Summer Research Projects, Department of Physics and Astronomy
If you are interested in research opportunities, please click on the links below. We also encourage you to contact the individual department members associated with the projects for further information about the research.
Program Dates
May 20, 2024 - July 26, 2024Click on the project name for a more detailed description of the project
Project Name: The torus and circumnuclear disk of NGC1068
Project Mentor: Jack Gallimore (with Violette Impellizzeri, Leiden University)
Project Code: (JG-1)
This project aims to map the molecular gas distribution in the center of one of the best-studied active nuclei: NGC1068. Recent studies by the ALMA telescopes (a large mm- and sub-millimeter telescope based in Chile) have revealed the presence of a molecular “torus," a parsec-scale, donut-like structure surrounding the central supermassive black hole, and the circumnuclear disk (CND), which resolves into a 100 parsec-radius, elliptical ring. The CND may be a reservoir of molecular gas that will eventually flow into the torus region.
Most studies of NGC1068 focus on either the parsec-scale gas *or* the outer CND, so observations are often treated separately. However, these two scales are not independent, and information is lost when only one spatial scale is handled at a time. For this reason, this project aims to join the high-resolution data obtained with ALMA and the low-resolution data, which is sensitive to larger scales and diffuse gas emission.
Despite many observations, the torus and dynamics of NGC1068 are still a puzzle to be solved, but it is one of a few active galaxies where such detailed information can be obtained. This new approach will result in state-of-the-art maps of molecular gas emission and allow us to trace accretion flows more precisely than ever.
OTHER INFORMATION: Python skills would be very beneficial but not required.
Project Name: Microscale mechanics of actomyosin networks
Project Mentor: Bekele Gurmessa
Project Code: (BJG-1)
Many intriguing phenomena are of fundamental scientific interest at a cellular scale. For example, several molecular interactions of cytoskeletal proteins can lead to large-scale collective motion of a cell. How can we integrate molecular-level knowledge to predict macroscopic assembly and structural re-organization in cytoskeletal proteins? One way is through exploring the mechanics, structural dynamics, and underlying physics of biological polymers of varying stiffnesses, compositions, and sizes at the molecular level. The cytoskeleton--a complex and dynamic network of biopolymers comprising actin, microtubules, and intermediate filaments--plays a vital role in several cellular processes ranging from the stability and rigidity of biological cells to cell motility and shape change. Central to this multifunctionality are the inherent stiffness of each filament and the myriad binding proteins that serve to crosslink, bundle, and stabilize these filaments. Exploring the mechanics and dynamics of in vitro reconstituted networks consisting of only one of these cytoskeletal components has been the subject of extensive experimental work. However, the role each cytoskeletal component plays in their composite networks' mechanical properties and structural dynamics is yet to be well understood. In this project, we couple optical trapping with advanced imaging to measure the nonlinear viscoelastic response and structural dynamics of in vitro reconstituted microtubules (MTs)--vimentin intermediate filaments (VIFs) composite networks by varying the relative concentration of MTs and VIFs. This project involves many hands-on experiments ranging from developing experimental protocols to creating \emph{in vitro} reconstituted composite networks and characterizing them via optical trapping and laser scanning confocal microscopy techniques. At the end of the summer, the student will develop skills in cutting-edge biophysical research (spectroscopy, advanced imaging, wet-lab handling, data acquisition, and analysis through Labview and Matlab, respectively), which are transferable to any future career (medical school, graduate school, etc.). Previous experiences in wet-lab, optical imaging, and programming in Matlab are desirable but not required.
Project Name: Characterizing Dark Matter
Detector Photosensors
Project Mentor: Abby Kopec
Project
Code: (AMK-1)
Dark Matter particles floating through space may collide with atomic nuclei. We can make an experiment to try to see this process with argon or xenon. These noble elements cause flashes of light and some nearby when they get bumped, and we can see individual photons with photosensors. Recently ordered 10 SiPM photosensors need to be set up and calibrated to photons. Additionally, scintillator-coupled photomultiplier tubes need to be set up with the aim to measure the local muon flux characteristics. This project will create a pipeline for data to go from producing controlled photons, to the photons hitting the sensor, to the signal waveforms being accessible as data arrays in python jupyter notebooks. The student will gain experience with electronics, circuits, and coding with C++, and Python.
