This invention comprises a new deflection structure which deflects a beam of charged particles, such as an electron beam, includes a serpentine set for transmitting a deflection field, and shielding frame for housing the serpentine set. The serpentine set includes a vertical serpentine deflection element and a horizontal serpentine deflection element. These deflection elements are identical and are interdigitatedly and orthogonally disposed relative to each other, for forming a central transmission passage, through which the electron beam passes and is deflected by the deflection field to minimize drift space signal distortion. The shielding frame includes a plurality of ground blocks and forms an internal serpentine trough within these ground blocks for housing the serpentine set. The deflection structure further includes a plurality of feedthrough connectors which are inserted through the shielding frame and which are electrically connected to the serpentine set.

This invention is an apparatus for use in 100% leak testing of food containers used in conjunction with a tracer gas. It includes a shell with entrance and exit air locks to create a controlled atmosphere through which a series of containers is conveyed by a conveyor belt. Pressure in the shell is kept lower than that in the containers and the atmosphere is made to flow with the containers so that a tracer gas placed in the packages before sealing them will leak more readily, but the leaked tracer gas will remain associated with the leaking package as it moves through the shell. The leaks are detected with a sniffer probe in fluid communication with a gas chromatograph (GC). The GC issues a signal when it detects a leak to an ejector that eject the leaking container from the conveyor. The system is timed so that the series of containers can move continuously into and out of the shell, past the probe and the ejector, without stopping, yet each package is tested for leaks and removed if leaking.