Multi Passage Spectrometer (MPS)
Since one of the future goals of MLLTRAP is to utilize highly-charged ions in mass measurements, a switch system is required in order to pass ions to a charge breeder and to re-inject them towards the experiment. A so-called multi-passage spectrometer (MPS), based on a magnetic 4-way beam bender, will be used for this purpose. The MPS will also serve as a q/A separator to select the desired charge state after the charge breeding and before the injection into the Penning traps.
Schematic layout of a 4-way multi-passage spectrometer.
The MPS consists of a of a fast-ramping, round-pole dipole magnet with a 4-way electrostatic mirror system (see figure). An ion beam injected from one of the beam directions can be reflected by 90 degree in the magnetic field of a field strength up to 1.2 T. Depending on the operation parameters of the electrostatic mirror system, an ion beam can be transported in three different directions. By choosing more than one passage through the system, the path length is increased and a higher resolution can be obtained in multi-passage operation. At present, the magnet system is installed at the MLL Lab and the electrostatic mirror system is being designed.
Photo of the MPS magnet system.
In order to measure a detailed map of the magnetic field strength distribution using a hall sensor, a 3D
automated scanning system for field mapping has been designed. It is based on three linear positioning
systems driven by stepper motors (see photograph below).
