Implantation of 30 keV Helium into Graphene-Coated Tungsten

Abstract

This technical note describes the use of graphene as a way to protect plasma facing components from erosion, sputtering and diminished plasma performance and to extend component lifetimes in experimental plasma devices. In this work, 30 keV ionized helium is used as a projectile on graphene covered tungsten over a range of fluences. Graphene’s vacancy yield (I_D) and natural resonance (I_G) are found at ~1350 cm⁻¹ and ~1550 cm⁻¹, respectively. Damage of each sample is quantified using the I_D/I_G ratio via Raman spectroscopy (RS) at the aforementioned wave numbers. The surface morphology is studied using Scanning Electron Microscopy (SEM) and the mass losses are recorded using a high-precision scale. The results from this study are of considerable importance since they indicate that a graphene coating could be an effective candidate for reducing erosion in different PFC materials.

Keywords:

• Graphene
• tungsten
• helium irradiation
• plasma facing components (PFCs)

Acknowledgments

The authors wish to acknowledge the financial support for this work from the Graduate Engineering Research Scholars, TEAM-Science (NIH Grant R25GM083252) at the University of Wisconsin-Madison, and the Grainger Foundation. We thank Robert Jacobberger for growing the graphene. The work of Richard Rojas Delgado and Professor Max G. Lagally was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences (DOE) Award DEFG02-03ER46028. We acknowledge the use of facilities and instrumentation supported by NSF through the University of Wisconsin Materials Research Science and Engineering Center, DMR-1121288.