Plasma blob dynamics on the high-field side in the proximity of a magnetic field null (X point) is investigated in TORPEX. A significant acceleration of the blobs towards the X point is observed. Close to the X point the blobs break apart. The E × B drifts associated with the blobs are measured, isolating the background drift component from the fluctuating contribution of the blob internal potential dipole. The time evolution of the latter is consistent with the fast blob dynamics. An analytical model based on charge conservation is derived for the potential dipole, including ion polarization, diamagnetic, and parallel currents. In the vicinity of the X point, a crucial role in determining the blob motion is played by the decrease of the poloidal magnetic field intensity. This variation increases the connection length that short circuits the potential dipole of the blob. Good quantitative agreement is found between the model and the experimental data in the initial accelerating phase of the blob dynamics. DOI: 10.1103/PhysRevLett.116.105001 Magnetic field nulls (X points) are ubiquitous in space and laboratory plasmas [1][2][3]. The transport of particles and heat across them is of utmost importance for a variety of systems [4]. For example, much effort has been devoted by the fusion community in the past decades to investigate diverted magnetic geometries [5], which allow channeling through an X point a significant fraction of the exhaust power to material surfaces. Cross-field drifts associated with the steady-state and turbulence-induced electric fields play an important role for plasma transport in the X-point region, as indicated by numerical and experimental studies [6,7]. However, experimental investigations close to X points are difficult, limiting the progress in the understanding of the X-point dynamics and simulationexperiment comparisons. In fusion plasmas, the diagnostic accessibility is challenged by the high power flux so that the generation and propagation of intermittent plasma blobs in the vicinity of an X point is largely unexplored [8][9][10].In this Letter, we present the first spatial and temporaldependent in situ measurements of turbulence-generated plasma blob dynamics around the X-point region. The blob motion towards the X point is tracked and analyzed, showing an acceleration in the initial phase that can be directly linked to the background radial flow and to the measured blob electric potential dipole. The acceleration of the blob towards the X point can be quantitatively described by an analytical model that includes the dominant perpendicular and parallel current contributions. In particular, a crucial role is played by the geometrical parameter L ∥ , expressing the length of the current path parallel to the magnetic field, along which the blob potential dipole is short-circuited.The measurements are performed on the Toroidal Plasma Experiment (TORPEX) [11] with diverted magnetic geometries. Tokamaklike configurations, such as first-order (X point) or second-order (snowflake) nu...