RF Results of Nb Coated SRF Accelerator Cavities via HiPIMS

Conference · Tue Jan 01 04:00:00 EST 2019

DOI:https://doi.org/10.18429/JACoW-LINAC2018-TUPO042· OSTI ID:1542092

Burton, Matthew Creed ^[1]; Palczewski, Ari D. ^[1]; Phillips, H. Larry ^[1]; Valente-Feliciano, Anne-Marie ^[1]; Reece, Charles E. ^[1]; Lukaszew, Rosa ^[2]

---

1. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2. College of William and Mary, Williamsburg, VA (United States)

Bulk Niobium (Nb) SRF (superconducting radio frequency) cavities are currently the preferred method for acceleration of charged particles at accelerator facilities around the world. However, bulk Nb cavities have poor thermal conductance and impose material and design restrictions on other components of a particle accelerator. Since the SRF phenomena occurs within a shallow depth of 40 nm (for Nb), a proposed solution to this problem has been to deposit a superconducting Nb thin film on the interior of a cavity made of a suitable alternative material such as copper or aluminum. While this approach has been attempted in the past using DC magnetron sputtering (DCMS), such cavities have never performed at the bulk Nb level. However, new energetic condensation techniques for film deposition offer the opportunity to create suitably thick Nb films with improved density, microstructure and adhesion compared to traditional DCMS. One such technique that has been developed somewhat recently is ?High Power Impulse Magnetron Sputtering? (HiPIMS). Here we report early results from various thin film coatings carried out on 1.3 GHz Cu cavities, a 1.5 GHz Nb cavity, and small Cu coupon samples coated at Jefferson Lab using HiPIMS.

• Research Organization: Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 1542092
• Report Number(s): JLAB-ACC-18-2835; DOE/OR/23177-4746; TUPO042
• Country of Publication: United States
• Language: English