given in Table 1. This paper briefly describes the design and development of the various subassemblies in this system and gives the initial factory test data.
Date: November 28, 2011
Creator: Anamkath, H.; Lyons, S.; Nett, D.; Treas, P.; Whitham, K.; Zante, T. et al.
Object Type: Article
System: The UNT Digital Library
B Decay and CP Violation: CKM Angles and Sides at the BABAR and BELLE B-Factories (open access)

B Decay and CP Violation: CKM Angles and Sides at the BABAR and BELLE B-Factories

A remarkable success has been achieved by the B-Factories, going beyond expectation in some field, like the measurement of {gamma}. BABAR has now finished its data taking, leaving BELLE alone in the 'race', but still many analyses are going on. The CKM UT is constrained by both measurements of CP-conserving and CP-violating quantities, leading to a picture of the CKM sector consistent with the SM. Measurements of semi-leptonic decays benefit from improving experimental techniques and more precise theoretical computations. The angle {beta} is a precision measurement, reaching accuracy of SM calculation. The angle {alpha} will ultimatly be limited by penguin pollution. The measurement of {gamma} is reaching the 13{sup o} precision.
Date: November 28, 2011
Creator: Verderi, Marc & Polytechnique, /Ecole
Object Type: Article
System: The UNT Digital Library
Rapid Exploitation and Analysis of Documents (open access)

Rapid Exploitation and Analysis of Documents

Analysts are overwhelmed with information. They have large archives of historical data, both structured and unstructured, and continuous streams of relevant messages and documents that they need to match to current tasks, digest, and incorporate into their analysis. The purpose of the READ project is to develop technologies to make it easier to catalog, classify, and locate relevant information. We approached this task from multiple angles. First, we tackle the issue of processing large quantities of information in reasonable time. Second, we provide mechanisms that allow users to customize their queries based on latent topics exposed from corpus statistics. Third, we assist users in organizing query results, adding localized expert structure over results. Forth, we use word sense disambiguation techniques to increase the precision of matching user generated keyword lists with terms and concepts in the corpus. Fifth, we enhance co-occurrence statistics with latent topic attribution, to aid entity relationship discovery. Finally we quantitatively analyze the quality of three popular latent modeling techniques to examine under which circumstances each is useful.
Date: November 28, 2011
Creator: Buttler, D J; Andrzejewski, D; Stevens, K D; Anastasiu, D & Gao, B
Object Type: Report
System: The UNT Digital Library
ORKA: Measurement of the $K^ \to \pi^+ \nu \bar{\nu}$ decay at Fermilab (open access)

ORKA: Measurement of the $K^ \to \pi^+ \nu \bar{\nu}$ decay at Fermilab

A high precision measurement of the ultra-rare K{sup +} {yields} {pi}{sup +} {nu}{bar {nu}} decay at Fermilab would be one of the most incisive probes of quark flavor physics this decade. Its dramatic reach for uncovering new physics is due to several important factors: (1) The branching ratio is sensitive to most new physics models which extend the Standard Model to solve its considerable problems. (2) The Standard Model predictions for the K{sup +} {yields} {pi}{sup +} {nu}{bar {nu}} and K{sub L}{sup 0} {yields} {pi}{sup 0} {nu}{bar {nu}} branching fractions are broadly recognized to be theoretically robust at the 5-10% level. Only a precious few accessible loop-dominated quark processes can be predicted with this level of certainty. (3) The K{sup +} {yields} {pi}{sup +} {nu}{bar {nu}} branching fraction is highly suppressed in the Standard Model to the level < 10{sup -10} (<1 part in 10 billion). This suppression allows physics beyond the Standard Model to contribute dramatically to the branching fraction with enhancements of up to factors of 5 above the Standard Model level. (4) The certainty with which the Standard Model contribution to K{sup +} {yields} {pi}{sup +} {nu}{bar {nu}} can be predicted will permit a 5{sigma} discovery potential …
Date: November 28, 2011
Creator: Comfort, Joseph; U., /Arizona State; Bryman, Douglas; Doria, Luca; Numao, Toshio; Sher, Aleksey et al.
Object Type: Report
System: The UNT Digital Library
THERMODYNAMIC AND KINETIC MODELING OF ADVANCED NUCLEAR FUELS - FINAL LDRD-ER REPORT (open access)

