Jefferson Lab > IT/CIO > IR
Privacy and Security Notice

JLab Library receives American Vacuum Society's rare and historical book collection

Edited Excerpts from: Canadian physicist remembered by John Chaput


Monday, August 22, 2005 - Special to The Globe and Mail

(Paul Redhead was born on May 25, 1924, in Brighton, England. He earned his BA from Cambridge University in 1944 and went on to earn his MA and PhD from Cambridge in 1948 and 1969, respectively. Dr. Redhead devoted much of his life in service to the NRC until his retirement in 1986 - his last 13 years as director of the Division of Physics. He died on July 9, 2005, in Ottawa of heart disease after 19 years of retirement. He is survived by his wife, Doris, and daughters Janet Randall and Pat Birchard.)

Over the course of 58 years at the National Research Council, Dr. Redhead established himself as one of the world's foremost authorities on vacuum technology, then in the related field of surface science. His work led to advances in products as massive as atomic-particle accelerators, as pervasive as semiconductor microchips, and as mundane as tinted windshields, plumbing fixtures and door handles.

"He understood the linkage between science, technology and products," says Denzil Doyle, chairman of Doyle Tech Corp. and a member of Dr. Redhead's NRC research team from 1949 to 1952. "Nowadays, 'commercialization' is the buzzword in scientific research, but if you suggested it 50 years ago, you'd be laughed out of the room. Scientists did science; it was someone else's job to develop a theory into a product. Paul broke that pattern of thinking."

Circumstances dictated a practical approach for the English-born scientist. On achieving his BA from Cambridge, he worked for the Department of Naval Ordnance on vacuum tubes for microwaves and proximity fuses. He remained in England after the Second World War to do experimental research and moved to Ottawa in 1947 to join the NRC's Division of Radio and Electrical Engineering to develop radar components.

A book co-authored by Dr. Redhead in 1968 with NRC colleagues Peter Hobson and Ernie Kornelson, The Physical Basis of Ultra High Vacuum, remains the definitive academic text on vacuum science to this day. An equally significant accomplishment was Dr. Redhead’s development of the magnetron gauge to measure the efficacy of vacuums.

The magnetron gauge, simply called the Redhead Gauge among scientists, can detect air pressure as light as 1/1014 Torr. A Torr is 1/760 of an atmosphere (normal air pressure at sea level), so the Redhead Gauge can detect one 76-quadrillionth (1/76,000,000,000,000,000) the density of normal air pressure.

The Redhead Gauge came in handy during the Apollo space program, when it was used to measure vacuums in space and the moon's atmosphere. It proved that the "vast emptiness" of outer space is not the nothing it's cracked up to be.

 Fred Dylla, a physicist at the Jefferson Lab in Newport News, Va., was able to appreciate Dr. Redhead on a personal as well as professional basis.

"I sent him my first article in the early '70s when I was a graduate student [at the Massachusetts Institute of Technology] and he was editor of the Journal of Vacuum Science and Technology," Dr. Dylla recalls. "I was young, very naive, and had questions about the article. Many scientists in a blind review would shy away from a request like that, but Paul had no problem discussing the article. From then on, we'd meet annually at the main symposium of the AVS. He was very approachable. By the time I was seriously into my career, he was formally retired but still active in the field of study: chairing committees, going to conferences and serving as the AVS's resident historian.

"He was captivated by what interested most real scientists: to observe a phenomenon in nature that you can then describe in a simple formula. Scientists are often either great theorists or great practitioners; the best scientists, like Paul, are comfortable in both worlds. They design and do an experiment, modeling the data based on a theory that precedes the observation.”

“While Dr. Redhead was capable of exceptional yet obscure leaps of scientific insight, he was equally comfortable explaining complex principles in basic terms. He was very much a team person, not stuffy at all. He would take the time to explain things to you.”

"His interests spanned both technology and science, which was far less common than it is today. He saw how one complemented the other. He had an unusual talent for sniffing out something interesting where others couldn't”.


(Benjamin Bonney Dayton was born in Rochester New York, February 25th 1914. He received his BS degree from Massachusetts Institute of Technology in 1937 and the Masters degree from University of Rochester in 1948. In 1943 he married Irene Glossenger and has two children, David and Glenn.)

 Dr. Dayton is a theoretical physicist with a background in nucleon structure. Early in his career he developed a love for vacuum science. From 1959 to 1972 he was US editor of the journal Vacuum. He was Chairman of the Advisory Committee of the National Standards Institute from 1964 to 1971 and a member of the Advisory Panel to the National Bureau of Standards from 1965-1971.

Dr. Dayton has promoted vacuum science and technology through years of devoted service and research at scientific and technical institutions and organizations. During the course of his career he was a devoted teacher and prolific author. In 1966-1972 he was Technical Director of the International union for Vacuum Science Technology and Applications from, staff lecturer at George Washington University and Rochester Institute of Technology from 1966-1968 and 1967-1969 respectively. Dr. Dayton also served as technical director, vacuum division, Bendix (1968-1969); consultant and chief scientist for HJ Ross Associates, Inc., the Scientific Instrument Division; consultant for Xerox Corp.

During the latter years of his career Dr. Dayton, taught math and physics for Blue Ridge Technical College (1980-1982); consulted for Babcox and Wilcox in Alliance Ohio (1982-1984) and Pickering Firm, Memphis Tennessee (1984-1992). He is now retired and living in East Flat Rock, North Carolina. He leaves to his credit, and as a significant contribution to the field of vacuum science, numerous publications in high vacuum equipment and systems, theory of molecular flow of gases, theory of photon transmission between emitter and absorber and six patents.