| 摘要 |
A gas injection system employs a crucible having a plurality of cylindrical bores within which gas is generated and a central passage leading to a dispensing nozzle. A chamber between the crucible bores and the central passage is sealed by a flexible membrane which is centrally clamped to a valve actuating rod that can be moved longitudinally via flexure of the membrane. A region behind the flexible membrane is sealed and vented to the system vacuum chamber whereby the enclosure within which the gas is generated is isolated.
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