TY - JOUR
T1 - A parasitic effect in neutral particle diagnostic using a helium probing beam
AU - Tobita, Kenji
AU - Kusama, Yoshinori
AU - Itoh, Takao
AU - Nemoto, Masahiro
AU - Takeuchi, Hiroshi
AU - Tsukahara, Yoshimitsu
PY - 1990/4
Y1 - 1990/4
N2 - This paper describes the characteristic and the physical picture of a parasitic disturbance, which can occur because of the drift motion of probing beam ions trapped at the plasma edge, in active neutral particle measurements for magnetically confined fusion devices. In the JT-60 experiments, the disturbance is observed under the condition in which a neutral particle analyzer views the high recycling region, i.e., the divertor, and the occurrence of the parasitic effect is substantially dependent on the safety factor at the plasma boundary. Also discussed are the validity of our interpretation and some measures for avoiding the disturbance.
AB - This paper describes the characteristic and the physical picture of a parasitic disturbance, which can occur because of the drift motion of probing beam ions trapped at the plasma edge, in active neutral particle measurements for magnetically confined fusion devices. In the JT-60 experiments, the disturbance is observed under the condition in which a neutral particle analyzer views the high recycling region, i.e., the divertor, and the occurrence of the parasitic effect is substantially dependent on the safety factor at the plasma boundary. Also discussed are the validity of our interpretation and some measures for avoiding the disturbance.
KW - Active beam scattering
KW - Banana orbit
KW - Beam probe
KW - JT-60
KW - Neutral particle diagnostic
KW - Tokamak
KW - Trapped particle
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U2 - 10.1143/JJAP.29.760
DO - 10.1143/JJAP.29.760
M3 - Article
AN - SCOPUS:0025414650
VL - 29
SP - 760
EP - 764
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 - 4 R
ER -