High power extreme ultraviolet source based on a Z-pinch

The 1Hz helium-xenon Z-pinch previously described(1) has been re-engineered with long-life thyratron switches to operate at 10Hz. At 10Hz, without a condenser, it currently delivers 0.2W in a 4 Angstrom band centered at 134.5A, into a solid angle of 0.03 sterad. We report on measurements of scaling of the in-band power with stored energy, and optimization of the spectrum, either for operation at 134A with Mo-Si multilayer mirrors, or at shorter wavelengths such as 113A for use with Mo-Be mirrors. We have measured an rms pulse-to-pulse amplitude stability of 2.1% (6% absolute). No measurable loss of transmission at 134A occurred in a 250nm silicon nitride membrane placed at 52cm axially from the plasma during a 10(5) pulse run at full energy, indicating that the source is clean. Electrode and pinch liner erosion is not significant in tests to the 10(6)pulse level and the life of these components is projected to exceed 5x10(7)pulses. The possible extension to a narrow beam of at least 4W in-band at 134A, via an increase of the repetition rate to 100Hz and solid angle to 0.06 sterad, is discussed.