The Muon g-2 experiment hopes to test the difference between the experimental and theoretical values of the anomalous magnetic moment of the muon (g-2) out to a greater statistical precision than has been previously accomplished. Such a discovery would provide strong evidence of new physics such as dark photons, supersymmetry, or possibly something not yet considered. During the experiment, muons are injected into a large superconducting ring. A muon decays to an electron and the electron curls to the inside of the storage ring and strikes an array of lead fluoride crystals. When an electron hits a crystal, it produces light that is proportional in intensity to the energy of the electron. The energy and the time of its arrival help to indicate the direction of the spin which is used in the calculation of g-2. My research investigates how light is propagated and distributed in these crystals and how different reflective or absorptive wrappings affect this distribution. I measure light yield and pulse width, which correspond to two different extremes of wrapping material. For maximum light yield, I use a special reflective white paper called Millipore, while shorter pulse widths are achieved using an absorptive black Tedlar paper. I have developed a 2x2 array of crystals coupled to light sensitive photomultiplier tubes. This setup, which is configured for easy switching of the wrapping material, captures cosmic ray muons that hit the surface of the earth. Capturing these muons simulates the conditions of the experiment. I analyze the resulting data by fitting the pulses and extracting the functional form of the light distribution. The results of this research will ultimately contribute to the development of more complete theories of the fundamental building blocks of the universe.

 By developing an efficient and generalized framework, data from test beam experiments can be analyzed in an effort to improve silicon detector technologies for use in the Large Hadron Collider (LHC). Before a prototype sensor can be used in the LHC, a test beam is run to collect performance data. Charged particles emitted from a beam are recorded as they pass through the sensor. This data is analyzed to measure how efficient the sensor is at detecting these particles. By modifying a generalized framework for specific applications, analysis can be used for different types of sensors. Current efforts are focused on measuring the edge efficiency of slim edge 3D silicon sensors. Once this work is completed, the framework will be adapted for use on new sensors requiring their own specific analysis.

In order to increase the accuracy of particle detectors, new sensors and digital acquisition systems must be developed. With the power of reconfigurable digital logic, an acquisition system has been created using a simple and fast architecture in order to test T3MAPS, a prototype sensor for the ATLAS detector. The firmware design of the system is modular to allow for iterative improvements over time and future changes to the sensor. Currently the systems first iteration is being tested using oscilloscopes, and then the system will be connected to T3MAPS for more advanced function tests. In the future the firmware will be ported to multiple platforms with additional functions to allow time over threshold test to be conducted on T3MAPS. T3MAPS is new sensor designed to detect high-energy particles generated by particle accelerators. The ATLAS detector is one of many particle detectors at the Large Hadron Collider, a particle accelerator run by CERN. The firmware for this system is written in a hardware description language, Verilog. This language is used to describe digital designs as a programming language, enabling reconfigurable digital circuits. This offers a vast level of flexibility. As nobody has tried to implement an acquisition system for T3MAPS, great care must be taken to insure that the signal to the sensor is correct and electrically clean. This is verified using a logic analyzer and an oscilloscope to insure the signal meets the specifications required. After signal verification, testing will be conducted on T3MAPS itself using the verified design. Tests will progress from simple configuration of the sensor to full pixel by pixel scans of the chip. Results from these tests will be analyzed to compare the speed and accuracy of this system vs. the existing manual methods.

The goal of this study is to search for a pseudo scalar Higgs boson. The recently discovered Higgs boson is only the simplest way to explain the generation of particle masses. It is possible to make a simple extension to the Standard Model by adding a second complex Higgs doublet which gives a rise to five Higgs bosons. A Monte Carlo simulation for the production of the A Higgs and its decay to two leptons and two b quarks was created. The simulation is used to fine tune an algorithm for distinguishing between the signal from this decay and background signals generated from other decay channels.It uses MadGraph, Pythia and Delphes for the different stages of simulation. The simulation data is compared against data available from ATLAS simulations. The study has shown how changes in parameters of the search algorithm lead to increase of the level of both signal and background. The expected results include better filtering of the signal from the background by analysis of the jet structure and increased sensitivity for higher masses of the A Higgs when using boosted jets in the analysis. The results of the study provide possiblities for creating a more complete model of the fundamentals of the physical world and practical ideas about how to analyze the data from the Large Hadron Colider in CERN.

