Dynamic Behavior of Debris in a Gas-Puff Z-Pinch

Z-pinch is a useful device for efficient energy injection to the plasma. High-temperature and high-density plasmas can be produced easily in the implosion process by self-magnetic field. Because the radiation from z-pinch plasma lie in various wavelength region, the application to pulsed and intense light source such as Extreme Ultra Violet (EUV) light for the next generation semiconductor lithography is actively investigated. As the plasmas touch the solid as the electrode material, a part of the materials (atoms and fine particles) besides x-rays scatter and sticks to the viewing window and diagnostic instruments. This is called debris. Plasma itself is also recognized as a part of the debris. Elimination of the debris or controlled formations of that are ones of the urgent tasks for the EUV lithography [1.2]. In spite of the importance, the exact origin of the debris and the passes of scattering are still not confirmed experimentally. In gas-puff z-pinch, cloud structure of x-ray radiations have often been observed around the high temperature areas (hotspot) of plasma column [3]. It can be ascribed to K� line radiations of electrode materials excited by electron beam generated at the pinch of the plasma [4]. From the reason, the cloud structures would be the major sources of debris.