Accession Number : ADA558440


Title :   Design and Characterization of a Three-Dimensional Positron Annihilation Spectroscopy System Using a Low-Energy Positron Beam


Descriptive Note : Master's thesis


Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT


Personal Author(s) : Jimenez, Stephen M


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a558440.pdf


Report Date : 22 Mar 2012


Pagination or Media Count : 132


Abstract : Previous forays by AFIT into positron research have resulted in the development of a new positron annihilation spectroscopy (PAS) technique and the procurement of a low-energy positron beam system. The primary purpose of this research was to design and build a state-of-the-art PAS laboratory at AFIT capable to address a myriad of DoD solid-state and surface physics questions. The main objectives were to acquire and assemble utilities to operate a positron beam, assemble and con gure an ultra-high vacuum (UHV) system for samples, design and build an interface with a magnetic eld to propagate positrons onto samples, and create a new version of the three-dimensional positron annihilation spectroscopy system (3DPASS). The 3DPASS, which measures coincidence Doppler broadening of annihilation radiation (CDBAR) and two-dimensional angular correlation of annihilation radiation (2D-ACAR), was characterized using a Cu-22Na positron annihilation source made as part of this project. Integration of the 3DPASS with low-energy positron beam will allow for energy-dependent, nondestructive characterization of materials using PAS.


Descriptors :   *ANNIHILATION RADIATION , *SPECTROSCOPY , DOPPLER EFFECT , POSITRONS , SOLID STATE ELECTRONICS


Subject Categories : Nuclear Physics & Elementary Particle Physics


Distribution Statement : APPROVED FOR PUBLIC RELEASE