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A 2-GHz Rectangular Corrugated Horn

Description: We have designed, constructed and tested a large, rectangular horn antenna with a center frequency of 2.0 GHz, corrugated on the E-plane walls, made out of aluminum sheet. A new technique has been developed to solder thin aluminum strips onto the back plane to form the corrugations. The radiation beam pattern shows half-power beamwidths of 12{sup 0} and 14{sup 0} in the H and E planes respectively, and side lobe response below -40 dB at angles greater than 50{sup 0} from horn axis. The measured return loss is less than -20 dB (VSWR < 1.22) between 1.7 and 2.3 GHz; insertion loss is less than 0.15 dB.
Date: October 1, 1991
Creator: Bersanelli, M.; Bensadoun, M.; De Amici, Giovanni; Limon, M.; Smoot, George F.; Tanaka, S. et al.
Partner: UNT Libraries Government Documents Department

Final Report: Establishment of an Institute for Fusion Studies, June 1, 1980 - March 1, 1998

Description: The mission of the Institute for Fusion Studies has been to serve as a national center for theoretical fusion and plasma physics research. As an independent scientific group of critical size, its objectives were to conduct research on fundamental phenomena important to fusion; to serve as a center for fusion theory exchange activities with other countries; to exchange scientific developments with other academic disciplines; and to train students and postdoctoral fellows in fusion and plasma physics research.
Date: December 3, 1999
Creator: Hazeltine, Richard D.
Partner: UNT Libraries Government Documents Department

Department of Energy Support for Operations of the WMO/GAW Quality Control/Science Activity Center for the Americas

Description: As a formal activity of the World Meteorological Organization's Global Atmosphere Watch, to provide, through agency collaboration, a center of excellence in the United States that would impose quality assurance techniques on data collected by national air and precipitation quality networks operating in the Americas (north, south, and central).
Date: November 13, 2003
Creator: Hicks, B. B.
Partner: UNT Libraries Government Documents Department

Foci of Volcanoes

Description: One may assume a center of volcanic activities beneath the edifice of an active volcano, which is here called the focus of the volcano. Sometimes it may be a ''magma reservoir''. Its depth may differ with types of magma and change with time. In this paper, foci of volcanoes are discussed from the viewpoints of four items: (1) Geomagnetic changes related with volcanic activities; (2) Crustal deformations related with volcanic activities; (3) Magma transfer through volcanoes; and (4) Subsurface structure of calderas.
Date: January 1, 1974
Creator: Yokoyama, I.
Partner: UNT Libraries Government Documents Department

Bent Superconducting Solenoids for the Muon Cooling Experiment

Description: This report describes some solenoid design work done for the cooling experiment for the muon collider collaboration. This report describes an analysis section of superconducting solenoids that have a center line induction of 3.0 T. The section is bent in the shape of an S. Each bend in the S bends the muon beam one radian (57.3 degrees). The warm bore diameter of the solenoid bent solenoid is 300 to 320 mm. The radius of the bend at the solenoid center line is 1000 mm. This report shows the results of three dimensional field calculations and presents a solenoid design that will include four TPC detectors that are 240 mm in diameter and 550 mm long as well as a 1300 mm long section of 1300 MHz RF cavities. The TPC sections need a solenoid wann bore diameter of about 300 320 mm while RF cavities require a warm bore diameter of 440 mm. The superconducting solenoid design must take into account the varying warm bore diameter requirements for the magnet string yet meet the stringent solenoidal field uniformity requirements within the active volume of the four TPCs.
Date: March 18, 1999
Creator: Green, M.A.; Eyssa, Y.; Kenney, S.; Miller, J. R.; Prestemon, S. & Wang, S.T.
Partner: UNT Libraries Government Documents Department

Measurement of the Branching Fraction for the DecayB^{\pm} to K^{*\pm} gamma, K^{*\pm} toK^{\pm} \pi^{0} with the BaBar Detector

