Development of the Langmuir probe diagnostic system on the Helimak device at Shenzhen University

This paper systematically presents the recent development of the Langmuir probe diagnostic system on the Shenzhen University Helimak device. By employing this probe array, high spatiotemporal resolution measurements of radial plasma parameters in the device’s vacuum chamber have been achieved. The system adopts a modular design and is coupled with a multi-channel high-speed data acquisition system, significantly enhancing the diagnostic capability in the boundary region of the Helimak device. During electron cyclotron resonance heating experiments, radial profiles of plasma parameters under different magnetic field configurations were obtained using this probe system. The results reveal a low-field-side shift of the heating peak relative to the electron cyclotron resonance layer. This phenomenon primarily arises from outward transport driven by the polarization electric field induced by ∇B drift and curvature drift. These findings not only demonstrate the reliable performance of the Helimak probe system but also establish an experimental foundation for further investigations into boundary transport, drift turbulence, and heat flux channel structures.