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Electric-dipole 5s - 5p Transitions in Promethiumlike Ions

Description: The 5s-5p electric-dipole resonance transitions in highly ionized promethiumlike ions have been studied applying relativistic multi-reference Moeller-Plesset second-order perturbation theory. The transition wavelengths are determined to within 0.2 {angstrom} in the more highly charged ions, where the level degeneracies are small. For somewhat lighter ions a very large reference space was used in order to account for the many degeneracies. In order to calculate transition probabilities and lifet… more
Date: February 29, 2008
Creator: Vilkas, M J; Ishikawa, Y & Trabert, E
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Partner: UNT Libraries Government Documents Department
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Investigation of the 2p3/2-3d5/2 line emission of Au53+ -- Au69+ for diagnosing high energy density plasmas

Description: Measurements of the L-shell emission of highly charged gold ions were made under controlled laboratory conditions using the SuperEBIT electron beam ion trap, allowing detailed spectral observations of lines from ironlike Au{sup 53+} through neonlike Au{sup 69+}. Using atomic data from the Flexible Atomic Code, we have identified strong 3d{sub 5/2} {yields} 2p{sub 3/2} emission features that can be used to diagnose the charge state distribution in high energy density plasmas, such as those found… more
Date: January 29, 2008
Creator: Brown, G V; Hansen, S B; Trabert, E; Beiersdorfer, P; Widmann, K; Chen, H et al.
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Partner: UNT Libraries Government Documents Department
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SIEMENS ADVANCED QUANTRA FTICR MASS SPECTROMETER FOR ULTRA HIGH RESOLUTION AT LOW MASS

Description: The Siemens Advanced Quantra Fourier Transform Ion Cyclotron Resonance (FTICR) mass spectrometer was evaluated as an alternative instrument to large double focusing mass spectrometers for gas analysis. High resolution mass spectrometers capable of resolving the common mass isomers of the hydrogen isotopes are used to provide data for accurate loading of reservoirs and to monitor separation of tritium, deuterium, and helium. Conventional double focusing magnetic sector instruments have a resolut… more
Date: July 8, 2008
Creator: Spencer, W & Laura Tovo, L
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Hyperfine Quenching of the 2s2p 3P0 State of Berylliumlike Ions

Description: The hyperfine-induced 2s2p {sup 3}P{sub 0}-2s{sup 2} {sup 1}S{sub 0} transition rate for Be-like {sup 47}Ti{sup 18+} was recently measured in a storage-ring experiment by Schippers et al. [Phys. Rev. Lett. 98, 033001 (2007)]. The measured value of 0.56(3) s{sup -1} is almost 60% larger than the theoretical value of 0.356 s{sup -1} from a multiconfiguration Dirac-Fock calculation by Marques et al. [Phys. Rev. A 47, 929 (1993)]. In this work, we use a large-scale relativistic configuration-intera… more
Date: March 13, 2008
Creator: Cheng, K T; Chen, M H & Johnson, W R
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Partner: UNT Libraries Government Documents Department
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RHIC performance with 56 MHz RF and gold ion beams pre-cooled at lower energy

Description: Presently there is an R&D ERL under construction at Collider-Accelerator Department (CAD) at BNL with its commissioning scheduled for FY09-10 [1]. The use of this full energy 21 MeV ERL in RHIC tunnel was recently proposed for a Proof-of-Principle demonstration of Coherent Electron Cooling of gold ions at 40 GeV/nucleon [2]. The purpose of this Note is to summarize numerical studies aimed at understanding the potential improvement of RHIC luminosity by using this R&D ERL for pre-cooling… more
Date: October 1, 2008
Creator: Fedotov,A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Polymer Growth Rate in a Wire Chamber with Oxygen,Water, or Alcohol Gas Additives

Description: The rate of polymer growth on wires was measured in a wire chamber while the chamber was aged initially with helium-isobutane (80:20) gas, and then with either oxygen, water, or alcohol added to the gas. At the completion of the aging process for each gas mixture, the carbon content on the wires was measured in a SEM/EDX instrument. The same physical wires were used in all the gas mixtures, allowing measurement of polymer build up or polymer depletion by each gas additive. It is found that the … more
Date: July 2, 2008
Creator: Boyarski, Adam
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Partner: UNT Libraries Government Documents Department
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Coherent Control of Multiphoton Transitions in the Gas and Condensed Phases with Shaped Ultrashort Pulses

Description: Controlling laser-molecule interactions has become an integral part of developing devices and applications in spectroscopy, microscopy, optical switching, micromachining and photochemistry. Coherent control of multiphoton transitions could bring a significant improvement of these methods. In microscopy, multi-photon transitions are used to activate different contrast agents and suppress background fluorescence; coherent control could generate selective probe excitation. In photochemistry, diffe… more
Date: September 23, 2008
Creator: Dantus, Marcos
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Direct Photons at RHIC

