We show that the electric activity of superfluid helium (HeII) observed in the experiments [3] during the excitation of standing second sound waves in an acoustic resonator can be described in terms of the phenomenological mechanism of the inertial polarization of atoms in a dielectric, in particular, in HeII, when the polarization field induced in the medium is proportional to the mechanical acceleration, by analogy with the Stewart-Tolman effect. The variable relative velocity w = v _n - v _s of the normal and superfluid HeII components that emerges in the second sound wave determines the mean group velocity of rotons, V _g ≈ w, with the density of the normal component related to their equilibrium number density in the temperature range 1.3 K ≤ T ≤ 2 K. Therefore, the acceleration of the 4He atoms involved in the formation of a roton excitation is proportional to the time derivative of the relative velocity.w. In this case, the linear local relations between the variable values of the electric induction, electric field strength, and polarization vector should be taken into account. As a result, the variable displacement current induced in the bulk of HeII and the corresponding potential difference do not depend on the anomalously low polarizability of liquid helium. This allows the ratio of the amplitudes of the temperature and potential oscillations in the second sound wave, which is almost independent of T in the above temperature range, consistent with experimental data to be obtained. At the same time, the absence of an electric response during the excitation of first sound waves in the linear regime is related to an insufficient power of the sound oscillations. Based on the experimental data on the excitation of first and second sounds, we have obtained estimates for the phenomenological coefficient of proportionality between the polarization vector and acceleration and for the drag coefficient of helium atoms by rotons in the second sound wave. We also show that the presence of a steady heat flow in HeII with nonzero longitudinal velocity and temperature gradients due to finite viscosity and thermal conductivity of the normal component leads to a change in the phase velocities of the first and second sound waves and to an exponential growth of their amplitudes with time, which should cause the amplitudes of the electric signals at the first and second sound frequencies to grow. This instability is analogous to the growth of the amplitude of long gravity waves on a shallow-water surface that propagate in the direction of decreasing basin depth.
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机译：我们表明，在实验[3]中观察到的超流体氦（HeII）的电活动，可以用电介质中原子惯性极化的现象学机制来描述，该第二声波在声共振器中激发。特别是在HeII中，类似于Stewart-Tolman效应，当介质中感应的极化场与机械加速度成比例时。在第二声波中出现的正常和超流体HeII分量的可变相对速度w = v _n-v _s决定了棒子的平均群速度V _g≈w，而正常分量的密度与其平衡数有关密度在1.3 K≤T≤2 K的温度范围内。因此，参与形成顿子激发的4 He原子的加速度与相对速度的时间导数成正比。在这种情况下，应考虑到电感应的变量值，电场强度和极化矢量之间的线性局部关系。结果，在大量的HeII中感应出的可变位移电流和相应的电势差并不取决于液态氦的异常低极化率。这使得第二声波中的温度振幅与电位振荡的比值几乎与上述温度范围内的T无关，从而与实验数据一致。同时，在线性状态的第一声波的激励期间没有电响应与声音振荡的功率不足有关。基于关于第一和第二声音的激励的实验数据，我们获得了极化矢量和加速度之间的比例现象学系数以及第二声波中ro子对氦原子的阻力系数的估计。我们还表明，由于正态成分的有限粘度和导热性，HeII中存在具有不为零的纵向速度和温度梯度的稳定热流会导致第一和第二声波的相速度发生变化，并导致指数变化它们的幅度随时间增长，这将导致电声在第一和第二声频处的幅度增长。这种不稳定性类似于在浅水表面上长重力波的振幅的增长，该重力波沿盆地深度减小的方向传播。
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