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Issues Concerning High Current Low Energy Electron Beams Required for Ion Cooling between EBIS LINAC and Booster
N/A
Date:
March 1, 2009
Creator:
A., Hershcovitch
Object Type:
Report
System:
The UNT Digital Library
Polarized proton beam acceleration with a single Siberian Snake in each RHIC ring
N/A
Date:
March 1, 2000
Creator:
A., Lehrach; Luccio, A. U. & Roser, T.
Object Type:
Report
System:
The UNT Digital Library
Pump Side-scattering in Ultra-powerful Backward Raman Amplifiers
Extremely large laser power might be obtained by compressing laser pulses through backward Raman amplification (BRA) in plasmas. Premature Raman backscattering of a laser pump by plasma noise might be suppressed by an appropriate detuning of the Raman resonance, even as the desired amplification of the seed persists with a high efficiency. In this paper, we analyze side-scattering of laser pumps by plasma noise in backward Raman amplifiers. Though its growth rate is smaller than that of backscattering, the side-scattering can nevertheless be dangerous, because of a longer path of side-scattered pulses in plasmas and because of an angular dependence of the Raman resonance detuning. We show that side-scattering of laser pumps by plasma noise in BRA might be suppressed to a tolerable level at all angles by an appropriate combination of two detuning mechanisms associated with plasma density gradient and pump chirp.
Date:
March 2, 2004
Creator:
A.A. Solodov, V.M. Malkin, and N.J. Fisch
Object Type:
Report
System:
The UNT Digital Library
Simulation of Alpha-Channeling in Mirror Machines
Applying α-channeling techniques to mirror machines can significantly increase their effective reactivity, thus making open configurations more advantageous for practical fusion. A large fraction of α particle energy can be extracted using rf waves. Effects employed to cool α particles can also in principle be used to heat the fusion ions; the possibility to design a configuration of rf waves which could be used to perform both tasks is demonstrated.
Date:
March 17, 2008
Creator:
A.I. Zhmoginov, N.J. Fisch
Object Type:
Report
System:
The UNT Digital Library
Diagnostics for the Biased Electrode Experiment on NSTX
A linear array of four small biased electrodes was installed in NSTX in an attempt to control the width of the scrape-off layer (SOL) by creating a strong local poloidal electric field. The set of electrodes were separated poloidally by a 1 cm gap between electrodes and were located slightly below the midplane of NSTX, 1 cm behind the RF antenna and oriented so that each electrode is facing approximately normal to the magnetic field. Each electrode can be independently biased to ±100 volts. Present power supplies limit the current on two electrodes to 30 amps the other two to 10 amps each. The effect of local biasing was measured with a set of Langmuir probes placed between the electrodes and another set extending radially outward from the electrodes, and also by the gas puff imaging diagnostic (GPI) located 1 m away along the magnetic field lines intersecting the electrodes. Two fast cameras were also aimed directly at the electrode array. The hardware and controls of the biasing experiment will be presented and the initial effects on local plasma parameters will be discussed.
Date:
March 20, 2009
Creator:
A.L. Roquemore, S.J. Zweben, C.E. Bush, R. Kaita, R. J. Marsalsa, and R.J. Maqueda
Object Type:
Article
System:
The UNT Digital Library
NUCLEAR WASTE GLASSES CONTINUOUS MELTING AND BULK VITRIFICAITON
This contribution addresses various aspects of nuclear waste vitrification. Nuclear wastes have a variety of components and composition ranges. For each waste composition, the glass must be formulated to possess acceptable processing and product behavior defined in terms of physical and chemical properties that guarantee the glass can be easily made and resist environmental degradation. Glass formulation is facilitated by developing property-composition models, and the strategy of model development and application is reviewed. However, the large variability of waste compositions presents numerous additional challenges: insoluble solids and molten salts may segregate; foam may hinder heat transfer and slow down the process; molten salts may accumulate in container refractory walls; the glass on cooling may precipitate crystalline phases. These problems need targeted exploratory research. Examples of specific problems and their possible solutions are discussed.
Date:
March 24, 2008
Creator:
AA, KRUGER & PR, HRMA
Object Type:
Article
System:
The UNT Digital Library
PROPOSAL FOR A SILICON VERTEX TRACKER (VTX) FOR THE PHENIX EXPERIMENT.
