A. G. Foyt^*

• Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts

R. E. Halsted^†

• General Electric Research and Development Center, Schenectady, New York

William Paul^‡

• Division of Engineering and Applied Physics, Harvard University, Cambridge, Massachusetts

• ^*Operated with support from the U. S. Air Force.
• ^†Work supported in part by the Aerospace Research Laboratories, Office of Aerospace Research, U. S. Air Force.
• ^‡Supported in part by the Office of Naval Research under Contract No. Nonr 1866(10), and by the Advanced Research Projects Agency under Contract No. Sd-88 and by the Division of Engineering and Applied Physics.