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Observation of Disappearance of Muon Neutrinos in the NuMI Beam

Description: The Main Injector Neutrino Oscillation Search (MINOS) is a two detector long-baseline neutrino experiment designed to study the disappearance of muon neutrinos. MINOS will test the {nu}{sub {mu}} {yields} {nu}{sub {tau}} oscillation hypothesis and measure precisely {Delta}m{sub 23}{sup 2} and sin{sup 2} 2{theta}{sub 23} oscillation parameters. The source of neutrinos for MINOS experiment is Fermilab's Neutrinos at the Main Injector (NuMI) beamline. The energy spectrum and the composition of the beam is measured at two locations, one close to the source and the other 735 km down-stream in the Soudan Mine Underground Laboratory in northern Minnesota. The precision measurement of the oscillation parameters requires an accurate prediction of the neutrino flux at the Far Detector. This thesis discusses the calculation of the neutrino flux at the Far Detector and its uncertainties. A technique that uses the Near Detector data to constrain the uncertainties in the calculation of the flux is described. The data corresponding to an exposure of 2.5 x 10{sup 20} protons on the NuMI target is presented and an energy dependent disappearance pattern predicted by neutrino oscillation hypotheses is observed in the Far Detector data. The fit to MINOS data, for given exposure, yields the best fit values for {Delta}m{sub 23}{sup 2} and sin{sup 2} 2{theta}{sub 23} to be (2.38{sub -0.16}{sup +0.20}) x 10{sup -3} eV{sup 2}/c{sup 4} and 1.00{sub -0.08}, respectively.
Date: May 1, 2008
Creator: Pavlovic, Zarko & U., /Texas
Partner: UNT Libraries Government Documents Department

Diagnostics of the Fermilab Tevatron using an AC dipole

Description: The Fermilab Tevatron is currently the world's highest energy colliding beam facility. Its counter-rotating proton and antiproton beams collide at 2 TeV center-of-mass. Delivery of such intense beam fluxes to experiments has required improved knowledge of the Tevatron's beam optical lattice. An oscillating dipole magnet, referred to as an AC dipole, is one of such a tool to non-destructively assess the optical properties of the synchrotron. We discusses development of an AC dipole system for the Tevatron, a fast-oscillating (f {approx} 20 kHz) dipole magnet which can be adiabatically turned on and off to establish sustained coherent oscillations of the beam particles without affecting the transverse emittance. By utilizing an existing magnet and a higher power audio amplifier, the cost of the Tevatron AC dipole system became relatively inexpensive. We discuss corrections which must be applied to the driven oscillation measurements to obtain the proper interpretation of beam optical parameters from AC dipole studies. After successful operations of the Tevatron AC dipole system, AC dipole systems, similar to that in the Tevatron, will be build for the CERN LHC. We present several measurements of linear optical parameters (beta function and phase advance) for the Tevatron, as well as studies of non-linear perturbations from sextupole and octupole elements.
Date: August 1, 2008
Creator: Miyamoto, Ryoichi & U., /Texas
Partner: UNT Libraries Government Documents Department

A search for sterile neutrinos in MINOS

Description: MINOS, the Main Injector Neutrino Oscillation Search, is a long baseline neutrino oscillation experiment based at Fermilab National Accelerator Laboratory. The experiment uses a neutrino beam, which is measured 1 km downstream from its origin in the Near detector at Fermilab and then 735 km later in the Far detector at the Soudan mine. By comparing these two measurements, MINOS can attain a very high precision for parameters in the atmospheric sector of neutrino oscillations. In addition to precisely determining {Delta}m{sub 23}{sup 2} and {theta}{sub 23} through the disappearance of {nu}{sub {mu}}, MINOS is able to measure {nu}{sub {mu}} {yields} {nu}{sub sterile} by looking for a deficit in the number of neutral current interactions seen in the Far detector. In this thesis, we present the results of a search for sterile neutrinos in MINOS.
Date: December 1, 2007
Creator: Osiecki, Thomas Henry & U., /Texas
Partner: UNT Libraries Government Documents Department

