Correlated measuring method for ion average velocity of orienting plasma beam

The invention discloses a related measurement method of the ion average speed of a directional plasma beam, which relates to a method for measuring the ion average speed of a directional plasma beam with density fluctuation property and aims at solving the problems that existing measurement methods have bigger error and more complex measurement process and cannot acquire the property of ion average speed change in the microsecond magnitude. The method of the invention consists of the following steps: step one, a steady plasma engine is started and adjusted to a state of stable discharging; step two, a positive bias power source is adjusted to lead the voltage loaded on two probes to be respectively in an electronic saturation region of electric current; step three, an oscillograph is started and adjusted to display a low-frequency oscillator signal clearly; step four, the data signal of the two probes in a same time section is recorded when the steady plasma engine works in a steady state; step five, the time difference when the relativity of the two probe signals is strongest is searched; step six, the ion average speed of the directional plasma beam is computed according to the formula that Vi equals to the result of L divided by Delta Tau.