Physics Lecture Series | Spring 2017

Geophysics is the study of the Earth using physics, math, computing and other aspects of science and math. There are a number of career opportunities based on geophysical research and applications. Some of these careers are in the energy industry (oil & gas), which is about to come out of a deep down cycle. Other careers lie in academia, government agencies, environment, mining, and ground water, to name a few.

This presentation will start with a brief overview of my 40-year career as a petroleum geophysicist. My intent is to give an example of a career using my own training and experiences. Then I'll speak briefly about other careers within geophysics and the outlook for jobs. Next I will tell you about the organization that is sponsoring this presentation — Incorporated Research Institutes for Seismology (IRIS). IRIS has a summer intern program for undergraduates. The bulk of the presentation will be on this program, how it works, and how to apply. There will be time at the end for questions about the intern program, geophysics careers, and other items of interest from the audience.

Hayabusa2 is an asteroid sample return mission to C-type asteroid Ryugu, operated by the Japanese space agency, JAXA, with participation from NASA and the Australian National University. It follows on from the previous Hayabusa Mission to S-type asteroid Itokawa and addresses engineering lessons learned from that mission. Hayabusa2 launched in December 2015, will arrive at the target asteroid in December 2018, and will return to earth with asteroid samples in December 2020.

Experimental observations have established that neutrinos undergo flavor oscillations as they propagate due to quantum mechanical mixing between the mass states and flavor states (electron, muon, tau). The Daya Bay Reactor Neutrino Experiment has observed the disappearance of electron-type antineutrinos from nuclear reactor cores at the Daya Bay nuclear power complex located in China. DUNE is a next-generation neutrino oscillation experiment that is being designed to address the remaining questions in the three-neutrino mixing model. In this talk, I will present an overview of neutrino oscillation measurements, including the most recent results from the Daya Bay experiment, and the experimental design and physics prospects for DUNE.

Lisa Whitehead is an Assistant Professor at University of Houston. She received her Bachelor's Degree from Vanderbilt University in 2002 and her Ph.D. from Stony Brook University in 2007. She did her postdoctoral research at Brookhaven National Laboratory before coming to University of Houston in 2011. Whitehead is an experimental particle physicist, and her research has focused on studying neutrino oscillations.

Due to the limited storage of fuel and coal, green energy is the main trend to replace the traditional mineral energy. Solar energy is considered as one of the most sustainable energy supply. What's the semiconductor solar cells' mechanism? How to achieve ultra-high conversion efficiency? Why can't solar cells reach 100% efficiency? Why can't the actual devices reach the theoretical conversion limit? Or say, what is the main energy loss? You are going to find out the answers in this talk. I will start from simple analysis, outside the devices and inside the devices on optics prospect. Outside devices means at the interface between air and device, before the photons are converted into electron-hole pairs. Inside the devices means that limited absorption coefficient required the absorber to be thick enough to utilize all the photons, but not too thick to let electron-hole pairs recombine. In the end, the experimental tools for fabricating light harvesting textures would be explained, with a full cutting edge solar cell structure.

Ion Beam Characterization of materials results from bombardment of atoms on the surface of a sample to be studied. Detection the consequences of such bombardment such as energy of the scattered projectile, or nuclear reaction induced by the bombardment, or X-ray production caused by the bombardment can reveal the composition, depth, and structure of the sample. In addition, ion beam processing of materials results from the introduction of atoms into the host materials, and modifying its solid state properties. In this talk, I will describe the principles, methods of the title subject. I will also present many examples to illustrate the utility of ion beam on material science research, and industrial applications.

Wei-Kan Chu is a Cullen University Professor in Physics Department at University of Houston. His research interest is related to ion-solid interaction and on Ion Beam Characterization of Materials and Ion Beam Modification of Materials. He is also an expert on High Temperature Superconductor applications in the area of HTS-magnetic Bearing and Levitation Flywheels.

