Electron cyclotron resonance ion trap: A hybrid magnetic system with very high mirror ratio for highly charged ion production and trapping

In the Paul Scherrer Institute [PSI Switzerland] an experimental program wa s started to measure the ground state shift and width of pionic hydrogen. T o calibrate the crystal spectrometer x-ray transitions in hydrogen-like hea vy ions (e.g., Ar17+), produced by electron cyclotron resonance (ECR) ion s ources, are necessary. In PSI a superconducting cyclotron trap magnet, orig inally developed for particle physics experiments, will be transformed into an ECR ion trap (ECRIT). The SC magnet can deliver more than 4 T magnetic fields with a mirror ratio of 2. A careful calculation showed this mirror r atio can be increased upto 10 and the trap can operate with frequencies bet ween 5 and 20 GHz. To form a closed resonance zone an open structure NdFeB hexapole will be applied. The first tests will be performed at 6.4 GHz. Lat er higher frequencies and the two-frequency heating (6.4+10, 6.4+14.5, or 1 0+14.5 GHz) are planned to be applied to get enough quantity of H-like heav y ions. The ECRIT will operate at ground potential while a simple 90 degree s beamline (at negative potential) will help the fine tuning of the plasma for very high charge states. <(C)> 2000 American Institute of Physics.