We propose the construction of a Silicon Vertex Tracker (VTX) for the PHENIX experiment at RHIC. The VTX will substantially enhance the physics capabilities of the PHENIX central arm spectrometers. Our prime motivation is to provide precision measurements of heavy-quark production (charm and beauty) in A+A, p(d)+A, and polarized p+p collisions. These are key measurements for the future RHIC program, both for the heavy ion program as it moves from the discovery phase towards detailed investigation of the properties of the dense nuclear medium created in heavy ion collisions, and for the exploration of the nucleon spin-structure functions. In addition, the VTX will also considerably improve other measurements with PHENIX. The main physics topics addressed by the VTX are: (1) Hot and dense strongly interacting matter--Potential enhancement of charm production; Open beauty production; Flavor dependence of jet quenching and QCD energy loss; Accurate charm reference for quarkonium; Thermal dilepton radiation; High p{sub T} phenomena with light flavors above 10-15 GeV/c in p{sub T}; and Upsilon spectroscopy in the e{sup +}e{sup -} decay channel. (2) Gluon spin structure of the nucleon--{Delta}G/G with charm; {Delta}G/G with beauty; and x dependence of {Delta}G/G with {gamma}-jet correlations. (3) Nucleon structure in nuclei--Gluon shadowing over …
Date:
March 30, 2004
Creator:
AKIBA,Y.
Object Type:
Report
System:
The UNT Digital Library
Methodology for characterizing modeling and discretization uncertainties in computational simulation
This research effort focuses on methodology for quantifying the effects of model uncertainty and discretization error on computational modeling and simulation. The work is directed towards developing methodologies which treat model form assumptions within an overall framework for uncertainty quantification, for the purpose of developing estimates of total prediction uncertainty. The present effort consists of work in three areas: framework development for sources of uncertainty and error in the modeling and simulation process which impact model structure; model uncertainty assessment and propagation through Bayesian inference methods; and discretization error estimation within the context of non-deterministic analysis.
Date:
March 1, 2000
Creator:
ALVIN,KENNETH F.; OBERKAMPF,WILLIAM L.; RUTHERFORD,BRIAN M. & DIEGERT,KATHLEEN V.
Object Type:
Report
System:
The UNT Digital Library
Operational Test Report for the 241-AZ-101 Ultrasonic Interface Level Analyzer
This document comprises the Operational Test Report for the 241-AZ-101 Ultrasonic Interface Level Analyzer. The objective of the testing was to verify that all equipment and components functioned as designed following construction completion and turnover to operations.
Date:
March 28, 2000
Creator:
ANDREWS, J.E.
Object Type:
Report
System:
The UNT Digital Library
Cultural Resources Survey Within the Green Acres South Campus Proposed Expansion Site
Archaeological survey results of 34 acre area of land for proposed development in Smith County, Texas.
Date:
March 22, 2004
Creator:
AR Consultants
Object Type:
Report
System:
The Portal to Texas History
WHITE PAPER ON PROTON - NUCLEUS COLLISONS.
The role of proton-nucleus (p-A) collisions in the study of strong interactions has a long history. It has been an important testing ground for QCD. At RHIC p-A studies have been recognized since the beginning as important elements of the program. These include so-called baseline measurements in cold nuclear matter, essential (along with p-p studies) to a systematic study of QCD at high temperatures and densities in the search for the quark gluon plasma. Also accessible is a study of QCD in the small x (parton saturation) regime, complementary to physics accessible in high-energy e-p and e-A collisions. The role of p-A physics at RHIC was reviewed and brought into sharp focus at a workshop conducted in October 2000 at BNL; the agenda is shown in Appendix 1. This document summarizes the case for p-A at RHIC during the period covered by the next Nuclear Physics Long Range Plan. In subsequent sections we cover the Physics Issues, Experiment Run Plans and Schedule, Detector Upgrade Issues, and Machine Issues & Upgrades.
Date:
March 1, 2001
Creator:
ARONSON,S.H. & PENG,J.C.