Description: Direct photons are ideal tools to investigate kinematical and thermodynamical conditions of heavy ion collisions since they are emitted from all stages of the collision and once produced they leave the interaction region without further modification by the medium. The PHENIX experiment at RHIC has measured direct photon production in p+p and Au+Au collisions at 200 GeV over a wide transverse momentum (p{sub T}) range. The p+p measurements allow a fundamental test of QCD, and serve as a baseline… more
Date: July 29, 2008
Creator: Gabor,D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Proceedings of RIKEN BNL Research Center Workshop: Understanding QGP through Spectral Functions and Euclidean Correlators (Volume 89)

Description: In the past two decades, one of the most important goals of the nuclear physics community has been the production and characterization of the new state of matter--Quark-Gluon Plasma (QGP). Understanding how properties of hadrons change in medium, particularly, the bound state of a very heavy quark and its antiquark, known as quarkonium, as well as determining the transport coefficients is crucial for identifying the properties of QGP and for the understanding of the experimental data from RHIC.… more
Date: June 27, 2008
Creator: Mocsy, A. & Petreczky, P.
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Partner: UNT Libraries Government Documents Department
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The glasma initial state and JIMWLK factorization

Description: We review recent work on understanding the next to leading order corrections to the classical fields that dominate the initial stages of a heavy ion collision. We have recently shown that the leading ln 1/x divergences of these corrections to gluon multiplicities can be factorized into the JIMWLK evolution of the color charge density distributions.
Date: August 26, 2008
Creator: Gelis, F.; Lappi, T. & Venugopalan, R.
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Partner: UNT Libraries Government Documents Department
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IBS suppression lattice in RHIC: theory and experimental verification

Description: Intra-beam scattering (IBS) is the limiting factor of the luminosity lifetime for Relativistic Heavy Ion Collider (RHIC) operation with heavy ions. Over the last few years the process of IBS was carefully studied in RHIC with dedicated IBS measurements and their comparison with the theoretical models. A new lattice was recently designed and implemented in RHIC to suppress transverse IBS growth, which lowered the average arc dispersion by about 20% [1]. This lattice became operational during RHI… more
Date: August 25, 2008
Creator: Fedotov, A. V.; Bai, M.; Bruno, D.; Cameron, P.; Connolly, R.; Cupolo, J. et al.
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Partner: UNT Libraries Government Documents Department
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Laser ion source for low charge heavy ion beams

Description: For heavy ion inertial fusion application, a combination of a laser ion source and direct plasma injection scheme into an RFQ is proposed. The combination might provide more than 100 mA of singly charged heavy ion beam from a single laser shot. A planned feasibility test with moderate current is also discussed.
Date: August 3, 2008
Creator: Okamura, M.; Pikin, A.; Zajic, V.; Kanesue, T. & Tamura, J.
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Partner: UNT Libraries Government Documents Department
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Search for a permanent electric dipole moment using liquid 129Xe

Description: Search for an electric dipole moment is one of the best motivated low-energy approaches for investigating physics beyond the Standard Model. Our experimental effort is focused on improving the limit on EDM in liquid 129Xe to put constraints on nuclear CP-violating interactions. High nuclear spin density and high electrical breakdown strength make 129Xe a promising medium for EDM searches. At the time the project started, the transverse nuclear spin relaxation time T2 of 129Xe was unknown. We ma… more
Date: November 24, 2008
Creator: ROMALIS, PROFESSOR MICHAEL
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Proceedings of RIKEN BNL Research Center Workshop entitled Hydrodynamics in Heavy Ion Collisions and QCD Equation of State (Volume 88)

Description: The interpretation of relativistic heavy-ion collisions at RHIC energies with thermal concepts is largely based on the relative success of ideal (nondissipative) hydrodynamics. This approach can describe basic observables at RHIC, such as particle spectra and momentum anisotropies, fairly well. On the other hand, recent theoretical efforts indicate that dissipation can play a significant role. Ideally viscous hydrodynamic simulations would extract, if not only the equation of state, but also tr… more
Date: April 21, 2008
Creator: Karsch, F.; Kharzeev, D.; Molnar, K.; Petreczky, P. & Teaney, D.
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Partner: UNT Libraries Government Documents Department
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Report of a Workshop on Parallelization of Coupled Cluster Methods

Description: The benchmark, ab initio quantum mechanical methods for molecular structure and spectra are now recognized to be coupled-cluster theory. To benefit from the transiiton to tera- and petascale computers, such coupled-cluster methods must be created to run in a scalable fashion. This Workshop, held as a aprt of the 48th annual Sanibel meeting, at St. Simns, Island, GA, addressed that issue. Representatives of all the principal scientific groups who are addressing this topic were in attendance, to … more
Date: May 8, 2008
Creator: Bartlett, Rodney J. & Deumens, Erik
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Final Technical Report, DOE Grant DE-FG02-98ER54496, Physics of High-Energy-Density X Pinch Plasmas

Description: Abstract for the Final Technical Report, DOE Grant DE-FG02-98ER54496 An X-pinch plasma is produced by driving a high current (100-500 kiloamperes) through two or more fine wires that cross and touch at a point, forming an X in the case of two wires. The wires explode because of the high current, and then the resulting plasma is imploded radially inward by the magnetic field from the current. When the imploding material briefly stagnates at very small radius and high density, an intense burst of… more
Date: December 3, 2008
Creator: Hammer, David
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Maximal Wavelength of Confined Quarks and Gluons and Properties of Quantum Chromodynamics

