The design goal of the project described was to develop a modestly priced system capable of reliably baking the 87-m IUCF (Indiana University Cyclotron Facility) Cooler Ring vacuum chamber to 250 degrees C. Digital-to-analog converters provide the seek command to proportional controllers; these controllers drive solid-state relays which in turn drive 110 VAC coaxial heating coils. Thermistors (not thermocouples) provide feedback to the controllers and readouts to the PC through a commercial 200-channel analog-to-digital converter interface. Insulation is provided by a combination of ceramic paper and ceramic wool. Average vacuum achieved to data is 2.0 ntorr. Total system cost is about $35k.
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