Heidelberg 1999 – scientific programme
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A: Atomphysik
A 18: Symposium Hochgeladene Ionen II Poster
A 18.17: Poster
Friday, March 19, 1999, 15:00–16:30, PY
REXTRAP/EBIS, ion accumulation, bunching and charge breeding for REX-ISOLDE — •P. Schmidt1, F. Ames1, J. Axelsson2, M. Björkhage2, G. Bollen3, P. Carlè2, O. Forstner3, G. Huber1, B. Jonson4, L. Liljeby2, G. Nyman4, M. Oinonen3, K-G. Rensfelt2, and F. Wenander3 — 1Institut für Physik, J. Gutenberg-Universität, D-55099 Mainz — 2MSL, Stockholm, Sweden — 3Cern, CH–1211 Geneva 23 — 4Chalmers University of Technology, Göteborg, Sweden
REX-ISOLDE, placed at the on line mass separator ISOLDE at CERN, is an experiment to post-accelerate radioactive ions up to an energy of 2.2 MeV/u. It consists of a Penning trap (REXTRAP), an electron beam ion source (REXEBIS) and a linear accelerator. This concept ensures an efficient and cost-effective post-acceleration.
In the REXTRAP the continuous beam of singly charged ions with an energy of 60 keV from ISOLDE is accumulated and cooled. The 90 cm long cylindrical trap is gas-filled and positioned in a 3 T magnetic field of a superconducting solenoid. After an electrostatic deceleration the ions are captured inside the trap and cooled by collisions with the buffer gas (p ≤ 10−3 mbar Ar). A capture efficiency of approximately 100 % is expected.
The ion bunches are transferred to REXEBIS where they are confined in an electron beam with a current density >200 A/cm2, and charge-bred to a q/A ≤ 1/4.5 within a breeding time <20 ms. The electron beam is compressed by a 2 T magnetic field created by a warm-bore superconducting solenoid. Before the ejection of the ions the REXEBIS potential is lowered to a potential of 20 kV to mat ch the requirements of the following linear accelerator.