In order to process large amounts of physical events and filter the interesting events worth investigating, a good detector must have a sophisticated Data Acquisition (DAQ) system. In an effort to improve and study its tasks in much detail, an identical DAQ system for the ATLAS Pixel Detector has been established in the lab environment. This flexible environment allows us to conduct various experiments for the current and future development of the Pixel DAQ System. Currently, the necessary hardware and software have been set up. Then the system will be connected to the Pixel Readout Driver, which is part of the current generation of the Pixel DAQ System to test its data acquisition performance. In the future, the system will test DAQ performance of the IBLROD, which is the new generation of the Pixel DAQ System. Also, a new data path firmware that is currently under development will be implemented in the system to evaluate its data processing performance.

Current research seeks to be able to produce detailed data through simulation for comparisons of the material budgets of individual layers, sub-layers, and components of different inner detector geometries for implementation in future ATLAS upgrades at the Large Hadron Collider (LHC). ATLAS, A Toroidal LHC Apparatus, is a particle detection experiment located at the LHC in Geneva, Switzerland. The inner tracker, a constituent ATLAS system, records the presence of particles at discrete points in space and time allowing for the reconstruction of the particles' trajectories; material budget is a measure of the energy loss of particles as they pass through the tracker. Upgrades and replacements of the current inner tracker will allow the detector to continue to function at optimal efficiency and collect more data at higher energies in the future. Present work involves simulating the performance of different geometries in order to reduce the overall material budget, thereby increasing low momentum resolution. Software is used to model the passage of non-interacting particles through the detector, recording the angle of their trajectories and the amount of matter through which each particle passes. These quantities can then be plotted against each other and compared for different geometries. Data for a forthcoming addition to the innermost section of the inner tracker and a proposed future replacement of the entire innermost layer have been produced at this time. Confirmation of a reduction in material budget for future upgrades is expected. This project will allow optimal specifications to be determined for the reduction of material budgets for future changes to the inner tracker.

Magnetohydrodynamic (MHD) propulsion uses water, electricity and magnets to create thrust.  The importance of MHD drives is that they require no moving parts, allowing for less energy loss due to friction as well as silent propulsion.  The MHD engine works by creating thrust when an electric current is run through a liquid or plasma in the presence of a magnetic field.  The interaction between the electrons in the medium and the electric field draws water in one end and expels it out the other, creating thrust.  Our project seeks to optimize the thrust of a MHD system in a saltwater solution so it is a viable replacement engine for a water craft.  We present here our design of a novel closed-circuit MHD-engine testing apparatus that allows for real-time varying of magnetic field strength and engine geometry in order to achieve optimal thrust configurations for a given MHD engine design.

Theoretical descriptions of nature often depend on perturbative approaches that seldom extend beyond linearized approximations, and this translates to a large body of our understanding of physical systems ranging from cosmology, to nonequilibrium chemical processes, to aerospace control systems being only poorly understood. Our research focuses on the question of the extent to which computational simulations of nonlinear systems is experimentally verifiable. Here we use a quantitative measure of computational vs. experimental agreement called the horizon time and demonstrate its use through direct comparison of theoretical, computational and experimental modes of analysis using a damped, coupled physical pendulum apparatus, and specially developed data acquisition and analysis software. We find that a strong sensitivity of initial conditions, shown in the Lyapunov exponents, causes a rapid divergence between nearby trajectories within a tolerance range for experimentally observed motion which limits the horizon time to between 0.9 and 4.3 seconds before our trajectories can no longer be distinguished. By creating our own modified horizon time definition for use in a characteristic state space of known dimensions, we can only predict up to 1.3 seconds of motion before the trajectories cannot be distinguished. This small temporal resolution severely limits how effectively our theory can function as a description of experimental motion.

