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Molecular Symmetry-Mixed Dichroism In Double Photoionization Of H2, Jean Marcel Ngoko Djiokap, Alexei V. Meremianin, N. L. Manakov, L. B. Madsen, S. X. Hu, Anthony F. Starace 2019 University of Nebraska-Lincoln

Molecular Symmetry-Mixed Dichroism In Double Photoionization Of H2, Jean Marcel Ngoko Djiokap, Alexei V. Meremianin, N. L. Manakov, L. B. Madsen, S. X. Hu, Anthony F. Starace

Anthony F. Starace Publications

Dichroism in double photoionization of H2 molecules by elliptically polarized extreme ultraviolet pulses is formulated analytically as a sum of atomiclike dichroism (AD) and molecular symmetry-mixed dichroism (MSMD) terms. The MSMD originates from an interplay of 1Σ+u and 1Π+u continuum molecular ionization amplitudes. For detection geometries in which the AD vanishes, numerical results for the sixfold differential probabilities for opposite pulse helicities show that the MSMD is significant in the electron momentum and angular distributions and is controllable by the ellipticity.


Polarization Analysis Of P̄ Produced In Pa Collisions, D. Grzonka, D. Alfs, A. Asaturyan, M. Carmignotto, M. Diermaier, W. Eyrich, B. Glowacz, F. Hauenstein, T. Horn, K. Kilian 2019 Old Dominion University

Polarization Analysis Of P̄ Produced In Pa Collisions, D. Grzonka, D. Alfs, A. Asaturyan, M. Carmignotto, M. Diermaier, W. Eyrich, B. Glowacz, F. Hauenstein, T. Horn, K. Kilian

Physics Faculty Publications

A quite simple procedure for the generation of a polarized antiproton beam could be worked out if antiprotons are produced with some polarization. In order to investigate this possibility measurements of the polarization of produced antiprotons have been started at a CERN/PS test beam. The polarization will be determined from the asymmetry of the elastic antiproton scattering at a liquid hydrogen target in the CNI region for which the analyzing power is well known. The data are under analysis and an additional measurement is done in 2018. Details on the experiment and the ongoing data analysis will be given.


Measurement Of The Beam Spin Asymmetry Of →Ep → E'P'Η In The Deep-Inelastic Regime With Clas, B. Zhao, A. Kim, K. Joo, I . Bedlinskiy, W. Kim, V. Kubarovsky, M. Ungaro, G. Gavalian, A. Klein, S. E. Kuhn, CLAS Collaboration 2019 Old Dominion University

Measurement Of The Beam Spin Asymmetry Of →Ep → E'P'Η In The Deep-Inelastic Regime With Clas, B. Zhao, A. Kim, K. Joo, I . Bedlinskiy, W. Kim, V. Kubarovsky, M. Ungaro, G. Gavalian, A. Klein, S. E. Kuhn, Clas Collaboration

Physics Faculty Publications

The beam spin asymmetry of the exclusive pseudoscalar channel ep→e′p′η was measured for the first time in the deep-inelastic regime (W > 2 GeV/c2 and Q2 > 1 GeV2 /c2) using a longitudinally polarized 5.78 GeV electron beam at Jefferson Lab with the CEBAF Large Acceptance Spectrometer. The data were accumulated in 144 four-dimensional bins of Q2, xB, −t and ϕ over a wide kinematic range, where ϕ is the azimuthal angle between the lepton and hadron scattering planes, The measured azimuthal dependence with large amplitudes of the sin ϕ moments is …


Spectroscopy Of Neon For The Advanced Undergraduate Laboratory, H. C. Busch, M. B. Cooper, C. I. Sukenik 2019 Old Dominion University

Spectroscopy Of Neon For The Advanced Undergraduate Laboratory, H. C. Busch, M. B. Cooper, C. I. Sukenik

Physics Faculty Publications

We describe a spectroscopy experiment, suitable for upper-division laboratory courses, that investigates saturated absorption spectroscopy and polarization spectroscopy in a neon discharge. Both experiments use nearly identical components, allowing students to explore both techniques in a single apparatus. Furthermore, because the wavelength of the laser is in the visible part of the spectrum (640 nm), the experiment is well-suited for students with limited experience in optical alignment. The labs nicely complement a course in atomic or plasma physics, provide students with the opportunity to gain important technical skills in the area of optics and lasers, and can provide an introduction …


