Ultrafast High Voltage Kicker System Hardware for Ion Clearing Gaps

High current energy recovery linacs (ERLs), such as the one proposed for the JLab Electron Ion Collider cooling system, need temporal “gaps” to alleviate the ions trapped by strong Coulomb forces. Nearly rectangular pulses should kick the beam for ~100 ns at ~1 MHz repetition rate, using very limited beamline space. These gaps must be imposed on a very low emittance, ultra-relativistic beam current of more than 100 mA. Such a high rep rate in combination with short interaction length leads to challenging requirements on the design of the very high voltage kicker and its driver operating at average power as high as 8 kW and with low parasitic impedances. RadiaBeam Systems is developing an ion clearing gap system integrating the following: i) a stripline kicker capable of 20 mrad deflection with 14 mm interaction gap and ~0.5 m length shaped to minimize wakefield- induced emittance dilution; and ii) 1.3968 MHz, +1175V/-1175V, 23.5A peak channel current per channel, 92 ns flat-top, <10 ns rise and fall times pulser. In Phase I, we defined the kicker specifications and validated the performance analytically and through simulations. We designed the high-voltage driver pulser system and performed a bench-top test of the critical components. In the proposed Phase II project, we will perform final electromagnetic and engineering design of the kicker; advance the HV switch-based pulse-forming circuitry and build a full-power double-channel pulser; fabricate the kicker and perform high-power tests of the two devices at RadiaBeam’s site; and deliver the fabricated kicker system to JLab for further testing. The target segment is nuclear physics accelerator labs, as well as free electron laser and advanced light source facilities. Other applications include civil and military electronic components including radars, power conversion devices, Pockels cells drivers for lasers and high-power electro-optics, ozonators, ground penetration radars, and pulsed radiolysis.