Abstract: An improved crucible cover for multiple pocket electron beam sources has been invented. The invention provides selection between one of the multiple pockets for evaporative heating and a noncontacting, line-of-sight blocking baffle between heated and unheated pockets. In one embodiment, the baffle is formed by the cooperation of a crucible surface groove with a cover feature that extends into the groove. In a second embodiment, the baffle is formed by a barrier extending upwards from the crucible surface between pockets that cooperates with a cover to form the line-of-sight baffle. The crucible and cover in these embodiments accommodate deposits without hindering the ability of the baffle to reduce contamination or interfere with the operation of the source. Additionally, the cover and crucible may be operated separately, with a cover lifting mechanism that lowers the cover to form a baffle and raises the cover to allow the separately controlled rotation of the crucible.