Patent ID: 7928381

Claim:
A charge particle energy analyzer, comprising: an electrostatic and non-magnetic lens arranged coaxially about a central axis for angularly focusing charged particles received from a sample disposed on the central axis onto an output and including a plurality of axially arranged and selectively and differentially electrically biasable electrodes capable of controlling an energy of the focused particles; a biasable iris having a central aperture through which the central axis extends from the sample, which is positioned on the output of the electrostatic lens, and through which the lens focuses the charged particles; an electrostatic and non-magnetic high-pass filter arranged coaxially about the central axis receiving the charged particles from the iris and rejecting those of the charged particles having an energy below a first energy; an electrostatic and non-magnetic low-pass filter arranged coaxially about the central axis receiving the charged particles not rejected by the high-pass filter and rejecting those of the charged particles having an energy above a second energy; and a charged particle detector receiving the charged particles not rejected by the low-pass filter.