Exploring The Structure Of The Bound Proton With Deeply Virtual Compton Scattering, M. Hattawy, N. A. Baltzell, R. Dupré, S. Bültmann, B. Torayev, G. Gavalian, F. Hauenstein, S. E. Kuhn, M. Khachatryan, M. Mayer, J. Poudel, Y. Prok, L. B. Weinstein, J. Zhang, Z. W. Zhao, CLAS Collaboration 2019 Old Dominion University

Exploring The Structure Of The Bound Proton With Deeply Virtual Compton Scattering, M. Hattawy, N. A. Baltzell, R. Dupré, S. Bültmann, B. Torayev, G. Gavalian, F. Hauenstein, S. E. Kuhn, M. Khachatryan, M. Mayer, J. Poudel, Y. Prok, L. B. Weinstein, J. Zhang, Z. W. Zhao, Clas Collaboration

Physics Faculty Publications

In the past two decades, deeply virtual Compton scattering of electrons has been successfully used to advance our knowledge of the partonic structure of the free proton and investigate correlations between the transverse position and the longitudinal momentum of quarks inside the nucleon. Meanwhile, the structure of bound nucleons in nuclei has been studied in inclusive deep-inelastic lepton scattering experiments off nuclear targets, showing a significant difference in longitudinal momentum distribution of quarks inside the bound nucleon, known as the EMC effect. In this Letter, we report the first beam spin asymmetry (BSA) measurement of exclusive deeply virtual Compton scattering …


Argon Metastable And Resonant Level Densities In Ar And Ar/Cl² Discharges Used For The Processing Of Bulk Niobium, Jeremy Peshl, Roderick McNeill, Charles I. Sukenik, Milka Nikolić, Svetozar Popović, Leposava Vŭsković 2019 Old Dominion University

Argon Metastable And Resonant Level Densities In Ar And Ar/Cl² Discharges Used For The Processing Of Bulk Niobium, Jeremy Peshl, Roderick Mcneill, Charles I. Sukenik, Milka Nikolić, Svetozar Popović, Leposava Vŭsković

Physics Faculty Publications

A comparative analysis of two popular spectroscopy techniques is conducted in a coaxial cylindrical capacitively coupled discharge designed for the plasma processing of superconducting radio frequency (SRF) cavities. The density of the metastable and resonant levels in Ar is measured in both Ar and Ar/Cl2 discharges to properly characterize the unique discharge system and aid in the development of a cavity etching routine. The first method, deemed the “branching fraction method,” utilizes the sensitivity of photon reabsorption of radiative decay to measure the lower state (metastable and resonant) densities by taking ratios of spectral lines with a common upper …


Characterization Of A Green Electric Solid Propellant For Electric Propulsion, Matthew Scott Glascock 2019 Missouri University of Science and Technology

Characterization Of A Green Electric Solid Propellant For Electric Propulsion, Matthew Scott Glascock

Doctoral Dissertations

"Electric solid propellants are advanced solid chemical rocket propellants that can be controlled (ignited, throttled and extinguished) through the application and removal of an electric current. These propellants are also being considered for use in ablative pulsed plasma thruster and multimode systems. In this work, the behavior and performance of a novel green electric solid propellant operating in an electrothermal ablation-fed pulsed plasma thruster was investigated. Using an inverted pendulum micro-Newton thrust stand, the impulse bit and specific impulse of the device using the electric solid propellant were measured for short-duration and long-duration runs to end-of-life, at energy levels of …


Compact -300 Kv Dc Inverted Insulator Photogun With Biased Anode And Alkali-Antimonide Photocathode, C. Hernandez-Garcia, P. Adderley, B. Bullard, J. Benesch, J. Grames, J. Gubeli, F. Hannon, J. Hansknecht, J. Jordan, R. Kazimi, G. A. Krafft, M. A. Mamun, M. Poelker, M. L. Stutzman, R. Suleiman, M. Tiefenback, Y. Wang, S. Zhang, H. Baumgart, G. Palacios-Serrano, S. Wijethunga, J. Yoskowitz, C. A. Valerio Lizarraga, R. Montoya Soto, A. Canales Ramos 2019 Old Dominion University

