The system includes a photocathode electron source, diffractive optical element, and a microlens array to focus the beamlets. A source directs a radiation beam to the diffractive optical element, which produces a beamlet array to be used in combination with a photocathode surface to generate an array of electron beams from the beamlets.

The present invention relates to a handheld material analyser comprising an air-tight chamber having an analysis aperture; an electron beam generation system adapted to direct a beam of electrons through the analysis aperture; an Energy-Dispersive X-ray (EDX) spectroscopy system having a detector located in the chamber; the chamber being adapted to operate at internal pressures between atmospheric pressure and a vacuum of the order of 1 Pa; and a gas inlet adapted to receive an inert gas for generating a plasma in the region of the photocathode. In this way, the plasma can clean the photocathode.

A photocathode structure, which can include one or more of Cs.sub.2Te, CsKTe, CsI, CsBr, GaAs, GaN, InSb, CsKSb, or a metal, has a protective film on an exterior surface. The protective film includes one or more of ruthenium, nickel, platinum, chromium, copper, gold, silver, aluminum, or an alloy thereof. The protective film can have a thickness from 1 nm to 10 nm. The photocathode structure can be used in an electron beam tool like a scanning electron microscope.

A transmission electron microscopy system for imaging a sample, comprising: a pulse generator for generating an initial electron pulse towards the sample, the initial electron pulse to be propagated through the sample to obtain a transmitted electron pulse; an encoding device for encoding the transmitted electron pulse according to a predefined pattern to obtain an encoded electron pulse; a shearing device for temporally shearing the encoded electron pulse in a given direction to obtain a given electron pulse; a detector for detecting the given electron pulse to obtain a single image of the sample; and a datacube generator for determining a spatiotemporal datacube from the single image using the predefined pattern, and outputting the spatiotemporal datacube.

System and method for Ultrafast Electron Diffraction (UED) and Microscopy (UEM) configured to image atomic motion in real time with sub-femtosecond temporal resolution. Presented methodology utilizes the interaction of the pump optical pulse with the initial electron pulse that has been gated with the gating optical pulse. The initial electron pulse is generated in the electron microscope by the pulse of auxiliary light. In one case, the pump and gating pulses have attosecond duration and are duplicates of one another. The use of attosecond optical pulse (with frequency spectrum extending over two octaves in the visible and flanking spectral ranges) for optical gating of a pulse of electrons.

A photocathode can include a body fabricated of a wide bandgap semiconductor material, a metal layer, and an alkali halide photocathode emitter. The body may have a thickness of less than 100 nm and the alkali halide photocathode may have a thickness less than 10 nm. The photocathode can be illuminated with a dual wavelength scheme.

Electron source designs are disclosed. The emitter structure, which may be silicon, has a layer on it. The layer may be graphene or a photoemissive material, such as an alkali halide. An additional layer between the emitter structure and the layer or a protective layer on the layer can be included. Methods of operation and methods of manufacturing also are disclosed.

The present invention relates to a handheld material analyser comprising an air-tight chamber having an analysis aperture; an electron beam generation system adapted to direct a beam of electrons through the analysis aperture; an Energy-Dispersive X-ray (EDX) spectroscopy system having a detector located in the chamber; the chamber being adapted to operate at internal pressures between atmospheric pressure and a vacuum of the order of 1 Pa; and a gas inlet adapted to receive an inert gas for generating a plasma in the region of the photocathode. In this way, the plasma can clean the photocathode.

A photocathode structure, which can include one or more of Cs.sub.2Te, CsKTe, CsI, CsBr, GaAs, GaN, InSb, CsKSb, or a metal, has a protective film on an exterior surface. The protective film includes one or more of ruthenium, nickel, platinum, chromium, copper, gold, silver, aluminum, or an alloy thereof. The protective film can have a thickness from 1 nm to 10 nm. The photocathode structure can be used in an electron beam tool like a scanning electron microscope.

The present invention addresses the problem of providing a sample inspection device and a sample inspection method, whereby noise is removed from a detection signal, and a generated electron beam is utilized effectively for inspection. A sample inspection device according to the present invention is provided with a light source for emitting frequency-modulated light, a photocathode for emitting an electron beam in response to receiving the frequency-modulated light, a detector for detecting electrons emitted from a sample irradiated by the electron beam and generating a detection signal, and a signal extractor for extracting a signal having a frequency corresponding to a modulation frequency of the frequency-modulated light from within the detection signal.