An imaging apparatus includes a laser to generate a single-mode laser beam of energy, a multichannel spatial light modulator accepting a plurality of modulating signals, and a beam multiplier between the radiation source and the SLM. The predetermined distance is configured such that the frame functions as an extension of a deflector and an operating temperature of the test specimens is shielded from external influences. The system includes a skimmer element having a skimmer orifice arranged to receive the sample ions from the first vacuum chamber into a second vacuum chamber where the skimmer orifice is of a first size.