Faraday rotator diode stack SHIVA (17 May 1977) (Engineering Materials). [21 drawings]
The Faraday rotator diode stack in Shiva is used to prevent a ringing waveform in the rotator circuits. Each rotator has a diode in shunt with it, so that instead of ringing, the current waveform through the diode and rotator has an L/R time-constant decay from the initial peak value. There are two main purposes for this addition to the circuit: (1) it reduces the number of coulombs switched in the capacitor discharge circuit supplying the rotator; and (2) it eliminates the problem of the switch tube turning off due to current reversal. The diode stack is conservatively rated for reliability. The voltage hold off is 54 kV (30 diodes, 1.8 kV each). The current rating for a surge condition is 30 kA. The diode is water cooled, both for temperature stability and voltage division. In addition, each diode is compensated with 1 ..mu..F of capacitance. The typical use of the diode is for a 15 kA pulser height and 10 ms pulse length with a 20 kV holdoff. These values are not stressing the diode at all. The diode has a spark gap across it for protection in the event a cable breaks and the inductive storage in the rotator coil causes a voltage spike. Assembly of the stack is important since the hockey puck package is subject to damage. The assembly drawing should be carefully followed.
- Research Organization:
- California Univ., Livermore (USA). Lawrence Livermore Lab.
- OSTI ID:
- 5337936
- Report Number(s):
- CAPE-2581
- Country of Publication:
- United States
- Language:
- English
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