2026 Internship Opportunities

Understanding low-pressure/near-vacuum gas flows is important for many environmental science and technology. For example, the upper atmosphere is a typical low-pressure environment, whose study helps clarify transport and diffusion phenomena of trace gases that play key roles in regulating ozone and the greenhouse effect. Closer to ground level, understanding low-pressure gas flow can enable more precise air quality monitoring for safety and health, as well as monitoring and control of pollutants in extreme or enclosed environments, such as in semiconductor production processes. Finally, many emerging environmental technologies involve low-pressure gas flows, such as carbon capture and storage, vacuum-based waste treatments, and solar panel manufacturing. Thus, understanding low-pressure or near-vacuum gas fields, particularly gas velocity distributions, will advance environmental science and technologies.

Laser diagnostics, owing to their non-intrusive nature, capability for simultaneous multi-parameter measurements, and high spatiotemporal resolution, are widely applied in gas
phase flow measurements. In particular, for velocity measurements, a very powerful class of diagnostic techniques relies on particle seeding, including particle imaging velocimetry (PIV), particle tracking velocimetry (PTV), and laser Doppler velocimetry (LDV). The velocity field of a gas flow can be indirectly inferred by measuring the velocity of the seeding particles. However, in near-vacuum gas environments, sufficient and uniform particle seeding is difficult to achieve, and the significant density difference between the gas and the tracer particles may lead to the failure of the neutral buoyancy condition and a non-negligible velocity lag.

Molecular tagging velocimetry (MTV), on the other hand, measures the flow velocity directly by tracking the displacement of a group of molecules in the gas flow that are tagged by a laser, providing more accurate velocity measurements in scenarios where particle followability deteriorates. By selecting lasers of specific wavelengths that target the resonant absorption of molecules, the molecules in the flow are pumped to an excited state. These excited-state molecules follow the flow while emitting light, and the velocity of the flow can be directly determined by imaging the luminescent distribution at different times.

The program that the intern will join will focuses on experimental work utilizing MTV in low pressure gas flow, and systematically study the evolution behavior of the gas flow field under low-pressure conditions.

Assist with designing and running experiments and with visualization and interpretation of measurements.

This project will facilitate the student gaining interdisciplinary knowledge in fluid mechanics, optics and laser spectroscopy, as well as the ability to design, conduct, and interpret fluid mechanics experiments.

Science or engineering major

Ideally, the student will possess basic background knowledge in optics and laser spectroscopy, fluid mechanics, or related disciplines, and have an interest in conducting experiments.

• Students will meet with internship mentors in the spring, prior to the internship start date. Reading materials may also be provided.
• Student(s) are responsible for securing accommodations for the duration of the internship.
• Students will need to consult UHS for travel medical requirements. It is the responsibility of the student to be aware of entry requirements and to obtain any necessary documentation. Valid passport required. Students are required to register their travel with the University through Enroll My Trip. Information related to the University’s Permissible Travel Guidelines can be found here. Funding is contingent on travel registration and University approval.