  In this paper, on the basis of the model Schr\"odinger equation, we consider
the tunneling mechanism of cavitation in liquid helium and obtain threshold
values of negative pressure as a function of temperature for 3He and 4He. The
results of calculating the surface tension coefficients for flat and curved
interfaces, obtained in the approximation of the Lenard-Jones interaction
potential, are presented. It is shown that the temperature dependence of the
critical pressure at which cavitation begins is stepwise in nature. The
obtained critical pressure values are in satisfactory agreement with the
experimental data.
