Direct Current Magnetic Hall Probe Technique For Measurement Of Field Penetration In Thin Film Superconductors For Superconducting Radio Frequency Resonators,
2022
Old Dominion University
Direct Current Magnetic Hall Probe Technique For Measurement Of Field Penetration In Thin Film Superconductors For Superconducting Radio Frequency Resonators, Iresha Harshani Senevirathne, Alex Gurevich, Jean Delayen
Physics Faculty Publications
Superconducting Radio Frequency (SRF) cavities used in particle accelerators are typically formed from or coated with superconducting materials. Currently, high purity niobium is the material of choice for SRF cavities that have been optimized to operate near their theoretical field limits. This brings about the need for significant R & D efforts to develop next generation superconducting materials that could outperform Nb and keep up with the demands of new accelerator facilities. To achieve high quality factors and accelerating gradients, the cavity material should be able to remain in the superconducting Meissner state under a high RF magnetic field without …
Evaluation Of Single-Cell Cavities Made Of Forged Ingot Niobium At Jefferson Lab,
2022
Old Dominion University
Evaluation Of Single-Cell Cavities Made Of Forged Ingot Niobium At Jefferson Lab, P. Dhakal, Bashu D. Khanal, Gianluigi Ciovati, G. R. Myneni
Physics Faculty Publications
Currently, fine grain niobium (Nb) (grain size ∼ 50 µm) and large grain Nb (grain size of a few cm) are being used for the fabrication of superconducting radio frequency (SRF) cavities. Medium grain forged ingot with grain size of a few hundred µm may be beneficial for cost-effectiveness as well as providing better performance for future SRF-based accelerators. Forged ingot Nb with medium grain size is a novel production method to obtain Nb discs used for the fabrication of superconducting radio frequency cavities. We have fabricated two 1.5 GHz single cell cavities made from forged Nb ingot with a …
Magnetic Flux Expulsion In Superconducting Radio-Frequency Niobium Cavities Made From Cold Worked Niobium,
2022
Old Dominion University
Magnetic Flux Expulsion In Superconducting Radio-Frequency Niobium Cavities Made From Cold Worked Niobium, Bashu D. Khanal, S. Balachandran, S. Chetri, P. J. Lee, P. Dhakal
Physics Faculty Publications
Trapped residual magnetic field during the cooldown of superconducting radio frequency (SRF) cavities is one of the primary source of RF residual losses leading to lower quality factor. Historically, SRF cavities have been fabricated from high purity fine grain niobium with grain size ~50 - 100 μm as well as large grain with grain size of the order of few centimeters. Non-uniform recrystallization of fine-grain Nb cavities after the post fabrication heat treatment leads to higher flux trapping during cooldown, hence the lower quality factor. We fabricated two 1.3 GHz single cell cavities from cold-worked niobium from different vendors and …
Lower Temperature Annealing Of Vapor Diffused Nb3Sn For Accelerator Cavities,
2022
Old Dominion University
Lower Temperature Annealing Of Vapor Diffused Nb3Sn For Accelerator Cavities, Jayendrika K. Tiskumara, Jean R. Delayen, G. V. Eremeev, U. Pudasaini
Physics Faculty Publications
Nb3Sn is a next-generation superconducting material for the accelerator cavities with higher critical temperature and superheating field, both twice compared to Nb. It promises superior performance and higher operating temperature than Nb, resulting in significant cost reduction. So far, the Sn vapor diffusion method is the most preferred and successful technique to coat niobium cavities with Nb3Sn. Although several post-coating techniques (chemical, electrochemical, mechanical) have been explored to improve the surface quality of the coated surface, an effective process has yet to be found. Since there are only a few studies on the post-coating heat treatment …
Improved Electrostatic Design Of The Jefferson Lab 300 Kv Dc Photogun And The Minimization Of Beam Deflection,
2022
Old Dominion University
Improved Electrostatic Design Of The Jefferson Lab 300 Kv Dc Photogun And The Minimization Of Beam Deflection, M. A. Mamun, D. B. Bullard, J. R. Delayen, J. M. Grames, C. Hernandez-Garcia, Geoffrey A. Krafft, M. Poelker, R. Suleiman, S.A.K. Wijethunga
Physics Faculty Publications
An electron beam with high bunch charge and high repetition rate is required for electron cooling of the ion beam to achieve the high luminosity required for the proposed electron-ion colliders. An improved design of the 300 kV DC high voltage photogun at Jefferson Lab was incorporated toward overcoming the beam loss and space charge current limitation experienced in the original design. To reach the bunch charge goal of ~ few nC within 75 ps bunches, the existing DC high voltage photogun electrodes and anode-cathode gap were modified to increase the longitudinal electric field (Ez) at the photocathode. The anode-cathode …