Description: The branching fraction of the radiative penguin B meson decay B{sup {+-}} {yields} K*{sup {+-}}{gamma} is measured at the PEP-II asymmetric energy e{sup +}e{sup -} collider, operating at a center of momentum energy of 10.58 GeV, the {Upsilon}(4S) resonance. This document concentrates on the case K*{sup {+-}} {yields} K{sup {+-}}{pi}{sup 0}; {pi}{sup 0} {yields} {gamma}{gamma}. This analysis is based on a dataset of 88.2-million {Upsilon}(4S) {yields} B{bar B} events corresponding to 81.3 fb{sup -1} collected with the BABAR detector.
Date: September 8, 2006
Creator: koeneke, K.
Partner: UNT Libraries Government Documents Department

Measurement of D* Mesons in Jets from p + p Collisions at sqrt s = 200 GeV

Description: We report the measurement of charged D* mesons in inclusive jets produced in proton-proton collisions at a center of mass energy {radical}s = 200 GeV with the STAR experiment at RHIC. For D* mesons with fractional momenta 0.2 < z < 0.5 in inclusive jets with 11.5 GeV mean transverse energy, the production rate is found to be N(D*{sup +} + D*{sup -})/N(jet) = 0.015 {+-} 0.008(stat) {+-} 0.007(sys). This rate is consistent with perturbative QCD evaluation of gluon splitting into a pair of charm quarks and subsequent hadronization.
Date: May 16, 2009
Creator: Coll, STAR
Partner: UNT Libraries Government Documents Department

DOE's SciDAC Visualization and Analytics Center for EnablingTechnologies -- Strategy for Petascale Visual Data Analysis Success

Description: The focus of this article is on how one group of researchersthe DOE SciDAC Visualization and Analytics Center for EnablingTechnologies (VACET) is tackling the daunting task of enabling knowledgediscovery through visualization and analytics on some of the world slargest and most complex datasets and on some of the world's largestcomputational platforms. As a Center for Enabling Technology, VACET smission is the creation of usable, production-quality visualization andknowledge discovery software infrastructure that runs on large, parallelcomputer systems at DOE's Open Computing facilities and that providessolutions to challenging visual data exploration and knowledge discoveryneeds of modern science, particularly the DOE sciencecommunity.
Date: October 1, 2007
Creator: Bethel, E. Wes; Johnson, Chris; Aragon, Cecilia; Prabhat, ???; Rubel, Oliver; Weber, Gunther et al.
Partner: UNT Libraries Government Documents Department

Preliminary mode distortion measurements on the Jefferson Lab IRFEL

Description: We previously reported analytical calculations of mirror distortion in a high power FEL with a near-concentric cavity. Naive assumptions about the FEL power vs. distortion led us to believe that mirror losses were much lower than expected. Recently we have directly measured the mode size and beam quality as a function of power using a resonator with a center wavelength of 5 microns. The resonator mirrors were calcium fluoride. This material exhibits a large amount of distortion for a given power but, due to the negative slope of refractive index v temperature, adds almost no optical phase distortion on the laser output. The mode in the cavity can thus be directly calculated from the measurements at the resonator output. The presence of angular jitter produced results inconsistent with cold cavity expectations. Removing the effects of the angular jitter produces results in reasonable agreement with analytical models assuming mirror losses comparable to the original expectations.
Date: August 1, 2001
Creator: Benson, Stephen V.; Gubeli, Joe & Shinn, Michelle D.
Partner: UNT Libraries Government Documents Department

Center of Excellence for Laser Applications in Medicine, Microlaser Microscope

Description: The Center of Excellence for Laser Applications in Medicine at the Schepens Eye Research Institute (SERI) is a Center for: A core group of researchers who support each other and their various projects for real-time medical imaging and diagnostics in contiguous space at SERI. Clinical collaborators who participate in the core research at SERI, MEEI, and local ophthalmology practices, and at associated sites around the world. Industrial partners who transfer our technology to commercial products that will reach clinical usage everywhere. Students, post-doctoral associates and medical fellows who work with us and learn how to practice real-time medical imaging and diagnostics.
Date: January 17, 2003
Creator: Webb, R. H.
Partner: UNT Libraries Government Documents Department

