We've done it before. Geiger and Marsden were the first to observe what is now often called the Rutherford gold foil experiment, https://en.wikipedia.org/wiki/G

We've done it before. Geiger and Marsden were the first to observe what is now often called the Rutherford gold foil experiment, https://en.wikipedia.org/wiki/Geiger%E2%80%93Marsden_experiment https://en.wikipedia.org/wiki/Geiger%E2%80%93Marsden_experim... . They used a microscope to look at the flashes of fluorescent light created after the alpha particle scatters from the foil. (We could repeat this experiment in upper-level physics lab class. The teacher said it takes about 20 minutes for the eye to become sensitive enough to see flashes. He said then that the eye could see a single photon. Looking around now, I confirmed that papers of the time only said that was needed no more than 10 quanta.) So while there may be some false positives, it's not high enough to make it useless.