Physics and astrophysics
Low background environments are needed for the experiments studying rare phenomena, like the interactions of neutrinos or of the dark matter. Natural background sources, such as gamma, alpha, beta and neutron radiation from building and detector materials, can be suppressed with proper shielding materials. However, for the high energy muons the only way to reduce the background is to locate the experiments deep underground thus increasing the depth of matter.
For extremely low rate interactions the deep underground laboratories (DUL) provide surroundings where the flux of easily penetrating high energy muons is close to zero. The rock-overburden, in astroparticle physics presented in metres of water equivalent (m.w.e.), acts as a barrier for these high energy particles.
Underground physics and astrophysics search answers to fundamental questions like:
- What happens inside the Sun?
- How do the supernovae explode?
- What is the dark matter of the Universe and what is the Universe made of, and how did it evolve?
- Why does matter dominate over antimatter?
- Are protons stable or unstable?