THERMODYNAMIC AND KINETIC MODELING OF ADVANCED NUCLEAR FUELS - FINAL LDRD-ER REPORT

This project enhanced our theoretical capabilities geared towards establishing the basic science of a high-throughput protocol for the development of advanced nuclear fuel that should couple modern computational materials modeling and simulation tools, fabrication and characterization capabilities, and targeted high throughput performance testing experiments. The successful conclusion of this ER project allowed us to upgrade state-of-the-art modeling codes, and apply these modeling tools to ab initio energetics and thermodynamic assessments of phase diagrams of various mixtures of actinide alloys, propose a tool for optimizing composition of complex alloys for specific properties, predict diffusion behavior in diffusion couples made of actinide and transition metals, include one new equation in the LLNL phase-field AMPE code, and predict microstructure evolution during alloy coring. In FY11, despite limited funding, the team also initiated an experimental activity, with collaboration from Texas A&M University by preparing samples of nuclear fuels in bulk forms and for diffusion couple studies and metallic matrices, and performing preliminary characterization.
Date: November 28, 2011
Creator: Turchi, P
Object Type: Report
System: The UNT Digital Library
Laboratory Studies on Surface Sampling of Bacillus anthracis Contamination: Summary, Gaps, and Recommendations (open access)

Laboratory Studies on Surface Sampling of Bacillus anthracis Contamination: Summary, Gaps, and Recommendations

This report summarizes previous laboratory studies to characterize the performance of methods for collecting, storing/transporting, processing, and analyzing samples from surfaces contaminated by Bacillus anthracis or related surrogates. The focus is on plate culture and count estimates of surface contamination for swab, wipe, and vacuum samples of porous and nonporous surfaces. Summaries of the previous studies and their results were assessed to identify gaps in information needed as inputs to calculate key parameters critical to risk management in biothreat incidents. One key parameter is the number of samples needed to make characterization or clearance decisions with specified statistical confidence. Other key parameters include the ability to calculate, following contamination incidents, the (1) estimates of Bacillus anthracis contamination, as well as the bias and uncertainties in the estimates, and (2) confidence in characterization and clearance decisions for contaminated or decontaminated buildings. Gaps in knowledge and understanding identified during the summary of the studies are discussed and recommendations are given for future studies.
Date: November 28, 2011
Creator: Piepel, Gregory F.; Amidan, Brett G. & Hu, Rebecca
Object Type: Report
System: The UNT Digital Library
Long-Range And Head-On Beam-Beam Compensation Studies in RHIC With Lessons for the LHC (open access)

Long-Range And Head-On Beam-Beam Compensation Studies in RHIC With Lessons for the LHC

Long-range as well as head-on beam-beam effects are expected to limit the LHC performance with design parameters. They are are also important consideration for the LHC upgrades. To mitigate long-range effects, current carrying wires parallel to the beam were proposed. Two such wires are installed in RHIC where they allow studying the effect of strong long-range beam-beam effects, as well as the compensation of a single long-range interaction. The tests provide benchmark data for simulations and analytical treatments. Electron lenses were proposed for both RHIC and the LHC to reduce the head-on beam-beam effect. We present the experimental long-range beam-beam program at RHIC and report on head-on compensations studies based on simulations.
Date: November 28, 2011
Creator: Fischer, W.; Luo, Y.; Abreu, N.; Calaga, R.; Montag, C.; Robert-Demolaize, G. et al.
Object Type: Article
System: The UNT Digital Library
Multicore Architecture-aware Scientific Applications (open access)

Multicore Architecture-aware Scientific Applications

Modern high performance systems are becoming increasingly complex and powerful due to advancements in processor and memory architecture. In order to keep up with this increasing complexity, applications have to be augmented with certain capabilities to fully exploit such systems. These may be at the application level, such as static or dynamic adaptations or at the system level, like having strategies in place to override some of the default operating system polices, the main objective being to improve computational performance of the application. The current work proposes two such capabilites with respect to multi-threaded scientific applications, in particular a large scale physics application computing ab-initio nuclear structure. The first involves using a middleware tool to invoke dynamic adaptations in the application, so as to be able to adjust to the changing computational resource availability at run-time. The second involves a strategy for effective placement of data in main memory, to optimize memory access latencies and bandwidth. These capabilties when included were found to have a significant impact on the application performance, resulting in average speedups of as much as two to four times.
Date: November 28, 2011
Creator: Srinivasa, Avinash
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Novel Approach to Linear Accelerator Superconducting Magnet System (open access)

Novel Approach to Linear Accelerator Superconducting Magnet System

Superconducting Linear Accelerators include a superconducting magnet system for particle beam transportation that provides the beam focusing and steering. This system consists of a large number of quadrupole magnets and dipole correctors mounted inside or between cryomodules with SCRF cavities. Each magnet has current leads and powered from its own power supply. The paper proposes a novel approach to magnet powering based on using superconducting persistent current switches. A group of magnets is powered from the same power supply through the common, for the group of cryomodules, electrical bus and pair of current leads. Superconducting switches direct the current to the chosen magnet and close the circuit providing the magnet operation in a persistent current mode. Two persistent current switches were fabricated and tested. In the paper also presented the results of magnetic field simulations, decay time constants analysis, and a way of improving quadrupole magnetic center stability. Such approach substantially reduces the magnet system cost and increases the reliability.
Date: November 28, 2011
Creator: Kashikhin, Vladimir
Object Type: Article
System: The UNT Digital Library
A 200 MHz 35 MW Multiple Beam Klystron for Accelerator Applications Final Report (open access)

