P(+)-n-n(+) structures based on 6H-SiC films grown by CVD on n(+) substrate were used. The initial concentration of uncompensated donors in the n-type layer was N(D)(+) - N(A)(-) =4.5*10(16) cm(-3) at layer thickness of several mum. The structures were exposed to a dose of 8*10(15) cm(-2) with 8 MeV protons and the effect of irradiation was studied by means of precise alpha -spectrometry. Results obtained in two modes were compared. (i) through-penetration of a particle across the structure and (ii) complete deceleration of a particle. It is shown that at (i)-mode and forward bias the signal is formed by the: mechanism of "through conducting channel" (TCC). The practical possibility is demonstrated of detecting ions by 6H-SiC films upon proton dose of similar to 10(16)cm (-2). The product of electron mobility by lifetime retains values sufficient for effective electron transport, including signal amplification in the TCC mode. The positive charge N(D)(+) - N(A)(-) is in fact determined by the concentration of initial uncompensated donors.