Deutron photodissociation in ultraperipheral relativistic heavyion on deutron collisions

Description: In ultraperipheral relativistic deuteron on heavy-ion collisions, a photon emitted from the heavy nucleus may dissociate the deuterium ion. We find deuterium breakup cross sections of 1.24 barns for deuterium-gold collisions at a center of mass energy of 200 GeV per nucleon, as studied at the Relativistic Heavy Ion Collider, and 2.35 barns for deuterium-lead collisions at a center of mass energy of 6.2 TeV, as proposed for the Large Hadron Collider. In the latter case, the cross section is as large as that of hadronic interactions. The estimated error is 5%. We discuss the use of this process as a luminosity monitor and a 'tag' for moderate impact parameter collisions.
Date: March 24, 2003
Creator: Klein, Spencer & Vogt, Ramona
Partner: UNT Libraries Government Documents Department

Longitudinal spin transfer in inclusive Lambda and Lambda barproduct ion in polarized proton-proton collisions at sqrt s = 200GeV

Description: This contribution reports on a proof-of-principle measurement of the longitudinal spin transfer D{sub LL} in inclusive {Lambda} and {Lambda} production in polarized proton-proton collisions at a center of mass energy {radical}s = 200 GeV. The data sample consists of about 3 x 10{sup 6} minimum bias events collected in the year 2005 by the STAR experiment at RHIC with proton beam polarizations of up to 50%. The {Lambda}({bar {Lambda}}) candidates are reconstructed at mid-rapidity (|{eta}| < 1) using the STAR Time Projection Chamber via the dominant decay channel {Lambda} {yields} p{pi}{sup -} ({Lambda} {yields} {bar p}{pi}{sup +}). Their mean transverse momentum p{sub T} is about 1.3 GeV/c and longitudinal momentum fraction x{sub F} = 7.5 x 10{sup -3}. The longitudinal {Lambda}({bar {Lambda}}) polarization is determined using a method in which the detector acceptance mostly cancels.
Date: October 1, 2006
Creator: Xu, Qinghua & Collaboration, STAR
Partner: UNT Libraries Government Documents Department

Mitigation of Emittance Dilution Due to Transverse Mode Coupling in the L-Band Linacs of the ILC

Description: The main L-band linacs of the ILC accelerate 2820 bunches from a center of mass of 10 GeV to 500 GeV (and in the proposed later upgrade, to 1 TeV). The emittance of the vertical plane is approximately 400 times less than that of the horizontal plane. Provided the vertical and horizontal mode dipole frequencies are degenerate then the motion in each plane is not coupled. However, in reality the frequency degeneracy is split and the eigenmodes are shifted due to inevitable manufacturing errors introduced in fabricating 20,000 cavities. This gives rise to a transverse coupling in the horizontal-vertical motion and can readily lead to a dilution in the emittance in the vertical plane. We investigate means to ameliorate this effect dilution by splitting the horizontal-vertical tune of the lattice.
Date: April 16, 2007
Creator: Jones, R.M.; Jones, R.M.; U., /Manchester; Miller, R.H. & /SLAC
Partner: UNT Libraries Government Documents Department

Discovery and measurement of excited b hadrons at the Collider Detector at Fermilab

