DRF1 Cavity Power Amplifier Repair
- Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
Please refer to Fermi drawing # 8000-ED-119522 for the complete details. The amplifier consists of two 3CPX10000U7s (Rotator) or similar 3CX10000U7s (Adiabatic). They are grounded grid air-cooled triodes connected in push-pull. The 50-Ohm inputs are applied to the cathode through a T matching circuit, (these are the only adjustable components). A positive bias voltage is also applied to the cathode (the filament is the directly heated cathode). This sets the tubes to run at class C operation. The bias is clamped at 155V with four 50-Watt zener diodes (currently these are RCA brand SK614s’ bench matched for same voltage @ 100mA). This keeps the tube from self-cutoff during large conduction swings of drive voltage. The RF is developed across the parallel combination of the tube input element characteristics (grid and cathode) and filament choke coil. The output is coupled into the cavity by a center-tapped coupling loop. It can be viewed as a single turn transformer winding where high voltage applied to the center tap (RF grounded) and the ends connected to the tube anodes (Plate). The interlocks include operational and safety concerns. Signaling is provided for airflow (air vane switch), temperature (klixon), filament (AC rectified), bias (Voltage divider), anode voltage (Voltage divider), access door and vents (magnetic switch).
- Research Organization:
- Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), High Energy Physics (HEP)
- DOE Contract Number:
- AC02-07CH11359
- OSTI ID:
- 1973979
- Report Number(s):
- FERMILAB-PBAR-NOTE--699; oai:inspirehep.net:864197
- Country of Publication:
- United States
- Language:
- English
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