Perfluoro ionomer membranes are tetrafluoro ethylene-based materials with microheterogeneous structures consisting of a hydrophobic polymer backbone and a hydrophilic side-chain cluster region. Due to the ionomer cluster morphology, these films exhibit unique transport properties. Recent investigations with perfluoro sulfonate and perfluoro sulfonate/carboxylate composite polymers have demonstrated their value in the dehydration of nitric acid and they show potential as an alternative to conventional, energy intensive unit operations in the concentration of acid feeds. As a result, investigations were conducted to determine the feasibility of using pure perfluoro carboxylate and mixed perfluoro sulfonate/carboxylate films for the dehydration of nitric acid because of the speculation of improved water selectivity of the carboxylate pendant chain. During the first phase of these investigations the effort was focused on generating a thin, solution cast perfluoro carboxylate ionomer film, to evaluate the general, chemical and physical characteristics of the polymer, and to assess the material's aqueous transport performance (flux and nitrate separation efficiencies) in pervaporation and high-pressure environments. Results demonstrated that generating robust solution-cast films was difficult yet a number of membranes survived high trans-membrane pressures up to 700 psig. General characterization of the solution cast product showed reduced ion exchange capacities when compared with thicker, …

An evidence of the existence of leptoquarks (LQ) would prove the validity of various extensions of the Standard Model of Particle Physics (SM). The search for first generation leptoquarks presented in this dissertation has been performed by analyzing a 1.02 fb{sup -1} sample of data collected by the D0 detector, events with a final state comprising two light jets and two electrons. The absence of an excess of events in comparison to SM expectations leads to exclude scalar LQ masses up to 292 GeV and vector LQ masses from 350 to 458 GeV, depending on the LQ-l-q coupling type. The great importance of a good jet energy measurement motivated the study of the instrumental backgrounds correlated to the calorimeter, as much as studies of the hadronic showers energy resolution in {gamma} + jets events.

The advance of High Energy Physics research using circulating accelerators strongly depends on increasing the magnetic bending field which accelerator magnets provide. To achieve high fields, the most powerful present-day accelerator magnets employ NbTi superconducting technology; however, with the start up of Large Hadron Collider (LHC) in 2007, NbTi magnets will have reached the maximum field allowed by the intrinsic properties of this superconductor. A further increase of the field strength necessarily requires a change in superconductor material; the best candidate is Nb{sub 3}Sn. Several laboratories in the US and Europe are currently working on developing Nb{sub 3}Sn accelerator magnets, and although these magnets have great potential, it is suspected that their performance may be fundamentally limited by conductor thermo-magnetic instabilities: an idea first proposed by the Fermilab High Field Magnet group early in 2003. This thesis presents a study of thermo-magnetic instability in high field Nb{sub 3}Sn accelerator magnets. In this chapter the following topics are described: the role of superconducting magnets in High Energy Physics; the main characteristics of superconductors for accelerator magnets; typical measurements of current capability in superconducting strands; the properties of Nb{sub 3}Sn; a description of the manufacturing process of Nb{sub 3}Sn strands; superconducting cables; …

Supersymmetry, extension of the Standard Model of Particle Physics (SM), is searched for by trying to observe the supersymmetric partner of bottom quark ({tilde b}). This search is performed using events with a final state comprising two acoplanar b-quark jets and missing transverse energy (MET) and coming from a sample of 992 pb{sup -1} of data collected by the D0 detector at the Tevatron, the Fermilab p{bar p} collider. The absence of an excess of events in comparison to MS expectations leads to exclude sb masses up to 201 GeV, neutralino masses up to 94 GeV. The MET has been studied under two points of view, because of its fundamental role in this search. First, at the level of the trigger system which allows the online selection candidate events, and then, within the framework of the ALPGEN generator, the simulation of the Z boson transverse momentum which appears as MET when the Z boson decays into neutrino.

