Collapse and revival of the electron spin echo of impurity Yb$^{3+}$ ions on hidden frequency combs of hyperfine interactions in a Y$_2$SiO$_5$ single crystal

The collapse and revival of Hahn electron spin echo signals excited on electron-nuclear spin levels of an impurity $^{173}$Yb$^{3+}$ ion in yttrium orthosilicate Y$_2$SiO$_5$ have been detected. A model of the phenomenon has been proposed on the basis of the combination of the conventional mechanism of the formation of two-pulse Hahn echo and the mechanism of the formation of echo signals on spin frequency combs that are hidden in the inhomogeneous width of resonance lines and are due to the hyperfine interaction of the electron spin of the Yb$^{3+}$ ion with surrounding nuclear spins of $^{89}$Y.