A narrow stream of monoenergetic electrons falls at an angle of incidence \(\theta=30^{\circ}\) on the natural facet of an aluminium single crystal. The distance between the neighbouring crystal planes parallel to that facet is equal to \(d=0.20 \mathrm{nm}\). The maximum mirror reflection is observed at a certain accelerating voltage \(V_{0} .\) Find \(V_{0}\) if the next maximum mirror reflection is known to be observed when the accelerating voltage is increased \(\eta=2.25\) times.