Room: TBD - will update by Friday, Jan 30
Speaker: Dr. Laura Zhang, Tokamak Energy
Title: Recent results and future plans of the ST40 spherical tokamak
Abstract:
ST40 is a compact, high-field spherical tokamak (ST) with a mission to expand the physics and technology basis for the ST route to fusion. The ST40 research programme covers transport and confinement, scrape-off-layer and divertor, advanced operating scenarios, high performance scenarios, and edge and pedestal. Parameters achieved by ST40 so far are: R0 ≈ 0.4−0.5m, Ip ≈ 0.25−1MA, Bt(R=0.4m) ≈ 0.7−2.1T, κ < 1.9, A ≈ 1.6−1.9, PNBI ~ 1.8MW, and tflattop ≤ 200ms. Recently, diverted H-mode scenarios with Ip > 750kA and tflattop ~ 50ms, were developed. At Ip = 450kA, early transition to diverted configuration enabled Ip flattops with up to 150ms of H-mode duration, with sustained ELM-free phases. In this talk, the ST40 tokamak and physics program will be introduced. Recent experimental results will also be highlighted. Plans for upgrade for the upcoming campaigns include EC heating and current drive system, pellet injectors for fueling studies, and lithium evaporation systems, as well as a comprehensive upgrade of the diagnostics set.
Bio: Dr. Laura Xin Zhang is a plasma physicist and team leader at Tokamak Energy, focusing on scrape-off-layer physics, integrated modeling, and tokamak design for future fusion pilot plants. She earned her Ph.D. in plasma physics from Princeton University, where she developed reduced-physics models for core–edge coupled simulations in tokamak plasmas. Laura leads the Integrated Core–SOL–Divertor team at Tokamak Energy, collaborates with researchers across the U.S. and U.K. fusion communities, and has co-authored peer-reviewed publications on a range of plasma physics topics. She is also active in mentoring early-career scientists, guest lecturing, and supporting diversity and inclusion efforts in plasma physics through APS and community outreach.
Seminar Access: In-person seminars are only available to CU ID holders. At this time, Non-Columbia affiliates and the general public are only invited to participate remotely. Contact [email protected] if you would like the Zoom link for this seminar.