Magnetic Field Sensors For Detection Of Trapped Flux In Superconducting Radio Frequency Cavities,
2021
Old Dominion University
Magnetic Field Sensors For Detection Of Trapped Flux In Superconducting Radio Frequency Cavities, Ishwari Prasad Parajuli, Gianluigi Ciovati, Jean R. Delayen
Physics Faculty Publications
Superconducting radio frequency (SRF) cavities are fundamental building blocks of modern particle accelerators. They operate at liquid helium temperatures (2–4 K) to achieve very high quality factors (1010–1011). Trapping of magnetic flux within the superconductor is a significant contribution to the residual RF losses, which limit the achievable quality factor. Suitable diagnostic tools are in high demand to understand the mechanisms of flux trapping in technical superconductors, and the fundamental components of such diagnostic tools are magnetic field sensors. We have studied the performance of commercially available Hall probes, anisotropic magnetoresistive sensors, and flux-gate magnetometers with …
Evaluation Of Anisotropic Magnetoresistive (Amr) Sensors For A Magnetic Field Scanning System For Srf Cavities,
2021
Old Dominion University
Evaluation Of Anisotropic Magnetoresistive (Amr) Sensors For A Magnetic Field Scanning System For Srf Cavities, Ishwari P. Parajuli, Gianluigi Ciovati, Jean R. Delayen, Alex V. Gurevich
Physics Faculty Publications
One of the significant causes of residual losses in superconducting radio-frequency (SRF) cavities is trapped magnetic flux. The flux trapping mechanism depends on many factors that include cool-down conditions, surface preparation techniques, and ambient magnetic field orientation. Suitable diagnostic tools are not yet available to quantitatively correlate such factors’ effect on the flux trapping mechanism. A magnetic field scanning system (MFSS) consisting of AMR sensors, fluxgate magnetometers, or Hall probes is recently commissioned to scan the local magnetic field of trapped vortices around 1.3 GHz single-cell SRF cavities. In this contribution, we will present results from sensitivity calibration and the …
Nb3Sn Coating Of Twin Axis Cavity For Accelerator Applications,
2021
Old Dominion University
Nb3Sn Coating Of Twin Axis Cavity For Accelerator Applications, Jayendrika K. Tiskumara, Subashini U. De Silva, Jean Delayen, U. Pudasaini, C. E. Reece, H. Park, G. Eremeev
Physics Faculty Publications
A Superconducting twin axis cavity consisting of two identical beam pipes that can accelerate and decelerate beams within the same structure has been proposed for the Energy Recovery Linac (ERL) applications. There are two niobium twin axis cavities at JLab fabricated with the intention of later Nb₃Sn coating and now we are progressing to coat them using vapor diffusion method. Nb₃Sn is a potential alternate material for replacing Nb in SRF cavities for better performance and reducing operational costs. Because of advanced geometry, larger surface area, increased number of ports and hard to reach areas of the twin axis cavities, …
Design Of An Rf-Dipole Crabbing Cavity System For The Electron-Ion Collider,
2021
Old Dominion University
Design Of An Rf-Dipole Crabbing Cavity System For The Electron-Ion Collider, Subashini U. De Silva, Jean R. Delayen, H. Park, F. Marhauser, J. Henry, R. A. Rimmer
Physics Faculty Publications
The Electron-Ion Collider requires several crabbing systems to facilitate head-on collisions between electron and proton beams in increasing the luminosity at the interaction point. One of the critical rf systems is the 197 MHz crabbing system that will be used in crabbing the proton beam. Many factors such as the low operating frequency, large transverse voltage requirement, tight longitudinal and transverse impedance thresholds, and limited beam line space makes the crabbing cavity design challenging. The rf-dipole cavity design is considered as one of the crabbing cavity options for the 197 MHz crabbing system. The cavity is designed including the HOM …
The Concept And Applications Of A Dual Energy Storage Ring,
2021
Old Dominion University
The Concept And Applications Of A Dual Energy Storage Ring, Bhawin Dital, Andrew Hutton, Geoffrey Krafft, Fanglei Lin, Vasiliy Morozov, Yuhong Zhang
Physics Faculty Publications
A dual energy electron storage ring configuration is initially proposed as an electron cooler to cool the ion beam in a collider. It consists of two energy loops, the electron beam in the high energy loop undergoes the synchrotron radiation damping to obtain the desired beam property and the beam in the low energy loop is for cooling of the ion beam. The two different energy loops are connected by an energy recovery linac. A lattice design of such a dual energy storage ring has been completed and beam stability conditions are established. We performed numerical simulations to demonstrate the …
Beam Dynamics Study In A Dual Energy Storage Ring For Ion Beam Cooling*,
2021
Old Dominion University
Beam Dynamics Study In A Dual Energy Storage Ring For Ion Beam Cooling*, B. Dhital, Y. S. Derbenev, D. Douglas, A. Hutton, Geoffrey A. Krafft, F. Lin, V. S. Morozov, Y. Zhang
Physics Faculty Publications
