The cryo-SEVI method has been described in detail previously. Here, NiO2¯ anions are formed via laser ablation using a rotating and translating nickel disk onto which a frequencydoubled Nd:YAG is focused. The resulting plasma is entrained within a pulse of He carrier gas from an Even-Lavie solenoid valve, with residual O2 in this carrier gas serving to form NiO2¯ as it passes through a narrow channel to foster collisional cooling and cluster formation. The ions then pass through a skimmer before entering a radiofrequency (RF) hexapole ion guide and RF quadrupole mass filter that direct them into a linear RF octupole ion trap held at 5 K and filled with a buffer gas mixture of 20:80 H2:He. Collisions with this cold buffer gas mixture result in effective vibrational, rotational, and electronic cooling of the ions, leading to internal temperatures of around 10 K. The ions are held approximately 40 ms in the trap before being extracted into an orthogonal Wiley-McLaren time-of-flight mass spectrometer and focused into the interaction region of a standard three-plate Eppink-Parker VMI electrostatic lens assembly. In the VMI spectrometer, the ions are photodetached using the frequency-doubled output of a dye laser pumped by the second harmonic of a Nd:YAG laser operating at 20 Hz.