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Old Dominion University

2019

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Articles 31 - 60 of 96

Full-Text Articles in Physics

Conformal Invariance Of Transverse-Momentum Dependent Parton Distributions Rapidity Evolution, Ian Balitsky, Giovanni A. Chirilli Jan 2019

Conformal Invariance Of Transverse-Momentum Dependent Parton Distributions Rapidity Evolution, Ian Balitsky, Giovanni A. Chirilli

Physics Faculty Publications

We discuss conformal properties of TMD operators and present the result of the conformal rapidity evolution of TMD operators in the Sudakov region.


Question 1: Cost To Carpool; Question 2: Waiting In Tsa Lines, Larry Weinstein Jan 2019

Question 1: Cost To Carpool; Question 2: Waiting In Tsa Lines, Larry Weinstein

Physics Faculty Publications

How much extra gasoline does it cost to carpool, i.e., to carry another passenger? How much time is spent each year in the U.S. waiting in security lines at airports? [Extracted from the article]


Quantifying The Concentration And Penetration Depth Of Long-Lived Rons In Plasma Activated Water By Uv Absorption Spectroscopy, Zhijie Liu, Chunxi Zhou, Dingxin Liu, Tongtong He, Li Guo, Dehui Xu, Michael G. Kong Jan 2019

Quantifying The Concentration And Penetration Depth Of Long-Lived Rons In Plasma Activated Water By Uv Absorption Spectroscopy, Zhijie Liu, Chunxi Zhou, Dingxin Liu, Tongtong He, Li Guo, Dehui Xu, Michael G. Kong

Bioelectrics Publications

Reactive oxygen and reactive nitrogen species (RONS) are believed to play a key role in biomedical applications, which means that RONS must reach the target tissue to produce a therapeutic effect. Existing methods (electron spin spectrometry and microplate reading) to determine the RONS concentration are not suitable for experimental real-time measurements because they require adding an indicating reagent to the plasma-treated medium, which may alter the chemical composition of the medium. In this paper, we propose a method to measure the long-lived RONS concentration in plasma-activated water (PAW) by using UV absorption spectroscopy. Based on an analysis and fit of …


Experimental Verification Of Transparent Spin Mode In Rhic, V. S. Morozov, P. Adams, Y. S. Derbenev, Y. Filatov, H. Huang, A. M. Kondratenko, M. A. Kondratenko, F. Lin, F. Méot, V. Ptitsyn, W. B. Schmidke, Y. Zhang Jan 2019

Experimental Verification Of Transparent Spin Mode In Rhic, V. S. Morozov, P. Adams, Y. S. Derbenev, Y. Filatov, H. Huang, A. M. Kondratenko, M. A. Kondratenko, F. Lin, F. Méot, V. Ptitsyn, W. B. Schmidke, Y. Zhang

Engineering Technology Faculty Publications

High electron and ion polarizations are some of the key design requirements of a future Electron Ion Collider (EIC). The transparent spin mode, a concept inspired by the figure 8 ring design of JLEIC, is a novel technique for preservation and control of electron and ion spin polarizations in a collider or storage ring. It makes the ring lattice "invisible" to the spin and allows for polarization control by small quasi-static magnetic fields with practically no effect on the beam’s orbital characteristics. It offers unique opportunities for polarization maintenance and control in Jefferson Lab’s JLEIC and in BNL’s eRHIC. The …


Spin Response Function For Spin Transparency Mode Of Rhic, V. S. Morozov, P. Adams, Y. S. Derbenev, Y. Filatov, H. Huang, A. M. Kondratenko, M. A. Kondratenko, F. Lin, F. Méot, V. Ptitsyn, W. B. Schmidke, Y. Zhang Jan 2019

Spin Response Function For Spin Transparency Mode Of Rhic, V. S. Morozov, P. Adams, Y. S. Derbenev, Y. Filatov, H. Huang, A. M. Kondratenko, M. A. Kondratenko, F. Lin, F. Méot, V. Ptitsyn, W. B. Schmidke, Y. Zhang

