Bulletin of the American Physical Society
Far West Section Fall 2022 Meeting
Volume 67, Number 10
Friday–Saturday, October 7–8, 2022; University of Hawaiʻi at Mānoa, Honolulu, HI
Session G02: Plasma, Nuclear, AMO Physics and Education |
Hide Abstracts |
Chair: Hendrik Ohldag, Lawrence Berkeley National Laboratory Room: University of Hawai'i at Manoa, East-West Center Asia |
Friday, October 7, 2022 1:45PM - 2:09PM |
G02.00001: Inner-shell Radiation Properties of Z-pinch Plasmas with Astrophysically Relevant Conditions Ryan R Childers, Alla S Safronova, Victor L Kantsyrev, Christopher J Butcher, Amandeep Gill Plasma comprises ≳95% of mass in the observable universe and prominently exists in thermonuclear environments. In recent years, plasma science has grown from purely observational to experimentally-controlled in laboratory settings. The significance of laboratory-produced plasmas is underscored by their application to inertial confinement fusion – where they are leading candidates for clean, sustainable energy – and laboratory astrophysics research, since they produce radiation from environments with astrophysically relevant conditions. This talk explores experimental and theoretical methods for the study of a laboratory magnetically-confined plasma, known as a ‘Z-pinch’. Experimental techniques consider pulsed-power X-pinch wire load types and relevant diagnostics used to measure and image the plasma sources. Theoretical methods include computational collisional-radiative atomic modeling of spectroscopic radiation emitted from inner-shell (n=1) plasma ions as well as intensity analysis to investigate plasma opacity. Two different experimental load geometries are presented and specific effects on plasma production and radiation properties are discussed. The relevance of this study as well as other Z-pinch examples to laboratory astrophysical research are considered. |
Friday, October 7, 2022 2:09PM - 2:21PM |
G02.00002: Kinetic simulation of magnetized plasma sheaths with oblique magnetic fields Andres Castillo, Kentaro Hara Plasma-wall interactions are an essential factor for the performance of devices with applied magnetic fields. Especially for Hall thrusters, magnetrons, and tokamak diverters, there are areas where the magnetic field lines have a noticeable angle relative to the wall. These areas are of particular interest, since the oblique magnetic field can create unique sheath structures capable of modifying the expected wall fluxes, as well as secondary and field emission from the wall. In this work, a one-dimensional, particle-in-cell (PIC) simulation is applied to study plasma interactions with a dielectric wall for a range of magnetic field angles and ion-to-electron temperature ratios. Verified and validated with non-magnetized and magnetized cases, respectively, the PIC model illustrates the magnetized sheath structures and explores the distinctive electron velocity distribution functions in the pre-sheath region. Additionally, secondary electron emission effects are presented, where the applied magnetic field is shown to delay the formation of virtual cathodes in space-charge limited sheaths. Furthermore, a variety of boundary treatments for the plasma injection are assessed for cases with high magnetic field angles and cold ions. |
Friday, October 7, 2022 2:21PM - 2:33PM |
G02.00003: Computational Fluid Dynamics Modeling of Droplets Heated by an X-ray Free Electron Laser Claudia Parisuana-Barranca, David C Eder, Aaron Fisher, Alice E Koniges, Maxence Gauthier, Christopher Schoenwaelder, Claudiu A Stan, Siegfried H Glenzer High Energy Density (HED) Physics study matter under extreme states of pressure and temperature present in planetary interiors, astrophysical jets or fusion devices. Exciting data was obtained from single shot experiments recreating these conditions in laboratory using energetic laser/ion-beam drivers. In recent years, driven by the development towards high-repetition-rate drivers, collecting HED related data at a greater frequency is now within reach. For high-repetition-rate operation, liquid droplets can be used to provide a continuously refreshing target. However, one must make sure that extreme conditions produced during the preceding interaction and target debris do not degrade the next target. This is a challenging computational fluid dynamics (CFD) problem that needs to model not only the initial dynamics of the heated droplet, but also the late time interaction with the following droplets. Here, the code PISALE is used to study the case of a liquid hydrogen droplet heated by an x-ray free electron laser. After showing high-resolution 2D results for a single heated droplet, we investigate in a 3D simulation the impact of the laser-droplet interaction on two subsequent droplets. |
Friday, October 7, 2022 2:33PM - 2:45PM |
G02.00004: Nuclear Physics with Short-Lived Beams John W Price Short-lived beam particles in nuclear physics present problems for both the beam flux and target thickness calculations. Historically, bubble chamber experiments measured these quantities directly during datataking. Although precise, they were statistics-limited, due to rate limitations of bubble chambers. Modern large-acceptance detectors can overcome this limitation, with data rates several orders of magnitude greater than those of bubble chambers. The final-state particles are either detected directly or reconstructed from the decay particles. The beam particle is not detected directly, but is inferred via a missing mass calculation. A recent study with the CLAS detector at Jefferson Lab in Newport News, Virginia used a version of this technique to measure the cross section for Λp→Λp. The scattered Λ was inferred via its decay to π-p; the presence of two protons in the final state reduced greatly the amount of data to be analyzed. Although the incident momentum range was limited, the number of events in this measurement was far greater than any previous measurement for this process. This talk will present the motivations for the development of short-lived beams, the present status of this project with the CLAS Collaboration, and plans for future improvements to the technique. |
