Very HighQMeasurements on a Fused Silica Monolithic Pendulum for Use in Enhanced Gravity Wave Detectors

We present for the first time the results of very high $Q$ factor measurements for a 2.8 kg fused silica mass suspended by two fused quartz fibers attached by a novel technique for joining fused silica or quartz. The $Q$ for the pendulum mode at 0.93 Hz was $(2.3\pm 0.2)\times {10}^7$, the highest value demonstrated to date for a mass of this size. By employing such a new suspension system the sensitivity of the gravitational wave detectors currently under construction can be increased up to 1 order of magnitude.