| 摘要 |
PROBLEM TO BE SOLVED: To control the destination of gas flow from a plurality of gas sources by using a plurality of position valves.SOLUTION: At one valve position, gas is caused to flow to a separated vacuum system, and a flow rate and a mixture can be adjusted before introducing the gas to a sample vacuum chamber. At another valve position, previously mixed gas is caused to flow from the separated vacuum chamber into the sample vacuum chamber through a needle. |
