Abstract
A volume-averaged equilibrium β value 〈β eq 〉 of 2.14% is achieved in a compact helical system using two neutral beam lines with balanced injection and intense wall conditioning with Ti gettering. This value is the highest β value realized so far in helical systems. Reheat mode, where the stored energy increases after turn-off of a strong gas puff, is employed in the experiment. Discharge conditions are as follows: B t = 0.61 T; beam power through the port, 1.1 MW (coinjection) and 0.8 MW (counterinjection); line-averaged electron density n e = 6.5 × 10 13 cm -3 . Amplitudes of magnetic fluctuations integrated over the frequency range from 3 kHz to 100 kHz become saturated at 〈β eq 〉 higher than 1%. Dominant coherent modes are m n = 2 1 and 1 1 when 〈β eq 〉 is lower and higher respectively than 1%. Dependence of the energy confinement time τ E on n e (up to 8 × 10 13 cm -3 ) and B t (from 0.6 to 1.8T) is also studied in this high β experiment. When the density increases τ E degrades compared with the LHD scaling; the density dependence exhibits Bohm-like behaviour. On the contrary, τ E scales as B t ≈0.75 , which is rather close to the LHD scaling (gyro-Bohm-like behaviour).
| Original language | English |
|---|---|
| Pages (from-to) | 135-140 |
| Number of pages | 6 |
| Journal | Fusion Engineering and Design |
| Volume | 26 |
| Issue number | 1-4 |
| DOIs | |
| Publication status | Published - Jan 1 1995 |
| Externally published | Yes |
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All Science Journal Classification (ASJC) codes
- Civil and Structural Engineering
- Nuclear Energy and Engineering
- Materials Science(all)
- Mechanical Engineering
Cite this
High β experiment and confinement regimes in a compact helical system. / Matsuoka, K.; Okamura, S.; Nishimura, K.; Tsumori, K.; Akiyama, R.; Yamada, H.; Sakakibara, S.; Lazaros, A.; Xu, J.; Ida, K.; Tanaka, K.; Morisaki, T.; Morita, S.; Arimoto, H.; Ejiri, A.; Fujiwara, M.; Idei, Hiroshi; Iguchi, H.; Kaneko, O.; Kawamoto, T.; Kubo, S.; Kuroda, T.; Motojima, O.; Ozaki, T.; Pustovitov, V. D.; Sagara, A.; Takahashi, C.; Toi, K.; Watari, T.; Yamada, I.
In: Fusion Engineering and Design, Vol. 26, No. 1-4, 01.01.1995, p. 135-140.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - High β experiment and confinement regimes in a compact helical system
AU - Matsuoka, K.
AU - Okamura, S.
AU - Nishimura, K.
AU - Tsumori, K.
AU - Akiyama, R.
AU - Yamada, H.
AU - Sakakibara, S.
AU - Lazaros, A.
AU - Xu, J.
AU - Ida, K.
AU - Tanaka, K.
AU - Morisaki, T.
AU - Morita, S.
AU - Arimoto, H.
AU - Ejiri, A.
AU - Fujiwara, M.
AU - Idei, Hiroshi
AU - Iguchi, H.
AU - Kaneko, O.
AU - Kawamoto, T.
AU - Kubo, S.
AU - Kuroda, T.
AU - Motojima, O.
AU - Ozaki, T.
AU - Pustovitov, V. D.
AU - Sagara, A.
AU - Takahashi, C.
AU - Toi, K.
AU - Watari, T.
AU - Yamada, I.
PY - 1995/1/1
Y1 - 1995/1/1
N2 - A volume-averaged equilibrium β value 〈β eq 〉 of 2.14% is achieved in a compact helical system using two neutral beam lines with balanced injection and intense wall conditioning with Ti gettering. This value is the highest β value realized so far in helical systems. Reheat mode, where the stored energy increases after turn-off of a strong gas puff, is employed in the experiment. Discharge conditions are as follows: B t = 0.61 T; beam power through the port, 1.1 MW (coinjection) and 0.8 MW (counterinjection); line-averaged electron density n e = 6.5 × 10 13 cm -3 . Amplitudes of magnetic fluctuations integrated over the frequency range from 3 kHz to 100 kHz become saturated at 〈β eq 〉 higher than 1%. Dominant coherent modes are m n = 2 1 and 1 1 when 〈β eq 〉 is lower and higher respectively than 1%. Dependence of the energy confinement time τ E on n e (up to 8 × 10 13 cm -3 ) and B t (from 0.6 to 1.8T) is also studied in this high β experiment. When the density increases τ E degrades compared with the LHD scaling; the density dependence exhibits Bohm-like behaviour. On the contrary, τ E scales as B t ≈0.75 , which is rather close to the LHD scaling (gyro-Bohm-like behaviour).
AB - A volume-averaged equilibrium β value 〈β eq 〉 of 2.14% is achieved in a compact helical system using two neutral beam lines with balanced injection and intense wall conditioning with Ti gettering. This value is the highest β value realized so far in helical systems. Reheat mode, where the stored energy increases after turn-off of a strong gas puff, is employed in the experiment. Discharge conditions are as follows: B t = 0.61 T; beam power through the port, 1.1 MW (coinjection) and 0.8 MW (counterinjection); line-averaged electron density n e = 6.5 × 10 13 cm -3 . Amplitudes of magnetic fluctuations integrated over the frequency range from 3 kHz to 100 kHz become saturated at 〈β eq 〉 higher than 1%. Dominant coherent modes are m n = 2 1 and 1 1 when 〈β eq 〉 is lower and higher respectively than 1%. Dependence of the energy confinement time τ E on n e (up to 8 × 10 13 cm -3 ) and B t (from 0.6 to 1.8T) is also studied in this high β experiment. When the density increases τ E degrades compared with the LHD scaling; the density dependence exhibits Bohm-like behaviour. On the contrary, τ E scales as B t ≈0.75 , which is rather close to the LHD scaling (gyro-Bohm-like behaviour).
UR - http://www.scopus.com/inward/record.url?scp=0029207647&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0029207647&partnerID=8YFLogxK
U2 - 10.1016/0920-3796(94)00178-A
DO - 10.1016/0920-3796(94)00178-A
M3 - Article
AN - SCOPUS:0029207647
VL - 26
SP - 135
EP - 140
JO - Fusion Engineering and Design
JF - Fusion Engineering and Design
SN - 0920-3796
IS - 1-4
ER -