Physics

Quantum Programming in Python: Quantum 1D Simple Harmonic Oscillator and Quantum Mapping Gate

Matthew Hoff — Tue, 14 May 2013 11:33:12 PDT

A common problem when learning Quantum Mechanics is the complexity in the mathematical and physical concepts, which leads to difficulty in solving and understanding problems. Using programming languages like Python have become more and more prevalent in solving challenging physical systems. An open-source computer algebra system, SymPy, has been developed using Python to help solve these difficult systems. I have added code to the SymPy library for two different systems, a One-Dimensional Quantum Harmonic Oscillator and a Quantum Mapping Gate used in Quantum Computing.

Ferrofluids

James Patt — Fri, 19 Apr 2013 16:50:38 PDT

Ferrofluids are truly fascinating. Technologically savvy artists have been able to capture the human imagination with little but a judicious application of a magnetic field. The substance seems to defy gravity, flowing and shaping itself seemingly like magic (see Figure 1). The true magic, however, is the vast range of properties that this intrinsically simple substance can exhibit. It can vary its viscosity given the strength of the magnetic field. It can draw heat away from an over worked mechanical component. It can even split a beam of light in two. It’s hard to imagine what kind of strange and incredibly complex process would result in such miraculous material. Clearly, such a material must be made up of some highly advanced ingredients, the likes of which the world can scarcely fathom. As it turns out, the situation is quite the opposite. Ferro fluids are little more than iron particles suspended in oil.

An Investigation into Dual-Axis Solar Tracking

Daniel Spaizman — Fri, 19 Apr 2013 16:50:36 PDT

This senior project aims to determine a) if using a controlled photon-tracking system does produce greater voltage output than a fixed panel and b) by how much, if so. To do this, I built a dual-axis solar tracker using a small solar panel, some stepper motors, and an Arduino Uno. The majority of my time was spent familiarizing myself with the electrical components and fabricating the device. To test the performance of the panel, the leads of the solar panel were attached to the Arduino to record the output voltages. Two experiments were carried out to discover the answers to both of the question posed above. The first was an indoor experiment in which a light source was fixed at an angle θ (only in one-axis) from the normal of the panel. The voltage and angle rotated through were sampled every second. The second experiment involved setting up the device outdoors for one hour and forty minutes to track the sun. As done indoors, the voltage and angles (both N-S and E-W this time) were sampled every second. These voltages were then compared with the angles, North-South axis as well as East-West axis. It was found, in each experiment, that the voltage output was highest when the angle between the light source and the normal of the panel was minimized. In the outdoor experiment the tracking device yielded a voltage 0.3 volts greater than the panel facing away from the sun.

Contributions to Background Reduction and Computer Simulations for CUORE & CUORE-0

Ivo J. Plamenac — Fri, 19 Apr 2013 16:50:34 PDT

CUORE and CUORE-0 aim to observe neutrinoless double beta decay in ¹³⁰Te; observing such this particular decay would substantiate the Majorana model for the neutrino and expand our current understanding of particle physics. This report will provide an overview of the Standard Model, our current framework for particle interactions, as well as the technical details of the CUORE experiment. Over the summers of 2010 and 2011, I contributed to the efforts of the CUORE collaboration by assisting in aspects such as background reduction, and explored detector behavior using computer simulations.

Density Functional Theory and the Calculation of TcMg₂O₄ Spinel Lattice Parameters

Jon Karlo Macias — Fri, 19 Apr 2013 16:50:32 PDT

The cohesive energy, lattice constant and bulk modulus of two simple HCP crystal structures of magnesium and technetium were calculated using the vienna ab initio simulation package (VASP) which is based on density functional theory (DFT). The same properties were determined for TcMg₂O₄ spinel. The theoretical results of the lattice constant of the pure crystals were compared to experimental results and found to be in excellent agreement with a difference of less than 2%. The results for the lattice constant of the TcMg₂O₄ spinel were found to be in excellent agreement as well with an error of less than 2%. The bulk modulus and cohesive energy could not be compared to experiment since these properties have not been analyzed for this specific spinel. However, the potential of DFT was recognized through this lack of information and proves to be an attractive method for guiding experimental synthesis. In the grand scheme of things, this was just one variation of the possible spinel’s which can be used to store radioactive Technetium-99 from spent nuclear fuel.

