Abstract: An electromagnetic switching apparatus includes a contact block to be inserted in an electric path, an electromagnet block for driving the contact block, the electromagnet block being configured to drive the contact block to close the electric path so as to become conductive when an excitation current is supplied from outside, a normally-closed type switch member inserted in a supply path of the excitation current, an acquisition unit configured to obtain an impact detection signal from an impact sensor that is configured to detect an impact, and a control unit configured, based on the impact detection signal obtained by the acquisition unit, to turn off the switch member so as to break the supply path when the impact sensor detects an impact of which magnitude is larger than a predetermined threshold.

Abstract: A standing-wave accelerating structure for accelerating charged particles wherein a converging force and a diverging force of an electric field to an electron beam are checked to improve the transmittivity of the electron beam through the accelerating structure and production of X-ray leakage is eliminated or minimized. The accelerating structure comprises a buncher section including at least one cavity for mainly bunching charged particles, and a regular section including at least one cavity. The diameter of a bore in the buncher section is smaller than the diameter of another bore in the regular section. A shorting bar for stopping propagation of microwaves is inserted in at least one of the cavities, and a means for accelerating the charged particles and for converging a beam is provided forwardly or rearwardly of the cavity in which the shorting bar is inserted.