MgB2 for application to RF cavities for accelerators

Authors

Tsuyoshi Tajima, Los Alamos National Laboratory, USA
Alberto Canabal, Los Alamos National Laboratory, USA
Yue Zhao, University of WollongongFollow
Alexander Romanenko, Cornell University, USA
Brian H. Moeckly, Superconductor Technologies , Inc, USA
Christopher D. Nantista, SLAC Menlo Park, USA
Sami Tantawi, SLAC Menlo Park, USA
Larry Phillips, JLAB, Newport News, USA
Yoshihisa Iwashita, Kyoto ICR, Japan
Isidoro E. Campisi, ORNL, USA

RIS ID

21889

Publication Details

Tajima, T, Canabal, A, Zhao, Y, Romanenko, A, Moeckly, B, Nantista, CD, Tantawi, S, Phillips, L, Iwashita, Y & Campisi, IE (2007), MgB2 for Application to RF Cavities for Accelerators, IEEE Transactions on Applied Superconductivity, 17(2), pp. 1330-1333.

Abstract

Magnesium diboride (MgB₂) has a transition temperature (T_c) of ~40 K, i.e., about 4 times as high as that of niobium (Nb).We have been evaluating MgB₂ as a candidate material for radio-frequency (RF) cavities for future particle accelerators. Studies in the last 3 years have shown that it could have about one order of magnitude less RF surface resistance (R_s) than Nb at 4 K. A power dependence test using a 6 GHz TE₀₁₁ mode cavity has shown little power dependence up to ~12 mT (120 Oe), limited by available power, compared to other high-T_c materials such as YBCO. A recent study showed, however, that the power dependence of Rs is dependent on the coating method. A film made with on-axis pulsed laser deposition (PLD) has showed rapid increase in R_s compared to the film deposited by reactive evaporation method. This paper shows these results as well as future plans.