Antihydrogen Via Two-Stage Charge Exchange
Fitzakerley, Daniel William
MetadataShow full item record
This thesis describes positron and antihydrogen research performed at CERN in the context of the ATRAP collaboration. Positrons emitted from a radioactive source are moderated in a layer of frozen neon. The rate at which slow positrons exit the moderating material is precisely determined. The slow positrons are trapped in a differentially pumped Penning trap. Large numbers of positrons are accumulated and transferred into a cryogenic Penning trap at a record rate. Plasmas of up to four billion positrons are created --- the largest number of positrons ever held in a single trap. Counting techniques for positron and electron plasmas are compared, validating the charge-counting techniques used for each. Positron plasmas are compressed using rotating electric fields in preparation of antihydrogen production experiments. Antihydrogen atoms are created via laser-controlled, two-stage charge exchange. These antihydrogen atoms, approximately 2000 per trial, should be created with low enough energy so that some of them can be confined in a magnetic quadrupole or octupole trap. The goal of ATRAP is to precisely measure the spectroscopy of these trapped antihydrogen atoms, and compare it to the spectroscopy of hydrogen to test CPT and Lorentz invariance.