Abstract: A protective cap for a medical device comprising two cap parts, an inner and an outer cap part, which two cap parts can be assembled, one inside the other, to form a single integrated cap. When assembled, the inner and outer cap parts have a gap in-between, where a user defined object can be inserted. Interlocking means are provided to hold the cap parts together, and seals can be provided to assure a tight enclosure. Elevations may be provided to locally narrow the gap between the two cap parts in order to hold the inserted object in place and a template may be provided to cut out the objects to be inserted in appropriate dimensions. The outer cap part may be transparent to make the inserted object visual, whereas the inner cap part may be impenetrable by light, to protect the medical device.

Abstract: A mass spectrometer (MS) which uses the Fourier transform ion cyclotron resonance (FTICR) technique to determine the mass of ions. The MS is prepared with a surface that guarantees that a particle striking the surface will have at least one contact with the cathode and will most likely be re-pumped before escaping into the vacuum chamber volume.