抄録
The effects of the 1 % local magnetic field asymmetry on the confinement of a low \dotB(≅108 Gauss/sec) theta pinch plasma were studied by means of high-speed photograph.
The plasma drifts radially toward the region where the strength of the magnetic field is minimum.
The mean drift velocity is several ×105 cm/sec.
It decreases appreciably as the field strength at the instant of the crowbar loweres less than 0.5 of the maximum in a half-cycle.
The outward acceleration in the early stage was found to be
(Remark: Graphics omitted.)
by the magnetohydrodynamic model where b⁄B0 is the degree of the field asymmetry and a is the radius of the plasma column.
The dependences of the observed drift velocity on the time of the crowbar and on the initial pressure are explained according to the above formula.
The 1 % local field asymmetry gives a serious limitation On containment of a high-temperature plasma.
