The penning trap electron gun for the KATRIN experiment

Abstract

The KArlsruhe TRitium Neutrino experiment (KATRIN) is currently in under construction, with plans to be activated in 2010. The experiment will measure the energy of electrons recoiling from the three body beta decay of Tritium (Hydrogen with two neutrons) in order to obtain the mass of the neutrino. The experiment will be sensitive down to 0.2ev/c2. My thesis focuses on the one of the calibration sources for this experiment: the Penning trap electron gun. This calibration source will use ion storage techniques usually used in high resolution mass spectroscopy to store and excite electrons to a known energy and then release them with a user-controlled angular distribution. These electrons will then travel through the experimental apparatus and be detected as if they were electrons from events in the experiment, thus providing valuable information on the response of the detector. In this thesis, I performed simulations in a windows-based ion flight package to measure the characteristic frequencies of an ion caught in the trap as well as to study the response of the system to driving by microwaves. I also worked on testing of the first two prototypes of the electron gun itself, concentrating on transitioning from a thermionic electron source to a photoelectric electron source.