A 200 MHz 35 MW Multiple Beam Klystron for Accelerator Applications Final Report

Calabazas Creek Research, Inc. (CCR) performed initial development of a compact and reliable 35 MW, multiple beam klystron (MBK) at 200 MHz with a pulse length of 0.125 ms and a 30 Hz repetition rate. The device was targeted for acceleration and ionization cooling of a muon collider, but there are several other potential applications in this frequency range. The klystron uses multiple beams propagating in individual beam tunnels to reduce space charge and allow reduction in the accelerating voltage. This allows a significant reduction in length over a single beam source. More importantly this allows more efficient and less expensive power supplies. At 200 MHz, the interaction circuit for a single beam klystron would be more than six meters long to obtain 50% efficiency and 50 dB gain. This would require a beam voltage of approximately 400 kV and current of 251 A for a microperveance of 1.0. For an eight beam MBK with the same beam perveance, a three meter long interaction circuit achieves the same power and gain. Each beam operates at 142 kV and 70A. The Phase I demonstrated that this device could be fabricated with funding available in a Phase II program and could achieve …
Date: November 28, 2011
Creator: Ives, R. Lawrence; Read, Michael; Ferguson, Patrick & Marsden, David
Object Type: Report
System: The UNT Digital Library
Event-by-Event Evaluation of the Prompt Fission Neutron Spectrum From 239pu(N,F) (open access)

Event-by-Event Evaluation of the Prompt Fission Neutron Spectrum From 239pu(N,F)

We have developed an improved evaluation method for the spectrum of neutrons emitted in fission of {sup 239}Pu induced by incident neutrons with energies up to 20 MeV. The <v> covariance data, including incident energy correlations introduced by the <v> evaluation method, were used to fix the input parameters in our event-by-event model of fission, FREYA, by applying formal statistical methods. Formal estimates of uncertainties in the evaluation were developed by randomly sampling model inputs and calculating likelihood functions based on agreement with the evaluated <v>. Our approach is able to employ a greater variety of fission measurements than the relatively coarse spectral data alone. It also allows the study of numerous fission observables for more accurate model validation. The combination of an event-by-event Monte Carlo fission model with a statistical-likelihood analysis is thus a powerful tool for evaluation of fission-neutron data. Our empirical model FREYA follows the complete fission event from birth of the excited fragments through their decay via neutron emission until the fragment excitation energy is below the neutron separation energy when neutron emission can no longer occur. The most recent version of FREYA incorporates pre-equilibrium neutron emission, the emission of the first neutron before equilibrium is …
Date: November 28, 2011
Creator: Vogt, R.; Randrup, J.; Brown, D. A.; Descalle, M. A. & Ormand, W. E.
Object Type: Article
System: The UNT Digital Library
U.S.-South Korea Relations (open access)

U.S.-South Korea Relations

This report covers the background and current state of the relationship of the United States with the Republic of Korea (ROK, formerly South Korea), including economic and trade issues, North Korea, naval, and military events. It is a general overview of the current state of relations with South Korea.
Date: November 28, 2011
Creator: Manyin, Mark E.; Chanlett-Avery, Emma & Nikitin, Mary Beth
Object Type: Report
System: The UNT Digital Library
Design and Fabrication of a Single-Aperture 11T Nb3Sn Dipole Model for LHC Upgrades (open access)

Design and Fabrication of a Single-Aperture 11T Nb3Sn Dipole Model for LHC Upgrades

The planned upgrade of the LHC collimation system includes additional collimators to be installed in the dispersion suppressor areas of points 2, 3 and 7. To provide the necessary longitudinal space for the collimators, a replacement of 8.33 T Nb-Ti LHC main dipoles with 11 T dipoles based on Nb{sub 3}Sn superconductor compatible with the LHC lattice and main systems is being considered. To demonstrate this possibility FNAL and CERN have started a joint program to develop a 2 m long single-aperture dipole magnet with the nominal field of 11 T at {approx}11.85 kA current and 60 mm bore. This paper describes the demonstrator magnet magnetic and mechanical designs and analysis, coil fabrication procedure. The Nb{sub 3}Sn strand and cable parameters and test results are also reported.
Date: November 28, 2011
Creator: Andreev, N.; Apollinari, G.; Barzi, E.; Bossert, R.; Nobrega, F.; Novitski, I. et al.
Object Type: Article
System: The UNT Digital Library
Collective Deceleration: Toward a Compact Beam Dump (open access)

