Effect of a magnetic field on the floating double-probe method

Effects of a magnetic field on the double-probe technique are studied experimentally by means of asymmetric double probes in a low-pressure, high-density plasma. It is found that the magnetic field can considerably affect ion probe currents, even if the ion gyro radius is very much larger than the probe size; for example, by a factor of seventy for transverse current collections. At strong fields the effective collecting area for parallel current collections becomes proportional to something like the periphery of the probe.