Coupled Bunch Instability from JLEIC Crab Cavity Higher Order Modes

Conference · Sun Jul 01 00:00:00 EDT 2018

DOI:https://doi.org/10.18429/JACoW-IPAC2018-THPAK070· OSTI ID:1473839

Sosa Guitron, Salvador I. ^[1]; de Silva, Subashini U. ^[1]; Delayen, Jean R. ^[1]; Park, HyeKyoung ^[2]; Li, Rui ^[3]; Morozov, Vasiliy ^[3]

---

1. Old Dominion Univ., Norfolk, VA (United States)
2. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Old Dominion Univ., Norfolk, VA (United States)
3. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

Particle bunches traveling in a ring can excite wakefields inside any radio-frequency (rf) element present. These electromagnetic modes can resonate long enough and interact with subsequent passing bunches. A coherent oscillation between bunches can quickly become an instability and needs to be addressed. The Jefferson Lab Electron-Ion Collider (JLEIC) has a large 50 mrad crossing angle and thus relies on bunch crabbing to achieve high luminosity. Bunch crabbing is done with compact superconducting rf dipole cavities. We study coupled bunch oscillations driven by the higher order modes (HOM) of multi-cell rf dipole (rfd) crab cavities under study for JLEIC, we calculate the instability growth time assuming a symmetric beam frequency spectrum, identify the HOM driving the instability and discuss mitigation measures.

• Research Organization: Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 1473839
• Report Number(s): JLAB-ACP-18-2764; DOE/OR/23177-4493
• Resource Relation: Conference: IPAC 2018, 29 Apr - 04 May 2018. Vancouver, BC Canada
• Country of Publication: United States
• Language: English