Object Type:
Report
System:
The UNT Digital Library
Innovative Design Approaches for Large Wind Turbine Blades
The primary goal of the WindPACT Blade System Design Study (BSDS) was investigation and evaluation of design and manufacturing issues for wind turbine blades in the one to ten megawatt size range. The initial project task was to assess the fundamental physical and manufacturing issues that govern and constrain large blades and entails three basic elements: (1) a parametric scaling study to assess blade structure using current technology, (2) an economic study of the cost to manufacture, transport, and install large blades, and (3) identification of promising innovative design approaches that show potential for overcoming fundamental physical and manufacturing constraints. This report discusses several innovative design approaches and their potential for blade cost reduction. During this effort we reviewed methods for optimizing the blade cross-section to improve structural and manufacturing characteristics. We also analyzed and compared a number of composite materials and evaluated their relative merits for use in large wind turbine blades in the range from 30 meters to 70 meters. The results have been summarized in dimensional and non-dimensional format to aid in interpretation. These results build upon earlier parametric and blade cost studies, which were used as a guide for the innovative design approaches explored here.
Date:
March 1, 2003
Creator:
ASHWILL, THOMAS D.
Object Type:
Report
System:
The UNT Digital Library
Search for Hadronic Decays of W and Z Bosons in Photon Events in p anti-p Collisions at s**(1/2) = 1.96-GeV
None
Date:
March 1, 2008
Creator:
Aaltonen, T.; Adelman, J.; Akimoto, T.; Albrow, M. G.; Alvarez Gonzalez, B.; Amerio, S. et al.
Object Type:
Article
System:
The UNT Digital Library
Measurement of the b-Hadron Production Cross Section Using Decays to MU- d0 X Final States in p anti-p Collisions at s**(1/2) = 1.96-TeV
We report a measurement of the production cross section for b hadrons in p{bar p} collisions at {radical}s = 1.96 TeV. Using a data sample derived from an integrated luminosity 83 pb{sup -1} collected with the upgraded Collider Detector (CDF II) at the Fermilab Tevatron, we analyze b hadrons, H{sub b}, partially reconstructed in the semileptonic decay mode H{sub b} {yields} {mu}{sup -} D{sup 0} X. Our measurement of the inclusive production cross section for b hadrons with transverse momentum p{sub T} > 9 GeV/c and rapidity |y| < 0.6 is {sigma} = 1.30 {micro}b {+-} 0.05 {micro}b(stat) {+-} 0.14 {micro}b(syst) {+-} 0.07 {micro}b({Beta}), where the uncertainties are statistical, systematic, and from branching fractions respectively. The differential cross sections d{sigma}/d{sub T}T are found to be in good agreement with recent measurements of the H{sub b} cross section and well described by fixed-order next-to-leading logarithm predictions.
Date:
March 1, 2009
Creator:
Aaltonen, T.; Adelman, Jahred A.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, Dante E. et al.
Object Type:
Article
System:
The UNT Digital Library
Search for Gluino-Mediated Sbottom Production in p anti-p Collisions at s**(1/2) = 1.96-TeV
We report on a search for the supersymmetric partner of the bottom quark produced from gluino decays in data from 2.5 fb{sup -1} of integrated luminosity collected by the Collider Detector at Fermilab at {radical}s = 1.96 TeV. Candidate events are selected requiring two or more jets and large missing transverse energy. At least two of the jets are required to be tagged as originating from a b quark to enhance the sensitivity. The results are in good agreement with the prediction of the standard model processes, giving no evidence for gluino decay to sbottom quarks. This result constrains the gluino-pair-production cross section to be less than 40 fb at 95% credibility level for a gluino mass of 350 GeV/c{sup 2}.
Date:
March 1, 2009
Creator:
Aaltonen, T.; Adelman, Jahred A.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, Dante E. et al.
Object Type:
Article
System:
The UNT Digital Library
Search for narrow resonances lighter than Upsilon mesons
We report a search for narrow resonances, produced in p{bar p} collisions at {radical}s = 1.96 TeV, that decay into muon pairs with invariant mass between 6.3 and 9.0 GeV/c{sup 2}. The data, collected with the CDF II detector at the Fermilab Tevatron collider, correspond to an integrated luminosity of 630 pb{sup -1}. We use the dimuon invariant mass distribution to set 90% upper credible limits of about 1% to the ratio of the production cross section times muonic branching fraction of possible narrow resonances to that of the {Upsilon}(1S) meson.
