Magneto-optical traps provide a cold, compact cloud of radioactive atoms and therefore are an ideal source for use in precision nuclear β decay studies. Optical pumping techniques can add a new dimension to such experiments by efficiently polarizing these samples to 99%. Triumf's experiment E925 is utilizing these techniques to prepare to measure the isospin mixing between the first two I π =2 + excited states of 3 6 Ar with the lowest 2 + , T=1 isobaric analog state. The spin-polarized 3 6 K β + decay observables will be measured using Triumf's neutral atom trap at Isac, Triumf's isotope separator and accelerator facility. The main purpose is to test isospin mixing models in the s,d-shell needed for determination of the superallowed Fermi strength in 0 + ->0 + decays.