Undergraduate Honors Theses

Thesis Defended

Spring 2018

Document Type


Type of Thesis

Departmental Honors



First Advisor

Heather Lewandowski (Thesis Advisor, Committee Member)

Second Advisor

John Cumalat (Committee Member)

Third Advisor

Joe Jupille (Committee Member)


The observed molecule signal in cold molecule experiments is limited by the molecule source and the efficiency of the detection method. The purpose of my thesis work was to improve the scientific apparatus physicists use to trap and detect cold molecules. The first part of my thesis focuses on improving a new cold molecule source known as a Nijmegen Pulsed Valve by optimizing the parameters used to run it. The valve worked best when operating at a voltage of 8-12V, valve pulse duration of 70-100 microseconds, and valve frequency of 1Hz. The new Neijmegen Pulsed Valve, run with optimized parameters, was then compared to the standard cold molecule source known as the Piezoelectric Valve. The two valves showed similar performance.

The second part of my thesis focuses on investigating a method used to detect cold molecules, known as photoionization spectrometry with vacuum ultraviolet (VUV) light, with the overall goal of improving the method. A common VUV light source is 118 nm light produced by third harmonic generation (THG) in a mixture of xenon and argon. According to theory, it is possible to increase the amount of 118 nm light from THG by increasing the pressure of the phased matched Xe-Ar mixture, however the amount of 118 nm light decreases with increasing mixture pressure. One untested factor thought to be causing this discrepancy is linear absorption of 118 nm light in xenon. However, the tests I performed show that linear absorption in xenon is not the issue.