There is an abundance of evidence that the majority of the mass of the universe is in the form of non-baryonic non-luminous matter that was non-relativistic at the time when matter began to dominate the energy density. Weakly Interacting Massive Particles, or WIMPs, are attractive cold dark matter candidates because they would have a relic abundance today of {approx}0.1 which is consistent with precision cosmological measurements. WIMPs are also well motivated theoretically. Many minimal supersymmetric extensions of the Standard Model have WIMPs in the form of the lightest supersymmetric partner, typically taken to be the neutralino. The CDMS II experiment searches for WIMPs via their elastic scattering off of nuclei. The experiment uses Ge and Si ZIP detectors, operated at <50 mK, which simultaneously measure the ionization and athermal phonons produced by the scattering of an external particle. The dominant background for the experiment comes from electromagnetic interactions taking place very close to the detector surface. Analysis of the phonon signal from these interactions makes it possible to discriminate them from interactions caused by WIMPs. This thesis presents the details of an important aspect of the phonon pulse shape analysis known as the ''Lookup Table Correction''. The Lookup Table Correction …

This thesis presents the results of atmospheric neutrino observations from a 12.23 ktyr exposure of the 5.42 kt MINOS Far Detector between 1st August 2003 until 1st March 2006. The separation of atmospheric neutrino events from the large background of cosmic muon events is discussed. A total of 277 candidate contained vertex {nu}/{bar {nu}}{sub {mu}} CC data events are observed, with an expectation of 354.4{+-}47.4 events in the absence of neutrino oscillations. A total of 182 events have clearly identified directions, 77 data events are identified as upward going, 105 data events are identified as downward going. The ratio between the measured and expected up/down ratio is: R{sup data}{sub u/d}/R{sup MC}{sub u/d} = 0.72{sup +0.13}{sub -0.11}(stat.){+-} 0.04 (sys.). This is 2.1{sigma} away from the expectation for no oscillations. A total of 167 data events have clearly identified charge, 112 are identified as {nu}{sub {mu}} events, 55 are identified as {bar {nu}}{sub {mu}} events. This is the largest sample of charge-separated contained-vertex atmospheric neutrino interactions so far observed. The ratio between the measured and expected {bar {nu}}{sub {mu}}/{nu}{sub {mu}} ratio is: R{sup data}{sub {bar {nu}}{nu}} / R{sup MC}{sub {bar {nu}}{nu}} = 0.93 {sup +0.19}{sub -0.15} (stat.) {+-} 0.12 (sys.). This is …

We measure the production cross section of t{bar t} events in p{bar p} collisions at {radical}s = 1.96 TeV. The data was collected by the CDF experiment in Run 2 of the Tevatron accelerator at the Fermi National Accelerator Laboratory between 2002 and 2007. 1.7 fb{sup -1} of data was recorded during this time period. We reconstruct t{bar t} events in the lepton+jets channel, whereby one W boson - resulting from the decay of the top quark pairs - decays leptonically and the other hadronically. The dominant background to this process is the production of W bosons in association with multiple jets. To distinguish t{bar t} from background, we identify soft electrons from the semileptonic decay of heavy flavor jets produced in t{bar t} events. We measure a cross section of {sigma}{sub p{bar p}} = 7.8 {+-} 2.4(stat) {+-} 1.6(syst) {+-} 0.5(lumi).

A search for directly produced Supersymmetric Higgs Bosons has been performed in the di-tau decay channel in 86.3 {+-} 3.5 pb{sup -1} of data collected by CDF during Run1b at the Tevatron. They search for events where one tau decays to an electron and the other tau decays hadronically. They perform a counting experiment and set limits on the cross section for Higgs production in the high tan {beta} region of the m{sub A}-tan {beta} plane. For a benchmark parameter space point where m{sub A} = 100 and tan {beta} = 50, they set a 95% confidence level upper limit at 891 pb compared to the theoretically predicted cross section of 122 pb. For events where the tau candidates are not back-to-back, they utilize a di-tau mass reconstruction technique for the first time on hadron collider data. Limits based on a likelihood binned in di-tau mass from non-back-to-back events alone are weaker than the limits obtained from the counting experiment using the full di-tau sample.

