Embodiments include a vacuum device, comprising: an enclosure configured to enclose a vacuum, comprising an external base forming at least a portion of the enclosure; an internal base within the enclosure; and at least one thermal dissipative strap assembly, comprising: an internal base thermal conductive base in contact with the internal base, an external base thermal conductive base in contact with the external base, and a flexible thermal dissipative strap coupling the internal base thermal conductive base to the external base thermal conductive base.

Embodiments include a vacuum device, comprising: an enclosure configured to enclose a vacuum, the enclosure including an external base including an opening; an internal base within the enclosure; and an adjustable support assembly adjustably coupling the internal base to the external base and extending through the opening, the adjustable support assembly comprising: a threaded shaft extending along a longitudinal axis and coupled to the internal base; a threaded hole component threadedly engaged with the threaded shaft and coupled to the external base such that the threaded hole component is axially constrained in a direction along the longitudinal axis relative to the external base independent of the threaded shaft; and a flexible component coupled to the external base and the threaded shaft and sealing the opening.

A tunneling electro source, an array thereof and methods for making the same are provided. The tunneling electron source is a surface tunneling micro electron source having a planar multi-region structure. The tunneling electron source includes an insulating substrate, and two conductive regions and one insulating region arranged on a surface of the insulating substrate. The insulating region is arranged between the two conductive regions and abuts on the two conductive regions. Minimum spacing between the two conductive regions, which equals to a minimum width of the insulating region, is less than 100 nm.

Example compact modular electron beam units are provided that can be used to generate electron beams using field emitter elements. A modular electron beam unit may comprise an electron beam source including a base portion, at least one field emitter element coupled to the base portion, the field emitter element including a field emitter tip, at least one gate electrode and a membrane window disposed over the at least one gate electrode.

Embodiments include a vacuum device, comprising: an enclosure configured to enclose a vacuum, comprising an external base forming at least a portion of the enclosure; an internal base within the enclosure; and at least one thermal dissipative strap assembly, comprising: an internal base thermal conductive base in contact with the internal base, an external base thermal conductive base in contact with the external base, and a flexible thermal dissipative strap coupling the internal base thermal conductive base to the external base thermal conductive base.

Embodiments include a vacuum device, comprising: an enclosure configured to enclose a vacuum, the enclosure including an external base including an opening; an internal base within the enclosure; and an adjustable support assembly adjustably coupling the internal base to the external base and extending through the opening, the adjustable support assembly comprising: a threaded shaft extending along a longitudinal axis and coupled to the internal base; a threaded hole component threadedly engaged with the threaded shaft and coupled to the external base such that the threaded hole component is axially constrained in a direction along the longitudinal axis relative to the external base independent of the threaded shaft; and a flexible component coupled to the external base and the threaded shaft and sealing the opening.

The present disclosure provides for various advantageous methods and apparatus of controlling electron emission. One of the broader forms of the present disclosure involves an electron emission element, comprising an electron emitter including an electron emission region disposed between a gate electrode and a cathode electrode. An anode is disposed above the electron emission region, and a voltage set is disposed above the anode. A first voltage applied between the gate electrode and the cathode electrode controls a quantity of electrons generated from the electron emission region. A second voltage applied to the anode extracts generated electrons. A third voltage applied to the voltage set controls a direction of electrons extracted through the anode.