Physics

Session I

Yiyang Ding, "Ramsey Interferometry Based Imaging with Ultracold Atoms"

This project aims to develop a Ramsey interferometry-based imaging technique for imaging a laser beam with ultracold atoms as an initial step toward advancing non-invasive electron beam imaging. Observing electrons without perturbing their state is a challenge in experimental physics, so such capability would be particularly beneficial for monitoring the high-power electron beams used at facilities like Jefferson Lab. This technique has the potential to enhance particle detection for electrons, protons, and muons, and to detect extremely weak electric and magnetic fields. These properties may also have broader applications, including the observation of various electromagnetic signals.

Student Major(s): Physics, Computer Science

Advisor: Dr. Seth Aubin

Hugh Muldrow, "Particle-In-Cell Simulations of a Hall Thruster"

Electric rocket propulsion is a promising technology for deep space exploration. Electric rockets can get better “gas mileage” and therefore ultimately travel further than conventional combustion rockets, but provide lower acceleration and require an external power source such as a solar array or nuclear reactor. Hall thrusters are a common subtype of electric propulsion. The conditions within a Hall thruster are a plasma; as such, they are difficult to describe without a simulation and empirical data. A variety of computational tools have been developed for analyzing plasma systems; my research explored the use of a particle-in-cell code called Epoch for simulating conditions in a Hall Thruster. Particle-in-cell codes divide the domain into hundreds of cells and solves for the electric and magnetic fields in each based on particle positions and velocities. It then moves the particles based on the fields, and reiterates the fields based on the new positions and velocities. This method allows for a high level of detail in the simulation, but is very computationally expensive relative to some other types of simulations. My research explored the capabilities and limitations of Epoch when simulating Hall thrusters, and compared the physics of three different propellant compositions in the thruster.

Student Major(s): Physics

Advisor: Dr. David Stark

Session II

Zachary Barnet, "Optical Plasma Diagnostics with Quantum Probes"

Heating plasma is a popular method for researching nuclear fusion. Current measurement tools must be physically inserted into the plasma which alters its condition. Helium is a promising candidate for a non-invasive measurement technique because it is a natural byproduct of these fusion reactors. It also has a long-lived excited state which leads to more stable behavior. This project works towards developing a non-invasive measurement method by characterizing Helium plasma inside of an external magnetic field. We measure the Helium atoms’ effect on the electric field of an infrared laser that we propagate through the plasma. We calculate this method to be sensitive to magnetic field changes of approximately 2 milligauss or about 0.5% of the Earth's magnetic field strength.

In addition, we plot the amount of laser light that is transmitted through the plasma at different wavelengths. By fitting an equation to this data, we extract the relative density of Helium atoms in the laser’s path.

Student Major(s): Physics

Advisor: Dr. Eugeniy Mikhailov

Aidan Hasling, Nathan Kulp, "Position and Force Calibration of Optical Tweezers for Biophysics Research"

Optical tweezers are a powerful tool used in biophysics research that uses focused laser light to gently trap and move tiny objects, such as parts of a cell, DNA, and proteins. They can be used to determine the strength of bonds within DNA and proteins, manipulate organelles within cells, construct biomaterials, and more with piconewton-scale forces. To determine the force exerted by the particles in the trap of the laser, several position and force calibration methods were conducted this summer. While the results had aligned with other studies, the calibrations were less precise than hoped. This was due to several constraints, the main one being a lack of accurate temperature measurements at the trap, reducing the reliability of the force calibrations. Collecting more data and improving the equipment in the future will help make these measurements more accurate, expanding the potential of optical tweezers for studying biophysics.

Student Major(s)/Minor: Aidan: Biology Major, Physics Minor Nathan: Physics

Advisor: Dr. Bjorg Larson

Ryan Locker, "Application of Carbon Quantum Dots in Early Detection of Melanoma"

The research aimed to identify a current gap in methods and technologies used by dermatologist to identify and skin cancer like melanoma. We interviewed dermatologists and reviewed literature to conclude that there’s a demand for a medical technology that offers more accuracy in ruling out benign moles to reduce the number of unnecessary biopsy that is often invasive. To address this issue, we started working on creating a hydrogel bandage with carbon quantum dots that will turn fluorescent in response to interacting with biomarkers for melanoma. Quantum dots are nanocrystals made of semiconductor that is capable of emitting different wavelengths of light. Although the application of QDs in medicine is still being explored, successful development of this bandage will save patients and doctors hundreds of thousands of unnecessary biopsy every year.

Student Major(s): Neuroscience, Physics

Advisor: Dr. Ran Yang

Owen Rollins, "Measuring Magnetic Field with Atoms"

Precise measurements of magnetic field are desirable for applications ranging from spacecraft to medical imaging. A promising technique for magnetic field measurement is atomic magnetometry, which leverages special frequencies of atoms called resonant frequencies. These frequencies are sensitive to magnetic field, but not temperature, pressure, or time, giving atomic magnetometry exciting potential. Furthermore, the transition of atoms between energy levels, induced by laser light, depends in part on the direction of magnetic field. We discuss a magnetometry technique centered around atomic transition amplitudes. We demonstrate sub-degree precision on angular measurements for a transverse magnetic field, and a full profile for all magnetic fields.

Student Major(s): Physics, Mathematics

Advisor: Dr. Irina Novikova

Dylan Serlin, "An Exploration of Stochastic Composite Gravity"

At the heart of modern physics lie deep paradoxes in quantum mechanics and quantum field theory, revealing tensions in how we describe reality. A central mystery is that multiple, seemingly equivalent mathematical formulations exist, raising a fundamental question: are we uncovering the true nature of reality, or are these just different approximations within our scientific models? This project explores a stochastic(random probability) approach to quantum mechanics and field theory, one that not only resolves several long-standing paradoxes but also unexpectedly suggests a natural way to rectify quantum theory with general relativity. The core of this research is a long-form study of stochastic mechanics and stochastic quantum field theory, revisiting its foundations and presenting a new derivation inspired by Hamilton-Jacobi theory that avoids unnecessary assumptions. The project will also formalize how microscopic randomness gives rise to quantum states and critically engage with common objections to stochastic interpretations. By refining and expanding this framework, this work aims to shed light on a rather underexplored yet promising perspective in fundamental physics, with potential implications for unifying our theories of the tiny and the massive: quantum theory and general relativity.

Student Major(s): Physics

Advisor: Dr. Joshua Erlich