Evaluation of high performance large grain medium purity SRF cavity from KEK

Conference · Fri Nov 01 00:00:00 EDT 2019

OSTI ID:1647455

Dhakal, P. ^[1]; Ciovati, G. ^[1]; Myneni, G. R. ^[1]

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1. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

We presented the RF measurement on a 1.3 GHz single cell cavity fabricated at KEK using large grain ingot niobium with RRR=107. The cavity reached to 35 MV/m with Q₀ = 2.0×10zEhNZeHn at 2.0 K, record performance on the cavity made from medium purity ingot niobium. The cavity was cool down with different temperature gradient along the cavity axis in order to understand the flux expulsion mechanism when the cavity does through the superconducting transition and effect of trap residual magnetic field on the residual resistance. The measurement showed the excellent flux expulsion with the flux trapping sensitivity of 0.29 nΩ/mG for electro polished surface and 0.44 nΩ/mG for cavity followed by low temperature baking at 120°C for 12 hours.

• 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: 1647455
• Report Number(s): JLAB-ACC-19-2975; DOE/OR/23177-4726
• Resource Relation: Conference: SRF 2019, Dresden, Germany, June 30-July 5, 2019
• Country of Publication: United States
• Language: English