Matching Items (5)
Description
Inductors are fundamental components that do not scale well. Their physical limitations to scalability along with their inherent losses make them the main obstacle in achieving monolithic system-on-chip platform (SoCP). For past decades researchers focused on integrating magnetic materials into on-chip inductors in the quest of achieving high inductance density and quality factor (QF). The state of the art on-chip inductor is made of an enclosed magnetic thin-film around the current carrying wire for maximum flux amplification. Though the integration of magnetic materials results in enhanced inductor characteristics, this approach has its own challenges and limitations especially in power applications. The current-induced magnetic field (HDC) drives the magnetic film into its saturation state. At saturation, inductance and QF drop to that of air-core inductors, eliminating the benefits of integrating magnetic materials. Increasing the current carrying capability without substantially sacrificing benefits brought on by the magnetic material is an open challenge in power applications. Researchers continue to address this challenge along with the continuous improvement in inductance and QF for RF and power applications.
In this work on-chip inductors incorporating magnetic Co-4%Zr-4%Ta -8%B thin films were fabricated and their characteristics were examined under the influence of an externally applied DC magnetic field. It is well established that spins in magnetic materials tend to align themselves in the same direction as the applied field. The resistance of the inductor resulting from the ferromagnetic film can be changed by manipulating the orientation of magnetization. A reduction in resistance should lead to decreases in losses and an enhancement in the QF. The effect of externally applied DC magnetic field along the easy and hard axes was thoroughly investigated. Depending on the strength and orientation of the externally applied field significant improvements in QF response were gained at the expense of a relative reduction in inductance. Characteristics of magnetic-based inductors degrade with current-induced stress. It was found that applying an externally low DC magnetic field across the on-chip inductor prevents the degradation in inductance and QF responses. Examining the effect of DC magnetic field on current carrying capability under low temperature is suggested.
In this work on-chip inductors incorporating magnetic Co-4%Zr-4%Ta -8%B thin films were fabricated and their characteristics were examined under the influence of an externally applied DC magnetic field. It is well established that spins in magnetic materials tend to align themselves in the same direction as the applied field. The resistance of the inductor resulting from the ferromagnetic film can be changed by manipulating the orientation of magnetization. A reduction in resistance should lead to decreases in losses and an enhancement in the QF. The effect of externally applied DC magnetic field along the easy and hard axes was thoroughly investigated. Depending on the strength and orientation of the externally applied field significant improvements in QF response were gained at the expense of a relative reduction in inductance. Characteristics of magnetic-based inductors degrade with current-induced stress. It was found that applying an externally low DC magnetic field across the on-chip inductor prevents the degradation in inductance and QF responses. Examining the effect of DC magnetic field on current carrying capability under low temperature is suggested.
ContributorsKhdour, Mahmoud (Author) / Yu, Hongbin (Thesis advisor) / Pan, George (Committee member) / Goryll, Michael (Committee member) / Bearat, Hamdallah (Committee member) / Arizona State University (Publisher)
Created2014
Description
Quark matter at sufficiently high density and low temperature is expected to be a color superconductor, and may exist in the interior of neutron stars. The properties of two simplest possible color-superconducting phases, i.e., the color-flavor-locked (CFL) and two-flavor superconducting (2SC) phases, are reviewed. The effect of a magnetic field on the pairing dynamics in two-flavor color-superconducting dense quark matter is investigated. A universal form of the gap equation for an arbitrary magnetic field is derived in the weakly coupled regime of QCD at asymptotically high density, using the framework of Schwinger-Dyson equation in the improved rainbow approximation. The results for the gap in two limiting cases, weak and strong magnetic fields, are obtained and discussed. It is shown that the superconducting gap function in the weak magnetic field limit develops a directional dependence in momentum space. This property of the gap parameter is argued to be a consequence of a long-range interaction in QCD.
