A linear radiofrequency ion trap for accumulation, bunching, and emittance improvement of radioactive ion beams

An ion beam cooler and buncher has been developed for the manipulation of radioactive ion beams. The gas-filled linear radiofrequency ion trap system is installed at the Penning trap mass spectrometer ISOLTRAP at ISOLDE/CERN. Its purpose is to accumulate the 60-keV continuous ISOLDE ion beam with high efficiency and to convert it into low-energy low-emittance ion pulses. The efficiency was found to exceed 10% in agreement with simulations. A more than 10-fold reduction of the ISOLDE beam emittance can be achieved. The system has been used successfully for first on-line experiments. Its principle, setup and performance will be discussed

Kinematics of charge transfer: Ar^++H2

This is the publisher's version, also available electronically from http://scitation.aip.org/content/aip/journal/jcp/67/6/10.1063/1.435181.Product angular and velocity vector distributions have been measured in a crossed beam experiment for the charge transfer process Ar++H2→Ar+H2 + at relative collision energies of 0.13, 0.48, and 3.44 eV. Charge transfer was found to occur by two distinct mechanisms: (1) a simple electron‐jump mechanism which preserves the quasirectilinear trajectories of the colliding species and which selectively produces H2 + in the vibrational state most nearly resonant with the reactant ion, and (2) an intimate‐collision mechanism which results in large‐angle scattering and which produces H2 + in a broad range of vibrational states