Alignment of the Near Detector scintillator modules using cosmic ray muons

Description: The authors describe the procedures and the results of the first alignment of the Near Detector. Using 15.5 million cosmic ray muon tracks, collected from October, 2004 through early january, 2005, they derive the effective transverse positions of the calorimeter scintillator modules. The residuals from straight line fits indicate that the current alignment has achieved better than 1 mm precision. They estimate the size of the remaining misalignment and using tracks recorded with a magnetic field test the effect of the magnetic field on the alignment.
Date: May 1, 2008
Creator: Ospanov, Rustem; Lang, Karol & U., /Texas
Partner: UNT Libraries Government Documents Department

Measurement of |V(Ub)| Using Inclusing Semileptonic B Meson Decays

Description: This dissertation presents a measurement of the CKM matrix element |V{sub ub}| made with a sample of 64 million B{bar B} events collected with the BABAR detector. Using Heavy Quark theory, we combine the observed yield of leptons from semileptonic B decay in the electron energy interval 2.1-2.6 GeV with a recent CLEO measurement of the B {yields} X{sub s}{gamma} photon spectrum to find |V{sub ub}| = (4.25 {+-} 0.35 {+-} 0.45 {+-} 0.20) x 10{sup -3}, where the first uncertainty is experimental and the last two are from theory.
Date: March 24, 2006
Creator: Kim, Hojeong & U., /Texas
Partner: UNT Libraries Government Documents Department

Long-baseline neutrino physics in the U.S

Description: Long baseline neutrino oscillation physics in the U.S. is centered at the Fermi National Accelerator Laboratory (FNAL), in particular at the Neutrinos at the Main Injector (NuMI) beamline commissioned in 2004-2005. Already, the MINOS experiment has published its first results confirming the disappearance of {nu}{sub {mu}}'s across a 735 km baseline. The forthcoming NOvA experiment will search for the transition {nu}{sub {mu}} {yields} {nu}{sub e} and use this transition to understand the mass heirarchy of neutrinos. These, as well as other conceptual ideas for future experiments using the NuMI beam, will be discussed. The turn-on of the NuMI facility has been positive, with over 310 kW beam power achieved. Plans for increasing the beam intensity once the Main Injector accelerator is fully-dedicated to the neutrino program will be presented.
Date: December 1, 2006
Creator: Kopp, Sacha E. & U., /Texas
Partner: UNT Libraries Government Documents Department

The NuMI neutrino beam at Fermilab

Description: The Neutrinos at the Main Injector (NuMI) facility at Fermilab began operations in late 2004. NuMI will deliver an intense {nu}{sub {mu}} beam of variable energy (2-20 GeV) directed into the Earth at 58 mrad for short ({approx}1km) and long ({approx}700-900 km) baseline experiments. Several aspects of the design and results from early commissioning runs are reviewed.
Date: May 1, 2005
Creator: Kopp, Sacha E. & U., /Texas
Partner: UNT Libraries Government Documents Department

First observation of dijet events with an antiproton tag at s**(1/2) = 1.96 TeV using the D0 Forward Proton Detector

Description: The Forward Proton Detector (FPD) is a new sub-system of the D0 detector, a 5000 ton particle physics detector located at the Fermilab Tevatron proton-antiproton collider. The FPD was implemented for the Tevatron Run II and gives access to a wide range of diffractive scattering processes, where one or both of the beam particles remain intact. The analysis described in this thesis makes use of the dipole spectrometer of the FPD to tag outgoing antiprotons in events that have a dijet signature in the central D0 calorimeter. Properties of jets with a diffractive tag signature are compared to jets without such a signature yielding the first observation of tagged diffractive dijets at a 1.96 TeV center-of-mass energy.
Date: July 1, 2005
Creator: Strang, Michael Allen & U., /Texas
Partner: UNT Libraries Government Documents Department

