{"id":3062,"date":"2020-12-18T05:48:43","date_gmt":"2020-12-18T13:48:43","guid":{"rendered":"https:\/\/www.rbdinstruments.com\/blog\/?p=3062"},"modified":"2023-08-10T07:56:33","modified_gmt":"2023-08-10T14:56:33","slug":"low-cost-high-potter","status":"publish","type":"post","link":"https:\/\/www.rbdinstruments.com\/blog\/low-cost-high-potter\/","title":{"rendered":"Low-Cost High-Potter"},"content":{"rendered":"\n

Occasionally Ion Pumps<\/a> can short out from the flakes that accumulate over the years because of using titanium sublimation pumps (TSP<\/a>).   An old trick is to use a high potter (high voltage potential generator) to create an arc which can sometimes (if you are lucky) burn off the short.   High potting can work well for ion pumps, ion guns and practically any electrical feedthrough on a vacuum chamber where flakes or deposition build up is an issue.<\/p>\n\n\n\n

High potting will only work on small flakes as the current generated is low (100uA max).  But the voltage generated is extremely high at 20,000 to 50,000 volts.  Think of this as a small Van der Graaf<\/a> generator where you can direct the arc towards the electrical feedthrough on the vacuum chamber. The voltage from the arc is applied to the shorted electrical feed though and will work it’s way to the short inside the vacuum chamber and if you are lucky, will melt the short. <\/p>\n\n\n\n

High potting does not always work but when it does it buys you\nsome time before you need to vent the chamber and perform the necessary maintenance\nto fix the underlying shorting issue.<\/p>\n\n\n\n

Back in the 80s it was common to see high potters in labs\nthat had vacuum chambers for analytical instruments or deposition systems. These\ndays you do not see high potters as often due to more stringent electrical safety\nstandards.   Used properly a high potter\nis perfectly safe.  Although it is a\nlittle bit exhilarating to be pointing a device that has a 50,000-volt arc\ncoming out of the end.  \ud83d\ude0a <\/p>\n\n\n\n

Electro-Technic Products, Inc. provides an assortment of high\nfrequency generator testers that work well as high-potters (high voltage\npotential) to melt away small particles and flakes that can cause shorts in\nhigh and ultrahigh vacuum applications. \nIn particular, these are useful for high-potting shorted ion pumps and\nion guns.<\/p>\n\n\n\n

\"\"