Fig. 3: VMI experiment and results.
Schematic setup of the VMI experiment (a) together with images for Ar+ from He*–Ar collisions (b) and Ar+ and NeAr+ from Ne*–Ar collisions (c), collected at collision energies E∕kB = 7.8 K and 14.0 K, respectively. The outer ring observed for Ar+ (from He*–Ar) corresponds to a kinetic energy comparable to the spin–orbit splitting, cf. Fig. 2, and indicates presence of FFR with lifetimes shorter than the TOF (~12 μs). The absence of such a ring (the expected position is indicated by the white circle in c) for Ar+ from Ne*–Ar suggests lifetimes significantly exceeding the TOF. The axes in b, c correspond to Ar+ velocities, where the collision axis lies along the green trajectory in a and points up in the VMI images as depicted by the white arrow in b, c. The image in b is taken with temporal mass selection of the Ar+ products, while in c the different masses are spatially separated on the detector by an external magnetic field as described in the Methods section.