Initial tests of an AC dipole for the Tevatron

Description: The AC dipole is a device to diagnose transverse motions of a beam. It can achieve large-amplitude oscillations without two inevitable problems of conventional kicker/pinger magnets: decoherence and emittance growth. While not the first synchrotron to operate with an AC dipole, the Tevatron can now make use of its recently upgraded BPM system, providing unprecedented resolution for use with an AC dipole, to measure both linear and nonlinear properties of the accelerator. Plans are to provide AC dipole systems for both transverse degrees of freedom. Preliminary tests have been done using an audio power amplifier with an existing vertical pinger magnet, producing oscillation amplitudes up to 2{sigma} at 150 GeV. In this paper, we will present the configuration of this system. We also show the analysis of a first few data sets, including the direct measurement of beta functions at BPM locations.
Date: June 1, 2006
Creator: Miyamoto, R.; U., /Texas; Jansson, A.; /Fermilab; Kopp, S.; U., /Texas et al.
Partner: UNT Libraries Government Documents Department

Nonlinear Dynamics of Single Bunch Instability

Description: A nonlinear equation is derived that governs the evolution of the amplitude of unstable oscillations with account of quantum diffusion effects due to the synchrotron radiation. Numerical solutions to this equation predict a variety of possible scenarios of nonlinear evolution of the instability some of which are in good qualitative agreement with experimental observations. Microwave single bunch instability in circular accelerators has been observed in many machines. The instability usually arises when the number of particles in the bunch exceeds some critical value, Nc, which varies depending on the parameters of the accelerating regime. Recent observations on the SLC damping rings at SLAC with a new low-impedance vacuum chamber revealed new interesting features of the instability. In some cases, after initial exponential growth, the instability eventually saturated at a level that remained constant through the accumulation cycle. In other regimes, relaxation-type oscillations were measured in nonlinear phase of the instability. In many cases, the instability was characterized by a frequency close to the second harmonic of the synchrotron oscillations. Several attempts have been made to address the nonlinear stage of the instability based on either computer simulations or some specific assumptions regarding the structure of the unstable mode. An attempt of a more general consideration of the problem is carried out in this paper. We adopt an approach recently developed in plasma physics for analysis of nonlinear behavior of weakly unstable modes in dynamic systems. Assuming that the growth rate of the instability is much smaller than its frequency, we find a time dependent solution to Vlasov equation and derive an equation for the complex amplitude of the oscillations valid in the nonlinear regime. Numerical solutions to this equation predict a variety of possible scenarios of nonlinear evolution of the instability some of which are in good qualitative agreement with ...
Date: September 9, 2011
Creator: Stupakov, G.V.; /SLAC; Breizman, B.N.; Pekker, M.S. & U., /Texas
Partner: UNT Libraries Government Documents Department

Direct measurements of beta-star in the Tevatron

Description: Simultaneous turn-by-turn beam position measurements across collider detector long straight sections provide full phase space information of a free oscillation. For signals with enough coherence (typically 1-2000 revolutions) the amplitude function and its slope at the two BPM's can be directly measured. Results for the Tevatron low-{beta} regions with a few percent accuracy are described.
Date: June 1, 2007
Creator: Syphers, M.J.; /Fermilab; Miyamoto, R. & U., /Texas
Partner: UNT Libraries Government Documents Department

Cycle-to-cycle extraction synchronization of the Fermilab Booster for multiple batch injection to the Main Injector

Description: We report on a system to ensure cycle-to-cycle synchronization of beam extraction from the Fermilab Booster accelerator to the Main Injector. Such synchronization is necessary for multiple batch operation of the Main Injector for the Run II upgrade of anti-proton production using slip-stacking in the Main Injector, and for the NuMI (Neutrinos at the Main Injector) neutrino beam. To perform this task a system of fast measurements and feedback controls the longitudinal progress of the Booster beam throughout its acceleration period by manipulation of the transverse position maintained by the LLRF (Low-level Radio Frequency) system.
Date: May 1, 2005
Creator: Zwaska, R.; Kopp, S.; U., /Texas; Pellico, W. & /Fermilab
Partner: UNT Libraries Government Documents Department

