Experiment of Beam Divergence Angle Measurement for Electric Propulsion by 1-Dimension Faraday Probe Array

1-dimension Faraday Probe Array(FPA) applied to beam divergence angle measurement for electric propulsion was developed, and the experiments of beam divergence angle measurement under fixed cross-section and multi cross-section were performed on LIPS-200 electric propulsion.The test results have shown that the beam divergence angle measured with 1-dimension FPA under fixed cross-section is 26.74° ±0.04° (P=95.45%), and the error of this result relative to the result of 27.07° ±0.18° (P=95.45%) measured with star-shaped FPA is 1.2%, and the combined standard uncertainty is only 22.2% of that measured with star-shaped FPA. Under multi cross-section, the beam divergence angle measured with 1-dimension FPA is 26.54° ±0.56° (P=95.45%), the error of this result relative to the result measured under fixed cross-section is 0.8%, which indicate that the beam divergence angle measuring technique with multi cross-section by 1-dimension FPA is credible. Comparing with star-shaped FPA, 1-dimension FPA has advantages of small size, light weight, high spatial resolution and large dynamic scanning range, but also can reduce the experimental cost by integrated with the thrust-measuring equipment.