There are more than 2.4 million miles of pipe in the United States energy infrastructure and over 65% of them were installed before 1970. In order to maintain the health of our infrastructure, a technique called inline inspection (ILI) is used. ILI consists of inserting a tool into the pipeline that is equipped with sensors that take various measurements of the pipe to assess its integrity. Some of these modalities are magnetic flux leakage (MFL), Ultrasonics (UT), Electromagnetic Acoustic Testing (EMAT) and Eddy Current Testing (ECT). Much of these technologies have been around for decades, but new physics applications are constantly being research to identify new threats and those that have been otherwise irreducible. This presentation will be a survey of the current state of physics being used in the analysis of various pipeline threats: corrosion, cracking, mechanical damage, hard spots, low toughness welds, pipe yield strength, etc.

Adrian Belanger is a systems engineer at T. D. Williamsons' Integrity Inspection Solutions division's Data Science department. Adrian has been at T.D. Williamson for five years with a total 20 years of pipeline inspection experience. He has developed the anomaly sizing algorithms for the magnetic flux leakage (MFL) tools and was responsible for tool accuracy and specifications. He developed a hardness prediction model using high field and residual magnetization for hard spots and is involved in the continuing development of such projects as crack detection using EMAT and mechanical damage prioritization using high and low field magnetizations. At present he is working on the next generation of pipeline threat analysis using Multiple Data Set technology.

Adrian earned his Master's in Physics in 1994 from Vanderbilt University. He earned his Bachelor's in Astronomy and Physics from Boston University in 1988. He is a member of IEEE, AGA, APS and ASNT.

Black holes are ubiquitous in the Universe at many scales, but their nature makes them almost impossible to detect directly. Observational work in different parts of the electromagnetic spectrum has given us only tantalizing glimpses of black holes through their interaction with their environment. Now that Advanced LIGO has made the first direct measurements of gravitational waves from the mergers of black-hole binaries, we've entered the era of Gravitational-Wave Astronomy. Still, the greatest insights will come from combining the new GW detections with more traditional EM ones. I'll present work on how we're trying to model both gravitational and electromagnetic aspects of the merger of comparable-mass black-hole binaries, with a special emphasis on the supermassive holes merging at the end-stages of galactic collisions.

Bernard Kelly is a CRESST Assistant Research Scientist at the University of Maryland, Baltimore County, working in the Gravitational Astrophysics Laboratory (Code 663) of NASA's Goddard Space Flight Center.

Bernard received his B.Sc. in Experimental Physics and Mathematical Physics in University College, Dublin in 1995, followed by a M.Sc. in Mathematical Physics at the same institution in 1996. After two years working in the financial mathematics of foreign currency trading in Dublin, he began graduate studies in gravitational physics at Penn State University. He received a Ph.D. in Physics in 2004, based on his work on the simulation of black-hole mergers with moving excision. He joined the numerical relativity group at the University of Texas at Brownsville as a Postdoctoral Scholar, before moving to Maryland and the Goddard Space Flight Center, first as a NASA Postdoctoral Fellow, then as a CRESST Researcher.

I discuss the physics behind both causes and effects of mutations, with emphasis on those affecting human mitochondrial DNA (mtDNA). Possible causes include hole localization, which may increase the likelihood of a hydrogen bond shift and base-pair mismatch during replication. Comparison of our quantum mechanical modeling results with human mtDNA suggests that sites where holes tend to localize have higher mutation rates. Next, I'll discuss electron and proton transport in the mitochondrial electron transport chain, and how this can be impaired in neurological disorders, cancer, and other major illnesses. We find, from molecular dynamics, that a single mutation replacing one amino acid with another in ATP synthase causes a 'short circuit' between two proton-transporting water channels. This provides the first clear explanation for how the mutation impairs ATP production and causes Leigh syndrome, a devastating mitochondrial disorder leading to short life spans in children. Finally, I'll discuss some recent experimental results on adverse effects of excess dopamine (a neurotransmitter) on mitochondria.

An analysis of the number and infrared emission emission of a sample of close major-merger galaxy pairs selected by apparent near-infrared brightness and redshift can lead to an understanding of the encounter physics in galaxy merging events. The selected pairs provide an estimate of the fraction of galaxies in ongoing merger events as well as their contribution to the overall star formation activity in the local universe. Use of the Spitzer and Herschel Space Telescopes and CIGALE (Code Investigating GALaxy Emission) to observe and model the mid- to far-infrared emission of a subsample of the pairs has given us the star formation rates, efficiencies and dust characteristics of these local major-merger precursors. The effects of interaction on these properties in star forming spiral galaxies differs by morphological type of the their companion galaxies. Spirals paired with ellipticals do not have the same level of enhancement of star formation and differ in dust composition. These mixed morphology pair results stand in contrast to what would be expected according to standard models of gas redistribution due to encounter torques and pave the way for further theoretical investigation into the full environmental effects on star formation.

