We carry out several numerical simulations to illustrate how the radial electric field (Er) impacts the edge magnetohydrodynamic (MHD) instabilities. The analyses reveal that Er-shear (Er′, here the prime denotes the derivative with respect to the radial direction) tends to stabilize the kink/Peeling–Ballooning modes by dephasing the perturbed radial velocity (ṽr) and displacement (ξ̃r). However, Er-curvature (Er″) tends to destabilize the kink/peeling modes by inducing a phase lock between ṽr and ξ̃r. More specifically, the ratio between them could be measured to quantify their relative competition strength. Consequently, the shape of Er is crucial to the shape of linear growth rate spectrum γ(n) (here n is the toroidal mode number), which further determines the nonlinear dynamics. On the one hand, relatively larger Er-curvature causes narrower γ(n), leading to larger nonlinear energy loss fraction. On the other hand, relatively larger Er-shear has the opposite effect.

To maximize the light yield of the liquid scintillator (LS) for the Jiangmen Underground Neutrino Observatory (JUNO), a 20 t LS sample was produced in a pilot plant at Daya Bay. The optical properties of the new LS in various compositions were studied by replacing the gadolinium-loaded LS in one antineutrino detector. The concentrations of the fluor, PPO, and the wavelength shifter, bis-MSB, were increased in 12 steps from 0.5 g/L and <0.01 mg/L to 4 g/L and 13 mg/L, respectively. The numbers of total detected photoelectrons suggest that, with the optically purified solvent, the bis-MSB concentration does not need to be more than 4 mg/L. To bridge the one order of magnitude in the detector size difference between Daya Bay and JUNO, the Daya Bay data were used to tune the parameters of a newly developed optical model. Then, the model and tuned parameters were used in the JUNO simulation. This enabled to determine the optimal composition for the JUNO LS: purified solvent LAB with 2.5 g/L PPO, and 1 to 4 mg/L bis-MSB.