Design and Construction of STAR_Lite: A Compact Modular Stellarator for Edge Topology and Divertor Physics Validation

Stellarators enable steady-state operation without large plasma currents, but they require complex, non-planar coils. STAR_Lite is a laboratory-scale modular stellarator (R=0.5m, |B|≈0.1T) under construction at Hampton University to study edge topology and divertor footprints under magnetic field errors relevant to optimized stellarators. The configuration, optimized from a QUASR database design with a tokamak-like outboard X-point geometry, produces a non-resonant divertor, promising resilience to field errors, as per recent computational studies. Two designs with 6 and 4 modular coils, respectively, will be evaluated against physics objectives. Hexagonal winding-pack modular coils will be fabricated in-house by winding 4-0 AWG copper cable around a 22mm stainless steel hollow pipe spine. Field validation will use a 16-probe Hall array on a 3-axis manipulator, providing microtesla sensitivity and <0.5mm spatial resolution. Magnetic field errors will be assessed through tolerance scans of manufactured coils and placement, comparing with computational models. STAR_Lite's low-cost, modular approach enables rapid prototyping iterations, providing a dedicated platform for edge/divertor physics validation supporting next-generation stellarator reactors.