TY - JOUR
T1 - Visible Fluctuation Measurements on the TST-2 Spherical Tokamak
AU - Ejiri, Akira
AU - Shiraiwa, Syun'ichi
AU - Takase, Yuichi
AU - Nagashima, Yoshihiko
AU - Kasahara, Hiroshi
AU - Yamada, Takuma
AU - Ushigome, Masayasu
AU - Iijima, Daisuke
AU - Kobori, Yousuke
AU - Nishi, Tomoichirou
AU - Taniguchi, Tomokazu
AU - Yamagishi, Kenichi
PY - 2003/12
Y1 - 2003/12
N2 - The four-beam correlation method has a potential of measuring fine-scale fluctuations locally. In the method, many lines of sight are measured and the coherences among them are calculated. As a proof of principle experiment, a visible fluctuation measurement system has been fabricated and applied to the TST-2 spherical tokamak plasma. Using this system, fluctuations were measured and high-frequency components (100 ± 12.5kHz) were analyzed. Because of a long parallel correlation length, local information was not obtained directly. However, comparison of the experimental results and those of a model calculation suggests that (i) the fluctuating emission is relatively localized in the peripheral region of the plasma, (ii) the perpendicular correlation length is of the order of 1 cm, while the parallel one is much longer than it and (iii) the magnetic field angle in the peripheral region agrees with that estimated from magnetic measurements.
AB - The four-beam correlation method has a potential of measuring fine-scale fluctuations locally. In the method, many lines of sight are measured and the coherences among them are calculated. As a proof of principle experiment, a visible fluctuation measurement system has been fabricated and applied to the TST-2 spherical tokamak plasma. Using this system, fluctuations were measured and high-frequency components (100 ± 12.5kHz) were analyzed. Because of a long parallel correlation length, local information was not obtained directly. However, comparison of the experimental results and those of a model calculation suggests that (i) the fluctuating emission is relatively localized in the peripheral region of the plasma, (ii) the perpendicular correlation length is of the order of 1 cm, while the parallel one is much longer than it and (iii) the magnetic field angle in the peripheral region agrees with that estimated from magnetic measurements.
UR - http://www.scopus.com/inward/record.url?scp=10744230133&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=10744230133&partnerID=8YFLogxK
U2 - 10.1143/jjap.42.7557
DO - 10.1143/jjap.42.7557
M3 - Article
AN - SCOPUS:10744230133
VL - 42
SP - 7557
EP - 7563
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
SN - 0021-4922
IS - 12
ER -