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LARP Long Nb3Sn Quadrupole Design.

Description: A major milestone for the LHC Accelerator Research Program (LARP) is the test, by the end of 2009, of two 4m-long quadrupole magnets (LQ) wound with Nb{sub 3}Sn conductor. The goal of these magnets is to be a proof of principle that Nb{sub 3}Sn is a viable technology for a possible LHC luminosity upgrade. The design of the LQ is based on the design of the LARP Technological Quadrupoles, presently under development at FNAL and LBNL, with 90-mm aperture and gradient higher than 200 T/m. The desig… more
Date: August 27, 2007
Creator: Ambrosio, G.; Andreev, N.; Anerella, M.; Barzi, E.; Bossert, R.; Caspi, S. et al.
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Partner: UNT Libraries Government Documents Department
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A scheme to improve the low energy luminosity in LEP

Description: In the design of large electron positron colliding beam facilities, it has become customary to use a certain optimization procedure to establish desired beam performance. The results of this procedure are the minimum requirements in terms of RF-power, bending radius and focusing to achieve a desired luminosity at a given energy. This procedure, however, neglects the optimization of the storage ring performance below and above that design energy. Below the design energy the luminosity is optimiz… more
Date: December 27, 1978
Creator: Wiedemann, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effects of core mixing on solar oscillation frequencies

Description: This paper discusses predicted p- and g-mode periods for two solar models provided by Schatzman and Maeder (1981). One model has no mixing while the other has turbulent diffusion mixing (allowed for by a Reynolds number of 100). The resulting g-mode period spacings allow a very close look at the central solar structure which, like the p-mode period splittings, indicate little or no mixing over the lifetime of the sun.
Date: July 27, 1984
Creator: Cox, A. N. & Kidman, R. B.
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Partner: UNT Libraries Government Documents Department
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Stochastic cooling requirements for a muon collider

Description: The most severe limitation to the muon production for a large-energy muon collider is the short time allowed for cooling the beam to dimensions small enough to provide reasonably high luminosity. The limitation is caused by the short lifetime of the particles that, for instance, at the energy of 100 GeV is of only 2.2 ms. Moreover, it appears to be desirable to accelerate the beam quickly, with very short bunches of about a millimeter so it can be made immediately available for the final collis… more
Date: September 27, 1993
Creator: Ruggiero, Alessandro G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Properties of RR Lyrae stars in the Inner Regions of the Large Magellanic Cloud

Description: We present the radial velocities, metallicities and the K-band magnitudes of 74 RR Lyrae stars in the inner regions of the LMC. The intermediated resolution spectra and the infrared images were obtained with FORS1 at the ESO VLT and with the SOFI infrared imager at the ESO NTT. The best 43 RR Lyrae with measured velocities yield an observed velocity dispersion of {sigma}=61{+-} 7 km s{sup -1}. We obtain a true LMC RR Lyrae velocity dispersion of {sigma}=53 km s{sup -1}, which is higher than the… more
Date: May 27, 2004
Creator: Borissova, J; Minniti, D; Rejkuba, M; Alves, D; Cook, K H & Freeman, K C
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Partner: UNT Libraries Government Documents Department
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The RHIC polarized source upgrade

Description: The RHIC polarized H{sup -} ion source is being upgraded to higher intensity (5-10 mA) and polarization for use in the RHIC polarization physics program at enhanced luminosity RHIC operation. The higher beam peak intensity will allow reduction of the transverse beam emittance at injection to AGS to reduce polarization losses in AGS. There is also a planned RHIC luminosity upgrade by using the electron beam lens to compensate the beam-beam interaction at collision points. This upgrade is also es… more
Date: September 27, 2010
Creator: Zelenski, A.; Atoian, G.; Davydenko, V.; Ivanov, A.; Kolmogorov, A.; Ritter, J. et al.
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Partner: UNT Libraries Government Documents Department
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Optimizing of the higher order mode dampers in the 56MHz SRF cavity

Description: Earlier, we reported that a 56 MHz cavity was designed for a luminosity upgrade of the RHIC, and presented the requirements for Higher Order Mode (HOM) damping, the design of the HOM dampers, along with measurements and simulations of the HOM dampers. In this report, we describe our optimization of the dampers performance, and the modifications we made to their original design. We also optimized the number of the HOM dampers, and tested different configurations of locations for them.
Date: January 27, 2010
Creator: Wu, Q. & Ben-Zvi, Ilan
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Interplay of space-charge and beam-beam effects in a collider

Description: Operation of a collider at low energy or use of cooling techniques to increase beam density may result in luminosity limitation due to the space-charge effects. Understanding of such limitation became important for Low-Energy RHIC physics program with heavy ions at the center of mass energies of 5-20 GeV/nucleon. For a collider, we are interested in a long beam lifetime, which limits the allowable space-charge tune shift. An additional complication comes from the fact that ion beams are collidi… more
Date: September 27, 2010
Creator: Fedotov, A. V.; Blaskiewicz, M.; Fischer, W.; Satogata, T. & Tepikian, S.
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Partner: UNT Libraries Government Documents Department
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Suppressing Electron Cloud in Future Linear Colliders

