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Production and Testing Experience with the SRF Cavities for the CEBAF 12 GeV Upgrade

Description: The CEBAF recirculating CW electron linear accelerator at Jefferson Lab is presently undergoing a major upgrade to 12 GeV. This project includes the fabrication, preparation, and testing of 80 new 7-cell SRF cavities, followed by their incorporation into ten new cryomodules for subsequent testing and installation. In order to maximize the cavity Q over the full operable dynamic range in CEBAF (as high as 25 MV/m), the decision was taken to apply a streamlined preparation process that includes a… more
Date: September 1, 2011
Creator: A. Burrill, G.K. Davis, F. Marhauser, C.E. Reece, A.V. Reilly, M. Stirbet
Partner: UNT Libraries Government Documents Department
open access

The Muon LINAC for the International Design Study of the Neutrino Factory

Description: The first stage of muon acceleration in the Neutrino Factory utilises a superconducting linac to accelerate muons from 244 MeV to 900 MeV. The linac was split into three types of cryomodules with decreasing magnetic fields and increasing amounts of RF voltage but with the design of the superconducting solenoid and RF cavities being the same for all cryomodules. The current status of the muon linac for the International Design Study for the Neutrino Factory will be presented including a final la… more
Date: September 1, 2011
Creator: A. Kurup, C. Bontoiu, Morteza Aslaninejad, J. Pozimski, A. Bogacz, V.S. Morozov, Y.R. Roblin, K.B. Beard
Partner: UNT Libraries Government Documents Department
open access

The RHIC polarized source upgrade

Description: N/A
Date: September 29, 2013
Creator: A., Zelenski; Atoian, G.; Raparia, D.; Ritter, J.; Steski, D.; Klenov, V. et al.
Partner: UNT Libraries Government Documents Department
open access

RF and structural characterization of new SRF films

Description: In the past years, energetic vacuum deposition methods have been developed in different laboratories to improve Nb/Cu technology for superconducting cavities. Jefferson Lab is pursuing energetic condensation deposition via Electron Cyclotron Resonance. As part of this study, the influence of the deposition energy on the material and RF properties of the Nb thin film is investigated. The film surface and structure analyses are conducted with various techniques like X-ray diffraction, Transmissio… more
Date: September 1, 2009
Creator: A.-M. Valente-Feliciano,H. L. Phillips,C. E. Reece,X. Zhao,D. Gu,R. Lukaszew,B. Xiao,K. Seo
Partner: UNT Libraries Government Documents Department
open access

Effects of the Thickness of Niobium Surface Oxide Layers on Field Emission

Description: Field emission on the inner surfaces of niobium superconducting radio frequency cavities is still one of the major obstacles for reaching high accelerating gradients for SRF community. Our previous experimental results* seemed to imply that the threshold of field emission was related to the thickness of Nb surface oxide layers. In this contribution, a more detailed study on the influences of the surface oxide layers on the field emission on Nb surfaces will be reported. By anodization technique… more
Date: September 1, 2011
Creator: A.T. Wu, S. Jin, J.D. Mammosser, R.A. Rimmer, X.Y. Lu, K. Zhao
Partner: UNT Libraries Government Documents Department
open access

Fastest Electropolishing Technique on Niobium for Particle Accelerators

Description: Field emission on the inner surfaces of niobium (Nb) superconducting radio frequency (SRF) cavities is still one of the major obstacles for reaching high accelerating gradients for SRF community. Our previous experimental results [1] seemed to imply that the threshold of field emission was related to the thickness of Nb surface oxide layers. In this contribution, a more detailed study on the influences of the surface oxide layers on the field emission on Nb surfaces will be reported. By anodiza… more
Date: September 1, 2011
Creator: A.T. Wu, S. Jin, R.A. Rimmer, X.Y. Lu, K. Zhao
Partner: UNT Libraries Government Documents Department
open access

AntiReflection Coating D

Description: Analytical expressions used to optimize AR coatings for single junction solar cells are extended for use in monolithic, series interconnected multi-junction solar cell AR coating design. The result is an analytical expression which relates the solar cell performance (through J{sub sc}) directly to the AR coating design through the device reflectance. It is also illustrated how AR coating design be used to provide an additional degree of freedom for current matching multi-junction devices.
Date: September 23, 1999
Creator: AIKEN,DANIEL J.
Partner: UNT Libraries Government Documents Department
open access

Investigation of Sodium Distribution in Phosphate Glasses Using Spin-Echo {sup 23}Na NMR

