Plasma engineering of gases in micro ion Atomic Clocks

Summary form only given. Atomic Clocks are quantum devices; when ions are used they also become plasma devices. This paper investigates the ions that can be produced from the gas available in a RF linear Paul quadrupole trap used for an Yb ion frequency standard. The gas issues in plasma science and engineering investigated include dimensionless stability parameters from Mathieu´s equation considering the clock ion, buffer gas ion and background gas ions. With the buffer gas having the highest partial pressure, the potential for a DC gas discharge is discussed. The coupling parameter is determined along with the potential depth and ion charge density for the ions previously mentioned. From these parameters it is determined that in this case the plasma is characterized as a weakly coupled nonneutral cold ion plasma gas. Using electron impact ionization and expected partial pressures, the reaction rates for ion production are also determined in order to compare how the different ions would fill up the trap. Considering the plasma characterization, ion particle traces for the configuration are determined and a comparison of analytical stability and numerical simulation stability is presented. The paper concludes with a discussion on the implications of the results on plasma engineering design for micro ion atomic clocks.