Precision high-voltage measurements for collision spectroscopy experiments

As a follow-up of the high precision monitoring of the CRYRING electron cooler voltage using the G35 divider developed in Münster, a new divider module is developed that is able to also measure short term voltage changes (on the 10 ms scale) with approximately 10 ppm precision for use in collision spectroscopy experiments. The new divider module will act as an add-on of the G35 divider, relying on the latter for calibration of the scale factor before and after a beamtime. Using the technique of frequency compensation the frequency dependence of the measurement process can be eliminated using a set of tuning capacitors.A first beam test of the new divider module produced promising results e.g. regarding the voltage stability of the scale factor of the device, which showed a variation of only <0.5 ppm over a 2 kV interval. The divider is currently being upgraded with an automated calibration of the frequency compensation and an improved data readout.

Besides the development activities, the Münster group participates in laser spectroscopy experiments at the storage rings ESR, CRYRING and at the SPECTRAP experiment, making use of fluorescence detection systems it developed in earlier funding periods.