The Joint Accelerator Conferences Website (JACoW) is an international collaboration that publishes the proceedings of accelerator conferences held around the world.
TY - CONF
AU - Martinello, M.
AU - Checchin, M.
AU - Grassellino, A.
AU - Melnychuk, O.S.
AU - Posen, S.
AU - Romanenko, A.
AU - Sergatskov, D.A.
AU - Zasadzinski, J.
ED - Schaa, Volker RW
ED - Power, Maria
ED - Shiltsev, Vladimir
ED - White, Marion
TI - Surface Impurity Content Optimization to Maximize Q-factors of Superconducting Resonators
J2 - Proc. of NAPAC2016, Chicago, IL, USA, October 9-14, 2016
C1 - Chicago, IL, USA
T2 - North American Particle Accelerator Conference
T3 - 3
LA - english
AB - Quality factor of superconducting radio-frequency (SRF) cavities is degraded whenever magnetic flux is trapped in the cavity walls during the cooldown. In this contribution we study how the trapped flux sensitivity, defined as the trapped flux surface resistance normalized for the amount of trapped flux, depends on the mean free path. A systematic study of a variety of 1.3 GHz cavities with different surface treatments (EP, 120 ^{°}C bake and different N-doping) is carried out. A bell shaped trend appears for the range of mean free path studied. Over-doped cavities fall at the maximum of this curve defining the largest values of sensitivity. In addition, we have studied the trend of the BCS surface resistance contribution as a function of mean free path, showing that N-doped cavities follow close to the theoretical minimum. Adding these results together we show that the 2/6 N-doping treatment gives the highest Q-factor values at 2 K and 16 MV/m, as long as the magnetic field fully trapped during the cavity cooldown is lower than 10 mG.
PB - JACoW
CP - Geneva, Switzerland
SP - 663
EP - 666
KW - ion
KW - cavity
KW - SRF
KW - factory
KW - niobium
DA - 2017/01
PY - 2017
SN - 978-3-95450-180-9
DO - 10.18429/JACoW-NAPAC2016-WEB1CO03
UR - https://jacow.org/napac2016/papers/web1co03.pdf
ER -