Compact -300 Kv Dc Inverted Insulator Photogun With Biased Anode And Alkali-Antimonide Photocathode, C. Hernandez-Garcia, P. Adderley, B. Bullard, J. Benesch, J. Grames, J. Gubeli, F. Hannon, J. Hansknecht, J. Jordan, R. Kazimi, G. A. Krafft, M. A. Mamun, M. Poelker, M. L. Stutzman, R. Suleiman, M. Tiefenback, Y. Wang, S. Zhang, H. Baumgart, G. Palacios-Serrano, S. Wijethunga, J. Yoskowitz, C. A. Valerio Lizarraga, R. Montoya Soto, A. Canales Ramos

Electrical & Computer Engineering Faculty Publications

This contribution describes the latest milestones of a multiyear program to build and operate a compact −300  kV dc high voltage photogun with inverted insulator geometry and alkali-antimonide photocathodes. Photocathode thermal emittance measurements and quantum efficiency charge lifetime measurements at average current up to 4.5 mA are presented, as well as an innovative implementation of ion generation and tracking simulations to explain the benefits of a biased anode to repel beam line ions from the anode-cathode gap, to dramatically improve the operating lifetime of the photogun and eliminate the occurrence of micro-arc discharges.


The Effect Of Tube Geometry On The Chiral Plasma, S. Jin, D. Zou, X. Lu, Mounir Laroussi 2019 Old Dominion University

The Effect Of Tube Geometry On The Chiral Plasma, S. Jin, D. Zou, X. Lu, Mounir Laroussi

Electrical & Computer Engineering Faculty Publications

A chiral plasma plume has recently been reported inside a circular quartz tube without the use of an external magnetic field. It is believed that the quartz tube plays an important role in the formation of the chiral plasma plume. In this paper, to better understand how this interesting structure is generated, the effect of the tube geometry on the chiral plasma is investigated. First, the effect of the thickness of the tube wall on the chiral plasma is investigated. It is interesting to find that a too thin or too thick tube wall is not favorable for generating the …


Carbon Multicharged Ion Generation From Laser-Spark Ion Source, Md. Mahmudur Rahman, Oguzhan Balki, Hani E. Elsayed-Ali 2019 Old Dominion University

Carbon Multicharged Ion Generation From Laser-Spark Ion Source, Md. Mahmudur Rahman, Oguzhan Balki, Hani E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

Multicharged carbon ions are generated by using a laser-assisted spark-discharge ion source. A Q-switched Nd:YAG laser pulse (1064 nm, 7 ns, ≤ 4.5 × 109 W/cm2) focused onto the surface of a glassy carbon target results in its ablation. The spark-discharge (∼1.2 J energy, ∼1 µs duration) is initiated along the direction of the plume propagation between the target surface and a grounded mesh that is parallel to the target surface. Ions emitted from the laser-spark plasma are detected by their time-of-flight using a Faraday cup. The ion energy-to-charge ratio is analyzed by a three-mesh retarding field …


Laser-Induced Plasma Analysis For Surrogate Nuclear Debris, Michael B. Shattan, John Auxier, A. C. Stowe, Christian G. Parigger 2019 Air Force Institute of Technology

Laser-Induced Plasma Analysis For Surrogate Nuclear Debris, Michael B. Shattan, John Auxier, A. C. Stowe, Christian G. Parigger

Faculty Publications

This work identifies analytical lines in laser-induced plasma for chemical analyses of major elements found in surrogate nuclear debris. These lines are evaluated for interferences and signal strength to insure they would be useful to measure relative concentrations. Compact, portable instruments are employed and can be included as part of a mobile nuclear forensics laboratory for field screening of nuclear debris and contamination. The average plasma temperature is measured using the well-established Boltzmann plot technique, and plasma's average electron density is determined using empirical formulae based on Stark broadening of the H-alpha line. These measurements suggest existence of partial local …


