July 2011

Conference Paper

Experiments to Measure Hydrogen Release from Graphite Walls During Disruptions in DIII-D

By:
Hollmann, E. M.; Pablant, N. A.; Rudakov, D.L.; Boedo, J.; Brooks, N. H.; Jernigan, Thomas C; Pigarov, A
Journal Name:
Journal of Nuclear Materials
Page Number:
597-601
Volume:
390-91
Issue Number:
N/A
Publication Date:
July 29, 2011
Conference Name:
18th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices
Conference Location:
Toldeo, Spain
Conference Sponsor:
Spanish Natl Fus Lab; Spanish Minist Sci & Innovat
View DOI Listing:
https://doi.org/10.1016/j.jnucmat.2009.01.124

Abstract

Spectroscopy and wall the bake-out measurements are performed in the DIII-D tokamak to estimate the amount of hydrogen stored in and released from the walls during disruptions. Both naturally occurring disruptions and disruptions induced by massive gas injection (MGI) are investigated. The measurements indicate that both types of disruptions cause a net release of order 10(21) hydrogen (or deuterium) atoms from the graphite walls. This is comparable to the pre-disruptions plasma particle inventory, so the released hydrogen is important for accurate modeling of disruptions. However, the amount of hydrogen released is small compared to the total saturated wall inventory of order 10(22)-10(23), So it appears that many disruptions are necessary to provide full pump-out of the vessel walls. (C) 2009 Published by Elsevier B.V.