Description: Because quarks and gluons are confined within hadrons, they have a maximum wavelength of order the confinement scale. Propagators, normally calculated for free quarks and gluons using Dyson-Schwinger equations, are modified by bound-state effects in close analogy to the calculation of the Lamb shift in atomic physics. Because of confinement, the effective quantum chromodynamic coupling stays finite in the infrared. The quark condensate which arises from spontaneous chiral symmetry breaking in t… more
Date: August 1, 2008
Creator: Brodsky, Stanley J. & Shrock, Robert
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Partner: UNT Libraries Government Documents Department
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The Baryon Anomaly: Evidence for Color Transparency and Direct Hadron Production at RHIC

Description: We show that the QCD color transparency of higher-twist contributions to inclusive hadroproduction cross sections, where baryons are produced directly in a short distance subprocess, can explain several remarkable features of high-p{sub T} baryon production in heavy ion collisions which have recently been observed at RHIC: (a) the anomalous increase of the proton-to-pion ratio with centrality (b): the increased power-law fall-off at fixed x{sub T} = 2p{sub T}/{radical}s of the charged particle … more
Date: April 30, 2008
Creator: Brodsky, Stanley J. & Sickles, Anne
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Partner: UNT Libraries Government Documents Department
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Evidence for Color Transparency and Direct Hadron Production at RHIC

Description: The QCD color transparency of higher-twist contributions to the inclusive hadroproduction cross section, where the trigger proton is produced directly in a short-distance subprocess, can explain several remarkable features of high-p{sub T} proton production in heavy ion collisions which have recently been observed at RHIC: (a) the anomalous increase of the p {yields} {pi} ratio with centrality (b): the more rapid power-law fall-off at fixed x{sub T} = 2p{sub T}/{radical}s of the charged particl… more
Date: February 4, 2008
Creator: Brodsky, S
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Partner: UNT Libraries Government Documents Department
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Dynamic versus Static Structure Functions and Novel Diffractive Effects in QCD

Description: Initial- and final-state rescattering, neglected in the parton model, have a profound effect in QCD hard-scattering reactions, predicting single-spin asymmetries, diffractive deep inelastic scattering, diffractive hard hadronic reactions, the breakdown of the Lam Tung relation in Drell-Yan reactions, and nuclear shadowing and non-universal antishadowing--leading-twist physics not incorporated in the light-front wavefunctions of the target computed in isolation. I also discuss the use of diffrac… more
Date: November 12, 2008
Creator: Brodsky, Stanley J.
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Partner: UNT Libraries Government Documents Department
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The Ridge, the Glasma and Flow

Description: I discuss the ridge phenomena observed in heavy ion collisions at RHIC. I argue that the ridge may be due to flux tubes formed from the Color Glass Condensate in the early Glasma phase of matter produced in such collisions.
Date: September 15, 2008
Creator: McLerran, L.
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Partner: UNT Libraries Government Documents Department
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Stability of Single Particle Motion with Head-On Beam-Beam Compensation in the RHIC

Description: To compensate the large tune shift and tune spread generated by the head-on beam-beam interactions in the polarized proton run in the Relativistic Heavy Ion Collider (RHIC), we proposed a low energy electron beam with a Gaussian transverse profiles to collide head-on with the proton beam. In this article, with a weak-strong beam-beam interaction model, we investigate the stability of single particle motion in the presence of head-on beam-beam compensation. Tune footprints, tune diffusion, Lyapu… more
Date: May 1, 2008
Creator: Luo, Y.; Fischer, W. & Abreu, N.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Understanding the anomalous dispersion of doubly-ionized carbon plasmas near 47 nm

Description: Over the last several years we have predicted and observed plasmas with an index of refraction greater than one in the soft X-ray regime. These plasmas are usually a few times ionized and have ranged from low-Z carbon plasmas to mid-Z tin plasmas. Our main calculational tool has been the average atom code. We have recently observed C{sup 2+} plasmas with an index of refraction greater than one at a wavelength of 46.9 nm (26.44 eV). In this paper we compare the average atom method, AVATOMKG, aga… more
Date: April 15, 2008
Creator: Nilsen, J.; Castor, J. I.; Iglesias, C. A.; Cheng, K. T.; Dunn, J.; Johnson, W. R. et al.
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Partner: UNT Libraries Government Documents Department
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Quarkyonic Matter and the Phase Diagram of QCD

Description: Quarkyonic matter is a new phase of QCD at finite temperature and density which is distinct from the confined and de-confined phases. Its existence is unambiguously argued in the large numbers of colors limit, N{sub c} {yields} {infinity}, of QCD. Hints of its existence for QCD, N{sub c} = 3, are shown in lattice Monte-Carlo data and in heavy ion experiments.
Date: May 15, 2008
Creator: McLerran, L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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