Comparison of cryogenic (hydrogen) and TESPEL (polystyrene) pellet particle deposition in a magnetically confined plasma
Abstract
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.
- Authors:
-
- 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
- Publication Date:
- Research Org.:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Org.:
- 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 Org.:
- TJ-II Team
- OSTI Identifier:
- 1427621
- Grant/Contract Number:
- AC05-00OR22725; 633053; ENE2013-48679-R; KEIN1102; KEIN1104; UFEX106
- Resource Type:
- Journal Article: Accepted Manuscript
- Journal Name:
- Europhysics Letters
- Additional Journal Information:
- Journal Volume: 120; Journal Issue: 2; Journal ID: ISSN 0295-5075
- Publisher:
- IOP Publishing
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY
Citation Formats
McCarthy, K. J., Tamura, N., Combs, S. K., Panadero, N., Ascabíbar, E., Estrada, T., García, R., Hernández Sánchez, J., López Fraguas, A., Navarro, M., Pastor, I., and Soleto, A. Comparison of cryogenic (hydrogen) and TESPEL (polystyrene) pellet particle deposition in a magnetically confined plasma. United States: N. p., 2018.
Web. doi:10.1209/0295-5075/120/25001.
McCarthy, K. J., Tamura, N., Combs, S. K., Panadero, N., Ascabíbar, E., Estrada, T., García, R., Hernández Sánchez, J., López Fraguas, A., Navarro, M., Pastor, I., & Soleto, A. Comparison of cryogenic (hydrogen) and TESPEL (polystyrene) pellet particle deposition in a magnetically confined plasma. United States. https://doi.org/10.1209/0295-5075/120/25001
McCarthy, K. J., Tamura, N., Combs, S. K., Panadero, N., Ascabíbar, E., Estrada, T., García, R., Hernández Sánchez, J., López Fraguas, A., Navarro, M., Pastor, I., and Soleto, A. 2018.
"Comparison of cryogenic (hydrogen) and TESPEL (polystyrene) pellet particle deposition in a magnetically confined plasma". United States. https://doi.org/10.1209/0295-5075/120/25001. https://www.osti.gov/servlets/purl/1427621.
@article{osti_1427621,
title = {Comparison of cryogenic (hydrogen) and TESPEL (polystyrene) pellet particle deposition in a magnetically confined plasma},
author = {McCarthy, K. J. and Tamura, N. and Combs, S. K. and Panadero, N. and Ascabíbar, E. and Estrada, T. and García, R. and Hernández Sánchez, J. and López Fraguas, A. and Navarro, M. and Pastor, I. and Soleto, A.},
abstractNote = {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.},
doi = {10.1209/0295-5075/120/25001},
url = {https://www.osti.gov/biblio/1427621},
journal = {Europhysics Letters},
issn = {0295-5075},
number = 2,
volume = 120,
place = {United States},
year = {Fri Jan 05 00:00:00 EST 2018},
month = {Fri Jan 05 00:00:00 EST 2018}
}
Web of Science
Figures / Tables:
Works referencing / citing this record:
Tracer-Encapsulated Solid Pellet (TESPEL) injection system for Wendelstein 7-X
journal, October 2018
- Bussiahn, R.; Tamura, N.; McCarthy, K. J.
- Review of Scientific Instruments, Vol. 89, Issue 10
The impact of fast electrons on pellet injection in the stellarator TJ-II
journal, November 2018
- McCarthy, K. J.; Panadero, N.; Combs, S. K.
- Plasma Physics and Controlled Fusion, Vol. 61, Issue 1
Plasma termination by excess pellet fueling and impurity injection in TJ-II, the Large Helical Device and Wendelstein 7-X
journal, May 2019
- Dinklage, A.; McCarthy, K. J.; Suzuki, C.
- Nuclear Fusion, Vol. 59, Issue 7
Hollow pellet injection for magnetic fusion
journal, June 2019
- Wang, Zhehui; Hoffbauer, M. A.; Hollmann, E. M.
- Nuclear Fusion, Vol. 59, Issue 8
Overview of recent TJ-II stellarator results
journal, July 2019
- Ascasíbar, E.; Alba, D.; Alegre, D.
- Nuclear Fusion, Vol. 59, Issue 11
Overview of recent TJ-II stellarator results
text, January 2019
- Ascasíbar, Enrique; Alba, D.; Alegre, Daniel
- ETH Zurich
Figures / Tables found in this record: