Impedance Measurements in the Kekb
نویسندگان
چکیده
In the KEKB storage rings, we have measured the current dependence of the betatron tunes and the damping rate to evaluate the broad-band transverse impedance. The measured impedances were cross-checked and exceeded the design value by a factor of more than five. The tranverse mode-coupling instability was observed in LER when chromaticity was reduced. We found that the main impedance source for the instability was caused by the vertical collimators. The impedance of the collimators was investigated by changing their aperture.
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