1. Foster, C., Bull. Am. Phys. Soc., 1980, vol. 25, p. 976.
2. Amenda, W. and Lang, R., Abstracts of Papers, Proc. 12th Symp. on Fusion Technology (Julich, Germany, 1982), Oxford: Pergamon, 1983, vol. 2, p. 1501.
3. Foster, C., J. Vac. Sci. Technol. A, 1983, vol. 1, no. 2, p. 952.
4. Amenda, W. and Lang, R., J. Phys. E: Sci. Instrum, 1986, vol. 19, p. 970.
5. Foster, C., Houlberg, W., Gouge, M., et al., Abstracts of Papers, Proc. 17th Symp. on Fusion Technology (Rome, 1992), Ferro, C., Gasparotto, M., and Knoepfel, H., Eds., Amsterdam: Elsevier, 1993, vol. 1, p. 496.