Structural, Electrical And Optical Properties Of Copper Oxide Phase Mixture: An Active Layer Of Solar Cell,
2022
Missouri State University
Structural, Electrical And Optical Properties Of Copper Oxide Phase Mixture: An Active Layer Of Solar Cell, Rifat Ara Shams
MSU Graduate Theses
Both CuO and Cu2O have been well studied and implemented individually as an active layer of a solar cell from early age of manufacturing. A mixture of these two-phase contents at different ratios can bring variance in absorbance which can present new and diverse aspect in solar cell fabrication with added efficiency. Previous works were successful to vary the phase mixture, and the nanostructures provided very high absorption co-efficient but poor optical response on electrical conductivity. The goal of this research is to find out the optimum parameter for the phase mixture of copper oxide with high absorption coefficient as …
Nb₃Sn Coating Of A 2.6 Ghz Srf Cavity By Sputter Deposition Technique,
2022
Old Dominion University
Nb₃Sn Coating Of A 2.6 Ghz Srf Cavity By Sputter Deposition Technique, M. S. Shakel, Wei Cao, H. Elsayed-Ali, G. V. Eremeev, U. Pudasaini, A. M. Valente-Feliciano
Electrical & Computer Engineering Faculty Publications
Nb₃Sn is of interest as a coating for SRF cavities due to its higher transition temperature Tc ~18.3 K and superheating field Hsh ~400 mT, both are twice that of Nb. Nb₃Sn coated cavities can achieve high-quality factors at 4 K and can replace the bulk Nb cavities operated at 2 K. A cylindrical magnetron sputtering system was built, commissioned, and used to deposit Nb₃Sn on the inner surface of a 2.6 GHz single-cell Nb cavity. With two identical cylindrical magnetrons, this system can coat a cavity with high symmetry and uniform thickness. Using Nb-Sn multilayer sequential sputtering followed by …
Sufficient Condition For The Possibility Of Completing The Pursuit,
2021
Andijan State University named after Z.M. Babur, Andijan 170100 Uzbekistan.
Sufficient Condition For The Possibility Of Completing The Pursuit, Nodirbek Umrzaqov
Scientific Bulletin. Physical and Mathematical Research
In this paper, the problem of chase is represented by a system of linear differential equations of motion dynamics. In this case, there is an integral limit to the control parameter of the evader, and a geometric limit to the control parameter of the pursuer. The pursuer is allowed to use the control that the fugitive has used so far to build his control. There are enough conditions for the game to end even if it starts from any starting point. An algorithm for constructing the control function of the pursuer is defined. It should also be noted that the …
Intracavity Phase Interferometry Based Fiber Sensors,
2021
University of New Mexico - Main Campus
Intracavity Phase Interferometry Based Fiber Sensors, Luke Jameson Horstman
Optical Science and Engineering ETDs
Intracavity Phase Interferometry (IPI) is a detection technique that exploits the inherent sensitivity of a laser's frequency to the parameters of its cavity. Intracavity interferometry is orders of magnitude more sensitive than its extracavity alternatives. This dissertation improves on previous free-space proof-of-concept designs. By implementing the technique in fiber optics, using optical parametric oscillation, and investigating non-Hermitian quantum mechanics and dispersion tailoring enhancement techniques, IPI has become more applicable and sensitive. Ring and linear IPI configurations were realized in this work, both operating as bidirectional fiber optical parametric oscillators. The benefit of using externally pumped synchronous optical parametric oscillation is …
Voltage Controlled Néel Vector Rotation In Zero Magnetic Field,
2021
University of Nebraska–Lincoln
Voltage Controlled Néel Vector Rotation In Zero Magnetic Field, Ather Mahmood, Will Echtenkamp, Mike Street, Jun Lei Wang, Shi Cao, Takashi Komesu, Peter Dowben, Pratyush Buragohain, Haidong Lu, Alexei Gruverman, Arun Parthasarathy, Shaloo Rakheja, Christian Binek
Peter Dowben Publications
Multi-functional thin films of boron (B) doped Cr2O3 exhibit voltage-controlled and nonvolatile Néel vector reorientation in the absence of an applied magnetic field, H. Toggling of antiferromagnetic states is demonstrated in prototype device structures at CMOS compatible temperatures between 300 and 400 K. The boundary magnetization associated with the Néel vector orientation serves as state variable which is read via magnetoresistive detection in a Pt Hall bar adjacent to the B:Cr2O3 film. Switching of the Hall voltage between zero and non-zero values implies Néel vector rotation by 90 degrees. Combined magnetometry, spin resolved inverse …
Sigesn Light-Emitting Devices: From Optical To Electrical Injection,
2021
University of Arkansas, Fayetteville
Sigesn Light-Emitting Devices: From Optical To Electrical Injection, Yiyin Zhou