Empirical Studies Related To Open Questions Regarding Geomagnetic Storms, Bruce Patrick Tepke 2019 WVU

Empirical Studies Related To Open Questions Regarding Geomagnetic Storms, Bruce Patrick Tepke

Graduate Theses, Dissertations, and Problem Reports

Earth’s magnetosphere is subject to disturbances, as evidenced by variations of the geomagnetic field in space and on the ground. It is generally understood that most such disturbances are controlled by variations in the solar wind, with interplanetary magnetic field orientations directed southward opposite to Earth’s dipole magnetic axis being most conducive to energy transfers into the magnetosphere, thus resulting in more disturbed intervals. However, the exact functional form for solar wind driving of the magnetosphere has been widely studied, with proposed functional forms varying from the simple half-wave electric rectifier to expressions with a much more complicated dependence upon …


Evaluation Of X-Ray Spectroscopic Techniques For Determining Temperature And Density In Plasmas, Theodore Scott Lane 2019 West Virginia University

Evaluation Of X-Ray Spectroscopic Techniques For Determining Temperature And Density In Plasmas, Theodore Scott Lane

Graduate Theses, Dissertations, and Problem Reports

Temperature and density measurements of plasmas are important for understanding various phenomena. For example, equations of state, most scaling arguments for Inertial Confinement Fusion and laboratory astrophysics all rely upon accurate knowledge of temperature and density. Spectroscopy is a non-invasive technique to measure these quantities. In this work we establish a new spectroscopic technique by using it to determine temperature. We also compare and contrast the capability of two codes, PrismSPECT and ATOMIC, to infer electron density from experimentally acquired spectra via Stark broadening.

We compare and contrast the capability of isoelectronic line ratios and inter-stage line ratios in an …


Dynamical Electron Vortices In Attosecond Double Photoionization Of H2, Jean Marcel Ngoko Djiokap, A. V. Meremianin, N. L. Manakov, L. B. Madsen, S. X. Hu, Anthony F. Starace 2018 University of Nebraska-Lincoln

Dynamical Electron Vortices In Attosecond Double Photoionization Of H2, Jean Marcel Ngoko Djiokap, A. V. Meremianin, N. L. Manakov, L. B. Madsen, S. X. Hu, Anthony F. Starace

Anthony F. Starace Publications

We study electron momentum vortices in single-photon double ionization of H2 by time-delayed, counterrotating, elliptically polarized attosecond pulses propagating along either parallel or perpendicular to the molecular axis R. For kˆ | R, kinematical vortices occur similar to those found for He. For R, we find dynamical vortex structures originating from an ellipticity-dependent interplay of 1+u and 1+u continuum amplitudes. We propose a complete experiment to determine the magnitudes and relative phase of these amplitudes by varying pulse ellipticities and time delays.


Determination Of The Magnetic Field Dependence Of The Surface Resistance Of Superconductors From Cavity Tests, J. R. Delayen, H. Park, S. Su. De Silva, G. Ciovati, Z. Li 2018 Old Dominion University

Determination Of The Magnetic Field Dependence Of The Surface Resistance Of Superconductors From Cavity Tests, J. R. Delayen, H. Park, S. Su. De Silva, G. Ciovati, Z. Li

Physics Faculty Publications

We present a general method to derive the magnetic field dependence of the surface resistance of superconductors from the Q-curves obtained during the cryogenic tests of cavities. The results are applied to coaxial half-wave cavities, TM-like “elliptical” accelerating cavities, and cavities of more complicated geometries.


Kinetics Of Higher Lying Potassium States After Excitation Of The D2 Transition In The Presence Of Helium, Austin J. Wallerstein 2018 Air Force Institute of Technology

Kinetics Of Higher Lying Potassium States After Excitation Of The D2 Transition In The Presence Of Helium, Austin J. Wallerstein

Theses and Dissertations

A kinetic model for the performance of a potassium Diode Pumped Alkali Laser (DPAL), including the role of higher lying states is developed to assess the impact on device efficiency and performance. A rate package for a nine level kinetic model including recommended rate parameters is solved under steady-state conditions. Energy pooling and far wing absorption populates higher lying states, with single photon and Penning ionization leading to modest potassium (K) dimer ion concentrations. The fraction of the population removed from the basic three levels associated with the standard model is less than 10% for all reasonable laser conditions, including …


