ILC coaxial blade tuner

A coaxial (blade) tuner solution has been developed for the compensation of the Lorentz force detuning of the superconducting cavities under the high gradient pulsed operation foreseen for ILC operation. The device is based on prototypes successfully tested at DESY in 2002 both on CHECHIA and on the superstructures inserted in the TTF string. During both tests the blade tuner performed as expected in terms of stiffness, frequency sensitivity and tuning capabilities. An improvement of the tuner characteristics has been designed by the integration of fast tuning capabilities by means of piezo-ceramic element. Two prototipes of the new INFN coaxial piezo blade tuner have just been manufactured and they will be tested at DESY and BESSY after the cavity integration. In this paper the blade tuner design and main characteristics are presented, together with the early interpretation of the cold test results.