At Fermilab's accelerator, a particle beam strikes a target of frozen ammonia. The hydrogen nuclei inside are like tiny tops, and physicists need them all spinning the same way. Then the collisions reveal how the proton's spin is put together. But getting billions of tops to point in one direction is like getting a stadium crowd to turn in unison at a whistle.

Microwaves at 140 gigahertz act as the conductor's baton. They flip the nuclear spins, and the nuclei gradually align. The trouble is that radiation from the beam messes up the tuning: the frequency drifts like an out-of-tune string. Previously, an operator had to turn a knob by hand, watching the signal. Now an automatic system does the job.

The engineers built a digital twin of the whole system — a computer model that mimics the real setup. It accounts for heating, radiation drift, and sensor noise. On this model, they trained several algorithms: one follows simple rules, another learns by trial and error, and a third finds patterns without hints. All of them can turn two knobs at once: the microwave frequency and their power.

The result: the target's polarization stays at its maximum even when the beam disrupts the tuning. The operator sits in a safe room watching plots, not turning knobs near radiation. The same approach will work for future spin experiments and for any cryogenic setup with finicky microwaves.