Comparison of cryogenic (hydrogen) and TESPEL (polystyrene) pellet particle deposition in a magnetically confined plasma
- Center for Energy, Environmental and Technological Research (CIEMAT), Madrid (Spain). National Fusion Lab.
- National Inst. for Fusion Science, Toki (Japan)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Fusion and Materials for Nuclear Systems Division
Here, a cryogenic pellet injector (PI) and tracer encapsulated solid pellet (TESPEL) injector system has been operated in combination on the stellarator TJ-II. This unique arrangement has been created by piggy-backing a TESPEL injector onto the backend of a pipe-gun–type PI. The combined injector provides a powerful new tool for comparing ablation and penetration of polystyrene TESPEL pellets and solid hydrogen pellets, as well as for contrasting subsequent pellet particle deposition and plasma perturbation under analogous plasma conditions. For instance, a significantly larger increase in plasma line-averaged electron density, and electron content, is observed after a TESPEL pellet injection compared with an equivalent cryogenic pellet injection. Moreover, for these injections from the low-magnetic-field side of the plasma cross-section, TESPEL pellets deposit electrons deeper into the plasma core than cryogenic pellets. Finally, the physics behind these observations and possible implications for pellet injection studies are discussed.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE; European Commission (EC); Ministry of Economy, Industry and Competitiveness (Spain); National Inst. for Fusion Science (NIFS); The National Inst. of Natural Sciences (NINS)
- Contributing Organization:
- TJ-II Team
- Grant/Contract Number:
- AC05-00OR22725; 633053; ENE2013-48679-R; KEIN1102; KEIN1104; UFEX106
- OSTI ID:
- 1427621
- Journal Information:
- Europhysics Letters, Vol. 120, Issue 2; ISSN 0295-5075
- Publisher:
- IOP PublishingCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Tracer-Encapsulated Solid Pellet (TESPEL) injection system for Wendelstein 7-X
|
journal | October 2018 |
The impact of fast electrons on pellet injection in the stellarator TJ-II
|
journal | November 2018 |
Plasma termination by excess pellet fueling and impurity injection in TJ-II, the Large Helical Device and Wendelstein 7-X
|
journal | May 2019 |
Hollow pellet injection for magnetic fusion
|
journal | June 2019 |
Overview of recent TJ-II stellarator results
|
journal | July 2019 |
Overview of recent TJ-II stellarator results
|
text | January 2019 |
Similar Records
Plasma fuelling with cryogenic pellets in the stellarator TJ-II
Tracer-Encapsulated Solid Pellet (TESPEL) Injection System for the TJ-II Stellarator