  Three prototype 6-cell superconducting cavities for acceleration in the
velocity range of 0.40 to 0.53 times the speed of light have been fabricated.
The quality factor (Q) of the first prototype cavity was above 1E10 for
accelerating gradients up to 11 MV/m. The highest gradient reached was about 16
MV/m; the Q was about 3E9 at the maximum gradient.