Description: This thesis presents evidence for the B**{sup 0} and {Sigma}{sub b}{sup (*){+-}} hadrons in proton-antiproton collisions at a center of mass energy of 1.96 TeV, using data collected by the Collider Detector at Fermilab. In the search for B**{sup 0} {yields} B{sup {+-}} {pi}{sup {-+}}, two B{sup {+-}} decays modes are reconstructed: B{sup {+-}} {yields} J/{Upsilon}K{sup {+-}}, where J/{Upsilon} {yields} {mu}{sup +}{mu}{sup -}, and B{sup {+-}} {yields} {bar D}{sup 0}{pi}{sup {+-}}, where {bar D}{sup 0} {yields} K{sup {+-}} {pi}{sup {+-}}. Both modes are reconstructed using 370 {+-} 20 pb{sup -1} of data. Combining the B{sup {+-}} meson with a charged pion to reconstruct B**{sup 0} led to the observation and measurement of the masses of the two narrow B**{sup 0} states, B{sub 1}{sup 0} and B*{sub 2}{sup 0}, of m(B{sub 1}{sup 0}) = 5734 {+-} 3(stat.) {+-} 2(syst.) MeV/c{sup 2}; m(B*{sub 2}{sup 0}) = 5738 {+-} 5(stat.) {+-} 1(syst.) MeV/c{sup 2}. In the search for {Sigma}{sub b}{sup (*){+-}} {yields} {Lambda}{sub b}{sup 0}{pi}{sup {+-}}, the {Lambda}{sub b}{sup 0} is reconstructed in the decay mode {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -}, where {Lambda}{sub c}{sup +} {yields} pK{sup -} {pi}{sup +}, using 1070 {+-} 60 pb{sup -1} of data. Upon combining the {Lambda}{sub b}{sup 0} candidate with a charged pion, all four of the {Sigma}{sub b}{sup (*){+-}} states are observed and their masses measured to be: m({Sigma}{sub b}{sup +}) = 5807.8{sub -2.2}{sup +2.0}(stat.) {+-} 1.7(syst.) MeV/c{sup 2}; m({Sigma}{sub b}{sup -}) = 5815.2 {+-} 1.0(stat.) {+-} 1.7(syst.) MeV/c{sup 2}; m({Sigma}*{sub b}{sup +}) = 5829.0{sub -1.8}{sup +1.6}(stat.){sub -1.8}{sup +1.7}(syst.) MeV/c{sup 2}; M({Sigma}*{sub b}{sup -}) - 5836.4 {+-} 2.0(stat.){sub -1.7}{sup +1.8}(syst.) MeV/c{sup 2}. This is the first observation of {Sigma}{sub b}{sup (*){+-}} baryons.
Date: June 1, 2007
Creator: Pursley, Jennifer Marie & U., /Johns Hopkins
Partner: UNT Libraries Government Documents Department

Precision Measurement of the Mass of the Top Quark in p anti-p Collisions

Description: We report a measurement of the mass of the top quark (m{sub top}) in p{bar p} collisions at a center of mass energy of 1.96 TeV. The analysis is based on p{bar p}{yields}t{bar t}{yields} lepton+jets data recorded with the D0 detector at the Fermilab Tevatron Collider. Events were preselected in the e+jets (913 events/pb of data) and in the {mu}+jets (871 events/pb of data) channels. These were analyzed through a comparison of the matrix element for the production and decay of the t{bar t} states with data, using a likelihood method and 'tagged' b quarks from the t {yields} Wb decays.
Date: January 1, 2007
Creator: Garcia, Carlos A. & U., /Rochester
Partner: UNT Libraries Government Documents Department

Measurement of the CP-violation parameter of B0 mixing and decay with p anti-p ---> mu mu X data

Description: The authors measure the dimuon charge asymmetry A in p{bar p} collisions at a center of mass energy {radical}s 1960 GeV. The data was recorded with the D0 detector and corresponds to an integrated luminosity of approximately 1.0 fb{sup -1}. Assuming that the asymmetry A is due to asymmetric B{sup 0} {leftrightarrow} {bar B}{sup 0} mixing and decay, they extract the CP-violation parameter of B{sup 0} mixing and decay: R({epsilon}{sub B{sup 0}}/1) + |{epsilon}{sub B{sup 0}}|{sup 2} = A{sub B{sup 0}}/4 = -0.0023 {+-} 0.0011(stat) {+-} 0.0008(syst). A{sub B{sup 0}} is the dimuon charge asymmetry from decays of B{sup 0}{bar B}{sup 0} pairs. The general case, with CP violation in both B{sup 0} and B{sub s}{sup 0} systems, is also considered. Finally they obtain the forward-backward asymmetry that quantifies the tendency of {mu}{sup +} to go in the proton direction and {mu}{sup -} to go in the anti-proton direction. The results are consistent with the standard model and constrain new physics.
Date: September 1, 2006
Creator: Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T. et al.
Partner: UNT Libraries Government Documents Department

