Louis Rosen (June 10, 1918 – August 15, 2009) was a nuclear physicist, the "father" of the Los Alamos Neutron Science Center accelerator (LAMPF, now known as LANSCE).
While most of his colleagues at Los Alamos did not stay, Rosen remained there his entire career, and was still working there two days before his death.
He initiated and led an effort to build in Los Alamos what was then the most intense atom smasher in the world, LAMPF.
It was 1000 times more powerful than any previously existing particle accelerator, and was used to study the interaction of pions with other nuclear materials.
[3] Dr. Rosen died of a subdural hematoma in Albuquerque, New Mexico, on August 15, 2009, reported by his granddaughter Ambyr Hardy.