BNL, Upton, Long Island, New York, USA
Stony Brook University, Stony Brook, USA
The eRHIC crab cavity adopts the double quarter wave structure developed at Brookhaven National Lab for the LHC Hi-Lumi upgrade crab cavities. The cavity's fundamental mode is at 338 MHz with the first higher order mode more than 180 MHz above that. We looked into the higher order mode distribution up to 2 GHz, and considered various locations and geometries of the coupling scheme. The cylindrical outer shell of the cavity allowed various possibilities for coupler port openings on all the walls, which were difficult for the narrow waist of the LHC double quarter wave crab cavities. Beam pipe absorbers are also options for simpler high frequency modes damping. Some preliminary high pass filter design will also be discussed in this paper.
BNL, Upton, Long Island, New York, USA
Fermilab, Batavia, Illinois, USA
The electron-ion collider eRHIC aims at a luminosity around 1034cm-2sec-1, using strong cooling of the hadron beam. Since the required cooling techniques are not yet readily available, an initial version with a peak luminosity of 3*1033cm-2sec-1 is being developed that can later be outfitted with strong hadron cooling. We will report on the current design status and the envisioned path towards 1034cm-2sec-1 luminosity.
BNL, Upton, Long Island, New York, USA
Stony Brook University, Stony Brook, USA
Crab cavities are deflecting cavities operated in such a way that the bunch center is in synchronism with the zero-crossing kick voltage. In that case, beam loading is zero for an on-axis beam. The crab cavity system of the future electron-ion collider eRHIC will manipulate 275 GeV proton beams. At high energies, the beam offset can be as large as 2 mm (including mechanical and electrical offset tolerances). The beam loading resulting from such offset can greatly incur in large power requirements to the RF amplifier. The choice of external Q for the Fundamental Power Coupler (FPC) is critical to limit the power requirement to practical values. The loaded Q of the eRHIC crab cavities is mainly governed by the external Q of the FPC, so the external Q will also define the cavity bandwidth and thus the tuning requirements to counteract frequency transients from external perturbations. This paper discusses the choice of external Q for the FPC of the eRHIC crab cavities and introduces the design of a preliminary FPC antenna concept that would provide the appropriate external Q.
BNL, Upton, Long Island, New York, USA
The electron-ion collider eRHIC requires a variety of kickers and septa for injection and extraction of beams throughout the entire collider complex. We plan to use pulsed systems for beam injection and extraction in Electron RCS, Electron Storage Ring, and Hadron ring. In this paper, we describe the pulsed systems required for beam transfer in the eRHIC Ring-Ring Pre-conceptual Design. We will outline the parameter ranges, technology choices, and opportunities for research and development in pulsed power technology.