| 摘要 |
A dish-shaped dispenser cathode (28) is mounted at one end of a cathode housing (10), with a heater wire coil (42) mounted behind the cathode (28). A warm-up power supply (70) electrically connected between the central region and the periphery of the cathode (28) causes heating current to flow through the cathode (28) during a short period of time at the start of cathode operation to provide rapid warm-up of the cathode (28). A sustaining power supply (76) electrically connected between the respective ends of the heater wire coil (42) causes sustaining current to flow through the heater wire coil (42) to provide sustaining heat to the cathode (28) by radiation from the heater coil (42) to maintain the cathode (28) at its desired operating temperature. |
