Christopher Geppert

TRIGA-SPEC: A setup for mass spectrometry and laser spectroscopy at the research reactor TRIGA Mainz

Abstract The research reactor TRIGA Mainz is an ideal facility to provide neutron-rich nuclides with production rates sufficiently large for mass spectrometric and laser spectroscopic studies. Within the TRIGA-SPEC project, a Penning trap as well as a beamline for collinear laser spectroscopy are being installed. Several new developments will ensure high sensitivity of the trap setup enabling mass measurements even on a single ion. Besides neutron-rich fission products produced in the reactor, also heavy nuclides such as 235 U or 252 Cf can be investigated for the first time with an off-line ion source. The data provided by the mass measurements will be of interest for astrophysical calculations on the rapid neutron-capture process as well as for tests of mass models in the heavy-mass region. The laser spectroscopic measurements will yield model-independent information on nuclear ground-state properties such as nuclear moments and charge radii of neutron-rich nuclei of refractory elements far from stability. TRIGA-SPEC also serves as a test facility for mass and laser spectroscopic experiments at SHIPTRAP and the low-energy branch of the future GSI facility FAIR. This publication describes the experimental setup as well as its present status.

A novel scheme for a highly selective laser ion source

A new type of resonance ionization laser ion source, which shall combine the advantages of a laser ion source with those of an ion trap, is proposed. The primary purpose of such a laser ion source trap, which is based on a gas-filled linear radio-frequency quadrupole ion trap system, is the decoupling of evaporation and ionization processes. Furthermore optimum temporal control on the generated ion bunch is obtained. Both effects will lead to a significantly increased isobaric selectivity and ion beams of low emittance. A large variety of operational modes, ranging from quasi-dc to microseconds-bunched radioactive ion beams with variable pulse width and repetition rate, can be chosen freely and beam energies can easily be altered. The principles and the layout of LIST will be discussed on the basis of atom and ion trajectory simulations and resulting performance parameters.

Nuclear spins, magnetic moments, and quadrupole moments of Cu isotopes from N = 28 to N = 46: Probes for core polarization effects

Measurements of the ground-state nuclear spins and magnetic and quadrupole moments of the copper isotopes from

High precision hyperfine measurements in Bismuth challenge bound-state strong-field QED

^{61}\mathrm{Cu}

An improved value for the hyperfine splitting of hydrogen-like 209Bi82+

up to

First observation of the ground-state hyperfine transition in 209Bi80+

^{75}\mathrm{Cu}

Temporal Control of Pulses from a High-Repetition-Rate Tunable Ti:Sapphire Laser by Active Q-switching

are reported. The experiments were performed at the CERN online isotope mass separator (ISOLDE) facility, using the technique of collinear laser spectroscopy. The trend in the magnetic moments between the

Comment on: “Lorentz violation in high-energy ions” by Santosh Devasia

N=28

Total angular momenta of even-parity autoionizing levels and odd-parity high-lying levels of atomic uranium

and

SPARC experiments at the high-energy storage ring

N=50