1. P. Basu, T. Ballinger, J.T. Yates Jr, Rev. Sci. Instrum. 59, 1321 (1988)
2. H.P. Wang, J.T. Yates Jr, J. Phys. Chem. 88, 852 (1984)
3. T.P. Beebe, P. Gelin, J.T. Yates Jr, Surface Sci. 148, 526 (1984)
4. Windows of CaF2 Single Crystal Mounted in Conflat Flanges may be Obtained from Harshaw Crystal and Electronic Products. Solon Technologies, 6801 Cochran Rd., Solon, OH, 44139
5. Custom Fabricated Grids made of W or Other Metals are Available from Buckbee Mears, 245 E. Sixth Street, St. Paul, MN 55101