This is best exemplified by the RCA Permanent-Magnet Electron Microscope, based on the work of John H. Reisner and collaborators.

“The permanent magnet as an energizing source for magnetic electron lenses is not new. The use of a permanent magnetic yoke for the comparatively coarse focusing of cathode-ray tubes has long been known. The advantages of permanent magnet lens energization are very appealing — excellent stability (beyond the ability of any regulator), no heating losses in energizing coils, no need for extensive current supplies and regulators — advantages which heretofore were limited to electrostatic lenses.”

The Paragon idea is that “die at once” exposure is the key to high-volume manufacturing with electron projection lithography. Anything that would “reduce system throughput and/or require registration of plural exposures” is forbidden.