1. Department of Physics and Astronomy and Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14627-0231, USA
2. Brookhaven National Laboratory, Upton, New York 11973-5000, USA
3. Savannah River National Laboratory, Aiken, New York 29803, USA
4. Institute of Electron Technology, Warszawa PL-02668, Poland
5. Institute of Physics, Polish Academy of Sciences, Warszawa PL-02668 Poland
6. Department of Electrical and Computer Engineering and Laboratory for Laser Energetics University of Rochester, Rochester, New York 14627-0231, USA