Emittance Measurement of the Multicusp H- Ion Source by Using an Electrical Sweep Scanner

摘要

The filament multicusp H~- source on the ion source test stand was used to study the emittance of the H~- ion beam injected into the Tanderm accelerator. The emittance measurements in the H~-ion source are performed with an electrical sweep scanner. The emittance measuring instrument was constructed and optimized to improve the signal-to-noise ratio. To get an accurate emittance, we studied various noise-compensate tools by using a current amplifier with high performance. Background fluctuations cause fluctuations in the rms emittance estimate and these fluctuations are an estimate of the uncertainty incurred through the analysis. Techniques to analyze the ellipse shapes and orientations were used to test the robustness of the results for the emittance and the acceptable emittance increased with the area of the ellipse. The normalized rms emittance of the ion source was measured to be less than 0.15 pi mm mrad.