Abstract:
According to one embodiment, an X-ray tube includes an anode target, a cathode including a filament and a convergence electrode which includes a groove portion, and an envelope. The groove portion includes a pair of first bottom surfaces which are located in the same plane as the filament and between which the filament is interposed in a width direction of the groove portion, and a pair of second bottom surfaces between which the filament and the pair of first bottom surfaces are interposed in a length direction of the groove portion and which are located closer to an opening of the groove portion than the pair of first bottom surfaces.
Abstract:
An electron source is made from mixed-metal carbide materials of high refractory nature. Producing field-enhanced thermionic emission, i.e., thermal-field or extended Schottky emission, from these materials entails the use of a certain low work function crystallographic direction, such as, for example, (100), (210), and (310). These materials do not naturally facet because of their refractory nature. The disclosed electron source made from transition metal carbide material is especially useful when installed in a scanning electron microscope (SEM) performing advanced imaging applications that require a high brightness, high beam current source.
Abstract:
In the present invention, a cathode for an x-ray tube is formed with a large area flat emitter. To reduce the aberrations to a minimum the emission area in the flat emitter has a non-rectangular shape and focusing pads arranged around the emitter. In an exemplary embodiment, the flat emitter has a non-rectilinear polygonal shape for an emission area on the emitter in order to increase the emission current from the emitter at standard voltage levels without the need to run the emitters at a higher temperature, add additional emitters to the cathode and/or to coat the emitters with a low work function material.
Abstract:
A first array of spaced wires is in angular contact with a second array of spaced wires so as to from a wire mesh. The first array has a fewer number of wires than the second array.
Abstract:
In the present invention, a cathode (60) for an x-ray tube (12) is formed with a large area flat emitter (55). To reduce the aberrations to a minimum, the emission area (237) in the flat emitter (55) has a non-rectangular shape and focusing pads (85) arranged around the emitter (55). In an exemplary embodiment, the flat emitter (55) has a non-rectilinear polygonal shape for an emission area (237) on the emitter (55) in order to increase the emission current from the emitter (55) at standard voltage levels without the need to run the emitters (55) at a higher temperature, add additional emitters (55) to the cathode (60) and/or to coat the emitters (55) with a low work function material.
Abstract in simplified Chinese:描述用于利用电子束检查样品的电子束设备。电子束设备包括电子束源,电子束源包括热场发射器,热场发射器包括具有发射刻面以及第一侧刻面与第二侧刻面的发射器尖端,发射刻面经配置以用于电子发射,其中发射刻面具有发射刻面宽度,其中边缘刻面系形成于第一侧刻面与第二侧刻面之间,边缘刻面具有边缘刻面宽度。边缘刻面宽度系在发射刻面宽度的20%与40%之间。电子束源进一步包括提取器设备与加热设备,加热设备用于加热热场发射器。电子束设备进一步包括电子束光学组件与侦测器设备,侦测器设备用于侦测在初级电子束碰撞或撞击至样品上而产生的次级带电粒子。