The materials analysis patticle probe (MAPP) diagnostic system in NSTX

Bryan Heim, S. Gonderman, C. N. Taylor, J. P. Allain, Z. C. Yang, M. Gonzalez, E. Collins, C. H. Skinner, B. Ellis, W. Blanchard, L. Roquemore, H. W. Kugel, R. Martin

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Lithium conditioning of plasma-facing surfaces (PFS) has been implemented in NSTX leading to improvements in plasma performance such as reduced D recycling and a reduction in edge localized modes (ELMS). Analysis of post-mortem tiles and offline experiments has identified interactions between Li-O-D and Li-C-D as chemical channels for deuterium retention in ATJ graphite. MAPP is the first in-vacuo surface analysis diagnostic directly integrated into a tokamak and capable of shot-to-shot chemical surface analysis of plasma material interactions (PMI). X-ray photoelectron spectroscopy (XPS) and low energy ion surface spectroscopy (LEISS) can show the chemical functionalities between D and lithiated graphite at both the near surface (5-10 nm) and top surface layer (0.3-0.6 nm) for XPS and LEISS respectively. MAPP will correlate plasma facing component (PFC) surface chemistry with plasma performance to lead the way to improved understanding of plasma-surface interactions and their effect on global plasma performance. Remote operation and data acquisition, integrated into NSTX diagnostic and interlocks, make MAPP an advanced PMI diagnostic with stringent engineering constraints.

Original languageEnglish (US)
Title of host publication2011 IEEE/NPSS 24th Symposium on Fusion Engineering, SOFE 2011
StatePublished - 2011
Event2011 IEEE/NPSS 24th Symposium on Fusion Engineering, SOFE 2011 - Chicago, IL, United States
Duration: Jun 26 2011Jun 30 2011

Publication series

NameProceedings - Symposium on Fusion Engineering


Conference2011 IEEE/NPSS 24th Symposium on Fusion Engineering, SOFE 2011
Country/TerritoryUnited States
CityChicago, IL

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Nuclear Energy and Engineering


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