Engineering Technology Faculty Publications

In the Spin Transparency (ST) mode of RHIC, the axes of its Siberian snakes are parallel. The spin tune in the ST mode is zero and the spin motion becomes degenerate: any spin direction repeats every particle turn. In contrast, the lattice of a conventional collider determines a unique stable periodic spin direction, so that the collider operates in the Preferred Spin (PS) mode. Contributions of perturbing magnetic fields to the spin resonance strengths in the PS mode are usually calculated using the spin response function. However, in that form, it is not applicable in the ST mode. This paper …


Question 1: Goosed; Question 2: Buying Groceries, Larry Weinstein Jan 2019

Question 1: Goosed; Question 2: Buying Groceries, Larry Weinstein

Physics Faculty Publications

The article presents two questions related to fermi which include injury of a celebrity colliding with a goose in the Apollo's Chariot roller coaster; and cost to purchase the contents of local large supermarket.


Large Transverse Momentum In Semi-Inclusive Deeply Inelastic Scattering Beyond Lowest Order, B. Wang, J. O. Gonzalez-Hernandez, T. C. Rogers, N. Sato Jan 2019

Large Transverse Momentum In Semi-Inclusive Deeply Inelastic Scattering Beyond Lowest Order, B. Wang, J. O. Gonzalez-Hernandez, T. C. Rogers, N. Sato

Physics Faculty Publications

Motivated by recently observed tension between O(α2s) calculations of very large transverse momentum dependence in both semi-inclusive deep inelastic scattering and Drell-Yan scattering, we repeat the details of the calculation through an O(α2s) transversely differential cross section. The results confirm earlier calculations, and provide further support to the observation that tension exists with current parton distribution and fragmentation functions.


A Multi-Layered Srf Cavity For Conduction Cooling Applications, Gianluigi Ciovati, G. Cheng, E. Daly, G. V. Eremeev, J. Henry, R. A. Rimmer, Ishwari Prasad Parajuli, U. Pudasaini Jan 2019

A Multi-Layered Srf Cavity For Conduction Cooling Applications, Gianluigi Ciovati, G. Cheng, E. Daly, G. V. Eremeev, J. Henry, R. A. Rimmer, Ishwari Prasad Parajuli, U. Pudasaini

Physics Faculty Publications

Industrial application of SRF technology would favor the use of cryocoolers to conductively cool SRF cavities for particle accelerators, operating at or above 4.3 K. In order to achieve a lower surface resistance than Nb at 4.3 K, a superconductor with higher critical temperature should be used, whereas a metal with higher thermal conductivity than Nb should be used to conduct the heat to the cryocoolers. A standard 1.5 GHz bulk Nb single-cell cavity has been coated with a ~2 µm thick layer of Nb₃Sn on the inner surface and with a 5 mm thick Cu layer on the outer …


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

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 …


Initial Implementation Of A Machine Learning System For Srf Cavity Fault Classification At Cebaf, A. Carpenter, K. M. Iftekharuddin, T. Powers, Y. Roblin, A. Solopava Shabalina, C. Tennant, L. Vidyaratne Jan 2019

Initial Implementation Of A Machine Learning System For Srf Cavity Fault Classification At Cebaf, A. Carpenter, K. M. Iftekharuddin, T. Powers, Y. Roblin, A. Solopava Shabalina, C. Tennant, L. Vidyaratne

Electrical & Computer Engineering Faculty Publications

The Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Laboratory is a high power Continuous Wave (CW) electron accelerator. It uses a mixture of of SRF cryomodules: older, lower energy C20/C50 modules and newer, higher energy C100 modules. The cryomodules are arrayed in two anti-parallel linear accelerators. Accurately classifying the type of cavity faults is essential to maintaining and improving accelerator performance. Each C100 cryomodule contains eight 7-cell cavities. When a cavity fault occurs within a cryomodule, all eight cavities generate 17 waveforms each containing 8192 points. This data is exported from the control system and saved for review. Analysis …


