42results about How to "Improve launch stability" patented technology

The method comprises: setting the data electrode on the glass cathode baseboard; on the data electrode, setting the dielectric layer with a horizontal bar shape and perpendicular with the data electrode; on the dielectric layer, setting the row scanning electrode; on the row scanning electrode, setting the connection electrode parallel with the data electrode; at the gap between the connection electrode and the row scanning electrode, setting a field emission material with a certain resistance property; on the glass cathode base board and the dielectric layer, setting the supporter; on the supporter, setting a anode glass baseboard; on the lower surface the glass anode baseboard, setting the anode electrode; on the lower surface of the anode electrode, setting a fluorescent powder layer.

The invention provides a cathode of a cold-cathode X-ray tube. The cathode of the cold-cathode X-ray tube comprises a cathode base and a grid electrode, wherein the cathode base is composed of an upper cylinder and a lower cylinder which are coaxially arranged, the section of the cathode base is in an inverted-T shape, a cathode bar through hole is formed in the central axis of the cathode base, a cathode bar is arranged in the through hole, the three-dimensional size of the cathode bar can be controlled, an electron emitter is arranged on a cathode head, the grid electrode is of an cup-shaped structure, an inverted-T-shaped groove which is matched with the cathode base is formed inside the grid electrode, the cathode base can be embedded in the groove of the grid electrode and does not make contact with the inner wall of the grid electrode, and a semi-conical electron transmission hole used for focusing electrons emitted by the cathode is formed in the center of the grid electrode. According to the cathode of the cold-cathode X-ray tube, the cold cathode made of carbon nanomaterials is used as the X-ray tube of an electron emission source, and preparation of the cathode and the emission area can be effectively controlled through the size of the cathode bar; the three-pole structure is adopted, a small focus point can be obtained through focusing of the grid electrode, and the resolution ratio of X-ray imaging is increased.

The invention discloses a lanthanum-carbide-tungsten hot cathode material and a preparation method thereof, belonging to the technical field of cathode materials of refractory metals. The lanthanum-carbide-tungsten hot cathode material is characterized by containing La2C3 and metallic tungsten powder, wherein the content of lanthanum carbide accounts for 5%-20% of the total weight of the material. The preparation method comprises the following steps of: mixing lanthanum hydride powder and graphite powder with the mass ratio of 8: 1 uniformly under protection of argon atmosphere, putting the mixture in a vacuum furnace, heating to 1200 DEG C, preserving the heat for 30 minutes and obtaining a product La2C3; mixing the prepared La2C3 and the tungsten powder uniformly in vacuum by using a ball milling method, then putting the powder in a grinding tool and using ion sintering methods such as discharging and the like to carry out sintering; and adopting a locomotive processing method to prepare the needed cathode. In the lanthanum-carbide-tungsten hot cathode material, the preparation process is simple, the heat emission performance is good and the emission stability is good.

A method for improving performance of carbon nanotube film electronic field emission by electrophoresis deposit means includes plating transition metal film on conductive substrate material by physical gas phase depositing process, utilizing plated conductive substrate as cathode to deposit carbon nanotube film on said cathode through electrophoresis depositing process and carrying out annealing treatment on cathode deposited with carbon nanotube film for raising field emission current density.