Persa Raymond ‘P. R.’ Bell

Abstract

Persa Raymond “P. R.” Bell, one of the founders of nuclear medicine and a versatile electronics expert, died 10 January 2001 of heart disease in Oak Ridge, Tennessee.Born on 24 April 1913 just outside Fort Wayne, Indiana, P. R. graduated in 1936 with a BSc in chemistry from Howard College (now Samford University) in Birmingham, Alabama. He repaired radios in several northern Alabama towns to earn enough money to enter graduate studies in physics at the University of Chicago, which he began attending in 1938.In 1940, P. R. joined the National Defense Research Committee’s Project Chicago as a staff member. He worked on high-speed counters for the project. In 1941, he was recruited from Chicago to MIT’s Radiation Lab, which worked in secret to develop radar. While there, he discovered the photoelectric effect in silicon. After the war ended, P. R. joined Clinton National Laboratory, now Oak Ridge National Laboratory (ORNL), where he applied his ingenuity in electronics to invent—with Walter Jordan—the famous A-1 amplifier. In the late 1940s, P. R. built some of the earliest crude spectrometers using organic scintillators. The first significant units, poor in resolution but still capable of resolving quite complex spectra, used 1.5-inch diameter by 1-inch thick thallium-doped sodium iodide crystals. Development of these units soon led to the use of scintillation spectrometry in the emerging field of nuclear medicine imaging. In 1966, P. R. helped design the large low-background spectrometers used in the Lunar Receiving Laboratory in Houston, Texas.In 1957, P. R. became an associate director of ORNL’s thermonuclear division, where he was instrumental in the design and operation of the DCX-2 mirror machine experiment. By connecting DCX-2 to a new Linc-8 computer from Digital Equipment Co, he did some of the first computer monitoring of plasma physics machines. Although strong radio-frequency oscillations eventually resulted in the termination of the DCX-2 experiment, P. R. noted that the experiment led to important research into the study of vacuum arcs—carbon, lithium, and deuterium—an important tool for work in space.During a leave of absence from ORNL from 1967 to 1969, P. R. was the manager of the Lunar Receiving Laboratory and chief of the lunar and Earth sciences division of NASA’s Manned Spacecraft Center in Houston when the first samples were taken from the Moon during the Apollo 11 mission. In 1969, the lunar material was returned in rock boxes and then studied in a containment vacuum system, which P. R. helped to develop. His innate enthusiasm was evident as he interacted with geologists and chemists during those studies.P. R. returned to ORNL in 1970 as the assistant director of the Molecular Anatomy Project. In 1974, he became a member of ORNL’s health and safety research division, within the biology division. In both capacities, he was concerned with the computer processing of nuclear medicine images. After retiring from ORNL in 1978, P. R. joined the Institute for Energy Analysis at Oak Ridge Associated Universities. There, during the 1980s, he began studying, and lecturing on, the problem of global climate change. He was one of the first scientists to point to the melting of methane hydrates as a contributor to greenhouse warming.P. R.’s accomplishments were recognized in 1964, when he received the Edward Longstreth Medal from the Franklin Institute for his pioneering work in nuclear medicine. In 1976, the bicentennial celebration calendar of Mallinckrodt Inc, based in St. Louis, Missouri, acknowledged P. R., citing that he “founded scintillation spectrometry; plotted [the] first scintillation beta spectrum; developed [a] basis for [the] widespread use of sodium iodide gamma counters; originated [the] ‘medical spectrometer’; [and was] active in development of scanning instrumentation.”Although an early onset of macular degeneration left P. R. legally blind throughout his adult life, he considered this just a minor obstacle to the pursuit of his goals. He was a man of broad interests: Everything in nature interested him, and he threw himself into each project with tremendous energy and enthusiasm. He wanted everyone to share in the wonders of this world and was well known locally for his down-to-earth talks to civic clubs and organizations. He had a great love of music and, in younger days when his eyesight was better, sketching and woodcarving.P. R. will be remembered for his love of science, his unassuming ways, the love he gave to his wife and son, his kind and gentle nature, and his happy disposition. Persa Raymond “P. R.” Bell PPT|High resolution© 2001 American Institute of Physics.