TrappedIons.org

Ch. Weinheimer

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

A. Krieger, Ch. Geppert, R. Catherall, F. Hochschulz, J. Krämer, R. Neugart, S. Rosendahl, J. Schipper, E. Siesling [1], Ch. Weinheimer [1], D. T. Yordanov [1], W. Nörtershäuser

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.

First detection and energy measurement of recoil ions following beta decay in a Penning trap with the WITCH experiment

M. Beck [1], S. Coeck [2], V. Yu. Kozlov, M. Breitenfeld [2], P. Delahaye [3], P. Friedag [1], M. Herbane [2], A. Herlert [3,2], I. S. Kraev, J. Mader [1], M. Tandecki [2], S. Van Gorp [2], F. Wauters [2], Ch. Weinheimer [1], F. Wenander [3], N. Severijns [2]

Abstract

The WITCH experiment (Weak Interaction Trap for CHarged particles) will search for exotic interactions by investigating the beta-neutrino angular correlation via the measurement of the recoil energy spectrum after beta decay. As a first step the recoil ions from the beta-minus decay of 124In stored in a Penning trap have been detected. The evidence for the detection of recoil ions is shown and the properties of the ion cloud that forms the radioactive source for the experiment in the Penning trap are presented.