The Undeniable Attraction Of Lunar Swirls, Cierra Waller, Dhananjay Ravat 2018 University of Kentucky

The Undeniable Attraction Of Lunar Swirls, Cierra Waller, Dhananjay Ravat

Posters-at-the-Capitol

Lunar swirls are complex patterns on the Moon with distinct brightness signatures and magnetic characteristics. Current research has suggested that the formation of lunar swirls relies on local magnetic fields to shield impinging solar wind, based on a shift in electromagnetic wavelength peaks related to solar radiation and space weathering. Our research combined recent models and methods to characterize these anomalies at the surface of the Moon, exploring the effects of field strength and position. We have produced a high resolution map of a famous swirl named Reiner Gamma using magnetic dipole modeling. These maps and models are considered when …


Investigation On The Rons And Bactericidal Effects Induced By He + O2 Cold Plasma Jets: In Open Air And In An Airtight Chamber, Han Xu, Dingxin Liu, Weitao Wang, Zhijie Liu, Li Guo, Mingzhe Rong, Michael G. Kong 2018 Old Dominion University

Investigation On The Rons And Bactericidal Effects Induced By He + O2 Cold Plasma Jets: In Open Air And In An Airtight Chamber, Han Xu, Dingxin Liu, Weitao Wang, Zhijie Liu, Li Guo, Mingzhe Rong, Michael G. Kong

Bioelectrics Publications

He + O2 plasma jets in open air and in an airtight chamber are comparatively studied, with respect to their production of gaseous/aqueous reactive species and their antibacterial effects. Under the same discharge power, the plasma jet in open air has higher densities of gaseous reactive species and a higher concentration of aqueous H2O2 but lower concentrations of aqueous OH and O2-. In addition, the increase in the O2 ratio in He in both plasma jets causes a linear decrease in the population of gaseous reactive species, except for O(3p5P) …


Effects Of Fabrication Errors On The Focusing Performance Of A Sector Metalens, S. S. Stafeev, A. G. Nalimov, Liam O’Faolain, M. V. Kotlyar 2018 Samara National Research University and RAS – Branch of the FSRC “Crystallography and Photonics” RAS, Molodogvardeyskaya 151, 443001, Samara, Russia

Effects Of Fabrication Errors On The Focusing Performance Of A Sector Metalens, S. S. Stafeev, A. G. Nalimov, Liam O’Faolain, M. V. Kotlyar

Cappa Publications

Using e-beam lithography, a 16-sector spiral metalens was fabricated in an amorphous silicon, capable of converting linearly polarized incident light into an azimuthally polarized optical vortex. When illuminated by a 633-nm linearly polarized laser beam, the metalens generated a near-surface subwavelength focal spot equal to 0.75 of the incident wavelength at full-width of half-maximum intensity. The focusing performance of the spiral metalens was numerically shown to be sensitive to the deviation of the factual microrelief from the calculated height. For the designed microrelief height, a circularly polarized incident beam was focused into a bright ring with a reverse energy flow …


Significance Of A Non-Thermal Plasma Treatment On Ldpe Biodegradation With Pseudomonas Aeruginosa, Laurence Scally, Miroslav Gulan, Lars Weigang, Patrick Cullen, Vladimir Milosavljevic 2018 Technological University Dulbin

Significance Of A Non-Thermal Plasma Treatment On Ldpe Biodegradation With Pseudomonas Aeruginosa, Laurence Scally, Miroslav Gulan, Lars Weigang, Patrick Cullen, Vladimir Milosavljevic

Articles

The use of plastics has spanned across almost all aspects of day to day life. Although their uses are invaluable, they contribute to the generation of a lot of waste products that end up in the environment and end up polluting natural habitats such as forests and the ocean. By treating low-density polyethylene (LDPE) samples with non-thermal plasma in ambient air and with an addition of 4% CO2, the biodegradation of the samples can be increased due to an increase in oxidative species causing better cell adhesion and acceptance on the polymer sample surface. It was, however, found that the …


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