RF Mass Filter and Diagnostics Unit
MLLTRAP is a double Penning trap system presently in its commissioning phase at the MLL, designed for high accuracy nuclear mass measurements of exotic species. While the trap system is presently operated offline, it is planned to connect it to the Tandem accelerator beamline in order to receive fusion products from nuclear reactions. In order to accomodate the acceptance requirements of the trapping potential, the energetic reaction products need to be thermalized in a buffer gas stopping cell, which is already operational (MLL IonCatcher). Optimizing the injection condition into the trap or any other subsequent component like a charge breeder or a multi-reflection time-of-flight mass spectrometer (MRTOF, as already developed as a prototype at the University of Giessen in the group of W. Plass) for isobaric purification outside the trap system, a diagnostics of the ions extracted from the gas cell is mandatory. Moreover, it is also desirable to add mass selectivity to the injection beam line prior to the ion transfer e.g. to the MRTOF and the Penning traps. Therefore a quadrupole mass separator (QMS) together with an in-line diagnostics unit was designed in collaboration with the Giessen group of W. Plass and set up behind the extraction radiofrequency quadrupole (RFQ) of the buffer gas cell. The picture shows a photograph of the two new components on their support stand.
Photograph of the newly developed diagnostics unit and quadrupole mass separator designed to be positioned behind the existing buffer gas stopping cell in the MLLTRAP beam line.