| 摘要 |
A vacuum chamber (1), wherein an emitter (3) and a target (7) are disposed so as to face each other, and a guard electrode (5) is provided on the outer periphery side of an electron generation unit (31) of the emitter (3). The emitter (3) is supported by a support part (4) so as to be movable in both-end directions of the vacuum chamber (1). A reforming treatment is performed on the guard electrode (5) by operating the support part (4), moving the emitter (3) to the side towards an opening (21) (i.e., to a non-discharge position), producing a state in which field emission by the electron generation unit (31) is suppressed, and applying a voltage to the guard electrode (5) to perform discharging repeatedly. After the reforming treatment, the support part (4) is again operated, the emitter (3) is moved to the side towards an opening (22) (i.e., to a discharge position), and a state in which the electron generation unit (31) can perform field emission is produced. |
