An object is to provide an electron gun that makes it possible to verify whether or not an electron beam emitted form a photocathode is misaligned from a designed emission center axis. The object can be achieved by an electron gun including: a light source; a photocathode; and an anode. The electron gun includes an intermediate electrode arranged between the photocathode and the anode, an electron beam shielding member configured to block a part of an electron beam, a measurement unit configured to measure an intensity of an electron beam blocked by the electron beam shielding member, and an electron beam emission direction deflector arranged between the anode and the electron beam shielding member and configured to change a position where an electron beam that passed through the anode reaches the electron beam shielding member. The intermediate electrode has an electron beam passage hole and a drift space.

An electron gun comprising a cathode having an electron emitting surface and whose planar shape is circular; a heater; an anode being arranged to oppose the cathode; and a heat resistant member. The anode applies a positive potential relative to the cathode to extract electrons in a predetermined direction. The cathode has, in a central portion thereof, a through hole along a central axis of the cathode. The heat resistant member has a first portion to close the through hole and a second portion being positioned between the cathode and the heater.

An electron gun comprising a cathode having an electron emitting surface and whose planar shape is circular; a heater; an anode being arranged to oppose the cathode; and a heat resistant member. The anode applies a positive potential relative to the cathode to extract electrons in a predetermined direction. The cathode has, in a central portion thereof, a through hole along a central axis of the cathode. The heat resistant member has a first portion to close the through hole and a second portion being positioned between the cathode and the heater.

An electron gun comprising a cathode having an electron emitting surface and whose planar shape is circular; a heater; an anode being arranged to oppose the cathode; and a heat resistant member. The anode applies a positive potential relative to the cathode to extract electrons in a predetermined direction. The cathode has, in a central portion thereof, a through hole along a central axis of the cathode. The heat resistant member has a first portion to close the through hole and a second portion being positioned between the cathode and the heater.

An electron gun comprising a cathode having an electron emitting surface and whose planar shape is circular; a heater; an anode being arranged to oppose the cathode; and a heat resistant member. The anode applies a positive potential relative to the cathode to extract electrons in a predetermined direction. The cathode has, in a central portion thereof, a through hole along a central axis of the cathode. The heat resistant member has a first portion to close the through hole and a second portion being positioned between the cathode and the heater.

An object is to provide an electron gun that makes it possible to verify whether or not an electron beam emitted form a photocathode is misaligned from a designed emission center axis. The object can be achieved by an electron gun including: a light source; a photocathode; and an anode. The electron gun includes an intermediate electrode arranged between the photocathode and the anode, an electron beam shielding member configured to block a part of an electron beam, a measurement unit configured to measure an intensity of an electron beam blocked by the electron beam shielding member, and an electron beam emission direction deflector arranged between the anode and the electron beam shielding member and configured to change a position where an electron beam that passed through the anode reaches the electron beam shielding member. The intermediate electrode has an electron beam passage hole and a drift space.

An object is to provide an electron gun that makes it possible to verify whether or not an electron beam emitted form a photocathode is misaligned from a designed emission center axis. The object can be achieved by an electron gun including: a light source; a photocathode; and an anode. The electron gun includes an intermediate electrode arranged between the photocathode and the anode, an electron beam shielding member configured to block a part of an electron beam, a measurement unit configured to measure an intensity of an electron beam blocked by the electron beam shielding member, and an electron beam emission direction deflector arranged between the anode and the electron beam shielding member and configured to change a position where an electron beam that passed through the anode reaches the electron beam shielding member. The intermediate electrode has an electron beam passage hole and a drift space.

An object of the present invention is to provide a charged particle beam device which can realize improved contrast of an elongated pattern in a specific direction, such as a groove-like pattern. In order to achieve the above-described object, the present invention proposes a charged particle beam device including a detector for detecting a charged particle obtained based on a charged particle beam discharged to a sample. The charged particle beam device includes a charged particle passage restricting member that has at least one of an arcuate groove and a groove having a longitudinal direction in a plurality of directions, and a deflector that deflects the charged particle discharged toward the groove from the sample. The charged particle discharged from the sample is deflected to a designated position of the groove.

Presented systems and methods facilitate efficient and effective monitoring of particle beams. In some embodiments, a radiation gun system comprises: a particle beam gun that generates a particle beam, and a gun control component that controls the gun particle beam generation characteristics, including particle beam fidelity characteristics. The particle beam characteristics can be compatible with FLASH radiation therapy. Resolution control of the particle beam generation can enable dose delivery at an intra-pulse level and micro-bunch level. The micro-bunch can include individual bunches per each 3 GHz RF cycle within the 5 to 15 sec pulse-width. The FLASH radiation therapy dose delivery can have a bunch level resolution of approximately 4.410{circumflex over ()}-6 cGy/bunch.