Measurement of the double differential diject mass cross section in pp(bar) collisions at sqrt(s) = 1.96 TeV

Description: This thesis presents the analysis of the double differential dijet mass cross section, measured at the D0 detector in Batavia, IL, using p{bar p} collisions at a center of mass energy of {radical}s = 1.96 TeV. The dijet mass was calculated using the two highest p{sub T} jets in the event, with approximately 0.7 fb{sup -1} of data collected between 2004 and 2005. The analysis was presented in bins of dijet mass (M{sub JJ}) and rapidity (y), and extends the measurement farther in M{sub JJ} and y than any previous measurement. Corrections due to detector effects were calculated using a Monte Carlo simulation and applied to data. The errors on the measurement consist of statistical and systematic errors, of which the Jet Energy Scale was the largest. The final result was compared to next-to-leading order theory and good agreement was found. These results may be used in the determination of the proton parton distribution functions and to set limits on new physics.
Date: July 1, 2009
Creator: Rominsky, Mandy Kathleen & U., /Oklahoma
Partner: UNT Libraries Government Documents Department

Evidence for an anomalous like-sign dimuon charge asymmetry

Description: We measure the charge asymmetry A of like-sign dimuon events in 6.1 fb{sup -1} of p{bar p} collisions recorded with the DO detector at a center of mass energy sqrt s = 1.96 TeV at the Fermilab Tevatron Collider.
Date: May 1, 2010
Creator: Abazov, Victor Mukhamedovich; /Dubna, JINR; Abbott, Braden Keim; U., /Oklahoma; Abolins, Maris A.; U., /Michigan State et al.
Partner: UNT Libraries Government Documents Department

ARF1 Frequency and Amplitude Curve Calibration

Description: ARF1 was calibrated and checked on 4/18/01. The technique used was to set the start/stop timers (A:R1LLT1 and A:R1LLT2) for duration of 200 msec. Driving the cavities for longer than 200 msec at full voltage could put some stress on the Hipotronics anode supply. The Camac curve generator card was substituted with a precision DC voltage source. Data for both amplitude and frequency were taken with the DC source. A HP 8563A spectrum analyzer in zero span with resolution bandwidth of 1 MHz at a center frequency of 52.818 MHz was used to take the amplitude data. The dynamic curve was a triangle waveform provided by a triggered HP3213A function generator. Frequency was measured on the Fluke frequency counter mounted in the rack in AP50 (with the high level RF off). The attached data and graph contain the current calibration. ARF1-1 is slightly lower voltage than ARF1-2, but well within spec. The calibration was made with the Anode supply at 9 Kvolts, the bend busses were off due to an access that was in progress. Due to the unregulated Anode supply, the voltage levels observed may be slightly higher than with bend busses on. The dynamic performance with the triangle waveform looks correct. The peak voltages measured for ARF1-1 and ARF1-2 were 27.1 KV and 32.9 KV respectively. The calibration for the fanback is 22 Kvolts per volt for ARF1-1&2, and 66 Kvolts per volt for ARF1 Sum. ARF1 has historically run with a flat top voltage duration of 160 msec. The current curve generator has lengthened that time considerably. The curve generator should take full advantage of the 65 dB dynamic range measured.
Date: April 20, 2001
Creator: Pasquinelli, Ralph J.
Partner: UNT Libraries Government Documents Department

