Precision Improvements of Penning Trap Mass Measurements Using Highly Charged Ions : Applications to solving current problems in fundamental physics
In my thesis I describe the improvements of the Penning trap mass spectrometer SMILETRAP. The objective of these improvements have been to increase the reliability and the accuracy with which an atomic mass can be measured using highly charged ions. The improvements have been achieved by stabilizing both the electric and magnetic fields of the trap and by improving the technical performance of the trap system. As a result it has been possible to measure accurately the mass of several atoms ranging from hydrogen to mercury using charge states from 1+ to 52+. It was only possible to use the highest charge states after applying a successful cooling of these ions with Helium during the charge breeding.The technical improvements made a number of interesting accurate mass measurements possible. The measurements of the 3H, 3He, and 4He masses showed that the previously values were wrong. The mass difference between 3H and 3He which is the Q-value of the tritium beta decay has been determined to 18.588(3) keV. The Q-value of the double ?-decay of 76Ge was measured at an accuracy of 50 eV. This value is indispensable for the evaluation the Heidelberg-Moscow experiment which aims at finding a possible neutrino-less decay which if present would be a violation of the standard model. The mass ratio of mCs/mp is used to determine the fine structure constant independent of QED calculations. The two decades old anomaly in the mass values of Hg was solved by the mass determination of 198Hg and 204Hg. The mass of 24Mg was measured at an uncertatinty of 0.6 ppb and will be used in the determination of the g-factor of a bound electron in a hydrogen like ions.
Source Type:Doctoral Dissertation
Keywords:NATURAL SCIENCES; Physics; Atomic and molecular physics; fysik; Physics
Date of Publication:01/01/2002