An interlockable panel for forming a generally planar surface. The holder defines an accommodation chamber. Furthermore, an examination for the simultaneous imaging and processing of an object is proposed which comprises, besides an electron microscopy system with the above-mentioned objective lens, also an ion beam processing system and an object support. The tantalum layer may have a body-centered cubic crystal structure. The first coaxial conductor is coupled to the second coaxial conductor, the second coaxial conductor is coupled to the third coaxial conductor; and the third coaxial conductor is coupled in use to a first termination impedance.