Title :
MgB2 for Application to RF Cavities for Accelerators
Author :
Tajima, Tsuyoshi ; Canabal, Alberto ; Zhao, Yue ; Romanenko, Alexander ; Moeckly, Brian H. ; Nantista, Christopher D. ; Tantawi, Sami ; Phillips, Larry ; Iwashita, Yoshihisa ; Campisi, Isidoro E.
Author_Institution :
Los Alamos Nat. Lab., Los Alamos
fDate :
6/1/2007 12:00:00 AM
Abstract :
Magnesium diboride (MgB2) has a transition temperature of (Tc) ~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 (Rs) 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- 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 compared to the film deposited by reactive evaporation method. This paper shows these results as well as future plans.
Keywords :
boron compounds; magnesium compounds; particle accelerators; pulsed laser deposition; superconducting microwave devices; surface resistance; MgB2 - Interface; coating method; magnesium diboride; on-axis pulsed laser deposition; particle accelerators; radio-frequency cavities; reactive evaporation method; surface resistance; transition temperature; Linear particle accelerator; Magnesium compounds; Materials testing; Niobium; Optical materials; Pulsed laser deposition; Radio frequency; Surface resistance; Tellurium; Temperature; ${hbox{MgB}}_{2}$; Co-evaporation; PLD; particle accelerators; superconducting RF cavities;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2007.899876
