| 摘要 |
PURPOSE: Gas is supplied to a laser by using two pumps at the starting time and during the operation of a laser respectively. CONSTITUTION: At the start of a laser operation, a gas discharge chamber 16 is exhausted by a first pump P1 with a relatively large suction function but with a short maintenance life time. When a laser is started, the second pump P2 with a relatively small suction function but a long maintenance life time discharges, in order to have a constant pressure of laser operating gas of a gas discharge chamber 16. |
