MiniBooNE
Like many detectors, this experiment at the Fermi National
Accelerator in Batavia, Illinois investigates the oscillation of
neutrinos from one type to another. Since 2003, it has observed
neutrinos created from protons in Fermilab's particle booster,
part of the system that the lab normally employs to accelerate
protons to higher energies for other experiments. MiniBooNE is a
40-foot-in-diameter spherical steel tank filled with 800 tons of
mineral oil and lined with 1,280 phototubes (some of which are
being adjusted in this image) that produce a flash of light when
charged particles travel through them. Analyses of these light
flashes are already providing tantalizing information about the
nonzero status of neutrino mass.