Laser spectroscopy of the [Formula: see text], [Formula: see text] transitions in stored and cooled relativistic C[Formula: see text] ions.

The [Formula: see text] and [Formula: see text] transitions in Li-like carbon ions stored and cooled at a velocity of [Formula: see text] in the experimental storage ring (ESR) at the GSI Helmholtz Centre in Darmstadt have been investigated in a laser spectroscopy experiment. Resonance wavelengths were obtained using a new continuous-wave UV laser system and a novel extreme UV (XUV) detection system to detect forward emitted fluorescence photons. The results obtained for the two transitions are compared to existing experimental and theoretical data. A discrepancy found in an earlier laser spectroscopy measurement at the ESR with results from plasma spectroscopy and interferometry has been resolved and agreement between experiment and theory is confirmed.

Ion source for tests of ion behavior in the Karlsruhe tritium neutrino experiment beam line.

An electron-impact ion source based on photoelectron emission was developed for ionization of gases at pressures below 10(-4) mbar in an axial magnetic field in the order of 5 T. The ion source applies only dc fields, which makes it suitable for use in the presence of equipment sensitive to radio-frequency (RF) fields. The ion source was successfully tested under varying conditions regarding pressure, magnetic field, and magnetic-field gradient, and the results were studied with the help of simulations. The processes in the ion source are well understood, and possibilities for further optimization of generated ion currents are clarified.

Feasibility of photoelectron sources with sharp lines of stable energy between 20 and 80 keV.

Photo-absorption of γ-rays in thin Al, Co, Ti, and Mo convertors was examined with the aim to produce quasi monoenergetic photoelectrons having an energy spread of 0.5-4.7eV about mean kinetic energies at discrete values between 18632 and 80321eV. The photoelectron rates were estimated for commercial photon sources of (241)Am, (119m)Sn, (125m)Te and (109)Cd with activities of 0.55-3.7GBq. Photoelectrons ejected by (241)Am γ- and X-rays from Co convertors were measured with two different electron spectrometers and obtained energy spectra were compared with Monte Carlo predictions.

Production of 83Rb for the KATRIN experiment.

For the neutrino mass determination experiment KATRIN, the long-term stability of the spectrometer voltage is of crucial importance. Therefore, it is planned to control the voltage continuously in a smaller spectrometer, which monitors the position of the conversion electron line emitted in the 32 keV transition in the decay of (83m)Kr. Due to the short half-life of (83m)Kr (t(1/2)=1.83h), it has to be supplied by a long-lived (83m)Kr((83)Rb) generator (t(1/2)=86d). Here, a hitherto unexploited method for the efficient production of (83)Rb and its suitability for its application in the KATRIN monitor spectrometer is described.