Ignition Of A Plasma Discharge Inside An Electrodeless Chamber: Methods And Characteristics, Mounir Laroussi Jan 2019

Ignition Of A Plasma Discharge Inside An Electrodeless Chamber: Methods And Characteristics, Mounir Laroussi

Electrical & Computer Engineering Faculty Publications

In this paper the generation and diagnostics of a reduced pressure (300 mTorr to 3 Torr) plasma generated inside an electrodeless containment vessel/chamber are presented. The plasma is ignited by a guided ionization wave emitted by a low temperature pulsed plasma jet. The diagnostics techniques include Intensified Charge Coupled Device (ICCD) imaging, emission spectroscopy, and Langmuir probe. The reduced-pressure discharge parameters measured are the magnitude of the electric field, the plasma electron number density and temperature, and discharge expansion speed.


Charge Storage In Wo³ Polymorphs And Their Application As Supercapacitor Electrode Material, Vaibhav Lokhande, Abhishek Lokhande, Gon Namkoong, Jin Hyeok Kim, Taeksoo Ji Jan 2019

Charge Storage In Wo³ Polymorphs And Their Application As Supercapacitor Electrode Material, Vaibhav Lokhande, Abhishek Lokhande, Gon Namkoong, Jin Hyeok Kim, Taeksoo Ji

Electrical & Computer Engineering Faculty Publications

Tungsten oxide is a versatile material with different applications. It has many polymorphs with varying performance in energy storage application. We report simple and facile way to synthesize four phases of tungsten oxide from same precursor materials only by changing the pH and temperature values. Monoclinic, hexagonal, orthorhombic and tetragonal phase obtained, were analyzed and tested for supercapacitor application. The electrochemical analysis of four phases indicates that the hexagonal phase is best-suited electrode material for supercapacitor. The hexagonal phase exhibits higher specific capacitance (377.5 Fg-1 at 2 mVs-1), higher surface capacitive contribution (75%), better stability and rate …


Instability Of Flux Flow And Production Of Vortex-Antivortex Pairs By Current-Driven Josephson Vortices In Layered Superconductors, Ahmad Sheikhzada, Alex Gurevich Jan 2019

Instability Of Flux Flow And Production Of Vortex-Antivortex Pairs By Current-Driven Josephson Vortices In Layered Superconductors, Ahmad Sheikhzada, Alex Gurevich

Physics Faculty Publications

We report numerical simulations of the nonlinear dynamics of Josephson vortices driven by strong dc currents in layered superconductors. Dynamic equations for interlayer phase differences in a stack of coupled superconducting layers were solved to calculate a drag coefficient η(J) of the vortex as a function of the perpendicular dc current density J. It is shown that Cherenkov radiation produced by a moving vortex causes significant radiation drag increasing η(v) at high vortex velocities v and striking instabilities of driven Josephson vortices moving faster than a terminal vc. The steady-state flux flow breaks down at ν > v …


Form Factors Of Two-Hadron States From A Covariant Finite-Volume Formalism, Alessandro Baroni, Raúl Briceño, Maxwell T. Hansen, Felipe G. Ortega-Gama Jan 2019

Form Factors Of Two-Hadron States From A Covariant Finite-Volume Formalism, Alessandro Baroni, Raúl Briceño, Maxwell T. Hansen, Felipe G. Ortega-Gama

Physics Faculty Publications

In this work we develop a Lorentz-covariant version of the previously derived formalism for relating finite-volume matrix elements to 2 + J → 2 transition amplitudes. We also give various details relevant for the implementation of this formalism in a realistic numerical lattice QCD calculation. Particular focus is given to the role of single-particle form factors in disentangling finite-volume effects from the triangle diagram that arise when J couples to one of the two hadrons. This also leads to a new finite-volume function, denoted G, the numerical evaluation of which is described in detail. As an example we discuss …