Donovan Domingue is currently the Kaolin Endowed Chair for Science and Professor in the Department of Chemistry, Physics and Astronomy at Georgia College. As the Kaolin Endowed Chair, Dr. Domingue has brought the national K-12 teacher/astronomer partnership program known as Project ASTRO to middle Georgia. He serves as facilitator of Georgia College's Pohl Observatory activities where he supervises undergraduate research groups engaging with diverse topics such as asteroid rotation and galaxy imaging. His personal research involves understanding the role of environment on the star formation occurring in galaxies and galaxy pairs. Before arriving at Georgia College in 2002, Dr. Domingue was a member of Spitzer Space Telescope research teams located at Caltech and taught physics and astronomy at California State University-Fullerton. Dr. Domingue earned his Ph.D. in Physics from the University of Alabama and his B.S. from Louisiana State University.

Coherent elastic neutrino-nucleus scattering (CEνNS) is a long-standing prediction of the Standard Model. Although the neutrino interacts very weakly, the fact that it may simultaneously (coherently) interact with the very large number of particles in a complex nucleus produces a large enhancement for this process, allowing for much lighter neutrino detectors to be employed than has been the case in the past. The historical difficulty with this approach is that a very small amount of energy is deposited into the recoil of the nucleus, and sufficiently sensitive detectors are just now on the verge of becoming a practical reality. This presentation will describe an upcoming experiment by the MINER Collaboration, which will deploy economical and scalable silicon and germanium detector arrays with very low recoil sensitivity immediately adjacent to a nuclear reactor neutrino source. If the CEνNS process is observed with large statistics, it will furthermore represent a new laboratory for testing theories of new particles and interactions beyond the Standard Model that are connected to the mysterious neutrino sector.

Secondary neutrons are a main source of stray and leakage radiation outside treatment fields in proton radiotherapy and therefore, pose a risk to patients for the development of second cancers. In addition, the nozzle components of the proton therapy unit remain "hot" some time after the treatment and induce time-dependent decays from mixed neutron/gamma-ray fields, which potentially put radiation therapists at risk for excessive cumulative dose exposures post treatment. The accuracy of the nuclear physics model used to predict stray neutron fields in proton radiotherapy is not clearly understood. The Tool for Particle Simulation (TOPAS) was used to calculate the therapeutic absorbed dose and neutron spectral fluence from a proton treatment unit using three nuclear physics models: the Bertini model, the Binary Cascade model and the INCL4/ABLA model. TOPAS is based on the platform of the Geant4 Monte Carlo Toolkit (version 9.6).

The purpose of this research is to compare and quantify differences in predictions from these models for an un-modulated and a range modulated 160 MeV proton therapy beam in 1) characteristics of the therapeutic absorbed dose and 2) stray neutron fields produced by a proton radiotherapy unit using the default Bertini model as the baseline of comparison. The therapeutic absorbed dose was calculated in a water phantom downstream of the nozzle exit, while the neutron spectral fluence was calculated in air. The ambient dose equivalent per therapeutic absorbed dose (H*(10)/D) of the secondary neutrons produced by the nozzle components was also calculated for each model. Based on these calculations, we determined H*(10)/D at the isocenter, 1 m downstream from the isocenter, and at lateral distances of 1 m from the isocenter. Our results indicate that calculations of the therapeutic absorbed dose ratios are in good agreement for all three nuclear models. However, the H*(10)/D values differed somewhat at the isocenter with or without range modulation using the alternative models for intranuclear cascade processes.

While the hard sciences offer excellent preparation for a career in industry, one often finds that private-sector human resources departments can perceive a mismatch between a broad and rigorous hard science education and skill-specific job requirements. Though this mismatch is false, it is nevertheless an obstacle prospective job hunters must navigate. In this talk, I will share my experiences and offer advice for transitioning from academia to industry. Specifically, I will talk about my career in the television advertising industry.