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Full-Text Articles in Physics

Investigation And Optimization Of A New Compact Superconducting Cavity For Deflecting And Crabbing Applications, Subashini Uddika De Silva Jul 2014

Investigation And Optimization Of A New Compact Superconducting Cavity For Deflecting And Crabbing Applications, Subashini Uddika De Silva

Physics Theses & Dissertations

Deflecting and crabbing structures have many applications in current accelerator systems. The primary use of a deflecting cavity is to separate a single beam into multiple beams. A crabbing cavity enables the head-on collision at the interaction point in particle colliders in order to increase the luminosity. The early uses of the deflecting structures have been in the early 1960s: these structures were disk loaded structures operating at room temperature. The crabbing structure which was installed at the NEK electron-positron collider was the first and only operational superconducting cavity of that kind. The most common design of superconducting deflecting and …


Analytic Evolution Of Singular Distribution Amplitudes In Qcd, Asli Tandogan Jul 2014

Analytic Evolution Of Singular Distribution Amplitudes In Qcd, Asli Tandogan

Physics Theses & Dissertations

Distribution amplitudes (DAs) are the basic functions that contain information about the quark momentum. DAs are necessary to describe hard exclusive processes in quantum chromodynamics. We describe a method of analytic evolution of DAs that have singularities such as nonzero values at the end points of the support region, jumps at some points inside the support region and cusps. We illustrate the method by applying it to the evolution of a flat (constant) DA, antisymmetric flat DA, and then use the method for evolution of the two-photon generalized distribution amplitude. Our approach to DA evolution has advantages over the standard …


Measurement Of Single And Double Spin Asymmetries In Semi-Inclusive Deep-Inelastic Scattering On Proton And Deuteron, Suman Bandhu Koirala Jul 2014

Measurement Of Single And Double Spin Asymmetries In Semi-Inclusive Deep-Inelastic Scattering On Proton And Deuteron, Suman Bandhu Koirala

Physics Theses & Dissertations

The EG1-DVCS experiment with CLAS at Jefferson Lab collected semi-inclusive pion electro-production data on longitudinally polarized solid state NH3 and ND3 targets with longitudinally polarized electrons of approximately 6 GeV energy. Data on all three pion channels, π +, π– and π0, were collected simultaneously. The charged pions were identified by their time-of-flight information whereas the neutral pions were reconstructed from the invariant mass of two photons. The experiment covered a wide kinematic range: 1 GeV 2Q2 ≤ 3.2 GeV2, 0.12 ≤ xB ≤ 0.48, 0.0 GeV ≤ Ph⊥ …


Direct Measurements Of Two Photon Exchange On Lepton-Proton Elastic Scattering Using Simultaneous Electron-Positron Beams In Clas, Dasuni Kalhari Adikaram Apr 2014

Direct Measurements Of Two Photon Exchange On Lepton-Proton Elastic Scattering Using Simultaneous Electron-Positron Beams In Clas, Dasuni Kalhari Adikaram

Physics Theses & Dissertations

The electric (GE) and magnetic ( GM) form factors of the proton are fundamental observables which characterize its charge and magnetization distributions. There are two methods to measure the proton form factors: the Rosenbluth separation method and the polarization transfer technique. However, the ratio of the electric and magnetic form factors measured by those methods significantly disagree at momentum transfer Q2 > 1 GeV2. The most likely explanation of this discrepancy is the inclusion of two-photon exchange (TPE) amplitude contributions to the elastic electron-proton cross section which significantly changes the extraction of GE from the …


Ionizing Radiation Detection Using Microstructured Optical Fiber, Stanton Dehaven Jan 2014

Ionizing Radiation Detection Using Microstructured Optical Fiber, Stanton Dehaven

Electrical & Computer Engineering Theses & Dissertations

Ionizing radiation detecting microstructured optical fibers are fabricated, modeled and experimentally measured for X-ray detection in the 10-40 keV energy range. These fibers operate by containing a scintillator material which emits visible light when exposed to ionizing radiation. An X-ray source characterized with a CdTe spectrometer is used to quantify the X-ray detection efficiency of the fibers. The solid state CdTe detector is considered 100% efficient in this energy range. A liquid filled microstructured optical fiber (MOF) is presented where numerical analysis and experimental observation leads to a geometric theory of photon transmission using total internal reflection. The model relates …


Photoproduction Of Π0 On Hydrogen With Clas From 1.1 Gev - 5.45 Gev Using E+E –Γ Decay, Michael C. Kunkel Jan 2014

Photoproduction Of Π0 On Hydrogen With Clas From 1.1 Gev - 5.45 Gev Using E+E –Γ Decay, Michael C. Kunkel

Physics Theses & Dissertations

Photoproduction of the π0 meson was studied using the CLAS detector at the Thomas Jefferson National Accelerator Facility using tagged incident photon energies spanning the range Eγ = 1.1 GeV - 5.45 GeV. The measurement is performed on a liquid hydrogen target in the reaction γppe +e(γ). The final state of the reaction is the sum of two subprocesses for π0 decay, the Dalitz decay mode of π0e +eγ and conversion mode where one photon from π0 → γγ decay is converted into a …