@article{befeae9bce2b4198a55a4ca2ae081023,
title = "Experimental verification of ion impact angle distribution at divertor surfaces using micro-engineered targets on DiMES at DIII-D",
abstract = "We report the first detailed experimental verification of the polar deuterium ion impact angle distribution (IAD) on the DIII-D divertor surface in L-mode plasmas using micro-engineered trenches in samples mounted on the DiMES probe. These trenches were fabricated via focused ion beam (FIB) milling of a silicon surface partially coated with aluminum. The sample surfaces were exposed to eight repeat L-mode deuterium discharges (30 s total exposure time). The samples were examined by scanning electron microscopy (SEM), which revealed changes on the trench floor due to material deposition and evidence for shadowing of the incident deuterium ions by the trench walls. The areal distribution of carbon and aluminum deposition was measured by energy-dispersive X-ray spectroscopy (EDS). One-dimensional profiles of this deposition are in agreement with net erosion profiles calculated from a Monte Carlo micro-patterning and roughness (MPR) code for ion sputtering using as input the polar and azimuthal deuterium IADs reported previously (Chrobak et al., Nucl. Fusion 58, 106,019 (2018)). The deposition profiles verified the characteristic shape of the polar IADs, which have a broad maximum from 79° to 86°, over the experimental range of 68°–83°, where 0° is the surface normal direction.",
keywords = "Deposition, DiMES, Divertor, Erosion, Ion impact angle, Plasma-material interaction, Sheath, Surface analysis",
author = "S. Abe and Skinner, {C. H.} and I. Bykov and Yeh, {Y. W.} and A. Lasa and J. Coburn and Rudakov, {D. L.} and Lasnier, {C. J.} and Wang, {H. Q.} and McLean, {A. G.} and T. Abrams and Koel, {B. E.}",
note = "Funding Information: The authors thank Roman Akhmechet, Zuzanna A. Lewicka, and David S. Barth of PRISM (Princeton University) for fabricating the aluminum coating, and John J. Schreiber for SEM/EDS analysis. We thank Dean Buchenauer and Josh Whaley (Sandia National Laboratories) for providing the Si(111) sample discs. We also thank Christopher P. Chrobak for advice on his IAD prediction. BEK acknowledges support of this work by the U.S. Department of Energy, Office of Science/Fusion Energy Sciences under Award Number DE-SC0019308. This work is also supported by US DOE Contract Nos. DE-AC02-09CH11466 and DE-FC02-04ER54698. The authors acknowledge the use of Princeton{\textquoteright}s Imaging and Analysis Center, which is partially supported through the Princeton Center for Complex Materials (PCCM), a National Science Foundation (NSF)-MRSEC program (DMR-2011750). The United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Publisher Copyright: {\textcopyright} 2021 The Authors",
year = "2021",
month = jun,
doi = "10.1016/j.nme.2021.100965",
language = "English (US)",
volume = "27",
journal = "Nuclear Materials and Energy",
issn = "2352-1791",
publisher = "Elsevier Limited",
}