Hello, A new project on the LCRC cluster has been requested. Please forward the information on to the LCRC Allocation sub-committee. Applicant's name: Emmanouil Doxastakis Applicant's institution: ANL Applicant's division: IME/MSD Project Name: ds_ime Project title: Modeling of Scattering from Block Copolymer Films Associated funding: IME/ANL FWP Solvent-Assisted Assembly Other Systems: Science: Grazing-Incidence Small Angle X-ray Scattering (GISAXS) is emerging as an efficient and accurate structural characterization technique at the nanoscale. GISAXS offers the ability to probe large sample areas, offering three-dimensional information at high detail in a thin film geometry. Furthermore, the potential to probe samples in different environments provides for an attractive technique with unique advantages. This departs significantly from other available methods which are often limited to small areas and/or two-dimensions. In this study we exploit the application of GISAXS to determine the structures formed at each step of LiNe (Liu-Nealey) flow using chemical patterns for directed self-assembly (DSA) of block copolymer (BCP) films. Experiments conducted at the Advanced Photon Source, Argonne National Laboratory provided characteristic scattering patterns at low incident angles that probed film characteristics at both parallel and normal di rections to the surface. Project description: The primary goal of the project is to build models of materials that would provide scattering patterns in agreement to current ongoing experiments at APS. Modeling of GISAXS data requires an accurate and precise description of scattering emanating both from a mean structure dominating the sample as well as variances around this shape. To recreate the scattering patterns we employ a hybrid computational model. Fist images generated at APS are loaded through a Python interface. Subsequently we construct a statistical model of the structure. Scattering is built employing an efficient Fortran subroutine, parallelized with OpenMP. Current efforts (depending on time allocated) will translate the form factor calculations to MPI. It is emphasized that there is minimal scalability issues since the main computational load is during the calculation of averages of scattering from i.e. 1000 structures representing individual fluctuations in the sample. This is performed with a simple reduction operation after which the predicted scattering pattern is available to compare to experiments. We also emphasize that this effort would advance significantly the current state-of-the art modeling of GISAXS data which focuses on extracting only the best average structure. Currently the whole modeling process is coupled to an optimization library (Nlopt) to reach beyond simple modeling and fit experimental spectra. We are also exploring other libraries (genetic algorithms) that will also scale well in high performance systems. Finally we are uniquely equipped with predictions of film structures from molecular simulations (de Pablo group). In a parallel effort we will recreate (rather than fit experimental data) scattering from structures predicted by simulations. This will allow for direct comparison to experimental data. Industry partnership: Project URL: Requested allocation: 480000 Q1: 120000 Q2: 120000 Q3: 120000 Q4: 120000 Justification: Storage requirements: The requester has used undetermined amount hours of their initial startup project. In addition to approving an initial amount, please specify a Category and Subcategory for this project. For a list of the current selection of approved categories, please see: https://wiki.lcrc.anl.gov/wiki/Processes/Categories Once the Allocation committee has approved the project, please go to the Project Management page to create it: https://accounts.lcrc.anl.gov/projects.php Thank You, The LCRC Accounts System