Der Ionenspeicherring TSR für REX-ISOLDE am CERN
The heavy ion storage ring TSR was constructed at the Max-Planck-Institut für Kernphysik in Heidelberg in order to perform accelerator, atomic and molecular physics experiments and it has been in operation since 1988. The ring has a circumference of 55.4m and a maximum rigidity of 1.5 Tm. The TSR receives heavy ions from a 12 MV tandem van de Graaff and a normal conducting linac combination. The overview of the lattice of the storage ring is shown in the figure below. Each of the four symmetric focusing periods consists of two 45° dipole magnets, five quadrupole magnets and three sextupole magnets. The straight sections between the 90° bends are 5.2 m long and contain the injection and extraction elements, electron cooler, experimental section and the RF-resonator and diagnostics elements. For both injection and extraction the same electrostatic septum is used, being located in the first straight section. The electron cooler delivers an intensive cold electron beam with densities up to 1.0E8 cm-3. Phase space compression of ion beams by electron cooling leads to ion beams with extreme small horizontal and vertical emittance of about 0.05 π mm mrad. The electron cooler is also used as an electron target for atomic and molecular physics experiments. For molecular and atomic ions, recombination measurements at variable electron energies can be performed with the electron beam of the cooler. A merged-beam arrangement of an electron , ion and photon beam offers favourable conditions for laser-induced recombination experiments. The next straight section is used for laser cooling experiments , where the laser beam is merged with the ion beam. Laser cooling can be applied to a selected number of heavy ion species and is by far the most efficient longitudinal cooling technique. It offers the possibility to study beam dynamics at very high phase space densities. The RF resonator located in the last straight section was developed in order to accelerate and decelerate the ion beam.