It is often forgotten students are learning to build a better future. As a group of students, we are looking to create a form of innovative technology that provides a learning experience through two of the most important learning methods: visual and kinesthetic. To provide hands on learning experience, we have created the Dynamic Mathematical Display (DMD). The DMD is a device with pins placed within a three by three grid. The pins are 10 cm long, 3.5 cm wide, and each controlled by individual motors and slide potentiometers. The dynamic movement of each pin is measured by the potentiometer's linear resistance, which is monitored electronically by a computer program. That program will engage the pin to move to a given point projected from 3D graph. The main purpose of the DMD project is to create a morphing table that will allow a user to visualize complicated 3D graphs with all their components such as depths and peaks. These components will be represented by red, green, and blue light emitting diodes (RGB LEDs), which are attached to each pin. The LED's are programmed to provide color based on the physical location of the pin at the time according to the projected graph. Both instructors and students will have the option to manipulate the brightness and color of the LEDs. While the pins provide kinesthetic information to a graph, the LEDs provide additional visual information similar to a topographic map, enhancing the learning experience of a student by presenting more realistic and information-rich representations of physical models. 

Ferrofluids are colloidal suspensions composed of iron based (Fe) particles with a diameter roughly 10 nanometers (nm) or less; these particles are dispersed in a carrier fluid containing a surfactant to prevent agglomeration. This fluid has the inherent ferromagnetic qualities of the metal particles, specifically the high magnetic permeability, and the very high thermal motion spin of a suspension fluid, resulting in a paramagnetic fluid attracted to applied magnetic fields. Since ferrofluids are influenced by applied magnetic fields, the particles are susceptible to increased friction as the relative particle velocity is reduced, thus causing an artificial increase in the viscosity which can be controlled through the strength of the magnetic field. Because of the refractive qualities and friction/flow control of ferrofluids, the specific viscosity measurements of fluids can be obtained through laser analysis. I present direct experimental verifications of Shliomis’ theory of ferrofluid magnetoviscosity using both gravimetric capillary viscometry and laser-pumped birefringent relaxation time.

Random fractal patterns exhibit an overwhelming distribution throughout the natural world, from the smallest scale we can see, to the most universal scales we can imagine, and appear to affect everything in between. In order to explore some small-scale examples of this, we used high voltage to burn surface tracking patterns into various media, then analyzed the fractal dimension of some of the better samples. Next, we theoretically modeled radial diffusion-limited aggregation clusters (DLA) and a linear dielectric breakdown model by computer simulations, and analyzed the Hausdorff dimensionality of those, as well. Similar to previous experiments by Kim and Roh, and Niemeyer et. al., the experimentally and physically modeled results agreed in their dimensionality. This comparative analysis model implies a method of non-destructive analysis for a broad spectrum of insulating materials. These processes could help engineers design more robust dielectric components or safer airplanes, help geologists better understand fault-fracture spreading and aid in earthquake prediction, or enable atmospheric scientists to study elusive lightning structures known as sprites.

By detecting interesting subatomic particles, physicists can understand fundamental constituents of the natural world. In detection processes, however, unwanted particles can mingle with those which are targets of investigations, and thus in any experiment it becomes necessary to extract the data corresponding to the wanted particles from the rest of the measurement results. In my research project, I analyzed data that were known to come from neutrons and those from alphas, both of which were obtained in a subterranean detector located in eastern Canada. Specifically, I tested the efficacy of a proposed method to discriminate the two types of particles. When detected, each particle gave rise to an electrical pulse. Based on the hypothesis that the shapes of the pulses are qualitatively different for different particles, I have mathematically analyzed the pulses by performing integrals on the pulse shapes and finding the numerical difference between each pair of the pulses. As a result, I found that about only 25% of neutrons could be clearly distinguished from alphas, but the others were indistinguishable, solely on the basis of this pulse shape analysis. Since this result is not satisfying, my goal of the next phase of this project is to devise an improved method that can distinguish the particles more efficiently.

