Streak tube

:

• A streak tube comprising:
• a container including an incident panel and an output panel;
• a photocathode provided in the container and configured to emit electrons in response to light to be measured incident from the incident panel;
• a sweep electrode provided in the container and including a pair of plate-shaped electrodes facing each other in a sweep direction along the output panel, the sweep electrode being configured to deflect the electrons in the sweep direction;
• a plurality of electrodes provided between the photocathode and the sweep electrode and forming an electron lens that focuses the electrons, each of the plurality of electrodes being provided with an opening portion through which the electrons pass;
• a controller configured to control a potential applied to the sweep electrode and a potential applied to at least one of the plurality of electrodes;
• a first slit member provided between the electron lens and the sweep electrode and having a first slit having a width smaller than a width of the opening portion of each of the plurality of electrodes in the sweep direction;
• and
• a second slit member provided between the electron lens and the incident panel and having a second slit having a width smaller than a width of the opening portion of each of the plurality of electrodes in the sweep direction,
• wherein the controller controls a potential applied to the sweep electrode, at a start of sweeping by the sweep electrode, to apply a positive potential to a first plate-shaped electrode, which is one of the pair of plate-shaped electrodes, and to apply a negative potential to a second plate-shaped electrode, which is the other of the pair of plate-shaped electrodes,
• a center of the first slit in the sweep direction is disposed at a position spaced apart from a center plane passing through a center of the electron lens and orthogonal to the sweep direction toward a side on which the first plate-shaped electrode is positioned, and
• a center of the second slit in the sweep direction is disposed at a position spaced apart from the center plane toward a side on which the second plate-shaped electrode is positioned.