Project Name: Building the Dark Matter Detector Apparatus
Project Mentor: Abby Kopec
Project
Code: (AMK-2)
Dark Matter particles floating through space may collide with atomic nuclei. We can make an experiment to try to see this process with liquid argon or xenon. The noble elements have to be in a well-sealed system, with the ability to purify and maintain thermal equilibrium. Work is needed to design and build the gas handling system with a purification loop and integrate all infrastructure to house the experiment's detector, which will need to be cooled to liquify the noble element. Work can also begin to set up the detector for operation and characterization, with the integration of the photosensors. The student will gain experience with vacuum system technology, drafting, and construction of a sensitive particle experiment.
Project Name: Chaotic mixing, swimming microbes, and propagating reaction fronts
Project Mentor: Tom Solomon
Project Code: (THS-1)
There is currently tremendous interest in "active matter" systems in the condensed matter physics and biophysics communities. These are complex fluid systems with components that have an internal energy source that causes spontaneous movement relative to the fluid. Examples include fluids with swimming and flying organisms (e.g., swimming microbes or fish and flying insects or birds), artificial devices that move relative to the surrounding fluid (active colloids, drug delivery devices, or boats/planes), reaction fronts that move relative to the fluid while consuming the reactants (e.g., a forest fire or an industrial chemical process), molecular "motors" in a living cells, growing biological colonies in flowing ecosystems, and the spreading of diseases in a moving population of animals or people.
We are conducting a wide range of experiments to test universally-applicable theories of "invariant manifolds" that predict invisible barriers that stop the motion of active tracers in laminar (smooth) fluid flows. In particular, we are studying the motion of reaction fronts and swimming bacteria/algae/shrimp in laboratory- and microfluidic-scale fluid flows. We are also studying "deterministic chaos" in these systems that can have a significant effect on the spreading of active impurities and on processes such as the "blooming" of reactions and colonies of microbes in a fluid flow, similar to algae blooms in the oceans.
There is a lot of hands-on work involved in these projects, including the designing, building and testing of the experimental apparatus, constructing and working with microfluidic devices, mixing chemicals for the reactions, culturing of bacteria or algae, microscopy, and doing numerous experimental data runs. The experimental work also involves a substantial amount of computer-aided image analysis, almost exclusively on Linux workstations running a program called IDL. We also frequently conduct numerical simulations of the phenomena, also with IDL. Although experience in computer analysis is useful, it is not required as long as the student involved is willing and eager to learn IDL.
Project Name: Development of Atomic and Induction Coil Magnetometers
Project Mentor: Ibrahim Sulai
Project Code: (IS-1)
In my lab, we are interested in developing sensors to measure magnetic fields at the femto-Tesla level (i.e. 10−15 Tesla). For scale, the earth's magnetic field is over 10^8 times larger at 50 micro Tesla level. The motivation for making measurements of such small fields is to probe effects arising from physics beyond the standard model -- that is from particles that have been theoretically proposed to help explain some outstanding questions in physics such as "axions", and "dark photons". This summer, we will be working on two magnetometer designs: a cesium atomic magnetometer, and an induction coil magnetometer.
Atomic magnetometers work on the basis of the interaction of the atomic spin and the background magnetic field. In our lab, we work with atomic spins in Rubidium, Cesium and Helium-3. Using resonant laser light, we can read out the atoms' interaction with the magnetic field. The goals of this project are to investigate ways of amplifying the signal using optical cavities, as well as to learn about the behavior of systems having different a mixture of species which may interact with each other. An induction coil magnetometer works on the basis of the Faraday effect, which states that a time varying magnetic field will induce a current in a coil.
Using low noise electronics, we plan to measure fields at the femto-Tesla level using both atomic magnetometers and the induction coil magnetometer. In addition to electronics, this project also involves work in optics, hardware development (machining, 3D printing etc), and signal analysis.
