Josephson voltage standards as ultra-stable low-noise voltage sources for precision Penning-trap experiments

Abstract

A high-precision Penning-trap experiment was operated with a programmable 20 V Josephson voltage source, providing a significantly higher stability of the electrostatic trapping potential. This increased the motional frequency stability of a trapped ion by about a factor of two with respect to state-of-the-art voltage sources. An absolute axial frequency stability of 7.8(6) mHz corresponding to a relative precision of 9.7(8)×10−9 at 795 kHz was demonstrated using a trapped 9Be3+ ion as a measurement probe. The enhanced stability in the trapping potential opens up the possibility for improved determinations of the proton and antiproton magnetic moments and direct high-precision measurements of the nuclear magnetic moments of 2H, 3He, and 7Li. In the field of mass spectrometry, the developments will enable measurements of cyclotron frequency ratios and, thus, mass ratio measurements with unprecedented relative statistical uncertainties below the 10−12 level.