An apparatus includes: a structure having a lumen for accommodating a beam, wherein the structure is a component of a medical radiation machine having a target for interaction with the beam to generate radiation; and a first beam position monitor comprising a first electrode and a second electrode, the first electrode being mounted to a first side of the structure, the second electrode being mounted to a second side of the structure, the second side being opposite from the first side; wherein the first beam position monitor is located upstream with respect to the target.

Provided is a field emission device including a cathode electrode and an anode electrode, which are spaced apart from each other, an emitter disposed on the cathode electrode, a gate electrode disposed between the cathode electrode and the anode electrode and including a gate opening that overlaps the emitter, and a plurality of alignment electrodes disposed between the gate electrode and the cathode electrode. Here, the alignment electrodes surround a side surface of the emitter.

A high-power vacuum electron device source of 10 mm-0.1 mm wavelength radiation is composed of an electron gun joined to a RF vacuum electronic circuit. The electron gun includes a cathode, a focus electrode, and a grid. It generates an electron beam that is injected into the circuit for amplifying RF waves. The circuit is composed of metal circuit plates, e.g., copper alloy, that mate with each other and are shaped to provide a beam tunnel and RF circuit envelopes. Precision alignment pins made of nickel super alloy, are used to mutually align the metal circuit plates using elastic averaging implemented by positioning the precision alignment pins in precision alignment holes in the metal circuit plates. Preferably, the electron gun is aligned with the circuit using quasi-kinematic coupling.

A high-power vacuum electron device source of 10 mm-0.1 mm wavelength radiation is composed of an electron gun joined to a RF vacuum electronic circuit. The electron gun includes a cathode, a focus electrode, and a grid. It generates an electron beam that is injected into the circuit for amplifying RF waves. The circuit is composed of metal circuit plates, e.g., copper alloy, that mate with each other and are shaped to provide a beam tunnel and RF circuit envelopes. Precision alignment pins made of nickel super alloy, are used to mutually align the metal circuit plates using elastic averaging implemented by positioning the precision alignment pins in precision alignment holes in the metal circuit plates. Preferably, the electron gun is aligned with the circuit using quasi-kinematic coupling.

A high-power vacuum electron device source of 10 mm-0.1 mm wavelength radiation is composed of an electron gun joined to a RF vacuum electronic circuit. The electron gun includes a cathode, a focus electrode, and a grid. It generates an electron beam that is injected into the circuit for amplifying RF waves. The circuit is composed of metal circuit plates, e.g., copper alloy, that mate with each other and are shaped to provide a beam tunnel and RF circuit envelopes. Precision alignment pins made of nickel super alloy, are used to mutually align the metal circuit plates using elastic averaging implemented by positioning the precision alignment pins in precision alignment holes in the metal circuit plates. Preferably, the electron gun is aligned with the circuit using quasi-kinematic coupling.

A high-power vacuum electron device source of 10 mm-0.1 mm wavelength radiation is composed of an electron gun joined to a RF vacuum electronic circuit. The electron gun includes a cathode, a focus electrode, and a grid. It generates an electron beam that is injected into the circuit for amplifying RF waves. The circuit is composed of metal circuit plates, e.g., copper alloy, that mate with each other and are shaped to provide a beam tunnel and RF circuit envelopes. Precision alignment pins made of nickel super alloy, are used to mutually align the metal circuit plates using elastic averaging implemented by positioning the precision alignment pins in precision alignment holes in the metal circuit plates. Preferably, the electron gun is aligned with the circuit using quasi-kinematic coupling.

Provided is a field emission device including a cathode electrode and an anode electrode, which are spaced apart from each other, an emitter disposed on the cathode electrode, a gate electrode disposed between the cathode electrode and the anode electrode and including a gate opening that overlaps the emitter, and a plurality of alignment electrodes disposed between the gate electrode and the cathode electrode. Here, the alignment electrodes surround a side surface of the emitter.

An apparatus includes: a structure having a lumen for accommodating a beam (e.g., electron beam, proton beam, or a charged particle beam), wherein the structure is a component of a medical radiation machine having a target for interaction with the beam to generate radiation; and a first beam position monitor comprising a first electrode and a second electrode, the first electrode being mounted to a first side of the structure, the second electrode being mounted to a second side of the structure, the second side being opposite from the first side; wherein the first beam position monitor is located upstream with respect to the target.

An apparatus includes: a structure having a lumen for accommodating a beam (e.g., electron beam, proton beam, or a charged particle beam), wherein the structure is a component of a medical radiation machine having a target for interaction with the beam to generate radiation; and a first beam position monitor comprising a first electrode and a second electrode, the first electrode being mounted to a first side of the structure, the second electrode being mounted to a second side of the structure, the second side being opposite from the first side; wherein the first beam position monitor is located upstream with respect to the target.