Supplemental ELM control in ITER through beryllium granule injection

Journal Article · Wed May 01 00:00:00 EDT 2019 · Nuclear Materials and Energy

DOI:https://doi.org/10.1016/j.nme.2019.02.005· OSTI ID:1529723

Lunsford, R.; Bortolon, A.; Maingi, R.; Mansfield, D. K.; Nagy, A.; Jackson, G. L.; Osborne, T.

Injection of low-Z granules into high performance discharges on DIII-D has been shown to promptly trigger Edge Localized Modes (ELMs) providing high-Z impurity control without significant plasma degradation. The ability to provide ELM triggering over a range of injection and discharge parameters suggests that the mechanical introduction of granules can be considered as an additional method of impurity control in ITER. Utilizing a spherically symmetric vapor shielding model for granule ablation, benchmarked with impurity granule injections on DIII-D, we simulate the injection of beryllium granules into ITER baseline discharges. By comparing the granule induced ELM triggering size required for deuterium and non-fuel pellets on DIII-D and cross-correlating with a previously simulated JOREK calcuation of D pellet size required for ELM triggering in ITER, we estimate that a beryllium pellet of 1.5 mm diameter should provide reliable ELM triggering on ITER. This size pellet, delivered at 200 m/s should penetrate 3.5 cm past the separatrix, solidly within the H-mode steep gradient region, a location found to be advantageous for ELM triggering with minimal pellet size.

• Research Organization: Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: FC02-04ER54698
• OSTI ID: 1529723
• Alternate ID(s): OSTI ID: 1506112
• Journal Information: Nuclear Materials and Energy, Journal Name: Nuclear Materials and Energy Vol. 19 Journal Issue: C; ISSN 2352-1791
• Publisher: Elsevier
• Country of Publication: Netherlands
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ELM pacing
granule injection
beryllium