The precision of a measurement can be enhanced by reducing the experimental cycle time, thus allowing a greater number of measurements for a given amount of time. In our apparatus, we utilize a coherent atomic source, Bose-Einstein condensates (BEC), for a precision interferometric measurement of a fundamental physical constant - the fine structure constant, which lies at the heart of atom-light interactons. The cycle time and therefore precision of these experiments is limited by the production time of BECs. A critical number of atoms must be collected in our atom trap for BEC production. This project explores the effectiveness of doppler cooling and collimating the transverse motion of a ytterbium atomic beam in reducing experiment cycle time. Transverse cooling is done using four lasers oriented orthogonally to the path of the beam and detuned from the resonant frequency of the 1S0 to 1P1 transition in Ytterbium. The optical pressure alters a significant fraction of trajectories to lead into the trap, as opposed to being lost due to large velocity components orthogonal (transverse) to the beam path. We have created a computer simulation of the doppler cooling technique to motivate design parameters such as the detuning frequency of the lasers. We will report on the experimental implementation of transverse cooling and compare it to our theoretical simulation

Following the discovery of graphene, other two-dimensional (2D) materials have been identified including a variety of truly 2D semiconductors. Because of their unique optical properties including a direct band-gap in the visible spectrum, these new semiconductors are exciting candidates for next-generation devices that can translate an electric signal into light or vice versa, known as optoelectronic devices. One such important device is the light emitting diode (LED), since they are essential components in displays and optical interconnects, logic, and circuits. Further, despite being atomically thin, techniques have recently been developed to transfer and stack these monolayer materials and produce arbitrarily complex devices and heterostructures, a structure composed of layers of different 2D materials. Here, we present our adaptation of these transfer techniques in conjunction with electron beam lithography to produce the first monolayer LED using 2D crystals of tungsten diselendide. Future work will focus on cleaner “dry” transfer techniques and the fabrication of LEDs based on heterostructures of two different 2D semiconductors. This new transfer process will allow for more efficient LED’s free from debris and contaminants. This research also enables the development of brand new nanoscale optoelectronic devices and the investigation of new 2D materials.

Trapped ion quantum computing uses trapped ions to represent information not only as 0s and 1s as in a classical computer, but also as a superposition of 0s and 1s. This provides many benefits over traditional computing, such as enhanced encryption and more efficient factorization of prime numbers. In our implementation, one of the first steps to trapping barium ions to use a qubits, the quantum equivalent of classical bits. We use a 791 nm laser to ionize barium-137, making further operations possible. In normal operations, the frequency of this laser can fluctuate unpredictably, making it unsuitable for ionization. To combat this problem, I designed and built an optical cavity to stabilize the laser. By arranging two mirrors so that the light interferes with itself, only a limited range of frequencies are allowed to pass through. First, a spacer with a low coefficient of thermal expansion keeps the mirrors at a fixed distance, while an analog circuit regulates the temperature of the spacer to insulate it from swings in ambient temperature. A second analog circuit then monitors the light coming out of the cavity and feeds back to the laser, allowing the user to lock onto a specific frequency. This locking system provides a low cost, yet effective method of stabilizing a laser  and will be easy to implement again, with other lasers. More generally, this shows how an ion trap can be improved with the relatively simple laser locking method used here.

 DNA sequencing is essential to life sciences and personalized medicine. Nanopore sequencing is a single molecule sequencing technique that promises both an increase in sequencing speed and a reduction in cost compared to current sequencing technologies. In nanopore sequencing, DNA is drawn through a nanometer-wide pore while we record any changes in ionic current. These current changes depending on the nucleotide sequence. Our lab uses the nanopore Mycobacterium smegmatis porin A (MspA), which was engineered to examine DNA with single nucleotide resolution. MspA is sensitive to the four standard nucleotides (A, T, C, G) as well as small chemical changes to those nucleotides. Uracil is a nucleotide that differs from thymine by a single methyl group which we now show we can detect with MspA. Using a process called bisulfite treatment, which converts cytosine to uracil, we obtain information that helps us to determine the input DNA sequence.