Measurement Of Nuclear Transparency Ratios For Protons And Neutrons, M. Duer, O. Hen, E. Piasetzky, L. B. Weinstein, A. Schmidt, I. Korover, E. O. Cohen, H. Hakobyan, S. Adhikari, G. Angelini, H. Avakian, C. Ayerbe Gayoso, L. Barion, M. Battaglieri, A. Beck, I. Bedlinski, A. S. Biselli, S. Boiarinov, W. J. Briscoe, X. Zheng, Et Al., The Clas Collaboration Jan 2019

Measurement Of Nuclear Transparency Ratios For Protons And Neutrons, M. Duer, O. Hen, E. Piasetzky, L. B. Weinstein, A. Schmidt, I. Korover, E. O. Cohen, H. Hakobyan, S. Adhikari, G. Angelini, H. Avakian, C. Ayerbe Gayoso, L. Barion, M. Battaglieri, A. Beck, I. Bedlinski, A. S. Biselli, S. Boiarinov, W. J. Briscoe, X. Zheng, Et Al., The Clas Collaboration

Physics Faculty Publications

This paper presents, for the first time, measurements of neutron transparency ratios for nuclei relative to C measured using the (e, e'n) reaction, spanning measured neutron momenta of 1.4 to 2.4 GeV/c. The transparency ratios were extracted in two kinematical regions, corresponding to knockout of mean-field nucleons and to the breakup of Short-Range Correlated nucleon pairs. The extracted neutron transparency ratios are consistent with each other for the two measured kinematical regions and agree with the proton transparencies extracted from new and previous (e, e'p) measurements, including those from neutron-rich nuclei such as lead. The data also agree with and …


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 Jan 2019

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.


Recent Results From Nb₃Sn Single Cell Cavities Coated At Jefferson Lab, U. Pudasaini, M. J. Kelley, Gianluigi Ciovati, G.V. Eremeev, M. J. Kelley, C. E. Reece, Ishwari Prasad Parajuli, Md. Nizam Sayeed Jan 2019

Recent Results From Nb₃Sn Single Cell Cavities Coated At Jefferson Lab, U. Pudasaini, M. J. Kelley, Gianluigi Ciovati, G.V. Eremeev, M. J. Kelley, C. E. Reece, Ishwari Prasad Parajuli, Md. Nizam Sayeed

Physics Faculty Publications

Because of superior superconducting properties (Tc ~ 18.3K, Hs h~ 425 mT and Δ ~ 3.1 meV) compared to niobium, Nb₃Sn promise better RF performance (Q₀ and Eacc) and/or higher operating temperature (2 K Vs 4.2 K) for SRF cavities. Nb₃Sn-coated SRF cavities are produced routinely by depositing a few micron-thick Nb₃Sn films on the interior surface of Nb cavities via tin vapor diffusion technique. Early results from Nb₃Sn cavities coated with this technique exhibited precipitous low field Q-slope, also known as Wuppertal slope. Several Nb₃Sn single cell cavities coated at JLab appeared to exhibit …


Announcement: In Memory Of Yong Ho Chin, Michael Thoennessen, Debbie Brodbar, Brant Johnson, Jean Delayen, Dan Kulp, Frank Zimmermann, Maria Poko Jan 2019

Announcement: In Memory Of Yong Ho Chin, Michael Thoennessen, Debbie Brodbar, Brant Johnson, Jean Delayen, Dan Kulp, Frank Zimmermann, Maria Poko

Physics Faculty Publications

No abstract provided.


Progress Report On The Relativistic Three-Particle Quantization Condition, Tyler D. Blanton, Raúl A. Briceño, Maxwell T. Hanson, Fernando Romero-Lopez, Stephen R. Sharpe Jan 2019

Progress Report On The Relativistic Three-Particle Quantization Condition, Tyler D. Blanton, Raúl A. Briceño, Maxwell T. Hanson, Fernando Romero-Lopez, Stephen R. Sharpe

Physics Faculty Publications

We describe recent work on the relativistic three-particle quantization condition, generalizing and applying the original formalism of Hansen and Sharpe, and of Briceño, Hansen and Sharpe. In particular, we sketch three recent developments: the generalization of the formalism to include K-matrix poles; the numerical implementation of the quantization condition in the isotropic approximation; and ongoing work extending the description of the three-particle divergence-free K matrix beyond the isotropic approximation.


