The magnetic field structure of a snowflake divertor

摘要: The snowflake divertor exploits a tokamak geometry in which the poloidal magnetic field null approaches second order; name stems from characteristic hexagonal, snowflakelike shape of separatrix for an exact second-order null. proximity structure to that substantially modifies edge properties compared standard X-point (with first-order null); this, turn, affects plasma behavior. Modifications include: (1) flux expansion near null-point becomes 2–3 times larger. (2) connection length between equatorial plane and plate increases. (3) Magnetic shear just inside much (4) In open-field-line region, squeezing flux-tubes increases, thereby causing stronger decoupling turbulence legs main scrape-off layer. These effects can be used reduce power load on plates and/or suppress “bursty” component heat flux. It is emphasized created by relatively simple set coils situated outside toroidal coils. Analysis robustness proposed configuration with respect changes current distribution presented it concluded that, even if close order, robust.