This thesis presents results of the MINOS long baseline neutrino oscillation experiment. Charged Current interactions of {nu}{sub {mu}} from the NuMI beamline have been recorded in both the Near and Far Detectors between May 2005 and February 2006, corresponding to 1.27 x 10{sup 20} protons being delivered to the NuMI target. Several techniques for improving the sensitivity of an oscillation measurement are discussed and their impact assessed. 378 events are observed in the Far Detector during this period, compared to a prediction of 459 {+-} 31 events are observed in the Far Detector during this period, compared to a prediction of 459 {+-} 31 events when the observed Near Detector spectrum is extrapolated to the Far Detector over the 735 km baseline with no oscillations. In addition to this deficit of observed events, there is also evidence for spectral distortion in the Far Detector. A maximum likelihood analysis is used to determine the best fit point and allowed regions in {Delta}m{sup 2}{sub 23} and sin{sup 2}2{theta}{sub 23} parameter space. The best fit values for {Delta}m{sup 2}{sub 23} and sin{sup 2}2{theta}{sub 23} are found to be 2.55{sup +0.39}{sub -0.24} x 10{sup -3} eV{sup 2} and > 0.87 (68% CL) respectively.

A description of the development of the mc{_}runjob software package used to manage large scale computing tasks for the D0 Experiment at Fermilab is presented, along with a review of the Digital Front End Trigger electronics and the software used to control them. A tracking study is performed on detector data to determine that the D0 Experiment can detect charged B mesons, and that these results are in accordance with current results. B mesons are found by searching for the decay channel B{sup {+-}} {yields} J/{psi}K{sup {+-}}.

MINOS is a long baseline neutrino oscillation experiment. A manmade beam of predominantly muon neutrinos is detected both 1 km and 735 km from the production point by two functionally identical detectors. A comparison of the energy spectra measured by the two detectors shows the energy-dependent disappearance of muon neutrinos characteristic of oscillations and allows a measurement of the parameters governing the oscillations. This thesis presents work leading to measurements of disappearance in the 6% {bar {nu}}{sub {mu}} background in that beam. A calibration is developed to correct for time-dependent changes in the responses of both detectors, reducing the corresponding uncertainty on hadronic energy measurements from 1.8% to 0.4% in the near detector and from 0.8% to 0.4% in the far detector. A method of selecting charged current {bar {nu}}{sub {mu}} events is developed, with purities (efficiencies) of 96.5% (74.4%) at the near detector, and 98.8% (70.9%) at the far detector in the region below 10 GeV reconstructed antineutrino energy. A method of using the measured near detector neutrino energy spectrum to predict that expected at the far detector is discussed, and developed for use in the {bar {nu}}{sub {mu}} analysis. Sources of systematic uncertainty contributing to the oscillation measurements …

The authors present the first measurement of the top quark mass using simultaneously data from two decay channels. They use a data sample of {radical}s = 1.96 TeV collisions with integrated luminosity of 1.9 fb{sup -1} collected by the CDF II detector. They select dilepton and lepton + jets channel decays of t{bar t} pairs and reconstruct two observables in each topology. They use non-parametric techniques to derive probability density functions from simulated signal and background samples. The observables are the reconstructed top quark mass and the scalar sum of transverse energy of the event in the dilepton topology and the reconstructed top quark mass and the invariant mass of jets from the W boson decay in lepton + jets channel. They perform a simultaneous fit for the top quark mass and the jet energy scale which is constrained in situ by the hadronic W boson resonance from the lepton + jets channel. Using 144 dilepton candidate events and 332 lepton + jets candidate events they measure: M{sub top} = 171.9 {+-} 1.7 (stat. + JES) {+-} 1.1 (other sys.) GeV/c{sup 2} = 171.9 {+-} 2.0 GeV/c{sup 2}. The measurement features a robust treatment of the systematic uncertainties, correlated between …

