Research

Dr. Tharp is a member of the ALPHA collaboration at CERN, an incredibly successful experiment studying antihydrogen. Our studies are designed to probe one of the great outstanding questions of physics:
Is antimatter a perfect reflection of matter, or is there an unexpected difference?

In ALPHA, we are making extremely precise measurements of antihydrogen spectroscopy to look for very tiny differences between Hydrogen and anti-Hydrogen. So far, our measurements have confirmed that atoms made of matter and antimatter have the same spectroscopic energy levels. We continue working to improve the precision of our measurement, which may yet detect a difference.

In parallel with these efforts, we are building a new experiment to test the gravitational interaction between antihydrogen and the Earth. Does antimatter fall up? We hope to answer this question soon, and then continue toward precision gravity measurements.

Diagnostic development

Dr. Tharp specializes in hardware development, including the plasma diagnostic stations for ALPHA. These diagnostics were designed and built at Marquette, and allow us to measure the non-neutral plasma properties, including density, shape, temperature, and reproducibility.

Vacuum compatibility testing at Marquette

We are also working to test the compatibility of 3-D printed components with the stringent vacuum requirements of ALPHA. The samples shown in the photo above were all made using various types of 3D printing. By measuring their outgassing rates, we can show that these materials are suitable for use in ALPHA and other high vacuum applications.

Lab renovation!

A fun photo series of my lab space renovation over time, from piles of abandoned equipment (left) to a modern research lab, including an enthusiastic summer student (right).

Magnetic Reconnection

Dr. Tharp previously worked in basic plasma physics on MST and MRX to understand the physical process of magnetic reconnection. Magnetic reconnection occurs in a plasma when magnetic fields of opposite direction are drawn together and annihilate. When this occurs, magnetic field energy can be converted into kinetic energy in the form of plasma flow and heat. Solar flares were one of the first cases of magnetic reconnection to be studied, and this process has since been identified in other plasmas, such as those at the Earth’s magnetopause and magnetotail, and in laboratory plasmas such as fusion experiments.

Research Students