| Paper | Title | Page |
|---|
| TUP04 | Cryogenic System for the KEKB Crab Cavities | 106 |
| | - H. Nakai, K. Hara, T. Honma, K. Hosoyama, A. Kabe, Y. Kojima, Y. Morita, K. Nakanishi
KEK - T. Kanekiyo
Hitachi Co. LTD - T. Yanagisawa
MHI Kobe
| |
| | The superconducting crab cavities, which change the
direction of beam bunches to increase the luminosity of
the KEKB accelerator, are successfully installed in the
KEKB and operated with the stable operation of the large
helium refrigerator for the KEKB.
Since the crab cavities requires unique devices, such
as long coaxial couplers, the cryostats for the crab
cavities have various special features in their design and
also in their cooling schemes. This paper describes such
features and cooling schemes of the cryogenic system for
the KEKB superconducting crab cavities.
Calorimetric measurements on Q-factors of the crab
cavities and static heat load (static loss) measurements of
the crab cavity cryostats are carried out after the cryostat
assembly. The results of these measurements are
acceptable, and from these results, it is found that the
crab cavity performance does not degrade so much
during the cryostat assembly. | |
| WEP27 | Horizontal tests for crab cavities in KEKB | 520 |
| | - Y. Yamamoto, K. Akai, K. Ebihara, T. Furuya, K. Hara, T. Honma, K. Hosoyama, A. Kabe, Y. Kojima, S. Mitsunobu, Y. Morita, H. Nakai, K. Nakanishi, M. Ono
KEK - H. Hara, K. Sennyu, T. Yanagisawa
MHI Kobe - T. Kanekiyo
HITACHI - T. Nakazato
JASRI
| |
| | Two Crab cavities were fabricated at KEK in 2006.
After the completion of the assembly, a horizontal test is
normally carried out for a superconducting cavity in KEK.
The horizontal test is an overall test for the cavity without
a beam. Both cavities achieved above an operational kick
voltage of 1.4MV. Although the HER (High Energy Ring
for electron) Crab cavity had no trouble, the LER (Low
Energy Ring for positron) had a trouble of tuner operation.
Due to the limited time, both cavities were installed into
the tunnel at the beginning of Jan. in 2007. After the beam
commissioning, it was found that this problem was not so
much significant for the operation. The LER Crab cavity
is being operated above 1A at present. | |