The discovery of neutrino mass through experimental evidence of neutrino oscillations at the end of the last century has provided the first proof that the Standard Model of particle physics is incomplete. To be able to extend the Standard Model to incorporate massive neutrinos first requires many theoretical uncertainties surrounding the particle and its interactions to be understood. Therefore, a dedicated experimental programme is needed over the coming decades to provide precision measurements of the neutrino oscillation parameters and also a possible measurement of CP violation in the lepton sector, which could have astrophysical consequences. An intense source of neutrinos is required to achieve these precision measurements and the leading contender proposed to provide this neutrino beam, is the Neutrino Factory. Before a Neutrino Factory facility can be realised, a number of technological challenges need to be evaluated and understood first. One of which, is reduce the large phase space volume (emittance) of the initial muon beam, which is eventually stored and through decay provides the neutrino beam. Ionisation cooling is the chosen method to achieve this and the Muon Ionisation Cooling Experiment (MICE) at Rutherford Laboratory in the UK, is required to demonstrate ionisation cooling and its feasibility for …

Plasma based accelerators are capable of producing electron sources which are ultra-compact (a few microns) and high energies (up to hundreds of MeVs) in much shorter distances than conventional accelerators. This is due to the large longitudinal electric field that can be excited without the limitation of breakdown as in RF structures.The characteristic scale length of the accelerating field is the plasma wavelength and for typical densities ranging from 1018 - 1019 cm-3, the accelerating fields and scale length can hence be on the order of 10-100GV/m and 10-40 mu m, respectively. The production of quasimonoenergetic beams was recently obtained in a regime relying on self-trapping of background plasma electrons, using a single laser pulse for wakefield generation. In this dissertation, we study the controlled injection via the beating of two lasers (the pump laser pulse creating the plasma wave and a second beam being propagated in opposite direction) which induce a localized injection of background plasma electrons. The aim of this dissertation is to describe in detail the physics of optical injection using two lasers, the characteristics of the electron beams produced (the micrometer scale plasma wavelength can result in femtosecond and even attosecond bunches) as well as a …

Data collected by the Fermilab CDF detector are used to measure the inclusive b{bar b} jet production cross section in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. Vertices displaced from the primary interaction point (secondary vertices) are a signature for long-lived decay and are used to identify jets originating from b quarks. An event sample containing two jets, each having an identified secondary vertex, is used. The jets are required to be within the pseudo-rapidity region |{eta}| < 1.2. One of the jets is required to have a transverse energy greater than 30 GeV and the other jet is required to have a transverse energy greater than 20 GeV. The results are compared to Leading Order (Pythia and Herwig) and Next to Leading Order (MC{at}NLO) predictions.

In this thesis we present a search for oscillations of B{sub s}{sup 0} mesons using semileptonic B{sub s}{sup 0} {yields} D{sub s}{sup -}{ell}{sup +}{nu} decays. Data were collected with the upgraded Collider Detector at Fermilab (CDFII) from events produced in collisions of 980 GeV protons and antiprotons accelerated in the Tevatron ring. The total proton-antiproton center-of-mass energy is 1.96 TeV. The Tevatron is the unique source in the world for B{sub s}{sup 0} mesons, to be joined by the Large Hadron Collider at CERN after 2007. We establish a lower limit on the B{sub s}{sup 0} oscillation frequency {Delta}m{sub s} > 7.7 ps{sup -1} at 95% Confidence Level. We also present a multivariate tagging algorithm that identifies semileptonic B {yields} {mu}X decays of the other B mesons in the event. Using this muon tagging algorithm as well as opposite side electron and jet charge tagging algorithms, we infer the B{sub s}{sup 0} flavor at production. The tagging algorithms are calibrated using high statistics samples of B{sup 0} and B{sup +} semileptonic B{sup 0/+} {yields} D{ell}{nu} decays. The oscillation frequency {Delta}m{sub d} in semileptonic B{sup 0} {yields} D{ell}{nu} decays is measured to be {Delta}m{sub d} = (0.501 {+-} 0.029(stat.) {+-} 0.017(syst.)) …