Description: Any accelerator circulating positively charged beams can suffer from a build-up of an electron cloud (EC) in the beam pipe. The cloud develops through ionization of residual gases, synchrotron radiation and secondary electron emission and, when severe, can cause instability, emittance blow-up or loss of the circulating beam. The electron cloud is potentially a luminosity limiting effect for both the Large Hadron Collider (LHC) and the International Linear Collider (ILC). For the ILC positron da… more
Date: May 27, 2005
Creator: Pivi, M; Kirby, R. E.; Raubenheimer, T. O. & Le Pimpec, F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Achieving Large Dynamic Aperture in the ILC Damping Rings

Description: The Damping Rings for the International Linear Collider have challenging requirements for the acceptance, because of the high average injected beam power and the large beam produced from the positron source. At the same time, the luminosity goals mean that the natural emittance must be very small, and this makes it particularly difficult to achieve a good dynamic aperture. We describe design approaches and lattice designs that meet the emittance specification and have very promising dynamic ape… more
Date: May 27, 2005
Creator: Wolski, A.; Cai, Y & /LBL, Berkeley /SLAC
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Simulation of BaBar Drift Chamber

Description: The BaBar drift chamber (DCH) is used to measure the properties of charged particles created from e{sup +}e{sup -} collisions in the PEP-II asymmetric-energy storage rings by making precise measurements of position, momentum and ionization energy loss (dE/dx). In October of 2005, the PEP-II storage rings operated with a luminosity of 10 x 10{sup 33} cm{sup -2}s{sup -1}; the goal for 2007 is a luminosity of 20 x 10{sup 33} cm{sup -2}s{sup -1}, which will increase the readout dead time, causing u… more
Date: September 27, 2006
Creator: Anderson, Rachel & /Wisconsin U., Eau Claire /SLAC
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Proposal of the Next Incarnation of Accelerator Test Facility at KEK for the International Linear Collider

Description: To reach design luminosity, the International Linear Collider (ILC) must be able to create and reliably maintain nanometer size beams. The ATF damping ring is the unique facility where ILC emittances are possible. In this paper we present and evaluate the proposal to create a final focus facility at the ATF which, using compact final focus optics and an ILC-like bunch train, would be capable of achieving 37 nm beam size. Such a facility would enable the development of beam diagnostics and tunin… more
Date: May 27, 2005
Creator: Araki, S.; Hayano, H.; Higashi, Y.; Honda, Y.; Kanazawa, K.; Kubo, K. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Precision Measurement and Improvement of e+, e- Storage Rings

Description: Through horizontal and vertical excitations, we have been able to make a precision measurement of linear geometric optics parameters with a Model-Independent Analysis (MIA). We have also been able to build up a computer model that matches the real accelerator in linear geometric optics with an SVD-enhanced Least-square fitting process. Recently, with the addition of longitudinal excitation, we are able to build up a computer virtual machine that matches the real accelerators in linear optics in… more
Date: June 27, 2006
Creator: Yan, Y. T.; Cai, Y.; Colocho, W.; Decker, F. -J.; Seeman, J.; Sullivan, M. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Studies of W + jets and prompt diphoton production with the CDF Detector

Description: The authors have studied the W + {ge} n jets process in Tevatron Run II experiment. This is the first result for the CDF Run II experiment. The data used corresponds to a total integrated luminosity of 72 pb{sup -1} taken from March 2002 through January 2003. The lowest order QCD predictions have been tested with a new prescription of the parton-jet matching, which allows to construct the enhanced LO phase space. They found a good agreement between data and theory in the typical kinematics dist… more
Date: April 27, 2004
Creator: Tsuno, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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D. acosta et al., the cdf collaboration,

Description: We present a measurement of the ratio of top-quark branching fractions R = {Beta}(t {yields} Wb)/{Beta}(t {yields} Wq) using lepton-plus-jets and dilepton data sets with integrated luminosity of {approx}162 pb{sup -1} collected with the Collider Detector at Fermilab during Run II of the Tevatron. The measurement is derived from the relative numbers of t{bar t} events with different multiplicity of identified secondary vertices. We set a lower limit of R > 0.61 at 95% confidence level.
Date: May 27, 2005
Creator: Physics, Top & Collid, Measurement of B (t -> Wb)/B(t -> Wq) at the
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Hadron calorimeters for future hadron colliders

Description: Hadron calorimeters are essential for jet and neutrino physics at collider experiments. Current hadron calorimeters for the ATLAS and CMS detectors are described. Increased energy and luminosity of future hadron colliders place constraints on detector technology. Difficulties for operation of the current detectors in future hadron collider environments are discussed. New experiments for future colliders should take notice of physics processes during jet evolution that place fundamental limits o… more
Date: January 27, 2004
Creator: Freeman, Jim
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Testing LMC Microlensing Scenarios: The Discrimination Power of the SuperMACHO Microlensing Survey

Description: Characterizing the nature and spatial distribution of the lensing objects that produce the observed microlensing optical depth toward the Large Magellanic Cloud (LMC) remains an open problem. They present an appraisal of the ability of the SuperMACHO Project, a next-generation microlensing survey pointed toward the LMC, to discriminate between various proposed lensing populations. they consider two scenarios: lensing by a uniform foreground screen of objects and self-lensing of LMC stars. The o… more
Date: May 27, 2004
Creator: Rest, A.; Stubbs, C.; Becker, A. C.; Miknaitis, G. A.; Miceli, A.; Covarrubias, R. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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DETERMINING THE RATIO OF THE H+ YIELDS TV TO H+ YIELDS TB DECAY RATES FOR LARGE TAN BETA AT THE LARGE HADRON COLLIDER.

