Prototype development of an inverted magnetron gauge controller

An Inverted Magnetron Gauge is preferably used in proton machines due to certain advantages such as: i) they are robust and can be run over long shielded cables which is required as the vacuum instrumentation needs to be placed outside the accelerator tunnel due to high radiation and ii) to avoid heat load in cryo module regions, which otherwise is caused if a hot cathode ionization gauge is used. A prototype Inverted Magnetron Gauge controller is developed for measurement of vacuum up to 1E-11 mbar. The work comprises design and development of a high voltage PWM SMPS based on Flyback topology, measurement circuitry for high voltage and low current, and display and process interlock circuitry via a microcontroller. The measured parameters are interfaced with the microcontroller based circuit to obtain proportional vacuum level. The controller displays pressure, high voltage, ionization current, under pressure/over pressure conditions on a LCD module and generates a trip in the event of over pressure condition. The controller is equipped with a keyboard interface for local operation and a serial communication interface for remote operation. A GUI is also developed for data logging and remote operation of the gauge. The controller has been tested with Pfeiffer make gauge head model IKR 270, to successfully measure vacuum in the range from 1E-05 to 5E-11 mbar. It is housed in a half 19", 3U, 305 mm depth unit. (author)