CONCEPT OF A HIGH-RESOLUTION ONLINE MASS SEPARATOR FOR THE MUNICH FISSION FRAGMENT ACCELERATOR

A fission fragment accelerator combined with the Munich high-flux reac tor FRM-II is under design for the delivery of intense beams of mass s eparated very neutron-rich fission fragments with energies at the Coul omb barrier They can be used to produce very heavy neutron-rich nuclei in fusion reactions. The large neutron excess will result in much lon ger lifetimes of the produced heavy elements, compared to neutron-defi cient ones produced in reactions with stable nuclear beams. Thus fast a-chains can no longer be used to identify the heavy reaction products . A new separator will be used consisting of a velocity filter, an ion guide system (IGISOL) and a Penning trap. The velocity filter separat es the primary beam and results in a strong background suppression. Th e IGISOL system improves the emittance and enriches the 1(+) ions in t he beam, which will then be efficiently transferred into a Penning tra p. In the Penning trap the ions are bunched, stopped and mass separate d with high resolving power (R approximate to 10(5)).