Pump limiter studies on the Heliotron-E device

Conference · Thu May 01 00:00:00 EDT 1986

OSTI ID:5841458

Hillis, D L; Mioduszewski, P K; Zuhr, R A; Clausing, R E; Baity, F W; Fowler, R H; Rome, J A; Motojima, O; Mitzuuchi, T; Mutoh, T

Particle control with pump limiters has been successfully demonstrated in a variety of tokamaks. This experiment has obtained, for the first time, experimental data on pump limiter operation in a heliotron configuration. A movable pump limiter module was installed on a horizontal midplane port of Heliotron-E. The limiter assembly consists of a TiC-coated graphite head with single-sided particle collection and active pumping. The location of the limiter is varied from near the vacuum vessel wall or up to 8 cm inside the last closed magnetic flux surface. This flexibility permits the study of a heliotron plasma that is limited either by the magnetic separatrix or by a material limiter. In the configuration investigated, only very low pressures are observed in the pump limiter when it is located outside the last closed flux surface, indicating that the scrape-off layer density is very low (<5 x 10/sup 11/cm/sup -3/). For limiter positions inside the last closed flux surface, pressures of 2 to 6 mTorr are observed (similar to comparable tokamak operation). Erosion patterns on the vacuum vessel, as well as hot spots on the limiter head, indicate that the particle flow out of the confined plasma exhibits complicated patterns.

• Research Organization: Oak Ridge National Lab., TN (USA); Kyoto Univ., Uji (Japan). Plasma Physics Lab.
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5841458
• Report Number(s): CONF-860522-9; ON: DE86011500
• Resource Relation: Conference: 7. international conference on plasma surface interactions in controlled fusion devices, Princeton, NJ, USA, 5 May 1986; Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
HELIOTRON
LIMITERS
PERFORMANCE TESTING
EROSION
GRAPHITE
TITANIUM CARBIDES
VACUUM SYSTEMS
CARBIDES
CARBON
CARBON COMPOUNDS
CLOSED PLASMA DEVICES
ELEMENTAL MINERALS
ELEMENTS
MINERALS
NONMETALS
TESTING
THERMONUCLEAR DEVICES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
700209* - Fusion Power Plant Technology- Component Development &amp; Materials Testing