Patent ID: 11361956

Abstract:
Inside a chamber (10) evacuated by a vacuum pump, a flight tube (12) is held via a support member (11) that is of insulation. The outside of the chamber (10) is surrounded by a temperature control unit (16) including a heater. A body (10a) of the chamber (10) is made of aluminum, and a coating layer (10b) by a black nickel plating is formed on the inner wall surface of the body (10a) of the chamber (10). Due to this, the radiation factor of the chamber (10) becomes higher than that of a conventional apparatus using only aluminum, and the thermal resistance of the radiation heat transfer path between the chamber (10) and the flight tube (12) becomes low, thus improving the temperature stability of the flight tube (12). Furthermore, the time constant of the temperature change of the flight tube (12) becomes small, thus reducing the time for the flight tube (12) to stabilize to a constant temperature.