Date:
March 1, 2009
Creator:
Aaltonen, T.; Adelman, Jahred A.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, Dante E. et al.
Object Type:
Article
System:
The UNT Digital Library
Search for Standard Model Higgs Boson Production in Association with a W Boson at CDF
We present a search for standard model Higgs boson production in association with a W boson in proton-antiproton collisions (p{bar p} {yields} W{sup {+-}}H {yields} {ell}{nu}b{bar b}) at a center of mass energy of 1.96 TeV. The search employs data collected with the CDF II detector which correspond to an integrated luminosity of approximately 1 fb{sup -1}. We select events consistent with a signature of a single lepton (e{sup {+-}}/{mu}{sup {+-}}), missing transverse energy, and two jets. Jets corresponding to bottom quarks are identified with a secondary vertex tagging method and a neural network filter technique. The observed number of events and the dijet mass distributions are consistent with the standard model background expectations, and we set 95% confidence level upper limits on the production cross section times branching ratio ranging from 3.9 to 1.3 pb for Higgs boson masses from 110 to 150 GeV/c{sup 2}, respectively.
Date:
March 1, 2008
Creator:
Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, J.; /Chicago U., EFI; Akimoto, T.; U., /Tsukuba et al.
Object Type:
Article
System:
The UNT Digital Library
Evidence for a Narrow Near-Threshold Structure in the $J/\psi\phi$ Mass Spectrum in $B^+\to J/\psi\phi K^+$ Decays
Evidence is reported for a narrow structure near the J/{psi}{phi} threshold in exclusive B{sup +} {yields} J/{psi}{phi}K{sup +} decays produced in {bar p}p collisions at {radical}s = 1.96 TeV. A signal of 14 {+-} 5 events, with statistical significance in excess of 3.8 standard deviations, is observed in a data sample corresponding to an integrated luminosity of 2.7 fb{sup -1}, collected by the CDF II detector. The mass and natural width of the structure are measured to be 4143.0 {+-} 2.9(stat) {+-} 1.2(syst) MeV/c{sup 2} and 11.7{sub -5.0}{sup +8.3}(stat) {+-} 3.7(syst) MeV/c{sup 2}.
Date:
March 1, 2009
Creator:
Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, Jahred A.; /Chicago U., EFI; Akimoto, T.; U., /Tsukuba et al.
Object Type:
Article
System:
The UNT Digital Library
First Measurement of the t anti-t Differential Cross Section d sigma/dM(t anti-t) in p anti-p Collisions at s**(1/2)=1.96-TeV
We present a measurement of the t{bar t} differential cross section with respect to the t{bar t} invariant mass, d{sigma}/dM{sub t{bar t}}, in p{bar p} collisions at {radical}s = 1.96 TeV using an integrated luminosity of 2.7 fb{sup -1} collected by the CDF II experiment. The t{bar t} invariant mass spectrum is sensitive to a variety of exotic particles decaying into t{bar t} pairs. The result is consistent with the standard model expectation, as modeled by PYTHIA with CTEQ5L parton distribution functions.
Date:
March 1, 2009
Creator:
Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, Jahred A.; /Chicago U., EFI; Akimoto, T.; U., /Tsukuba et al.
Object Type:
Article
System:
The UNT Digital Library
A Measurement of the t anti-t Cross Section in p anti-p Collisions at s**(1/2) = 1.96-TeV using Dilepton Events with a Lepton plus Track Selection
This paper reports a measurement of the cross section for the pair production of top quarks in p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron. The data was collected from the CDF II detector in a set of runs with a total integrated luminosity of 1.1 fb{sup -1}. The cross section is measured in the dilepton channel, the subset of t{bar t} events in which both top quarks decay through t {yields} Wb {yields} {ell}{nu}b, where {ell} = e, {mu}, or {tau}. The lepton pair is reconstructed as one identified electron or muon and one isolated track. The use of an isolated track to identify the second lepton increases the t{bar t} acceptance, particularly for the case in which one W decays as W {yields} {tau}{nu}. The purity of the sample may be further improved at the cost of a reduction in the number of signal events, by requiring an identified b-jet. They present the results of measurements performed with and without the request of an identified b-jet. the former is the first published CDF result for which a b-jet requirement is added to the dilepton selection. In the CDF data there are 129 pretag lepton …
Date:
March 1, 2009
Creator:
Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, Jahred A.; /Chicago U., EFI; Akimoto, T.; U., /Tsukuba et al.
