Honors Theses and Capstones

Date of Award

Spring 2019

Project Type

Senior Thesis

Program or Major

Physics

First Advisor

Elena Long

Abstract

This thesis project presents a novel method of 3D printing with the fluoroplastic Kel-F (PCTFE) as an alternative to traditional machining and demonstrates its use in creating target cups for dynamic nuclear polarization (DNP) experiments. Kel-F is used by the UNH Nuclear Physics Group in its tensor-polarized target project because the material has several properties that make it well-suited to this purpose: transparency to millimeter-waves, plasticity at cryogenic temperatures, and the absence of any unpaired protons that would add an unwanted background to the NMR signal used to measure nucleon polarization. As this paper shows, these properties are not significantly altered by the printing process, validating the use of 3D-printed Kel-F components in a DNP system. This paper also explores the possibility of using 3D printing to create mm-wave Kel-F lenses to be implemented into a DNP target system and presents the results of five such lenses using a 140 GHz Gaussian beam source and custom mm-wave imaging equipment. The results show that Kel-F lenses can be used to redistribute a mm-wave beam, but often at considerable power loss. These results highlight some of the design challenges to be overcome before such lenses will be effective at enhancing nucleon polarization.

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