A realistic lattice model is a fundamental basis for the operation of a synchrotron. In this study various beam-based measurements, including orbit response matrix (ORM) and BPM turn-by-turn data are used to verify and calibrate the lattice model of the Fermilab Booster. In the ORM study, despite the strong correlation between the gradient parameters of adjacent magnets which prevents a full determination of the model parameters, an equivalent lattice model is obtained by imposing appropriate constraints. The fitted gradient errors of the focusing magnets are within the design tolerance and the results point to the orbit offsets in the sextupole field as the source of gradient errors. A new method, the independent component analysis (ICA) is introduced to analyze multiple BPM turn-by-turn data taken simultaneously around a synchrotron. This method makes use of the redundancy of the data and the time correlation of the source signals to isolate various components, such as betatron motion and synchrotron motion, from raw BPM data. By extracting clean coherent betatron motion from noisy data and separates out the betatron normal modes when there is linear coupling, the ICA method provides a convenient means to measure the beta functions and betatron phase advances. It also …

A search for the Standard Model Higgs boson was carried out in WH {yields} {ell}{nu}b{bar b} process in p{bar p} collisions at a center of mass energy of 1.96 TeV, where W, H, {ell}, {nu}, b and p denote either a W{sup +} or W{sup -} boson, Higgs boson, lepton (electron or muon), neutrino, bottom quark and proton, respectively. The data were collected with the Collider Detector at Fermilab from February 2002 to August 2004. The corresponding integrated luminosity is 319 pb{sup -1}. We select events containing a single high-p{sub T} electron or muon, a large imbalance of the total transverse energy from a neutrino and two b quark jets. The main backgrounds are the W + light flavor/gluon jets and W + heavy flavor jets processes. Requiring the secondary vertex b-tagging enables us to reject the W + light flavor/gluon jets events effectively. After all event selections, they observe 187 events which is in agreement with the Standard Model background expectation of 175.2 {+-} 26.3 events, and there is no significant excess originating from the Higgs boson in the reconstructed dijet invariant mass distribution. They thus set a 95% confidence level upper limit on the production cross section times …

For over decades, focused ion beam (FIB) has been playing a very important role in microscale technology and research, among which, semiconductor microfabrication is one of its biggest application area. As the dimensions of IC devices are scaled down, it has shown the need for new ion beam tools and new approaches to the fabrication of small-scale devices. In the meanwhile, nanotechnology has also deeply involved in material science research and bioresearch in recent years. The conventional FIB systems which utilize liquid gallium ion sources to achieve nanometer scale resolution can no longer meet the various requirements raised from such a wide application area such as low contamination, high throughput and so on. The drive towards controlling materials properties at nanometer length scales relies on the availability of efficient tools. In this thesis, three novel ion beam tools have been developed and investigated as the alternatives for the conventional FIB systems in some particular applications. An integrated focused ion beam (FIB) and scanning electron microscope (SEM) system has been developed for direct doping or surface modification. This new instrument employs a mini-RF driven plasma source to generate focused ion beam with various ion species, a FEI two-lens electron (2LE) column …

This dissertation has involved the exploration of a new effect in photoelectron emission, multi-atom resonant photoemission (MARPE), as well as the development of new software, data analysis techniques, and detectors of general use in such research. We present experimental and theoretical results related to MARPE, in which the photoelectron intensity from a core level on one atom is influenced by a core-level absorption resonance on another. We point out that some of our and others prior experimental data has been strongly influenced by detector non-linearity and that the effects seen in new corrected data are smaller and of different form. Corrected data for the MnO(001) system with resonance between the O 1s and Mn 2p energy levels are found to be well described by an extension of well-known intraatomic resonant photoemission theory to the interatomic case, provided that interactions beyond the usual second-order Kramers-Heisenberg treatment are included. This theory is also found to simplify under certain conditions so as to yield results equivalent to a classical x-ray optical approach, with the latter providing an accurate and alternative, although less detailed and general, physical picture of these effects. Possible future applications of MARPE as a new probe of near-neighbor identities and …