ContributorsYu, Lang (Author) / Shovkovy, Igor A. (Thesis advisor) / Lunardini, Cecilia (Committee member) / Schmidt, Kevin (Committee member) / Alarcon, Ricardo (Committee member) / Lebed, Richard (Committee member) / Arizona State University (Publisher)
Created2012
Description
This project details a magnetic field detection system that can be mounted on an unmanned aerial vehicle (UAV). The system is comprised of analog circuitry to detect and process the magnetic signals, digital circuitry to sample and store the data outputted from the analog front end, and finally a UAV to carry and mobilize the electronic parts. The system should be able to sense magnetic fields from power transmission lines, enabling the determination of whether or not current is running through the power line.
ContributorsTheoharatos, Dimitrios (Co-author) / Brazones, Ryan (Co-author) / Pagaduan, Patrick (Co-author) / Allee, David (Thesis director) / Karady, George (Committee member) / Barrett, The Honors College (Contributor) / Electrical Engineering Program (Contributor)
Created2015-05
Description
A self-stirring syringe pump was created in order to fill a void in the market for a medical device that could perform a lengthy drug infusion. This was accomplished by using a magnetic field mechanism that enclosed the body of a syringe. A stator was created in order to facilitate the induction of magnetic fields around the syringe body. A flexible magnetic stir bar was created to rotate within the syringe body while also being able to conform to the syringe plunder as an infusion occurred. In order for the stator with the syringe to fit onto a conventional syringe pump, a mount had to be made. This mount was removable to ensure easy access to the syringe once an infusion had occurred. A study was performed to determine whether or not the self-stirring syringe pump could keep a suspension homogenous over a lengthy infusion. It was found that the self-stirring syringe pump was able to accomplish this task.
ContributorsWitting, Avery Amadeus (Author) / Vernon, Brent (Thesis director) / Goryll, Michael (Committee member) / Faigel, Douglas (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
The interactions that take place in the ionized halo of gas surrounding galaxies, known as the circumgalactic medium (CGM), dictates the host galaxy's evolution throughout cosmic time. These interactions are powered by inflows and outflows that enable the transfer of matter and energy, and are driven by feedback processes such as accretion, galactic winds, star formation and active galactic nuclei. Such feedback and the interactions that ensue leads to the formation of non-equilibrium chemistry in the CGM. This non-equilibrium chemistry is implied by observations that reveal the highly non-uniform distribution of lower ionization state species, such as Mg II and Si II, along with widespread higher ionization state material, such as O VI, that is difficult to match with equilibrium models. Given these observations, the CGM must be viewed as a dynamic, multiphase medium, such as occurs in the presence of turbulence. To better understand this ionized halo, I used the non-equilibrium chemistry package, MAIHEM, to perform hydrodynamic (HD) simulations. I carried out a suite of HD simulations with varying levels of artificially driven, homogeneous turbulence to learn how this influences the non-equilibrium chemistry that develops under certain conditions present in the CGM. I found that a level of turbulence consistent with velocities implied by observations replicated many observed features within the CGM, such as low and high ionization state material existing simultaneously. At higher levels of turbulence, however, simulations lead to a thermal runaway effect. To address this issue, and conduct more realistic simulations of this environment, I modeled a stratified medium in a Milky Way mass Navarro-Frenk-White (NFW) gravitational potential with turbulence that decreased radially. In this setup and with similar levels of turbulence, I alleviated the amount of thermal runaway that occurs, while also matching observed ionization states. I then performed magneto-hydrodynamic (MHD) simulations with the same model setup that additionally included rotation in the inner halo. Magnetic fields facilitate the development of an overall hotter CGM that forms dense structures within where magnetic pressure dominates. Ion ratios in these regions resemble detections and limits gathered from recent observations. Furthermore, magnetic fields allow for the diffusion of angular momentum throughout the extended disk and gas cooling onto the disk, allowing for the maintenance of the disk at late times.
ContributorsBuie II, Edward (Author) / Scannapieco, Evan (Thesis advisor) / Borthakur, Sanchyeeta (Committee member) / Groppi, Christopher (Committee member) / Jacobs, Danny (Committee member) / Young, Patrick (Committee member) / Arizona State University (Publisher)
Created2022