DESIGN AND FABRICATION OF AN INVERTED TORSION PENDULUM FOR INTERNAL-FRICTION MEASUREMENTS

We describe the design and construction of an inverted torsion pendulu m for the measurement of the internal friction in high-damping solids in the frequency range 10(-3)-200 Hz and temperature range 4-600 K. Th e pendulum is attractive because of its simple construction and the us e of many parts that are easily fabricated and/or readily available co mmercially. The sensitivity of the pendulum to internal friction as de termined by tests on low-damping brass was found to be better than 0.5 x 10(-3). We also present internal friction measurements on two metal dichalcogenides to demonstrate the versatility of the device.