ALIVE – Measuring High Voltages with ppm Accuracy using Collinear Laser Spectroscopy

Collinear laser spectroscopy has been used for studying nuclear properties of exotic isotopes at online facilities for many years. The potential of this technique to measure high voltages with high accuracy was already proposed by Poulsen et al. in the 1980s. A precursor experiment, carried out at GSI and the University of Mainz was limited by systematic uncertainties to an accuracy of 100ppm. With the ALIVE setup we want to revive this idea and try to improve on the accuracy by choosing a very narrow atomic transition combined with a two-stage laser interaction and a frequency comb to measure the laser frequency. With these improvements, we aim for an accuracy of 1 ppm which would compete with the world´s best high-voltage dividers and could serve as a future high voltage standard. The talk will focus on the experimental technique and the experimental results of collinear spectroscopy of calcium ions, where we have reached unprecedented accuracy. Furthermore, the planned developments to improve precision and accuracy will be discussed.