Graduate Theses and Dissertations
Si photonics is a fast-developing technology that impacts many applications such as data centers, 5G, Lidar, and biological/chemical sensing. One of the merits of Si photonics is to integrate electronic and photonic components on a single chip to form a complex functional system that features compact, low-cost, high-performance, and reliability. Among all building blocks, the monolithic integration of lasers on Si encountered substantial challenges. Si and Ge, conventional epitaxial material on Si, are incompetent for light emission due to the indirect bandgap. The current solution compromises the hybrid integration of III-V lasers, which requires growing on separate smaller size substrates …
Interplay Between The Lattice And Spin Degrees Of Freedom In Magnetoelectric And Magnetic Materials,
2021
University of Arkansas, Fayetteville
Interplay Between The Lattice And Spin Degrees Of Freedom In Magnetoelectric And Magnetic Materials, Temuujin Bayaraa
Graduate Theses and Dissertations
This dissertation contains several investigations on the cross-coupling between structural and spin degrees of freedom in multiferroic and ferrimagnetic compounds by means of first-principles calculations and ab-initio-based Monte-Carlo simulations. We start with the reviews of magnetoelectricity, ferrimagnetism, strain engineering, followed by a brief introduction to first-principles computational methods, magnetic effective Hamiltonians, and other techniques that are utilized here. The results section of the dissertation can be divided into two parts. The first half focuses on magnetoelectric effects arising from different sources, while the second half is about the ferrimagnetic nature of materials. In the first part, we examine the epitaxial …
Theoretical Investigations Of The Structural, Dynamical, Electronic, Magnetic, And Thermoelectric Properties Of Corhysi (Y = Cr, Mn) Quaternary Heusler Alloys,
2021
University of Arkansas, Fayetteville
Theoretical Investigations Of The Structural, Dynamical, Electronic, Magnetic, And Thermoelectric Properties Of Corhysi (Y = Cr, Mn) Quaternary Heusler Alloys, Abdullah Hussain Hzzazi
Graduate Theses and Dissertations
Thermoelectric materials have potential properties for utilizing waste heat. The computations are used to estimate the electronic structure of CoRhYSi (Y = Cr, Mn) Quaternary Heusler alloys, as well as their elastic and magnetic characteristics. The full-potential linearized augmented plane wave is used in the calculations. The exchange-correlations are addressed using Perdew–Burke and Ernzerhof's generalized gradient approximation (GGA-PBE). With the exception of CoRhCrSi and CoRhMnSi, which are simple ferromagnets that are approximately half metallic in nature, electronic structure calculations demonstrate that these compounds have a gap in the minority states band and are obviously half-metallic ferromagnets. The magnetic moments of …
Acoustic/Gravity Wave Phenomena In Wide-Field Imaging: From Data Analysis To A Modeling Framework For Observability In The Mlt Region And Beyond,
2021
Embry-Riddle Aeronautical University
Acoustic/Gravity Wave Phenomena In Wide-Field Imaging: From Data Analysis To A Modeling Framework For Observability In The Mlt Region And Beyond, Jaime Aguilar Guerrero
Doctoral Dissertations and Master's Theses
Acoustic waves, gravity waves, and larger-scale tidal and planetary waves are significant drivers of the atmosphere’s dynamics and of the local and global circulation that have direct and indirect impacts on our weather and climate. Their measurements and characterization are fundamental challenges in Aeronomy that require a wide range of instrumentation with distinct operational principles. Most measurements share the common features of integrating optical emissions or effects on radio waves through deep layers of the atmosphere. The geometry of these integrations create line-of-sight effects that must be understood, described, and accounted for to properly present the measured data in traditional …
Developing A Monte Carlo Simulation For Time- Series Analysis Of Actinium-225 Decay,
2021
Agnes Scott College
Developing A Monte Carlo Simulation For Time- Series Analysis Of Actinium-225 Decay, Victoria Wood
The Journal of Advanced Undergraduate Physics Laboratory Investigations, JAUPLI-B
This report describes the development of a script programmed in the Python language designed to simulate radioactive decay using Monte Carlo methods. This is to conduct analysis on the equilibrium behavior of a specific radioactive decay chain, replacing the traditional method of deriving a mathematical representation via differential equations. The resulting script produces a stacked histogram illustrating the decay of Actinium-225 over time and more closely models the potential for irregularities in the natural phenomenon. The script has potential applications in nuclear imaging and medical physics.
