1. Work supported in part by a grant from the National Science Foundation.
2. E. L. Ginzton,Microwave Measurements, McGraw-Hill, New York, 1957.
3. E. C. Jordan,Electromagnetic Waves and Radiating Systems, Prentice-Hall, New York, 1960.
4. S. C. Brown,Basic Data of Plasma Physics, Wiley, New York, 1959.