Quenching experiments on very thin films (≃ 1 000 Å) of symmetric diblock copolymer deposited on solid substrates result in the formation of circular relief domains at the free surface of the sample. It is due to the quantization of the possible thicknesses of the sample which accompanies the lamellar ordering of the two species parallel to the substrate. Depending on the average thickness of the film, the domains can be depressions or elevations. Based on the conjecture of a simple dislocation structure of the domain edge, equations governing the time evolution of the domain size distribution are proposed. The flows involved in the domain growth are shown to be confined into a bilayer which is disrupted at the dislocation lines. The hypothesis is made that interlayer frictions dominate. The growth kinetics of a single hole in a finite film is finally solved explicitely. Its radius is found to decay as a 1/3 power law of its life time
Optical microscopy and X-ray reflectivity have been used to investigate the behavior of ultrathin films of a symmetric diblock poly (styrene-5-methyl methacrylate) (P(S-5-MMA)) copolymer deposited on a silicon substrate. Thick films of such a copolymer exhibit, at equilibrium, a multilayer structure where the lamellae, of thickness L, are oriented parallel to the substrate and the PS and PMMA blocks are located respectively at the air/polymer and substrate/ polymer interfaces. The influence of the thickness constraints on the morphology of the free surface has been studied. For copolymer whose molecular weight M" is 91 500, spin-coated films with thicknesses less them the lamellar period have been annealed under vacuum at 170 °C. Different morphologies are encountered depending on the annealing time and the thickness. For thin films whose thickness £ac is such that L/2 < £ac < L, either a stretched monolayer or the formation of islands is observed. When the film thickness is equal to L/2, a stable monolayer of low surface roughness is found, while, for thicknesses less than L/2, the monolayer is not stable.
This document presents the as-run analysis of the AGR-1 irradiation experiment. AGR-1 is the first of eight planned irradiations for the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. Funding for this program is provided by the U.S. Department of Energy as part of the Next Generation Nuclear Plant Project. The objectives of the AGR-1 experiment are to: (a) Gain experience with multi-capsule test train design, fabrication, and operation with the intent to reduce the probability of capsule or test train failure in subsequent irradiation tests. (b) Irradiate fuel produced in conjunction with the AGR fuel process development effort. (c) Provide data that will support the development of an understanding of the relationship between fuel fabrication processes, fuel product properties, and irradiation performance.
This document presents the as-run analysis of the AGR-1 irradiation experiment. AGR-1 is the first of eight planned irradiations for the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. Funding for this program is provided by the U.S. Department of Energy as part of the Next Generation Nuclear Plant Project. The objectives of the AGR-1 experiment are to: (a) Gain experience with multi-capsule test train design, fabrication, and operation with the intent to reduce the probability of capsule or test train failure in subsequent irradiation tests. (b) Irradiate fuel produced in conjunction with the AGR fuel process development effort. (c) Provide data that will support the development of an understanding of the relationship between fuel fabrication processes, fuel product properties, and irradiation performance.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.