Description: The spatial arrangement of sodium cations for a series of sodium phosphate glasses, xNa{sub 2}O(100-x)P{sub 2}O{sub 5} (x<55), were investigated using {sup 23}Na spin-echo NMR spectroscopy. The spin-echo decay rate is a function of the Na-Na homonuclear dipolar coupling and is related to the spatial proximity of neighboring Na nuclei. The spin-echo decay rate in these sodium phosphate glasses increases non-linearly with higher sodium number density, and thus provides a measure of the Na-Na e… more
Date: September 16, 1999
Creator: ALAM, TODD M.; BOYLE, TIMOTHY J.; BROW, RICHARD K.; CLICK, CAROL C.; CONZONE, SAM; McLAUGHLIN, JAY et al.
Partner: UNT Libraries Government Documents Department
open access

MICROHOLE TECHNOLOGY PROGRESS ON BOREHOLE INSTRUMENTATION DEVELOPMENT

Description: Microhole technology development is based on the premise that with advances in electronics and sensors, large conventional-diameter wells are no longer necessary for obtaining subsurface information. Furthermore, microholes offer an environment for improved substance measurement. The combination of deep microholes having diameters of 1-3/8 in. at their terminal depth and 7/8-in. diameter logging tools will comprise a very low cost alternative to currently available technology for deep subsurfac… more
Date: September 1, 2000
Creator: ALBRIGHT, J.
Partner: UNT Libraries Government Documents Department
open access

Alignment validation

Description: The four experiments, ALICE, ATLAS, CMS and LHCb are currently under constructionat CERN. They will study the products of proton-proton collisions at the Large Hadron Collider. All experiments are equipped with sophisticated tracking systems, unprecedented in size and complexity. Full exploitation of both the inner detector andthe muon system requires an accurate alignment of all detector elements. Alignmentinformation is deduced from dedicated hardware alignment systems and the reconstruction … more
Date: September 6, 2008
Creator: ALICE; ATLAS; CMS; LHCb & Golling, Tobias
Partner: UNT Libraries Government Documents Department
open access

Field Quality Study of the LARP Nb3Sn 3.7m-Long Quadrupole Models of LQ Series

Description: After the successful test of the first long Nb{sub 3}Sn quadrupole magnet (LQS01), the US LHC Accelerator Research Program (LARP) has assembled and tested a new 3.7 m-long Nb{sub 3}Sn quadrupole (LQS02). This magnet has four new coils made of the same conductor as LQS01 coils, and it is using the same support structure. LQS02 was tested at the Fermilab Vertical Magnet Test Facility with the main goal to confirm that the long models can achieve field gradient above 200 T/m, LARP target for 90-mm… more
Date: September 1, 2011
Creator: AMbrosio, G.; Andreev, N.; Bossert, R.; Chlachidze, G.; DiMarco, J.; Kashikhin, V.V. et al.
Partner: UNT Libraries Government Documents Department
open access

HANFORD REGULATORY EXPERIENCE REGULATION AT HANFORD A CASE STUDY

Description: Hanford has played a pivotal role in the United States' defense for more than 60 years, beginning with the Manhattan Project in the 1940s. During its history, the Hanford Site has had nine reactors producing plutonium for the United States' nuclear weapons program. All the reactors were located next to the Columbia River and all had associated low-level radioactive and hazardous waste releases. Site cleanup, which formally began in 1989 with the signing of the Hanford Federal Facility Agreement… more
Date: September 24, 2007
Creator: AR, HAWKINS
Partner: UNT Libraries Government Documents Department
open access

Bipolaron Hopping Conduction in Boron Carbides

Description: The electrical conductivities of boron carbides, B{sub 12+x}C{sub 3{minus}x} with 0.1 < x < 1.7, between 300 and 1200K suggest the hopping of a nearly temperature-independent density of small (bi)polarons. The activation energies of the nobilities are low, {approx} 0.16 eV, and are nearly independent of the composition. At lower temperatures, conductivities have non-Arrhenius temperature dependencies and strong sensitivity to carbon concentration. Percolative aspects of low-temperature ho… more
Date: September 20, 1999
Creator: ASELAGE, TERRENCE L.; EMIN, D. & MCCREADY, STEVEN S.
Partner: UNT Libraries Government Documents Department
open access

Alignment strategy for the ATLAS tracker

Description: The ATLAS experiment is a multi-purpose particle detector that will study high-energy particle collisions produced by the Large Hadron Collider. For the reconstruction of charged particles, and their production and their decay vertices, ATLAS is equipped with a sophisticated tracking system, unprecedented in size and complexity. Full exploitation of both the Inner Detector and the muon spectrometer requires an accurate alignment. The challenge of aligning the ATLAS tracking devices is discussed… more
Date: September 23, 2007
Creator: ATLAS & Golling, T.
Partner: UNT Libraries Government Documents Department
open access

