Test modulator of AGS injection fast kicker

A test modulator of the Brookhaven AGS injection fast kicker is described. During the fourth batch transfer of the proton beam from the booster to AGS, the fall time of the AGS injection kicker has to be very fast (<140 ns), so that it does not appreciably deflect the first batch of injected protons that is circulating in the AGS. A test modulator was built, which consists of a PFN (pulse forming network), a tail-biting section, and two thyratron switches. One thyratron switches the current to the load magnet, and another bites down the current at the end of the pulse. The load and circuit stray inductance is about 1.95 μH to 2.15 μH, and the required peak current is about 1000 A. The current pulse waveform, tested at half current level (500 A), has a fast fall time as well as a fast rise time