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The new generation of lithography tools use high energy EUV radiation which ionizes the present background gas due to photoionization. To predict and understand the long term impact on the highly delicate mirrors It is essential to characterize these kinds of EUV-induced plasmas. We measured the electron density evolution in argon gas during and just after irradiation by a short pulse of EUV light at 13.5 nm by applying microwave cavity resonance spectroscopy. Dependencies on EUV pulse energy and gas pressure have been explored over a range relevant for industrial applications.Our experimental results show that the maximum reached electron density depends linearly on pulse energy. A quadratic dependence caused by photoionization and subsequent electron impact ionization by free electrons -is found from experiments where the gas pressure is varied. This is demonstrated by our theoretical estimates presented in this manuscript as well.PACS numbers: 52.70.Gw,81.16.Nd Submitted to: J. Phys. D: Appl. Phys. time ( s) 1.5 J 15 J 29 J 44 J 59 J 73 J 88 J 100 J 150 J

Applying capillary zone electrophoresis with UV detection, both UV-absorbing and UV-transparent components can be present in electropherograms as negative peaks (dips) or as positive peaks. Starting from Kohlrausch's regulation function, derived for fully ionized monovalent ionic constituents and under the assumption that the molar absorptivities of the UV-absorbing components are identical, eight different cases can be distinguished and in several cases components can occur both as peaks or as dips depending on their mobilities and those of the co-ions of the system. Applying background electrolytes containing two co-ions, system peaks are present, with a mobility that is between the mobilities of the two co-ions and determined by the concentration ratio of these two co-ions. In the background electrolytes studied, containing the co-ions potassium and histidine, UV-transparent sample components with a mobility higher than that of the system peak migrate as a positive peak, whereas UVtransparent components with lower mobilities migrate as negative peaks. System peaks themselves can also be peaks or dips depending on the sample composition. Sample peaks in the vicinity of system peaks interact with the system peaks through which both sample and system peaks are enlarged and quantitative properties are lost. Similar phenomena can be measured for anions in background electrolytes containing the co-ions phenylacetate and acetate, indicating that these phenomena are probably not associated with adsorption phenomena of cations on the fused-silica surface.

Non-steady-state processes in capillary electrophoresis can be estimated by applying a steady-state mathematical model. Calculations with a steady-state model indicate that in capillary electrophoresis, moving boundary zones can originate from discontinuities in the concentration of the co-ions and/or the pH of the background electrolyte. Calculations showed that cationic moving boundaries with high mobilities originate with low system pH values. If the separation capillary and anode compartment are filled with electrolytes, different in concentration or pH, a shift of the baseline UV signal can occur. Block-shaped discontinuities in pH and/or concentrations split up in a migrating part with a mobility determined by the composition of the background electrolyte and a part migrating with the velocity of the electroosmotic flow at the position of the original disturbance. As a result, dips of the electroosmotic flow marker (low background concentration) split up and a negative system peak migrates through the system at low system pH values. Injections of high concentrations of background electrolyte or samples at high ionic strength lead to positive system peaks. These system peaks are, of course, only visible if the background electrolyte shows UV-absorbing properties. Experimentally determined data match the calculated values for these mobilities and baseline shifts.

We used microparticles under hypergravity conditions, induced by a centrifuge, in order to measure nonintrusively and spatially resolved the electric field strength as well as the particle charge in the collisional rf plasma sheath. The measured electric field strengths demonstrate good agreement with the literature, while the particle charge shows decreasing values towards the electrode. We demonstrate that it is indeed possible to measure these important quantities without changing or disturbing the plasma.