Simulation Study Of The Emittance Measurements In Magnetized Electron Beam, S.A.K. Wijethunga, J. Benesch, Jean R. Delayen, F. E. Hannon, Geoffrey A. Krafft, M. A. Mamun, G. Palacios-Serrano, M. Poelker, R. Suleiman, S. Zhang Jan 2019

Simulation Study Of The Emittance Measurements In Magnetized Electron Beam, S.A.K. Wijethunga, J. Benesch, Jean R. Delayen, F. E. Hannon, Geoffrey A. Krafft, M. A. Mamun, G. Palacios-Serrano, M. Poelker, R. Suleiman, S. Zhang

Physics Faculty Publications

Electron cooling of the ion beam is key to obtaining the required high luminosity of proposed electron-ion colliders. For the Jefferson Lab Electron Ion Collider, the expected luminosity of 10³⁴ 〖 cm〗⁻² s⁻¹ will be achieved through so-called ’magnetized electron cooling’, where the cooling process occurs inside a solenoid field, which will be part of the collider ring and facilitated using a circulator ring and Energy Recovery Linac (ERL). As an initial step, we generated magnetized electron beam using a new compact DC high voltage photogun biased at -300 kV employing an alkali-antimonide photocathode. This contribution presents the characterization of …


A Review: Thermal Stability Of Methylammonium Lead Halide Based Perovskite Solar Cells, Tanzila Tasnim Ava, Abdullah Al Mamun, Sylvain Marsillac, Gon Namkoong Jan 2019

A Review: Thermal Stability Of Methylammonium Lead Halide Based Perovskite Solar Cells, Tanzila Tasnim Ava, Abdullah Al Mamun, Sylvain Marsillac, Gon Namkoong

Electrical & Computer Engineering Faculty Publications

Perovskite solar cells have achieved photo-conversion efficiencies greater than 20%, making them a promising candidate as an emerging solar cell technology. While perovskite solar cells are expected to eventually compete with existing silicon-based solar cells on the market, their long-term stability has become a major bottleneck. In particular, perovskite films are found to be very sensitive to external factors such as air, UV light, light soaking, thermal stress and others. Among these stressors, light, oxygen and moisture-induced degradation can be slowed by integrating barrier or interface layers within the device architecture. However, the most representative perovskite absorber material, CH3 …


Question 1: Losing Weight; Question 2: Artificial Moon, Larry Weinstein Jan 2019

Question 1: Losing Weight; Question 2: Artificial Moon, Larry Weinstein

Physics Faculty Publications

The article presents questions related to Fermi which include mass lost by Sun over its lifetime; and size of artificial satellite needed to provide as much illumination as a full moon.


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 Jan 2019

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 …


Drift Chamber Calibration And Particle Identification In The P-349 Experiment, D. Alfs, A. Asaturyan, M. Carmignotto, M. Diermaier, W. Eyrich, B. Glowacz, D. Grzonka, Florian Hauenstein, T. Horn, K. Kilian, D. Lersch, S. Malbrunot-Ettenauer, A. Mkrtchyan, H. Mkrtchyan, P. Moskal, P. Nadel-Turonski, W. Oelert, J. Ritman, T. Sefzick, V. Tadevosyan, E. Widmann, M. Wolke, S. Zhamkochyan, M. Zieliński, A. Zink, J. Zmeskal Jan 2019

Drift Chamber Calibration And Particle Identification In The P-349 Experiment, D. Alfs, A. Asaturyan, M. Carmignotto, M. Diermaier, W. Eyrich, B. Glowacz, D. Grzonka, Florian Hauenstein, T. Horn, K. Kilian, D. Lersch, S. Malbrunot-Ettenauer, A. Mkrtchyan, H. Mkrtchyan, P. Moskal, P. Nadel-Turonski, W. Oelert, J. Ritman, T. Sefzick, V. Tadevosyan, E. Widmann, M. Wolke, S. Zhamkochyan, M. Zieliński, A. Zink, J. Zmeskal

Physics Faculty Publications

The goal of the P-349 experiment is to test whether 3.5 GeV/c antiprotons produced in high-energy proton-proton collisions are polarized in view of the preparation of a polarized antiproton beam. In this article, we present the details of the ongoing analysis focused on the drift chambers calibration and particle identification with DIRC.