Project Name: Spectroscopy of Palladium Atoms and Ions
Project Mentor: Ibrahim Sulai
Project Code: (IS-2)
Palladium has six stable isotopes -- five of which have nuclear spin of zero. A consequence of this is that there is no nuclear magnetic interaction between the electrons and the nucleus and so the atomic structure of five of the six isotopes is significantly simplified. We are interested in determining the energy levels of some narrow transitions in the neutral and singly ionized palladium. The narrowness of the transition is related to the Heisenberg principle, as the excited states are long lived, and hence we call them metastable.
We are able to determine the energy levels with high precision and this precision will allow us to search for (or constrain) subtle signatures of physics beyond the standard model that arise in interactions between neutrons and electrons. Last year, we developed a metastable atom source. This summer, we will excite the atoms with an external light source in order to obtain their absorption spectra. We also plan to investigate transitions in palladium ions – and work on developing an ion trap system that will allow us to acquire spectra from samples containing few ions. The work involves electronics, hardware design and optics.
Shear and clogging in granular materials with pinned disorder
Project Mentor: Brian Utter
Project Code: (BU-1)
The flow of granular materials is an example of a complex system, where simple, frictional interactions of many particles lead to complex responses of the material, for instance sudden jamming and avalanching behavior. In this project, we will perform experiments using photoelastic grains to visualize forces under shear. We will introduce fixed pins as a source of imposed structural order to understand the stress and flow response either under shear or in suspension flow. Potential applications include designer materials, with tunable rheological properties, and clogging in pedestrian dynamics. This project involves the collaboration of colleagues working on related experiments and simulations.
To conduct these table-top experiments, students will participate in constructing/ modifying experimental apparatuses, acquiring data, performing image analysis, and carrying out subsequent data analysis. Projects are accessible to students while being visually engaging and requiring transferable skills such as statistical analysis, image processing, and model fitting.
Note: this project will be conducted at the University of California, Merced. Travel costs will be provided. The schedule will be different, starting probably on June 3.
Searching for Magnetic Interaction between Stars and Planets
Project Mentor: Jackie Villadsen
Project Code: (JV-1)
As the moon Io sweeps through Jupiter's magnetic field, it causes Jupiter to emit bright bursts of radio waves. Models predict that this should also happen when extrasolar planets orbit very close to their stars, causing the star to emit bursts of radio waves. If we can detect such radio bursts and measure their brightness, we can estimate the magnetic field strength of exoplanets, which is otherwise very hard to measure. Such radio bursts from such star-planet magnetic interaction have never been detected, but there are newly discovered exoplanet systems that make good targets. In this project, you will analyze radio telescope data for a nearby star with a close-in planet. You will use Fourier transform software to convert interferometer data to create an image of the sky, measuring the brightness of radio-emitting galaxies near the star in order to remove them from the data. Then you will use Python to graph the brightness over time of the star and look for any bursts that may recur with the planet's orbital period. This project does not require prior knowledge of Fourier transforms or python - you will learn on the job. There are two positions for this project.
Computer Simulation of a Jammed Granular System
Project Mentor: Katharina Vollmayr-Lee
Project Code: (KVL-1)
Examples for granular materials are soap bubbles, rice grains, sand, and snow. At high density granular systems display fascinating phenomena such as avalanches and the jamming transition. In this project we study a system of disks which are packed in between two rough walls. The top wall is pulled to the right and the bottom wall is pulled to the left. In addition to the moving disks are not moving tiny disks, pins. We study how these pins influence the jamming transition, the structure (spatial arrangement) and the dynamics of the moving disks. We address questions like: How exactly do local sudden rearrangements look like? Do, and if so, how, do the pins change the nearby and distant structure? Do the pins change the motion of the disks? This project is part of a collaboration with the research the research groups of A. Bug, and C. Bester in Swarthmore, and B. Utter at UC Merced.
The student would work on implementing and running computer simulations on a super computer and using the public software package LAMMPS, as well as working on the analysis of the resulting simulations. No prior computer programming skills are required.