Testing a Passive Autocatalytic Recombiner in the Surtsey Facility

Description: Performance tests of a scaled passive autocatalytic recombine (PAR) were performed in the Surtsey test vessel at Sandia National Laboratories. Measured hydrogen depletion rate data were obtained and compared with previous work. Depletion rate is most likely proportional to PAR scale. PAR performance in steamy environments (with and without hydrophobic coating) was investigated. The tests determined that the PAR startup delay times decrease with increasing hydrogen concentrations in steamy environments. Tests with placement of the PAR near a wall (as opposed to a center location) yielded reduced depletion rates. Tests at low oxygen concentrations also showed a reduced recombination rate. The PAR repeatedly ignited hydrogen at about 6 mol% concentration with a catalyst temperature near 940 K. Velocity data at the PAR exhaust were used to calculate the volumetric flow rate through the PAR as a function of the vessel hydrogen concentration.
Date: July 1, 1999
Creator: Blanchat, Thomas K. & Malliakos, Asimios
Partner: UNT Libraries Government Documents Department

Probing physics beyond the SM at Tevatron

Description: Tevatron Experiments: CDF and 6 D0 collected during October 1992 and February 1996 (Run I) a data sample of roughly 120 pb{sup -1} p {bar p} collisions at a center of mass energy {radical}s = 1.8 TeV. A large variety of physical studies have been performed using these data. Current paper reviews last results obtained searching for physics beyond the Standard Model. Direct Supersymmetry (SUSY) searches are not part of this review.
Date: October 14, 2002
Creator: Pagliarone, C.
Partner: UNT Libraries Government Documents Department

Top physics: search for electroweak single top quark production in p anti-p collisions at s**(1/2) = 1.96 tev

Description: We report on a search for Standard Model t-channel and s-channel single top quark production in p{bar p} collisions at a center of mass energy of 1.96 TeV. We use a data sample corresponding to 162 pb{sup -1} recorded by the upgraded Collider Detector at Fermilab. We find no significant evidence for electroweak top quark production and set upper limits at the 95% confidence level on the production cross section, consistent with the Standard Model: 10.1 pb for the t-channel, 13.6 pb for the s-channel and 17.8 pb for the combined cross section of t- and s-channel.
Date: January 12, 2005
Creator: Acosta, D. & Collaboration, The CDF
Partner: UNT Libraries Government Documents Department


Description: Soon after the LHC is commissioned with proton beams the ATLAS experiment will begin studies of Pb-Pb collisions with a center of mass energy of {radical}s{sub NN} = 5.5 TeV. The ATLAS program is a natural extension of measurements at RHIC in a direction that exploits the higher LHC energies and the superb ATLAS calorimeter and tracking coverage. At LHC energies, collisions will be produced with even higher energy density than observed at RHIC. The properties of the resulting hot medium can be studied with higher energy probes, which are more directly interpreted through modification of jet properties emerging from these collisions, for example. Other topics which are enabled by the 30-fold increase in center of mass energy include probing the partonic structure of nuclei with hard photoproduction (in UltraPeripheral collisions) and in p-Pb collisions. Here we report on evaluation of ATLAS capabilities for Heavy Ion Physics.
Date: February 5, 2005
Creator: White, S.
Partner: UNT Libraries Government Documents Department

Rare B meson decays at the Tevatron

Description: Rare B meson decays are an excellent probe for beyond the Standard Model physics. Two very sensitive processes are the B{sub s,d}{sup 0} {yields} {mu}{sup +}{mu}{sup -} and b {yields} s{mu}{sup +}{mu}{sup -} decays. We report recent results at a center of mass energy of {radical}s = 1.96 TeV from the CDF II and D0 collaborations using between 3.7 fb{sup -1} and 6.9 fb{sup -1} taken during Run II of the Fermilab Tevatron Collider.
Date: August 1, 2011
Creator: Hopkins, Walter & /Cornell U., Phys. Dept.
Partner: UNT Libraries Government Documents Department