Collective Deceleration: Toward a Compact Beam Dump

With the increasing development of laser accelerators, the electron energy is already beyond GeV and even higher in near future. Conventional beam dump based on ionization or radiation loss mechanism is cumbersome and costly, also has radiological hazards. We revisit the stopping power of high-energy charged particles in matter and discuss the associated problem of beam dump from the point of view of collective deceleration. The collective stopping length in an ionized gas can be several orders of magnitude shorter than the Bethe-Bloch and multiple electromagnetic cascades stopping length in solid. At the mean time, the tenuous density of the gas makes the radioactivation negligible. Such a compact and non-radioactivating beam dump works well for short and dense bunches, which is typically generated from laser wakefield accelerator.
Date: November 28, 2011
Creator: Wu, H.-C.; Tajima, T.; Habs, D.; Chao, A.W. & Meyer-ter-Vehn, J.
Object Type: Article
System: The UNT Digital Library
Public Financing of Presidential Campaigns: Overview and Analysis (open access)

Public Financing of Presidential Campaigns: Overview and Analysis

This report discusses current controversies and arguments for and against public financing of presidential campaigns; legislative history; elements of the program; taxpayer and candidate participation; financial status of the program; recent legislation; and analysis of various policy proposals. If Congress chooses to alter the program, consensus will be necessary in what has historically been a particularly complex and contentious area of campaign finance policy.
Date: November 28, 2011
Creator: Garrett, R. Sam
Object Type: Report
System: The UNT Digital Library
Proposals to Eliminate Public Financing of Presidential Campaigns (open access)

Proposals to Eliminate Public Financing of Presidential Campaigns

None
Date: November 28, 2011
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Cuba’s Offshore Oil Development: Background and U.S. Policy Considerations (open access)

Cuba’s Offshore Oil Development: Background and U.S. Policy Considerations

This report discusses Cuba's Offshore Oil Development. It points out about Cuba's Oil sector, Implications and Considerations for U.S. Policy and Legislative Initiatives and Oversight.
Date: November 28, 2011
Creator: Nerurkar, Neelesh & Sullivan, Mark P.
Object Type: Report
System: The UNT Digital Library
Summary of HQ01e magnetic measurements (open access)

Summary of HQ01e magnetic measurements

The magnetic measurements of HQ01e, a 1 m long LHC Accelerator Research Program (LARP) high-gradient quadrupole model, were performed at 4.4 K and above 40 K at the magnet test facility of LBNL in July 2011. The 120 mm aperture cos2θ Nb{sub 3}Sn magnet was designed with accelerator magnet features including alignment and field quality. Conductor-limited gradient was 195 T/m at 4.4 K. During the measurement, a ramp rate of 10 A/s was used and measurements at the nominal current of 14.2 kA (82% of short-sample limit with a gradient of 160 T/m) were performed using the 250 mm long printed-circuit board rotating probe developed by FNAL. At 14.2 kA, 2.7 units of b{sub 6} and 0.7 units of b{sub 10} were measured. Large persistent current contribution and strong dynamic effects were observed. We analyzed the allowed and non-allowed harmonics obtained during the measurements above 40 K and at the nominal current. Significant change of the skew sextupole occurred between 50 K and 95 K. The allowed multipole and the low-order non-allowed multipoles at the straight section were explained through the rigid displacement of coil blocks with an amplitude less than 100 μm. We also attempted to correlate the coil …
Date: November 28, 2011
Creator: Wang, X.; Caspi, S.; Cheng, D. W.; Dietderich, D. R.; Felice, H.; Ferracin, P. et al.
Object Type: Report
System: The UNT Digital Library
Navy Force Structure and Shipbuilding Plans: Background and Issues for Congress (open access)

Navy Force Structure and Shipbuilding Plans: Background and Issues for Congress

This report provides background information and presents potential issues for Congress concerning the Navy's ship force-structure goals and shipbuilding plans. The planned size of the Navy, the rate of Navy ship procurement, and the prospective affordability of the Navy's shipbuilding plans have been matters of concern for the congressional defense committees for the past several years. Decisions that Congress makes on Navy shipbuilding programs can substantially affect Navy capabilities and funding requirements, and the U.S. shipbuilding industrial base.
Date: November 28, 2011
Creator: O'Rourke, Ronald
Object Type: Report
System: The UNT Digital Library
Circular A-76 and the Moratorium on DOD Competitions: Background and Issues for Congress (open access)

Circular A-76 and the Moratorium on DOD Competitions: Background and Issues for Congress

This report discusses the current moratorium on the conduct of Department of Defense (DOD) public-private competitions under Office of Management and Budget (OMB) Circular A-76 and issues for Congress.
Date: November 28, 2011
Creator: Grasso, Valerie Bailey
Object Type: Report
System: The UNT Digital Library