0 citations0 references

Critical angles for channeling of low energy ions in tungsten

Canadian Journal of Physics1968Vol. 46(23), pp. 2679–2682

Citations Over TimeTop 17% of 1968 papers

I. Bergström, K. Björkqvist, Bengt Domeij, G. Fladda, Stine Maria Lund Andersen

Abstract

The critical angle ψ for channeling of light and heavy ions in crystals has been studied around the [Formula: see text] direction in a tungsten single crystal by measuring the yield of backscattered ions at room temperature. The ions and their energies E were chosen such that the critical angle was comparable to, or larger than, the ratio between the screening radius a and the atom spacing along the string d. According to Lindhard [Formula: see text] for ψ < a/d and [Formula: see text]. We have studied the variation of the critical angle with E/Z 1 for the ions 1 H, 2 H, 4 He, 12 C, 20 Ne, 40 Ar, and 84 Kr in the critical angle region 4a/d > ψ > a/d. For 12 C, 20 Ne, 40 Ar, and 84 Kr, most of our data is in the transition region between ψ 1 and ψ 2 , but an approach to the ψ 2 behavior can be seen at the low energy end. For 1 H, 2 H, and 4 He, however, the energy dependence is rather of the ψ 1 -type for the whole region studied, that is even for critical angles as large as ψ = 4a/d. The value of the multiplicative constant C 2 is also different for the two cases, being close to 1 for the heavy ions but about 2 or larger for the light ions.

Citations Over TimeTop 17% of 1968 papers

Abstract

Related Papers