Superconducting Josephson Junctions may be an enabling technology for the next generation of supercomputers. Breakthroughs in nanotechnology have allowed for transistors to close in on their theoretical limit of several nm in size, allowing for tens of billions of transistors per square inch to be fabricated on integrated circuits. As the transistor count increases processor power consumption will become a limiting factor. Josephson Junctions are a promising candidate to replace silicon transistor based switching as they consume several orders of magnitude less power than current silicon transistors while promising even faster switching speeds. Furthermore Josephson Junctions have been shown to be a possible basis for a scalable quantum computing architecture, increasing their usefulness beyond advanced classical computing applications. We characterize Josephson Junctions fabricated at the University of Washington using both room temperature and cryogenic measurements as part of a preliminary effort to further develop this technology.

Graphene, a material consisting of only one layer of carbon atoms, was isolated and electrically measured for the first time in 2004. New physics is rising that can be studied with graphene, such as half integer quantum hall and Klein tunneling and etc. Its excellent physical properties and chemically inactive nature make graphene and other 2D materials promising for both device applications and fundamental research. My project is making 2D-material based devises I learned to make tape with a variety of 2D materials (including insulators, conductors, ferromagnets), to exfoliate those materials onto silicon oxide chips, and to search for monolayers. Since the charge carriers in 2D materials are exposed to environment, they are very sensitive to the impurities from the surroundings including substrates. To fabricate high quality nano-devices, putting these materials in an ultraclean environment is very important. One strategy is to sandwich a material in two boron nitride flakes to build heterostructures. I will present the process I use for making graphene structures by van der Waal’s transfer technique. Van der walls forces are utilized to pick up a boron nitride flake on silicon oxide with a PPC (Polypropylene carbonate a thin clear copolymer) spin coating on PDMS (a clear rubber). A monolayer can then be picked up by the boron nitride and then one more layer of boron nitride completes the sandwich. The PPC is melted off the PDMS, and its residue is washed away. The devices I have made were characterized by atomic force microscopy, scanning electron microscopy, and electronic transport measurements. The measurements made on my devices pave the way to making state-of-the-art low dimensional electron systems.

 The spins of electrons bound to donors are promising candidates as qubits for quantum information processing. The quantum properties of these donor-shy bound electrons are studied in high magnetic fields while immersed in liquid helium at 4K. For stability reasons, the level of liquid helium in the experiment must be monitored with a sensor. An effective way of implementing a sensor is with a superconducting wire. Super conductors have the property of having zero electrical resistance when they are cooled below a critical temperature. Above this critical temperature, the superconductor has significant electrical resistance. Using these characteristics, a superconducting wire can be used to construct a liquid helium level sensor. When current is run through a thin wire submerged in liquid helium, a relationship can be established between the voltage drop across the sensor and the amount of wire submerged in the liquid helium, allowing the liquid helium level to be measured. Results will be presented on the sensor design and performance.

The ability to optically isolate single gallium arsenide (GaAs) electron donors has many implications both in quantum information science as well as semiconductor physics. However, conventional methods of fluorescence microscopy are fundamentally limited by diffraction, which sets a minimum resolvable feature size preventing the direct optical imaging of nanoscale structures. At the University of Washington Optical Spintronics and Sensing laboratory we are building a super-resolution optical microscope, based on ground state depletion, to isolate single GaAs donors. A critical component of the microscope is the two-dimensional methodical scanning of laser beams over the sample, for which we have elected to use a piezoelectric fast-steering mirror. I have designed a scanning system capable of under 1 nm mechanical resolution, which will be sufficient for our target optical resolution of about 100 nm to isolate single donors. I will present preliminary results on the performance of the test system using a transmission electron microscopy (TEM) grid as a test sample, which will allow us to evaluate the achieved accuracy and resolution of the imaging due to its regular features. Isolating single donors in GaAs using this super-resolution microscopy technique may lead to new insights in how to localize and evaluate impurities such as donors and acceptors for quantum information as well as classical applications.