Friday, October 7, 2022 2:45PM - 2:57PM |
G02.00005: Measuring Radiation from Source and Background using a HPGe Detector Franciska Sprok
|
Friday, October 7, 2022 2:57PM - 3:09PM |
G02.00006: Rapid and high-resolution chemical sensing using linear and nonlinear dual frequency comb spectroscopy Skyler Weight, Peter Hovland, Peyton Clark, Bachana Lomsadze In recent years dual-comb spectroscopy (DCS) has emerged as a powerful method that can obtain linear absorption spectra of different analytes rapidly and with high spectral resolution. However, an important limitation of DCS is that the linear spectra obtained cannot distinguish between a three-level system with two resonant frequencies f1 and f2, and a mixture of two independent two-level systems with the same frequencies. This information is important for chemical sensing applications. In order to make this distinction, multidimensional coherent spectroscopy can be used but it requires long acquisition times and uses complex apparatus. Here we propose a different approach that uses a simple acquisition scheme and does not require the measurements of full multidimensional coherent spectra. This approach is based on photon echo spectroscopy and the dual-comb spectroscopy detection technique and enables the measurement of linear and nonlinear (photon-echo) signals from a sample of interest rapidly and with high spectral resolution. We show that the measured nonlinear signal contains spectroscopic information that, in conjunction with a linear signal, can be used to identify analytes in a mixture without measuring a full multidimensional coherent spectrum. |
Friday, October 7, 2022 3:09PM - 3:21PM |
G02.00007: The functional relationship between the ratio of the wavelength of light quantum and the radius of light quantum Han y yong Quan The distance between the centers of two photons is the wavelength of the photons. One of the light quantum conclusions I introduced: Q=M^2R=1.83×10^-78——(1), where R is the radius of the photon, M is the mass of the photon, and the Q constant. The second conclusion of light quantum: mλ=H——(2), where m is the mass of the photon, λ is the wavelength of this type of photon, H is a constant, H=h/c=2.21×10^-42. Simultaneously (1) and (2) are solved: δ=λ/ R=HM/Q——(3), that is, the ratio of the wavelength of the photon to the radius of the photon is a proportional function, and it is an increasing function——and the photon is proportional to the quality. That is to say, the greater the mass of the light quantum, the greater the relative distance between the light quantum (the more open the two light quantum is), the smaller the wavelength, the less obvious the wave property, that is, the more obvious the particle property, and vice versa. We are calculating the proportionality constant of the δ(m) function, H/Q=2.21×10^-42/1.83×10^-78=1.21×10^36, we can see that the ratio of the wavelength of the light quantum to the radius is a proportional function, And the proportionality constant (slope) is large. |
Friday, October 7, 2022 3:21PM - 3:33PM |
G02.00008: Don't Lecture Me: A brief sample of tutorial-based learning for High School Physics. Tiffany Coke, Jamey Clarke Punahou School physics teachers, working in cooperation with the University of Washington Physics Education Research Group, have written a comprehensive High School Physics curriculum across pacing levels: from Conceptual to AP Physics C. Students engage with physics topics through tutorial style instruction and peer learning. The tutorials focus on building conceptual understanding and guide students to confront common misconceptions head on. Much has been written about the success of such instruction in helping a broad segment of students succeed not only in concept development but also in performance on traditional assessments. Historical data from Punahou School students shows marked improvement in test scores following implementation of tutorial-based learning. Qualitative data from student surveys at the end of their physics classes demonstrates their eventual appreciation for this pedagogy. Our talk will provide a brief sample of the learning environment. Interested participants can learn more by starting a dialog with the presenters who will provide contact information for follow-up. |
Friday, October 7, 2022 3:33PM - 3:45PM |
G02.00009: Thermal-Buoyancy Driven Flows around a Japanese Kyusu Nagahiro Ohashi, John S Allen, Alexander Ribao The Japanese teapot also known as the kyusu has a unique design for its handle, allowing for a cool to touch pouring. The handle acts as a fin and the traditional hollow, cylindrical design is hypothesized to be cooled by a thermo-buoyancy driven flow. Though fins are ubiquitous in practical heat transfer applications, the underlying heat transfer mechanism for these geometries are not well understood. Analytical solutions are only available for simple fins, often with assumptions of constant cross section, one-dimensional and steady state. Infrared thermography was used for investigation of spatial distribution of the temperature in the pot handles. Four different kyusu designs were studied: ceramic, black with a tapered hollow handle, white, porcelain with a solid handle, orange, clay with a hollow variable cross section handle, and clear glass with a hollow handle. Simplified models, such as solid cylinders, hollow cylinders of uniform and varying cross-sectional geometry, and 3D models of actual handle designs were used for analysis and comparison with data. Temperature profiles were compared against each other for the different handle designs. The hollow ones maintained a degree of temperature variation in length while the solid handle acted primarily as a fin of uniform temperature. The experimental data was also used to develop a computational fluid dynamics model of the thermo-buoyancy driven flow in the hollow handle cases. Previously unreported recirculation was found to be the primary mechanism for the convective cooling. |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700