Studies of beam heating of proton beam profile monitor SEM's

Description: The authors present calculations of the expected temperature rise of proton beam profile monitors due to beam heating. The profile monitors are secondary emission monitors (SEM's) to be made of Titanium foils. The heating is studied to understand whether there is any loss of tension or alignment of such devices. Additionally, calculations of thermally-induced dynamic stress are presented. Ti foil is compared to other materials and also to wire SEM's. The calculations were initially performed for the NuMI beam, where the per-pulse intensity is quite high; for completeness the calculations are also performed for other beam energies and intensities.
Date: May 1, 2005
Creator: Pavlovich, Zarko; Osiecki, Thomas H.; Kopp, Sacha E. & U., /Texas
Partner: UNT Libraries Government Documents Department

Precision monitoring of relative beam intensity for Mu2e

Description: For future experiments at the intensity frontier, precise and accurate knowledge of beam time structure will be critical to understanding backgrounds. The proposed Mu2e experiment will utilize {approx}200 ns (FW) bunches of 3 x 10{sup 7} protons at 8 GeV with a bunch-to-bunch period of 1695 ns. The out-of-bunch beam must be suppressed by a factor of 10{sup -10} relative to in-bunch beam and continuously monitored. I propose a Cerenkov-based particle telescope to measure secondary production from beam interactions in a several tens of microns thick foil. Correlating timing information with beam passage will allow the determination of relative beam intensity to arbitrary precision given a sufficiently long integration time. The goal is to verify out-of-bunch extinction to the level 10{sup -6} in the span of several seconds. This will allow near real-time monitoring of the initial extinction of the beam resonantly extracted from Fermilabs Debuncher before a system of AC dipoles and collimators, which will provide the final extinction. The effect on beam emittance is minimal, allowing the necessary continuous measurement. I will present the detector design and some concerns about bunch growth during the resonant extraction.
Date: April 1, 2011
Creator: Evans, N.J.; Kopp, S.E.; U., /Texas; Prebys, E. & /Fermilab
Partner: UNT Libraries Government Documents Department

An Estimate of Out of Time Beam Upon Extraction for Mu2e

Description: For future experiments at the intensity frontier precise and accurate knowledge of beam time structure will be critical to understanding backgrounds. The proposed Mu2e experiment calls for {approx} 200ns (FW, 40 ns rms) bunches of 3 x 10{sup 7} 8 GeV protons and a bunch spacing of 1695 ns. The interbunch beam must be suppressed from the main pulse by a factor of 10{sup -10}, this is known as the beam extinction requirement. Beam from Fermilab's Booster will be formed into 2.5 MHz buckets in the Fermilab Recycler then transferred to the Delivery Ring (formerly the Debuncher) and slow spilled from a single filled bucket in an h = 4 RF system. Because the final extinction level is not expected from the Delivery Ring an AC dipole and collimation system will be used to achieve final extinction. Here I present calculations leading to a first estimate of the extinction level expected upon extraction from the Delivery Ring of {le} 3.36 x 10{sup -4}. Intrabunch, residual gas scattering and scattering off the extraction septum are included. Contributions from bunch formation are not considered.
Date: May 1, 2012
Creator: Prebys, E.; /Fermilab; Evans, N.J.; Kopp, S.E. & U., /Texas
Partner: UNT Libraries Government Documents Department

Geometrical interpretation of nonlinearities from a cylindrical pick-up

Description: In many accelerators, cylindrical pick-ups are used to measure transverse beam positions. Theoretically, signals from these pick-ups are related to infinite power series of the beam position but, in practice, only finite number of terms are considered and the position measurements degrade when a beam is far from the center of a pick-up. This paper shows there is actually a simple geometrical relation between a beam position and induced signals. With help of the geometrical relation, the beam position can be written in a compact function of signals. The paper is concluded with numerical simulations and a test to show this geometry based expression can calculate a beam position better than the conventional methods.
Date: June 1, 2007
Creator: Miyamoto, R.; Kopp, S.E.; U., /Texas; Jansson, A.; Syphers, M.J. & /Fermilab
Partner: UNT Libraries Government Documents Department