Reversed field pinch experiments have been performed by using a small
size device, which is characterized a high aspect ratio and high curre
nt density. The RFP configuration has been achieved as follows; the du
ration is about 0.3 ms, the plasma current is 25 kA that corresponds t
o the average current density exceeds 4 MA/m(2), and the loop voltage
is about 40 V. In the plasma, we have observed asymmetry in the radial
profile of the magnetic field and dynamic behavior of the RFP plasma
disruption. From the relation between the toroidal magnetic flux and t
he plasma current, the effective inductance is obtained and compared w
ith the theoretical value.