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We present data for energy dissipation factor (Q^{-1}) over a broadtemperature range at various pressures of a torsion pendulum setup used tostudy 3He confined in a 98% open silica aerogel. Values for Q^{-1} above T_care temperature independent and have a weak pressure dependence. Below T_c, adeliberate axial compression of the aerogel by 10% widens the range ofmetastability for a superfluid Equal Spin Pairing (ESP) state; we observe thisESP phase on cooling and the B phase on warming over an extended temperatureregion. While the dissipation for the B phase tends to zero as T goes to 0,Q^{-1} exhibits a peak value greater than that at T_c at intermediatetemperatures. Values for Q^{-1} in the ESP phase are consistently higher thanin the B phase and are proportional to \rho_s/\rho until the ESP to B phasetransition is attained. We apply a viscoelastic collision-drag model, whichcouples the motion of the helium and the aerogel through a frictionalrelaxation time \tau_f. Our dissipation data is not sensitive to the dampingdue to the presumed small but non-zero value of \tau_f. The result is that anadditional mechanism to dissipate energy not captured in the collision-dragmodel and related to the emergence of the superfluid order must exist. Theextra dissipation below T_c is possibly associated with mutual friction betweenthe superfluid phases and the clamped normal fluid. The pressure dependence ofthe measured dissipation in both superfluid phases is likely related to thepressure dependence of the gap structure of the "dirty" superfluid. The largedissipation in the ESP state is consistent with the phase being the A or thePolar with the order parameter nodes oriented in the plane of the cell andperpendicular to the aerogel anisotropy axis.

Dissipation signatures of the normal and superfluid phases in torsion pendulum experiments with 3He in aerogel