P3HT:PCPDTBT:PCBM Multi- polymer single layer solar cells

Ted Andreas — Fri, 19 Apr 2013 16:50:29 PDT

OPV efficiencies are limited by their narrow absorption; rather than using tandem architecture to overcome this obstacle, our group combined P3HT and PCPDTBT into a single layer BHJ solar cell that achieved 2.0% PCE. This is 33% higher than the pure P3HT control from this group, proving that multi-polymer solar cells have the potential to outperform their single-polymer components.

Determining Stellar Velocity Dispersion in Active Galaxies: Is the [OIII] Width a Valid Surrogate?

Kelsi Flatland — Fri, 19 Apr 2013 16:50:27 PDT

The tight empirical relation between the stellar velocity dispersion (sigma) of the bulge and the mass of the supermassive black hole (BH) at its center indicates a close connection between galactic evolution and BH growth. The evolution of this relation with cosmic time provides valuable clues to its origin. While the mass of the BH can be easily estimated using the Doppler broadening of the Hbeta emission line in type I active galactic nuclei (AGNs), measuring sigma simultaneously is challenging, since the nuclear emission outshines the host galaxy. Thus, it is highly desirable to find an alternative way to estimate sigma. In the literature, the width of the [OIII] emission line has been used as a surrogate, assuming that the narrow-line region follows the gravitational potential of the bulge. While the [OIII] line has the great advantage of being easily measurable in AGNs out to large redshifts, it is also known to be affected by outflows and jets. For a sample of about 100 nearby active galaxies, we determine the width of the [OIII] line using two Gaussians to exclude any outflowing component. The resulting width is compared to a single Gaussian fit and Gauss-Hermite polynomial fit, and finally to sigma measurements previously compiled from Keck spectroscopy for the entire sample to determine the method's viability. It is found that though subtracting the wing component makes for a much better fit, there is significant scatter in each of the fits, implying no linear relation between the width of [OIII] and sigma.

Investigation of Optical Dipole Traps for Trapping Neutral Atoms for Quantum Computing

Danielle May — Fri, 19 Apr 2013 16:50:25 PDT

Aspects of General Relativity in 1+1 Dimensions

Richard D. Mellinger Jr — Tue, 18 Dec 2012 11:07:03 PST

What would be the properties of a universe with only one spatial dimension and one time dimension? General relativity in 1+1 dimensions is unique since the two curvature terms in the Einstein field equations cancel. This makes the Einstein field equations algebraic rather than differential equations. This special feature can make 1+1 dimensionality attractive as an instructional tool to simplify the mathematics that many beginners find opaque. We explore the implications and features of the Einstein field equations in 1+1 dimensions and find they provide a surprisingly rich and interesting model. We then study an alternate theory and its implications for a potentially stable wormhole solution.

Building an Alpha Spectrometer for the CUORE Collaboration

David J. Miller — Tue, 18 Dec 2012 11:07:02 PST

This paper will give the reader a brief introduction to the Standard Model, Neutrinoless Double Beta Decay (0νββ), and the CUORE experiment under construction at Gran Sasso National Lab in Assergi, Italy. The remainder of the paper will describe the process of creating a working alpha spectrometry system using silicon detectors and NIM and CAMAC electronics. Extensive details of the troubleshooting and calibration period are presented as a way for the reader to better understand the concepts involved in alpha spectroscopy and to not repeat mistakes made in this development process.

How to Build a Nixie Clock

Shepherd Darquea — Tue, 18 Dec 2012 11:07:00 PST

Analysis of Cornell Electron-Positron Storage Ring Test Accelerator's Double Slit Visual Beam Size Monitor

Robert Campbell — Tue, 25 Sep 2012 14:57:30 PDT

In the past year, a double slit interferometer was installed to measure the horizontal beam size in the Cornell Electron-Positron Storage Ring Test Accelerator (CesrTA) at Cornell University in Ithaca, NY. To better understand the systematics of this device, a replica of the CesrTA instrument was assembled at California Polytechnic State University San Luis Obispo. From the prototype, it was found that the device will produce a calculated beam size that agrees with measurements as long as it is optimized with the proper double slits for a small range of beam sizes.

Nuclear Waste Policy Act: Where We've Been and Where We're Headed

Kevin Flournoy — Wed, 25 Jul 2012 14:12:45 PDT

The Nuclear Waste Policy Act is analysed in its practical and political impact. A policy recommendation is made of greater state and regional autonomy of on-site waste storage.

