To do that, scientists look at the probability that one type of neutrino will change into another type. The probability of that transmutation oscillates like a wave, and it increases as the distance grows between where the particle is created and where it is detected. It also depends on the difference in mass between the first type of neutrino and the second. Though Wojcicki's research base is SLAC in California, he travels to Illinois's Fermilab for his neutrinos. It's like a beam of flashlight where the farther you go, the fainter is the light.
Accelerators allow scientists to pulse the beam.
So while the background noise from natural radiation sources, such as cosmic rays, will be constant, the neutrino signal will be pulsed from the direction of Fermilab. The underground location of the detector shields it from cosmic rays, reducing the background significantly. Then protons are allowed to strike the target. They make short-lived particles called pions. You make a beam of the pions, and they travel through a vacuum pipe about half a mile long.