The motivation of this work is to develop high reflectance normal-incidence multilayer mirrors in the 8-12 nm wavelength region for applications in astronomy and extreme ultraviolet lithography. To achieve this goal, Mo/Sr and Mo/Y multilayers were studied. These multilayers were deposited with a UHV magnetron sputtering system and their reflectances were measured with synchrotron radiation. High normal-incidence reflectances of 23% at 8.8 nm, 40.8% at 9.4 nm, and 48.3% at 10.5 nm were achieved. However, the reflectance of Mo/Sr multilayers decreased rapidly after exposure to air. Attempts to use thin layers of carbon to passivate the surface of Mo/Sr multilayers were unsuccessful. Experimental results on the refractive index {tilde n} = 1-{delta} + i{beta} of yttrium and molybdenum in the 50-1300 eV energy region are reported in this work. This is the first time ever that values on the refractive index of yttrium are measured in this energy range. The absorption part {beta} was determined through transmittance measurements. The dispersive part {delta} was calculated by means of the Kramers-Kronig formalism. The newly determined values of the refractive index of molybdenum are in excellent agreement with the published data. Those of yttrium are more accurate and contain fine structures around the …

This thesis presents two-dimensional hydrodynamic disk simulations with embedded protoplanets, emphasizing the non-linear dynamics in the co-orbital region. In particular, it demonstrates how a protoplanetary disk responds to embedded low mass planets at the inviscid limit. Since the potential vorticity (PV) flow is not conserved, due to the spiral shocks and possibly boundary layer effects emanating from the planet, the PV profile develops inflection points which eventually render the flow unstable. Vortices are produced in association with the potential vorticity minima. Born in the separatrix region, these vortices experience close encounters with the planet, consequently exerting strong torques on the planet. The existence of these vortices, if confirmed, have important implications on planetary migration rates. The formation of vortices is discussed in more detail and a key parameter is found which depends solely on planet mass and sound speed. With this key parameter, one can predict the disk evolution, PV growth rates, and threshold conditions for forming vortices in the co-orbital region. An analytical estimate for the change of PV due to shocks is compared to the actual change in PV in the hydrodynamic simulations. They match well except in the inner region where vortices form. In addition, extensive resolution …

Particle physics deals with the fundamental building blocks of matter and their interactions. The vast number of subatomic particles can be reduced to twelve fundamental fermions, which interact by the exchange of spin-1 particles as described in the Standard Model (SM) of particle physics. The SM provides the best description of the subatomic world to date, despite the fact it does not include gravitation. Following the relation {lambda} = h/p, where h is Planck's constant, for the examination of physics at subatomic scales with size {lambda} probes with high momenta p are necessary. These high energies are accessible through particle colliders. Here, particles are accelerated and brought to collision at interaction points at which detectors are installed to record these particle collisions. Until the anticipated start-up of the Large Hadron Collider at CERN, the Tevatron collider at Fermilab near Chicago is the highest energy collider operating in the world, colliding protons and anti-protons at a center-of-mass energy of {radical}s = 1.96 TeV. Its two interaction points are covered by the multi purpose particle detectors D0 and CDF. During the first data-taking period, known as Run I, the Tevatron operated at a center-of-mass energy of 1.8 TeV. This run period lasted …

The Main Injector Neutrino Oscillation Search (MINOS) is a long-baseline accelerator neutrino experiment designed to measure properties of neutrino oscillation. Using a high intensity muon neutrino beam, produced by the Neutrinos at Main Injector (NuMI) complex at Fermilab, MINOS makes two measurements of neutrino interactions. The first measurement is made using the Near Detector situated at Fermilab and the second is made using the Far Detector located in the Soudan Underground laboratory in northern Minnesota. The primary goal of MINOS is to verify, and measure the properties of, neutrino oscillation between the two detectors using the {nu}{sub {mu}} {yields} V{sub {tau}} transition. A complementary measurement can be made to search for the existence of sterile neutrinos; an oft theorized, but experimentally unvalidated particle. The following thesis will show the results of a sterile neutrino search using MINOS RunI and RunII data totaling {approx}2.5 x 10{sup 20} protons on target. Due to the theoretical nature of sterile neutrinos, complete formalism that covers transition probabilities for the three known active states with the addition of a sterile state is also presented.