A charged particle gun for a charged particle beam device is described. The charged particle gun includes a gun housing; an emitter provided in the gun housing, the emitter being configured to emit a charged particle beam along an axis; an emitter power supply connected to the emitter; a trapping electrode provided in the gun housing, the trapping electrode at least partially surrounding the axis; a trapping power supply connected to the trapping electrode; and a shielding element shielding an electrostatic field of the trapping electrode from the axis during operation of the gun housing.

A charged particle gun for a charged particle beam device is described. The charged particle gun includes a gun housing; an emitter provided in the gun housing, the emitter being configured to emit a charged particle beam along an axis; an emitter power supply connected to the emitter; a trapping electrode provided in the gun housing, the trapping electrode at least partially surrounding the axis; a trapping power supply connected to the trapping electrode; and a shielding element shielding an electrostatic field of the trapping electrode from the axis during operation of the gun housing.

A method of operating a charged particle gun is described. The method includes providing an emitter at a first emitter potential within the charged particle gun and providing a trapping electrode at a first electrode potential within the charged particle gun, wherein the first emitter potential and the first electrode potential is provided to have an electrical field of essentially zero at the emitter and at the trapping electrode; switching the trapping electrode from the first electrode potential to a second electrode potential different from the first electrode potential to generate an electrostatic trapping field at the trapping electrode; and after switching the trapping electrode from the first electrode potential to the second electrode potential, switching on an electrostatic emission field at the emitter.