Description: We present results on the determination of the observable ratio R = BR(H{sup +} {yields} {tau}{sup +}{nu}{sup -})/BR(H{sup +} {yields} t{bar b}) of charged Higgs boson decay rates as a discriminant quantity between Supersymmetric and non-Supersymmetric models. Simulation of measurements of this quantity through the analysis of the charged Higgs production process gb {yields} tbH{sup +} and relative backgrounds in the two above decay channels has been performed in the context of ATLAS. A {approx… more
Date: May 27, 2003
Creator: ASSAMAGAN,K. A. GUASCH,J. MORETTI,S. PENARANDA,S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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High-Performance Computing in Accelerating Structure Design And Analysis

Description: Future high-energy accelerators such as the Next Linear Collider (NLC) will accelerate multi-bunch beams of high current and low emittance to obtain high luminosity, which put stringent requirements on the accelerating structures for efficiency and beam stability. While numerical modeling has been quite standard in accelerator R&D, designing the NLC accelerating structure required a new simulation capability because of the geometric complexity and level of accuracy involved. Under the US DO… more
Date: June 27, 2006
Creator: Li, Z. H.; Folwell, N.; Ge, Li-Xin; Guetz, A.; Ivanov, V.; Kowalski, M. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Measurement of B -> D Form Factors in the Semileptonic Decay B -> D* l nu at BaBar

Description: We present here the results of a measurement of the three semileptonic form factors involved in the decay B{sup 0} {yields} D*{ell}{nu}, where {ell} is one of the two light charged leptons (i.e. an electron or muon--though the final results in this work are determined only for {ell} = electron). This measurement uses the Babar 2000-2002 data set, which is altogether approximately 85 x 10{sup 6} B{bar B}-pairs in 78 fb{sup -1} of integrated luminosity. The D*{sup +} was reconstructed in the chan… more
Date: January 27, 2006
Creator: Gill, Mandeep Singh
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Parameters for a Super-Flavor-Factory

Description: A Super Flavor Factory, an asymmetric energy e{sup +}e{sup -} collider with a luminosity of order 10{sup 36} cm{sup -2} s{sup -1}, can provide a sensitive probe of new physics in the flavor sector of the Standard Model. The success of the PEP-II and KEKB asymmetric colliders in producing unprecedented luminosity above 10{sup 34} cm{sup -2} s{sup -1} has taught us about the accelerator physics of asymmetric e{sup +}e{sup -} collider in a new parameter regime. Furthermore, the success of the SLAC… more
Date: June 27, 2006
Creator: Seeman, J. T.; Cai, Y.; Ecklund, S.; Novokhatski, A.; Seryi, A.; Sullivan, M. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Contact Interaction and Resonant-Like Physics at Present and Future Colliders from Unparticles

Description: High scale conformal physics can lead to unusual unparticle stuff at our low energies. In this paper we discuss how the exchange of unparticles between Standard Model fields can lead to new contact interaction physics as well as a pseudoresonance-like structure, an unresonance, that might be observable at the Tevatron or LHC in the Drell-Yan channel. The specific signatures of this scenario are quite unique and can be used to easily identify this new physics given sufficient integrated luminosi… more
Date: June 27, 2007
Creator: Rizzo, Thomas G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The ILC Beam Delivery System - Conceptual Design and RD Plans

Description: The Beam Delivery System of the ILC has many stringent and sometimes conflicting requirements. To produce luminosity, the beams must be focused to nanometer size. To provide acceptable detector backgrounds, particles far from the beam core must be collimated. Unique beam diagnostics and instrumentation are required to monitor parameters of the colliding beams such as the energy spectrum and polarization. The detector and beamline components must be protected against errant beams. After collisio… more
Date: May 27, 2005
Creator: Seryi, Andrei
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Partner: UNT Libraries Government Documents Department
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ATF2 Proposal Volume 2

Description: For achieving the high luminosity required at the International Linear Collider (ILC), it is critical to focus the beams to nanometer size with the ILC Beam Delivery System (BDS), and to maintain the beam collision with a nanometer-scale stability. To establish the technologies associated with this ultra-high precision beam handling, it has been proposed to implement an ILC-like final focus optics in an extension of the existing extraction beamline of ATF at KEK. The ATF is considered to be the… more
Date: February 27, 2006
Creator: Grishanov, B.I.; Logachev, P.; Podgorny, F.; Telnov, V.; /Novosibirsk, IYF; Angal-Kalinin, D. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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