The electron cooling device for the heavy ion storage ring TSR

This paper reports on an electron cooling system for the heavy ion storage ring TSR developed for electron energies of 3-20 keV according to the ion energies available in the first phase of operation of the TSR. The electron gun has a Pierce geometry and is immersed in a longitudinal magnetic field. By use of resonant focusing for acceleration it can deliver cold electron beams with variable gun perveance and small guiding magnetic field. Transverse energies smaller than 0.2 eV were calculated for magnetic fields below 600 G. A collector for the electron beam was designed and tested in a linear arrangement which showed an excellent current collection efficiency of up to 0.99999. Measurements of the magnetic confinement system which can be operated at a maximum field strength of 3 kG are in progress. First results indicate that the cooling solenoid was produced with a good field parallelity Bt/Bl ≤ 1.5 · 10-4