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 Jan 2019

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 Jan 2019

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 …


Question 1: Losing Weight; Question 2: Shampoo Bottles, Larry Weinstein Jan 2019

Question 1: Losing Weight; Question 2: Shampoo Bottles, Larry Weinstein

Physics Faculty Publications

How much weight would you lose climbing stairs every day (assuming that neither diet nor metabolism changes in response to the extra effort)? The California Assembly voted to ban single-use hotel shampoo bottles. How much impact would this have if it was applied nationwide? [Extracted from the article]


Pdfs In Small Boxes, Raúl A. Briceño, Juan V. Guerrero, Maxwell T. Hansen, Christopher J. Monahan Jan 2019

Pdfs In Small Boxes, Raúl A. Briceño, Juan V. Guerrero, Maxwell T. Hansen, Christopher J. Monahan

Physics Faculty Publications

PDFs can be studied directly using lattice QCD by evaluating matrix elements of non-local operators. A number of groups are pursuing numerical calculations and investigating possible systematic uncertainties. One systematic that has received less attention is the effect of calculating in a finite spacetime volume. Here we present first attempts to assess the role of the finite volume for spatially non-local operators. We find that these matrix elements may suffer from large finite-volume artifacts and more careful investigation is needed.


High Current High Charge Magnetized And Bunched Electron Beam From A Dc Photogun For Jleic Cooler, S. Zhang, P. A. Adderley, J. F. Benesch, D. B. Bullard, Jean R. Delayen, J. M. Grames, J. Guo, F. E. Hannon, J. Hansknecht, C. Hernandez-Garcia, R. Kazimi, Geoffrey A. Krafft, M. A. Mamun, M. Poelker, R. Suleiman, M.G. Tiefenback, Y.W. Wang, S.A.K. Wijethunga Jan 2019

High Current High Charge Magnetized And Bunched Electron Beam From A Dc Photogun For Jleic Cooler, S. Zhang, P. A. Adderley, J. F. Benesch, D. B. Bullard, Jean R. Delayen, J. M. Grames, J. Guo, F. E. Hannon, J. Hansknecht, C. Hernandez-Garcia, R. Kazimi, Geoffrey A. Krafft, M. A. Mamun, M. Poelker, R. Suleiman, M.G. Tiefenback, Y.W. Wang, S.A.K. Wijethunga

Physics Faculty Publications

A high current, high charge magnetized electron beamline that has been under development for fast and efficient cooling of ion beams for the proposed Jefferson Lab Electron Ion Collider (JLEIC). In this paper, we present the latest progress over the past year that include the generation of picosecond magnetized beam bunches at average currents up to 28 mA with exceptionally long photocathode lifetime, and the demonstrations of magnetized beam with high bunch charge up to 700 pC at 10s of kHz repetition rates. Detailed studies on a stable drive laser system, long lifetime photocathode, beam magnetization effect, beam diagnostics, and …


Compact Srf Linac For High Brilliance Inverse Compton Scattering Light Source, Kirsten E. Deitrick, Jean R. Delayen, Geoffrey A. Krafft, Balša Terzić Jan 2019

Compact Srf Linac For High Brilliance Inverse Compton Scattering Light Source, Kirsten E. Deitrick, Jean R. Delayen, Geoffrey A. Krafft, Balša Terzić

Physics Faculty Publications

New designs for compact SRF linacs can produce micron-size electron beams. These can can be used for inverse Compton scattering light sources of exceptional flux and brilliance.