Horizontal n_TOF tunnel at CERN
This is a story of a gutsy proton producing neutrons which survive 200 m of underground tunnel, reaching the experimental gallery, reporting to the experimentalist’s detector. What is so special about this story? It is very special because this proton makes it where most others can’t reach without variance reduction (also known as biasing). For a primer on variance reduction please see Chapter 5 Section 1 of an ancient writing. This history has been cherry-picked (for the greatest survivor) from a simulation of 20 GeV protons impinging a 40 cm-deep lead spallation target. This is the horizontal, older beamline of n_TOF, as opposed to the new vertical flight path. n_TOF is one of the many experiments around CERN’s accelerator complex. It is the brainchild of Carlo Rubbia, Nobel laureate, who was the Director General of CERN. Many cross-section and astrophysical experiments have been reported from here for some years.
