Edge Radial Electric Field in Positive and Negative Triangularity Plasmas in the TCV Tokamak

S. Rienäcker; P. Hennequin; L. Vermare; C. Honoré; R. Bouffet-Klein; S. Coda; B. Labit; B. Vincent; K. E. Thome; O. Krutkin; A. Balestri; Y. Nakeva; the TCV team

paper

Edge Radial Electric Field in Positive and Negative Triangularity Plasmas in the TCV Tokamak

arXiv:2507.08682

Abstract

We present the first edge $E_{r}$ measurements in negative triangularity (NT) TCV plasmas. The Doppler backscattering measurements of $v_{⊥} \approx E_{r} / B$ reveal a significant impact of triangularity on the $E_{r}$ well: In Ohmic, NBI, and ECRH heated discharges, the $E_{r}$ well and associated $E_{r} \times B$ shear are stronger in NT-shaped plasmas compared to their positive triangularity (PT) counterpart. This suggests a connection to the concomitant NT performance gain relative to PT L-mode.