Measurement of Resonance Parameters of Orbitally Excited Narrow B^0 Mesons

Description: The authors report a measurement of resonance parameters of the orbitally excited (L = 1) narrow B{sup 0} mesons in decays to B{sup (*)+}{pi}{sup -} using 1.7 fb{sup -1} of data collected by the CDF II detector at the Fermilab Tevatron. The mass and width of the B*{sub 2}{sup 0} state are measured to be m(B*{sub 2}{sup 0}) = 5740.2{sub -1.8}{sup +1.7}(stat.){sub -0.8}{sup +0.9}(syst.) MeV/c{sup 2} and {Lambda}(B*{sub 2}{sup 0}) = 22.7{sub -3.2}{sup +3.8}(stat.){sub -10.2}{sup +3.2}(syst.) MeV/c… more
Date: September 1, 2008
Creator: Aaltonen, : T.
Partner: UNT Libraries Government Documents Department
open access

Global Search for New Physics with 2.0 fb88-1 at CDF

Description: Data collected in Run II of the Fermilab Tevatron are searched for indications of new electroweak-scale physics. Rather than focusing on particular new physics scenarios, CDF data are analyzed for discrepancies with the standard model prediction. A model-independent approach (VISTA) considers gross features of the data, and is sensitive to new large cross-section physics. Further sensitivity to new physics is provided by two additional algorithms: a Bump Hunter searches invariant mass distribut… more
Date: September 1, 2008
Creator: Aaltonen, T.; Adelman, J.; Akimoto, T.; Albrow, Michael G.; Alvarez Gonzalez, B.; Amerio, S. et al.
Partner: UNT Libraries Government Documents Department
open access

Measurement of the Single Top Quark Production Cross Section at CDF

Description: We report a measurement of the single top quark production cross section in 2.2 fb{sup -1} of p{bar p} collision data collected by the Collider Detector at Fermilab at {radical}s = 1.96 TeV. Candidate events are classified as signal-like by three parallel analyses which use likelihood, matrix element, and neural network discriminants. These results are combined in order to improve the sensitivity. We observe a signal consistent with the standard model prediction, but inconsistent with the backg… more
Date: September 1, 2008
Creator: Aaltonen, T.; Adelman, J.; Akimoto, T.; Albrow, Michael G.; Alvarez Gonzalez, B.; Amerio, S. et al.
Partner: UNT Libraries Government Documents Department
open access

Search for a Higgs Boson Decaying to Two W Bosons at CDF

Description: We present a search for a Higgs boson decaying to two W bosons in p{bar p} collisions at {radical}s = 1.96 TeV center-of-mass energy. The data sample corresponds to an integrated luminosity of 3.0 fb{sup -1} collected with the CDF II detector. We find no evidence for production of a Higgs boson with mass between 110 and 200 GeV/c{sup 2}, and determine upper limits on the production cross section. For the mass of 160 GeV/c{sup 2}, where the analysis is most sensitive, the observed (expected) lim… more
Date: September 1, 2008
Creator: Aaltonen, T.; Adelman, J.; Akimoto, T.; Albrow, Michael G.; Alvarez Gonzalez, B.; Amerio, S. et al.
Partner: UNT Libraries Government Documents Department
open access

Search for Maximal Flavor Violating Scalars in Same-Charge Lepton Pairs in p anti-p Collisions at s**(1/2) = 1.96-TeV

Description: Models of Maximal Flavor Violation (MxFV) in elementary particle physics may contain at least one new scalar SU(2) doublet field {Phi}{sub FV} = ({eta}{sup 0},{eta}{sup +}) that couples the first and third generation quarks (q{sub 1}; q{sub 3}) via a Lagrangian term L{sub FV} = {zeta}{sub 13}{Phi}{sub FV}q{sub 1}q{sub 3}. These models have a distinctive signature of same-charge top-quark pairs and evade flavor-changing limits from meson mixing measurements. Data corresponding to 2 fb{sup -1} co… more
Date: September 1, 2008
Creator: Aaltonen, T.; Adelman, J.; Akimoto, T.; Albrow, Michael G.; Alvarez Gonzalez, B.; Amerio, S. et al.
Partner: UNT Libraries Government Documents Department
open access

The First measurement of the top quark mass at CDF II in the lepton+jets and dilepton channels simultaneously

Description: The authors present a measurement of the mass of the top quark using data corresponding to an integrated luminosity of 1.9 fb{sup -1} of p{bar p} collisions collected at {radical}s = 1.96 TeV with the CDF II detector at Fermilab's Tevatron. This is the first measurement of the top quark mass using top-antitop pair candidate events in the lepton + jets and dilepton decay channels simultaneously. They reconstruct two observables in each channel and use a non-parametric kernel density estimation t… more
Date: September 1, 2008
Creator: Aaltonen, T.; Adelman, J.; Akimoto, T.; U., /Tsukuba; Albrow, Michael G.; Alvarez Gonzalez, B. et al.
Partner: UNT Libraries Government Documents Department
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