| Paper | Title | Page |
|---|
| MO403 | Development of the Superconducting CH-Cavity and Applications to Proton and Ion Acceleration | 48 |
| | - H. Podlech, A. Bechtold, M. Busch, H. Klein, H. Liebermann, U. Ratzinger
IAP, Frankfurt University
| |
| | The Crossbar-H-mode (CH)-structure which has been
developed at the IAP in Frankfurt is a multi-cell drift tube
structure for the efficient acceleration of low and medium
energy protons and ions [1, 2]. A superconducting CHcavity
with 19 cells (f=360 MHz, beta=0.1) has been built and
tested successfully (see fig. 1) [2, 3]. After the localization
of a field emission site an additional surface treatment has
been performed. Recent tests showed a significant increase
in performance. A gradient of 7 MV/m in cw operation has
been reached, corresponding to an effective voltage gain
of 5.6 MV in that cavity. This shows that high real estate
gradients can be achieved in superconducting low energy
mulit-cell cavities. Several projects like IFMIF or EUROTRANS/
ADS with fixed velocity profile driver linacs could
profit from this development. | |
 | Slides(PDF) | |
| WEP54 | A tuner for a superconducting CH-prototype cavity | 618 |
| | - A. Bechtold, M. Busch, H. Liebermann, H. Podlech, U. Ratzinger
IAP, J. W. Goethe-Universitaet
| |
| | The superconducting CH multi-cell prototype cavity
will be equipped with a frequency tuning system. The rftuning
during operation bases on the principle of a slight
elastic deformation at both ends of the tank. This is
causing a change in the gap width of the first and last
accelerating cell and the accompanying variation of
capacity finally results in a frequency shift. The effects on
rf-frequency and field distribution have been measured
and were compared with previous calculations. The tuning
system implies two stages, a slow mechanical device and
a fast piezo system, all parts were manufactured already.
Additionally, the mechanical resonances of the cavity
have been investigated experimentally in the environment
of an acoustical laboratory at room temperature and
recently within the vertical cryostat at 4 K. Moreover, an
active periodic cavity detuning provided by the piezo
tuners was implied, while stable superconducting cavity
operation was kept by a frequency control loop acting on
the rf-frequency oscillator. | |