Plasma and Fusion Research
Volume 17, 1201082 (2022)
Rapid Communications
- Department of Quantum Science and Energy Engineering, Tohoku University, Sendai 980-8579, Japan
- 1)
- National Institutes for Quantum Science and Technology, Rokkasho 039-3212, Japan
Abstract
The rollover of electron density, a common indicator for the onset of volumetric recombination, was observed in hydrogen plasma, for the first time in the DT-ALPHA. Electron density and electron temperature were measured near the plasma production region and secondary gas feeding position with various conditions regarding the amount of hydrogen secondary gas. A rollover of electron density was observed at the secondary gas feeding position, whereas electron density near the plasma production region remained nearly constant. This behavior indicates an enhancement of hydrogen molecular-activated recombination.
Keywords
divertor, molecular-activated recombination, hydrogen plasma, radio-frequency plasma, DT-ALPHA
Full Text
References
- [1] S.I. Krasheninnikov et al., Phys. Lett. A 214, 285 (1996).
- [2] N. Ohno et al., Phys. Rev. Lett. 81, 818 (1998).
- [3] L. Cai et al., Phys. Plasmas 15, 102505 (2008).
- [4] G.R.A. Akkermans et al., Phys. Plasmas 27, 102509 (2020).
- [5] S. Kado et al., J. Nucl. Mater. 337-339, 166 (2005).
- [6] K. Verhaegh et al., Nucl. Mater. Energy 26, 100922 (2021).
- [7] J.L. Terry et al., Phys. Plasmas 5, 1759 (1998).
- [8] M. Sakamoto et al., Nucl. Mater. Energy 12, 1004 (2017).
- [9] N. Ezumi et al., Nucl. Fusion 59, 066030 (2019).
- [10] S. Abe et al., Nucl. Mater. Energy 19, 390 (2019).
- [11] T. Seino et al., Plasma Fusion Res. 15, 1201056 (2020).
- [12] A. Okamoto et al., Plasma Fusion Res. 3, 059 (2008).
- [13] H. Takahashi et al., Phys. Plasmas 23, 112510 (2016).