Energy spectra of &agr;-particles channeling along the optical axis (c-axis) of a quartz crystal in the energy regionE&agr;=3.0–3.5&hthinsp;Mevin the backscattering geometry were taken and analyzed. Computer simulations based on the assumption that the dechanneling of &agr;-particles follows an exponential law are in good agreement with the measured spectra, yielding electronic stopping powers for the specific crystal orientation that vary between 17.82 and 16.12 eV/Å respectively for the energy interval into consideration. ©2001 American Institute of Physics.