Mass Coupling and Q-1 of Impurity-Limited Normal 3He in a Torsion Pendulum

We present results of the Q(-1) and period shift, Delta P, for He-3 confined in a 98% nominal open aerogel on a torsion pendulum. The aerogel is compressed uniaxially by 10% along a direction aligned to the torsion pendulum axis and was grown within a 400 mu m tall pancake (after compression) similar to an Andronikashvili geometry. The result is a high Q pendulum able to resolve Q(-1) and mass coupling of the impurity-limited He-3 over the whole temperature range. After measuring the empty cell background, we filled the cell above the critical point and observe a temperature dependent period shift, Delta P, between 100 mK and 3 mK that is 2.9% of the period shift (after filling) at 100 mK. The Q(-1) due to the He-3 decreases by an order of magnitude between 100 mK and 3 mK at a pressure of 0.14 +/- 0.03 bar. We compare the observable quantities to the corresponding calculated Q(-1) and period shift for bulk He-3.