Prof. Jörg Schreiber’s team is hard at work on the LION Cave in CALA, where the ATLAS laser beam is focused onto its target, an extremely thin carbon foil. Each encounter will accelerate ionized carbon atoms to energies of up to 400 MeV/nucleon (Laser-driven ION Acceleration). Leonard Doyle and Jens Hartmann are setting the next building block on the new mobile beam dump, which will effectively screen the workspace from the resulting radiation. The brightly lit vessel in the picture will later be filled with water, which acts as a neutron moderator to slow down the fast neutrons produced in experiments. The bulk(!) of the facility is made of blocks (of up to 900 kg) of a special type of concrete and, including the water tank, the whole thing weighs around 12 tons.