When an incident shock collides with a corrugated interface separating two fluids of different densities, the interface is prone to Richtmyer-Meshkov instability (RMI). Based on the formal perturbation expansion method as well as the potential flow theory, we present a simple method to investigate the cylindrical effects in weakly nonlinear RMI with the transmitted and reflected cylindrical shocks by considering the nonlinear corrections up to fourth order. The cylindrical results associated with the material interface show that the interface expression consists of two parts: the result in the planar system and that from the cylindrical effects. In the limit of the cylindrical radius tending to infinity, the cylindrical results can be reduced to those in the planar system. Our explicit results show that the cylindrical effects exert an inward velocity on the whole perturbed interface, regardless of bubbles or spikes of the interface. On the one hand, outgoing bubbles are constrained and ingoing spikes are accelerated for different Atwood numbers (A) and mode numbers k 0 . On the other hand, for ingoing bubbles, when jAjk 03=2 . 1, bubbles are considerably accelerated especially at the small jAj and k 0 ; otherwise, bubbles are decelerated. For outgoing spikes, when jAjk 0 & 1, spikes are dramatically accelerated especially at large jAj and k 0 ; otherwise, spikes are decelerated. Furthermore, the cylindrical effects have a significant influence on the amplitudes of the ingoing spike and bubble for large k 0 . Thus, it should be included in applications where the cylindrical effects play a role, such as inertial confinement fusion ignition target design. V C 2012 American Institute of Physics. [http://dx.

The fundamentals of droplet-based cleaning of photomasks are investigated and performance regimes that enable the use of binary spray technologies in advanced mask cleaning are identified. Using phase Doppler anemometry techniques, the effect of key performance parameters such as liquid and gas flow rates and temperature, nozzle design, and surface distance on droplet size, velocity, and distributions were studied. The data are correlated to particle removal efficiency (PRE) and feature damage results obtained on advanced photomasks for 193-nm immersion lithography.