Modeling The Motion Of A Volleyball With Spin,
2021
Amherst College
Modeling The Motion Of A Volleyball With Spin, Julian Ricardo
The Journal of Advanced Undergraduate Physics Laboratory Investigations, JAUPLI-B
Though a qualitative understanding of how spin affects a ball’s trajectory can be easily developed, a quantitative one is relatively difficult to hone. Additionally, although projectile motion is an extensively covered topic in introductory physics courses, friction and drag—let alone spin—receive little to no attention. Here we use a volleyball and video modeling software to compare the behavior of a non-spinning ball with one that has topspin in order to assess the accuracy of our various models incorporating drag and the Magnus effect.
Electrical And Magnetic Properties Of High Temperature Superconductors Using Varying Forms Of Data Acquisition,
2021
Austin College
Electrical And Magnetic Properties Of High Temperature Superconductors Using Varying Forms Of Data Acquisition, Aryn M. Hays, Lindsay Bechtel, Colton Turbeville, Anthony Johnsen, Chris A. Tanner
The Journal of Advanced Undergraduate Physics Laboratory Investigations, JAUPLI-B
High temperature superconductors (HTS) are materials that display superconducting properties at temperatures above that of liquid nitrogen. Possible applications and ease of use in a typical physics laboratory make them interesting systems to study. In this experiment we measured the critical temperatures of two samples made of different HTS materials. We also devised a method that makes taking data automated.
Shape And Size Matter For Projectile Drag,
2021
Harvard University
Shape And Size Matter For Projectile Drag, Daniel Gordon Ang
The Journal of Advanced Undergraduate Physics Laboratory Investigations, JAUPLI-B
Newtonian mechanics is a fundamental building block of physics education, allowing us to characterize the motion of various objects in every day life. Here, we set out to investigate the effect of air resistance on projectile motion. We use high-speed cameras to record the flight of three different projectiles and compare this motion to a trajectory generated based on our theoretical model. We find that we are able to fit our model to the actual trajectory reasonably well, and find evidence that drag depends on the size and shape of the projectile.
Modeling A Swinging Atwood Machine,
2021
Amherst College
Modeling A Swinging Atwood Machine, Parker W. Moody
The Journal of Advanced Undergraduate Physics Laboratory Investigations, JAUPLI-B
The motion of a Swinging Atwood Machine is a difficult to solve for using Newtonian Mechanics. Lagrangian Mechanics, on the other hand, is extremely useful tool for a system that can seem overwhelmingly difficult to solve in Newtonian Mechanics. In this Lab we find the Lagrangian for this Swinging Atwood system, solve for the equation of motion, and compare our model to that of the observed motion of the system. Our model provides a good approximation of the motion, with small discrepancies due to the unknown mass of our pulley and dissipative forces.
Atomic Force Microscopy,
2021
Minnesota State University - Moorhead
Atomic Force Microscopy, Tyler Lane
The Journal of Advanced Undergraduate Physics Laboratory Investigations, JAUPLI-B
The goal of this experiment is to use the Atomic Force Microscope (AFM) to get images of selected items and determine some distances of the characteristics of each sample. The ultimate goal is to measure the length of a nanotube, but unfortunately there were none left on the slide that was supposed to contain them. From the results of the lab and the lab manual of “companies” with possible lengths for each sample, Lindaas-Lahti Industries seems to have the best fit overall.