The Double Pendulum: Construction and Exploration

Benjamin J. Knudson — Wed, 25 Jul 2012 14:12:41 PDT

The exploration of a nonlinear mechanical system, the Double Pendulum, a physical pendulum on the end of a physical pendulum, using analytic and experimental approaches. Also included discussion of the design and construction of the Double Pendulum apparatus to work with Vernier LabPro and LoggerPro. The apparatus outputs live data of the angles to a LoggerPro which collects and produces time evolution graphs as well as a corresponding animation lending itself to comparison with theoretical models. Normal mode frequencies are found both analytically and experimentally for the the general (real) double pendulum. Examples of both simple (periodic) and complex (chaotic) behavior are presented.

Multipolymer Interactions in Bulk Heterojunction Photovoltaic Devices

Grant Olson — Mon, 02 Jul 2012 08:33:35 PDT

Multipolymer photovoltaics, single layer devices made up of multiple photoactive polymers, can create organic photovoltaics (OPVs) with a wider spectral response than single polymer systems without the difficult fabrication of a tandem. Our group has successfully created multipolymer solar devices with 2% power conversion efficiency. We have analyzed the optical and electrical properties of these devices, and found that it may be possible for polymers to assist each other with charge extraction, though combining polymers disrupts single polymer crystallinity.

Estimates of the density contrast at Earth’s inner-core boundary beneath central Mexico

Wade Kelley — Wed, 27 Jun 2012 12:15:15 PDT

Seismograms recorded in the western United States from a Guatemalan earthquake are examined for matching pairs of PKiKP and PcP waveforms for use in estimating the density contrast at earth’s inner-core boundary via a PKiKP/PcP amplitude ratio analysis. Examination of waveforms from the SN, SC, TA, US and CI arrays finds 68 visually identifiable PKiKP and PcP pairs from which 17 were judged to be of sufficient quality (low signal-to-noise ratio) for use in the PKiKP/PcP amplitude ratio analysis. The epicentral distance range of the selected data spans epicentral distances from 22 – 37 degrees inside of which stations are generally in narrow epicentral range clusters. The observed amplitude ratios are generally higher than the AK135 Earth Model value of 0.6 g/cm3, although the amplitude ratios do decrease with increasing epicentral distance. On average, the data suggests a density contrast at the inner-core boundary of 0.9 g/cm3. However, substantial variation in the density contrast estimate occurs over narrow epicentral distance ranges. This observation is consistent with a recent model of the inner-core boundary surface as made up of a mosaic of patches where the liquid to solid phase transformation is solidified in some locations, and mushy mixed-phase layer in others.

Digital Holography and Applications in Microscopic Interferometry

Cody Jenkins — Wed, 27 Jun 2012 12:15:07 PDT

In this project I demonstrate recording holograms using an electronic camera as the photosensitive element and subsequent numerical reconstruction in a digital computer. The technique is employed to show extended depth of field imaging as well as phase contrast imaging via microscopic interferometry.

Analysis of Focal-Plane Measurements for VERITAS Telescopes

William Hemmo Schuur — Thu, 21 Jun 2012 14:50:28 PDT

In this experiment we measured the Point Spread Function (PSF) of the telescope at different image locations using a python GUI and servo motors to automate a screen along the focal axis of the telescope. Our results show that the telescope T4 has a well-defined image distance at each elevation, but this distance shifts as the telescope is lowered. Additionally, off-axis telescope orientations are degraded by aberrations and at low elevation possibly some structural warping of the mirror. The VERITAS Telescopes are located in Southern Arizona at the Fred Lawrence Whipple Observatory.

Building and Characterization of Laser Diodes as Well as System Design of a Dual Wavelength Fabry-Perot Interferometer

Nicholas Czapla — Thu, 21 Jun 2012 14:50:21 PDT

Studying Beam Dynamics at CesrTA

Matthew (Matt) Randazzo — Thu, 21 Jun 2012 14:50:14 PDT

The Cornell Electron Storage Ring Test Accelerator (CesrTA) is a particle accelerator acting primarily as a laboratory for studying accelerator physics under a variety of conditions. Here, the experimental program on electron cloud effects is one of the highest-priority research and development projects during the International Linear Collider (ILC) Technical Design Phase 1. These electron clouds are of particular concern for the design of future low emittance rings like those in the ILC because of how they can adversely affect the performance of accelerators. The impact of electron clouds on the dynamics of individual bunches along a train known as the tune indicate the magnitude of electron cloud growth within the accelerator. This paper provides explanation as to how these electron clouds are created, how they affect beam dynamics, as well as the techniques for calculating tune shifts for observing this phenomenon.