NOVEL FIELD EMISSION ELECTRON SOURCE

A NOVEL DIAMOND-LIKE CARBON COATING HAS BEEN DEVELOPED THAT HAS AN EXTREMELY LOW WORK FUNCTION. USING A PROPRIETARY DEPOSITION METHOD, THIS MATERIAL CAN BE COATED ON A VARIETY OF METAL AND CERAMIC PARTS. THIS PROJECT TESTS THE APPLICABILITY OF THIS MATERIAL FOR USE AS A COLD FIELD EMISSION SOURCE OF ELECTRONS TO REPLACE HOT FILAMENTS IN ELECTRON GUNS. THE CONCEPT IS TESTED BY OBTAINING EMISSION FROM A SHARP TUNGSTEN TIP COATED WITH THIS CARBON MATERIAL, REPLACING THE HOT FILAMENT CATHODE IN AN ELECTRON GUN, AND OBTAINING PRELIMINARY OPERATING PARAMETERS (E.G., MAXIMUM EMISSION CURRENT, EMISSION VOLTAGE, ETC.) FOR THE GUN. THIS INFORMATION IS USED TO DESIGN A DIRECT REPLACEMENT TIP FOR HOT FILAMENT ELECTRON GUNS. SINCE THIS MATERIAL HAS A VERY LOW WORK FUNCTION, THE WEHNELT POWER SUPPLY IN MOST ELECTRON GUNS SERVES AS THE EXTRACTOR SUPPLY.