Intense Neutron Source
The era of “applied accelerators” (accelerators built not primarily for nuclear physics studies) at CRNL began in early 1964 with a proposal presented by W.B. Lewis to the AECL Board of Directors for the construction of an accelerator-based Intense Neutron Source (ING). ING was proposed as the next high thermal-flux neutron source after NRU and was projected to have a maximum thermal neutron flux approaching 100 times that of NRU.
The facility proposed would consist of a 1.6 km long linear accelerator that would accelerate a very intense (65 mA average) proton beam as well as a lower intensity, (1 mA) negatively-charged, hydrogen beam to an energy approaching 1000 MeV. The negatively-charged beam could be used for meson-physics experiments while the intense proton beam would be directed to a liquid lead/bismuth target where it would generate the intense neutron flux via the “spallation” process. Experiments and calculations showed that a single proton of this energy can “spall” or knock out 40-50 neutrons when it strikes the nucleus of an atom in the lead-bismuth part of the periodic table. Full details of the project are described in the publication AECL-2600. See link (AA1).
Photo source- AECL.