Abstract: An ion implantation system for producing silicon wafers having relatively low defect densities, e.g., below about 1×106/cm2, includes a fluid port in the ion implantation chamber for introducing a background gas into the chamber during the ion implantation process. The introduced gas, such as water vapor, reduces the defect density of the top silicon layer that is separated from the buried silicon dioxide layer.

Abstract: In a breakaway trailer brake activating mechanism mounted on a trailer surge brake actuator, one end of a tension coil spring is attached to the breakaway activating mechanism while the other end of the spring is connected to an intermediate link on a breakaway chain. The connection is such that a surplus, predetermined number of breakaway chain links, forming a slack section of the breakaway chain, are connected between the ends of the spring. The spring prevents the slack section of the breakaway chain connected between the ends of the spring from being pulled tight so as to allow for tow vehicle turns even if the breakway chain is incorrectly secured. Thus, during a sharp turn of the tow vehicle, the spring will allow the reserve links of the slack section of chain to extend but not so far as to cause the trailer brake to be activated.

Abstract: A locking mechanism for a trailer coupler such as a ball and socket coupler having a release handwheel. The locking mechanism includes a shelf which in one embodiment, surrounds the handwheel to prevent accidental or unauthorized rotation of the release handwheel. In other embodiments, the shelf covers or abuts the handwheel. A padlock may be used to lock the locking shelf in position.