Object Type:
Article
System:
The UNT Digital Library
Evidence for production of single top quarks
We present first evidence for the production of single top quarks in the D0 detector at the Fermilab Tevatron p{bar p} collider. The standard model predicts that the electroweak interaction can produce a top quark together with an antibottom quark or light quark, without the antiparticle top quark partner that is always produced from strong coupling processes. Top quarks were first observed in pair production in 1995, and since then, single top quark production has been searched for in ever larger datasets. In this analysis, we select events from a 0.9 fb{sup -1} dataset that have an electron or muon and missing transverse energy from the decay of a W boson from the top quark decay, and two, three, or four jets, with one or two of the jets identified as originating from a b hadron decay. The selected events are mostly backgrounds such as W+jets and t{bar t} events, which we separate from the expected signals using three multivariate analysis techniques: boosted decision trees, Bayesian neural networks, and matrix element calculations. A binned likelihood fit of the signal cross section plus background to the data from the combination of the results from the three analysis methods gives a cross …
Date:
March 1, 2008
Creator:
Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Object Type:
Article
System:
The UNT Digital Library
First direct two-sided bound on the B0(s) oscillation frequency
The authors report the first direct two-sided bound on the B{sub s}{sup 0} oscillation frequency using a large sample of B{sub s}{sup 0} semileptonic decays corresponding to approximately 1 fb{sup -1} of integrated luminosity collected by the D0 experiment in 2002-2006 during Run II of the Fermilab Tevatron Collider. The flavor (i.e., B{sub s}{sup 0} or B{sub s}{sup 0}) of the B{sub s}{sup 0} meson at the time of production was found using an opposite-side tagging technique, and the flavor at the time of decay was determined from the charge of the muon in the partially reconstructed decay B{sub s}{sup 0} {yields} {mu}{sup +} D{sub s}{sup -}X, D{sub s}{sup -} {yields} {phi}{pi}{sup -}, {phi} {yields} K{sup +}K{sup -}. A likelihood scan over the oscillation frequency, {Delta}m{sub s}, gives a most probable value of 19 ps{sup -1} and a range of 17 < {Delta}m{sub s} < 21 ps{sup -1} at the 90% C.L. At {Delta}m{sub s} = 19 ps{sup -1}, the amplitude method yields a result that deviates from the hypothesis of an oscillation amplitude of zero by 2.5 standard deviations, corresponding to a two-sided C.L. of 1%.
Date:
March 1, 2006
Creator:
Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Object Type:
Article
System:
The UNT Digital Library
First study of the radiation-amplitude zero in W gamma production and limits on anomalous WW gamma couplings at s**(1/2) = 1.96- TeV
None
Date:
March 1, 2008
Creator:
Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Object Type:
Article
System:
The UNT Digital Library
Measurement of B(t ---> Wb)/B(t ---> Wq) at s**(1/2) = 1.96-TeV
The authors present the measurement of R = {Beta}(t {yields} Wb)/{Beta}(t {yields} Wq) in p{bar p} collisions at {radical}s = 1.96 TeV, using 230 pb{sup -1} of data collected by the D0 experiment at the Fermilab Tevatron Collider. They fit simultaneously R and the number (N{sub t{bar t}}) of selected top quark pairs (t{bar t}), to the number of identified b-quark jets in events with one electron or one muon, three or more jets, and high transverse energy imbalance. To improve sensitivity, kinematical properties of events with no identified b-quark jets are included in the fit. They measure R = 1.03{sub -0.17}{sup +0.19}(stat+syst), in good agreement with the standard model. They set lower limits of R > 0.61 and |V{sub tb}| > 0.78 at 95% confidence level.
Date:
March 1, 2006
Creator:
Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Object Type:
Article
System:
The UNT Digital Library