An emitter is configured to emit charged particles. The emitter comprises a body, a metal layer and a charged particle source layer. The body has a point. The metal layer is of a first metal on at least the point. The charged particle source layer is on the metal layer. The point comprises a second metal other than the first metal.

A charged particle beam source, such as for use in an electron microscope, can include a mounting member defining a first opening at a free end of the mounting member and a bore extending from the first opening into the mounting member along a longitudinal axis of the mounting member. A second opening can be defined in a side wall of the mounting member and can extend between an outer surface of the mounting member and the bore, the second opening being spaced apart from the first opening along the longitudinal axis of the mounting member. An emitter member can be received in the bore and aligned along the longitudinal axis of the mounting member. A fixative material can be received in the bore and in the second opening to retain the emitter member in the bore.

A system and method for injecting a medication, the system comprising an injection syringe comprising a sensor, an indicator light, and/or a digital meter. The sensor can be a blood vessel sensor, such as, a blood pressure sensor, a pressure sensor, and/or a RAMAN spectroscopy tool. The method can comprise, obtaining the syringe filled with a fluid, inserting the needle, checking the indicator, and based on the indicator, dispensing the fluid.

A charged particle beam source, such as for use in an electron microscope, can include an electrically conductive support member coupled to a base, a mounting member coupled to the support member and defining a bore, and an emitter member received in the bore and retained by a fixative material layer flowed around the emitter member in the bore.

An electron source has an insulating base, a pair of conductive terminals, an insulating support member, a drift isolation member, an emitter-cathode, and one or more heating elements. The conductive terminals are exposed from a first surface of the insulating base. The insulating support member extends from the first surface of the insulating base. The drift isolation member is disposed at an end of the insulating support member remote from the insulating base. The emitter-cathode is coupled to the drift isolation member. The one or more heating elements are coupled to the conductive terminals and the drift isolation member. The combination of the drift isolation member with the insulating support member can prevent stress-induced drift from impacting position of the emitter-cathode, thereby improving the mechanical stability of the electron source.

In one embodiment, a system includes a cathode and a thermionic emitter installed at least partially within the cathode tube of the cathode. The thermionic emitter is in a shape of a hollow cylinder. The hollow cylinder includes an outer surface and an unsmooth inner surface. The outer surface is configured to contact an inner surface of the cathode tube. The unsmooth inner surface includes a plurality of structures that provide an increase in surface area over a smooth surface.

A charged particle beam source, such as for use in an electron microscope, can include an electrically conductive support member coupled to a base, a mounting member coupled to the support member and defining a bore, and an emitter member received in the bore and retained by a fixative material layer flowed around the emitter member in the bore.

Electron emitters and method of fabricating the electron emitters are disclosed. According to certain embodiments, an electron emitter includes a tip with a planar region having a diameter in a range of approximately (0.05-10) micrometers. The electron emitter tip is configured to release field emission electrons. The electron emitter further includes a work-function-lowering material coated on the tip.

In one embodiment, a system includes a cathode and a thermionic emitter installed at least partially within the cathode tube of the cathode. The thermionic emitter is in a shape of a hollow cylinder. The hollow cylinder includes an outer surface and an unsmooth inner surface. The outer surface is configured to contact an inner surface of the cathode tube. The unsmooth inner surface includes a plurality of structures that provide an increase in surface area over a smooth surface.

Electron emitters and methods of fabricating the electron emitters are disclosed. According to certain embodiments, an electron emitter includes a tip with a planar region having a diameter in a range of approximately (0.05-10) micrometers. The electron emitter tip is configured to release field emission electrons. The electron emitter further includes a work-function-lowering material coated on the tip.