Influence of plasma resistance and fluctuation on probe characteristics indetached recombining plasmas

In order to find the causes of the strong anomaly of current-voltage charac teristics of Langmuir probe observed in detached recombining plasmas in a l inear divertor plasma simulator, NAGDIS-II, we have investigated plasma res istance along a magnetic field and potential fluctuations in the detached r ecombining plasmas. Simple calculation on the ratio between the plasma leng th, at which plasma resistance and resistance of ion sheath formed around a probe tip become equal, and an electron collection length indicates that t he evaluation of electron temperature T-e becomes inaccurate at Te of less than 0.6 eV when plasma density and neutral pressure are 1.0 x 10(18) m(-3) and 10 mtorr, respectively. The potential fluctuation in detached recombin ing plasmas was found to be so large compared to T-e/e, which can also modi fy the probe characteristics.