Calibration of the ISOLDE acceleration voltage using a high-precision voltage divider and applying collinear fast beam laser spectroscopy

TL;DR

This paper presents a high-precision calibration of ISOLDE's acceleration voltage using a ppm-level voltage divider and collinear laser spectroscopy, ensuring accurate isotope shift measurements and analyzing voltage stability.

Contribution

It introduces a new high-precision voltage calibration method for ISOLDE and validates it through beam velocity and isotope shift measurements.

Findings

Beam velocity measurements agree with the new calibration.

Consistent isotope shift results across different spectroscopy methods.

Analysis of voltage stability and transient behavior.

Abstract

A high-voltage divider with accuracy at the ppm level and collinear laser spectroscopy were used to calibrate the highvoltage installation at the radioactive ion beam facility ISOLDE at CERN. The accurate knowledge of this voltage is particularly important for collinear laser spectroscopy measurements. Beam velocity measurements using frequencycomb based collinear laser spectroscopy agree with the new calibration. Applying this, one obtains consistent results for isotope shifts of stable magnesium isotopes measured using collinear spectroscopy and laser spectroscopy on laser-cooled ions in a trap. The long-term stability and the transient behavior during recovery from a voltage dropout were investigated for the different power supplies currently applied at ISOLDE.