A dual energy storage ring designed for beam cooling consists of two closed rings with significantly different energies: the cooling and damping rings. These two rings are connected by an energy recovering superconducting RF structure that provides the necessary energy difference. In our design, the RF acceleration has a main linac and harmonic cavities both running at crest that at first accelerates the beam from low energy E_{L} to high energy E_{H} and then decelerates the beam from E_{H} to E_{L} in the next pass. The purpose of the harmonic cavities is to extend the bunch length in a dual …
Estimates Of Damped Equilibrium Energy Spread And Emittance In A Dual Energy Storage Ring,
2021
Old Dominion University
Estimates Of Damped Equilibrium Energy Spread And Emittance In A Dual Energy Storage Ring, B. Dhital, Y. S. Derbenev, D. Douglas, A. Hutton, G. A. Krafft, F. Lin, V.S. Morozov, Y. Zhang
Physics Faculty Publications
A dual energy storage ring design consists of two loops at markedly different energies. As in a single-energy storage ring, the linear optics in the ring design may be used to determine the damped equilibrium emittance and energy spread. Because the individual radiation events in the two rings are different and independent, we can provide analytical estimates of the damping times in a dual energy storage ring. Using the damping times, the values of damped energy spread, and emittance can be determined for a range of parameters related to lattice design and rings energies. We present analytical calculations along with …
Improving The Operational Lifetime Of The Cebaf Photo-Gun By Anode Biasing,
2021
Old Dominion University
Improving The Operational Lifetime Of The Cebaf Photo-Gun By Anode Biasing, J. T. Yoskowitz, G. A. Krafft, G. Palacios-Serrano, S. Wijethunga, J. Grames, J. Hansknecht, C. Hernandez-Garcia, M. Poelker, M. Stutzman, R. Suleiman, S. B. Van Der Geer
Physics Faculty Publications
The operating lifetime of GaAs-based photocathodes in DC high voltage electron photo-guns is dominated by the ionization rate of residual beamline gas molecules. In this work, experiments were performed to quantify the improvement in photocathode charge lifetime by biasing the photo-gun anode with a positive voltage, which repels ions generated downstream of the anode. The photo-cathode charge lifetime improved by almost a factor of two when the anode was biased compared to the usual grounded configuration. Simulations were performed using the particle tracking code General Particle Tracer (GPT) with a new custom element. The simulation results showed that both the …
Potential Applications Of Electrodynamic Tethers,
2021
FIITJEE Junior College, Saifabad
Potential Applications Of Electrodynamic Tethers, Sai Charan Petchetti
International Journal of Aviation, Aeronautics, and Aerospace
In recent decades, alternative propulsion systems have been investigated and have attracted great interest in the space community. Most of these alternative propulsion systems need propellants. One alternative propulsion system that does not require propellants and is not often discussed is electrodynamic tethers (EDTs). This paper speculates the potential applications of EDTs ranging from radiation belt remediation to momentum exchange tether re-boosting.
Cylindrical Magnetron Development For Nb₃Sn Deposition Via Magnetron Sputtering,
2021
Old Dominion University
Cylindrical Magnetron Development For Nb₃Sn Deposition Via Magnetron Sputtering, Md. Nizam Sayeed, Hani Elsayed-Ali, C. Côté, M. A. Farzad, A. Sarkissian, G. V. Eremeev, A-M. Valente-Feliciano
Electrical & Computer Engineering Faculty Publications
Due to its better superconducting properties (critical temperature Tc~ 18.3 K, superheating field Hsh~ 400 mT), Nb3Sn is considered as a potential alternative to niobium (Tc~ 9.25 K, Hsh~ 200 mT) for superconducting radiofrequency (SRF) cavities for particle acceleration. Magnetron sputtering is an effective method to produce superconducting Nb3Sn films. We deposited superconducting Nb3Sn films on samples with magnetron sputtering using co-sputtering, sequential sputtering, and sputtering from a stoichiometric target. Nb3Sn films produced by magnetron sputtering in our previous experiments have achieved DC superconducting critical temperature up to …
Using Ai For Management Of Field Emission In Srf Linacs,
2021
Old Dominion University
Using Ai For Management Of Field Emission In Srf Linacs, A. Carpenter, P. Degtiarenko, R. Suleiman, C. Tennant, D. Turner, L. S. Vidyaratne, Khan Iftekharuddin, Md. Monibor Rahman
Electrical & Computer Engineering Faculty Publications
Field emission control, mitigation, and reduction is critical for reliable operation of high gradient superconducting radio-frequency (SRF) accelerators. With the SRF cavities at high gradients, the field emission of electrons from cavity walls can occur and will impact the operational gradient, radiological environment via activated components, and reliability of CEBAF’s two linacs. A new effort has started to minimize field emission in the CEBAF linacs by re-distributing cavity gradients. To measure radiation levels, newly designed neutron and gamma radiation dose rate monitors have been installed in both linacs. Artificial intelligence (AI) techniques will be used to identify cavities with high …
Initial Studies Of Cavity Fault Prediction At Jefferson Laboratory,
2021
Old Dominion University
Initial Studies Of Cavity Fault Prediction At Jefferson Laboratory, L.S. Vidyaratne, A. Carpenter, R. Suleiman, C. Tennant, D. Turner, Khan Iftekharuddin, Md. Monibor Rahman
Electrical & Computer Engineering Faculty Publications
The Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Laboratory is a CW recirculating linac that utilizes over 400 superconducting radio-frequency (SRF) cavities to accelerate electrons up to 12 GeV through 5-passes. Recent work has shown that, given RF signals from a cavity during a fault as input, machine learning approaches can accurately classify the fault type. In this paper we report on initial results of predicting a fault onset using only data prior to the failure event. A data set was constructed using time-series data immediately before a fault (’unstable’) and 1.5 seconds prior to a fault (’stable’) gathered …
Treated Hfo2 Based Rram Devices With Ru, Tan, Tin As Top Electrode For In-Memory Computing Hardware,
2020
New Jersey Institute of Technology
Treated Hfo2 Based Rram Devices With Ru, Tan, Tin As Top Electrode For In-Memory Computing Hardware, Yuvraj Dineshkumar Patel
Theses
The scalability and power efficiency of the conventional CMOS technology is steadily coming to a halt due to increasing problems and challenges in fabrication technology. Many non-volatile memory devices have emerged recently to meet the scaling challenges. Memory devices such as RRAMs or ReRAM (Resistive Random-Access Memory) have proved to be a promising candidate for analog in memory computing applications related to inference and learning in artificial intelligence. A RRAM cell has a MIM (Metal insulator metal) structure that exhibits reversible resistive switching on application of positive or negative voltage. But detailed studies on the power consumption, repeatability and retention …
Drawing Parallels In Art Science For Collaborative Learning: A Case Study,
2020
University of Dundee
Drawing Parallels In Art Science For Collaborative Learning: A Case Study, Karen Westland
The Transdisciplinary STEAM+ Journal
This research paper explores drawing as a tool to facilitate interdisciplinary practice. Outlined is the personal experience of PhD researcher [name removed] in their physics/craft research project, combined with thoughts and opinions from collaborators gathered through group discursive interviews. Interdisciplinary projects face interpersonal and conceptually ambiguous challenges which can be addressed through adopting drawing techniques for educational purposes. Findings highlight that drawing can assist across a breadth of applications as a learning tool for everyone, regardless of drawing ability, to improve the functionality of collaborative projects. Specifically, drawing combined with other communication techniques develops a performative communicative approach that enriches …
Numerical Simulation Of Nonlinear Vibrations Of Discrete Mass With Harmonic Force Perturbation,
2020
Chirchik State Pedagogical Institute of Tashkent region
Numerical Simulation Of Nonlinear Vibrations Of Discrete Mass With Harmonic Force Perturbation, M. Yusupov, B. A. Akhmedov, Olga Karpova
Acta of Turin Polytechnic University in Tashkent
The problem of vibration of a single-mass system under the force excitation of vibration associated with a fixed base by a weightless nonlinear viscoelastic spring is considered. To take into account the rheological properties of the spring material, the Boltzmann-Volterra principle was used. Mathematical models of the problem under consideration are obtained, which are described by integro-differential equations. A solution method based on the use of quadrature formulas has been developed and a computer program has been compiled on its basis, the results obtained are presented in the form of graphs. The influence of nonlinear and rheological properties of a …
Electronic Profiling Of Synthetic Dna Using Schottky Junctions,
2020
Universiti Malaya
Electronic Profiling Of Synthetic Dna Using Schottky Junctions, Souhad M.A Daraghma
Student Works (2020-2029)
Deoxyribonucleic acid (DNA) has attracted a lot of attention lately owing to the discovery of its semiconducting property and is considered as an interesting material that could find applications in nanotechnology and electronic devices. In-depth understanding of its charge transfer mechanism is however required for effective development of DNA-based technology. This unfortunately remains still a non-trivial task despite the numerous theoretical and experimental studies that have been conducted to date. The complexity of the previously employed methods, and their lack of accuracy has made it difficult to grasp the clear understanding of the electronic behaviors of the DNA molecules under …
1. Test Data,
2020
University of Mississippi
1. Test Data, Zhiqu Lu, Likun Zhang, Lei Cao
Gulf Research Program Data Sets
This data set contains recorded and processed bubble sounds under different conditions: a few bubbles vs. constant flow bubbles. Each condition is tested with nitrogen and with methane.
2. Modeling,
2020
University of Mississippi
2. Modeling, Zhiqu Lu, Likun Zhang, Lei Cao
Gulf Research Program Data Sets
This data set contains the results for acoustic bubble modeling.
3. Localization,
2020
University of Mississippi
3. Localization, Zhiqu Lu, Likun Zhang, Lei Cao
Gulf Research Program Data Sets
This data set contains the results for oil leakage source localization.
4. Metadata Files,
2020
University of Mississippi
4. Metadata Files, Zhiqu Lu, Likun Zhang, Lei Cao
Gulf Research Program Data Sets
This data set contains all ReadMe files for test data, modeling data, and localization data, as well as the corresponding codes.
