Further, the present specification is directed towards personnel screening systems comprising modular components, including detector and source units, where a dual axis scanning beam is employed. In one configuration, the subject under inspection remains stationary and is positioned between two scanning modules. The X-ray source assembly is designed to minimize the overall system footprint while still yielding the requisite field of view, low radiation exposure level, and required resolution. The modular components allow for a compact, light and yet sufficiently rugged overall structure that can be disassembled for ease of transportation and is also simple to reassemble at a required site for inspection.