Evans Hayward

She was born at Camp Dix, New JerseyNew JerseyNew Jersey is a state in the eastern United States on the Atlantic Ocean, bordered by New York State, Delaware, and Pennsylvania, with the Hudson River forming its northeastern boundary and the Delaware River its western boundary; its capital is Trenton and its largest city is Newark. One of the original 13 colonies, it became the third state to ratify the U.S. Constitution on December 18, 1787, and its population in the 2020 census (April 1, 2020) was 9,288,994.Open the full entry, on February 17, 1922.⁠[1]

In 1942 she received a B.A. in physics from Smith CollegeSmith CollegeSmith College is a liberal arts college for women in Northampton, Massachusetts, United States. Chartered in 1871 under the bequest of Sophia Smith and opened in 1875, it is one of the Seven Sisters schools.Open the full entry.⁠[1][2]

She then did graduate work at the University of California, receiving a master’s degree in 1945 (an MS in the Physics Today obituary, an M.A. in physics in the NIST staff profile) and a Ph.D. in 1947.⁠[1][2]

The obituary describes her doctoral thesis as a cloud-chamber study of the ionization produced by high-energy cosmic-ray electrons; the NIST staff profile says that she did her thesis research on cloud-chamber studies of cosmic rays at the University of California Radiation Laboratory.⁠[1][2]

At Berkeley she met Raymond W. Hayward, and they married in 1947; his obituary names her before her marriage as the experimental physicist Evans Vaughan.⁠[1][3]

From 1947 to 1950 she did what the obituary calls postgraduate work at the Radiation Laboratory in BerkeleyUniversity of California, BerkeleyThe University of California, Berkeley (UC Berkeley) is a campus of the University of California system; the University of California was founded in 1868 through a merger of two institutions and moved to Berkeley, California, in 1873.Open the full entry, including cloud-chamber studies of synchrotron-produced electrons and cyclotron-produced mesons.⁠[1]

She also used a cloud chamber to measure the angular distribution of protons scattered by neutrons in the neutron beam from the Berkeley cyclotron; the results showed that the scattering is not isotropic in the center-of-mass system and not symmetric about 90°, and the obituary takes the forward peak of protons as a sign that a certain amount of charge exchange takes place between neutron and proton. In addition, she measured the energy spectrum of delayed neutrons from oxygen-17, obtaining information on the excited states of that nucleus.⁠[1]

Raymond W. Hayward’s obituary relates that toward the end of their studies, around 1950, Emilio Segrè let her know that Ugo Fano of the National Bureau of Standards in Washington, DC, had an opening suitable for Raymond W. Hayward to carry out an experimental program in beta spectrometry, and that as a result both of them obtained positions at the bureau.⁠[3]

In 1950 she was hired into the bureau’s Neutron Physics Section. Her first experiments there used gamma rays from a cobalt-60 source and a 50 MeV betatron.⁠[2][1]

One of her first collaborations at the bureau was with John Hubbell: they measured the albedo of 1 MeV photons reflected at various angles of incidence from semi-infinite slabs of water, aluminum, copper, tin and lead, and then carried out Monte Carlo calculations on a desk calculator, which confirmed the experimental results.⁠[1]

In 1958 she received the Silver Medal of the U.S. Department of Commerce.⁠[2][1]

NBS Report 6255, “Elastic Scattering of Photons,” dated January 1, 1959, and signed by E. G. Fuller and Evans Hayward of the bureau’s High Energy Radiation Section, Atomic and Radiation Physics Division, is a final report to the Nuclear Physics Division of the Air Force Office of Scientific Research (ARDC) summarizing measurements of photon elastic scattering cross sections; its summary notes that the forward scattering cross section is related to the total absorption cross section by a dispersion relation. Its cover also carries the numbers AFOSR TR-58-162 and ASTIA AD 207 250.⁠[4]

The report includes five papers she co-wrote: “Nuclear Elastic Scattering of Photons” by E. G. Fuller and Evans Hayward, Phys. Rev. 101, 692 (1956); “Photon Self-Absorption and Scattering by the 15.1-Mev Level in C12” by Evans Hayward and E. G. Fuller, Phys. Rev. 106, 991 (1957); “Shape of the High-Energy End of the Electron-Bremsstrahlung Spectrum” by E. G. Fuller, E. Hayward and H. W. Koch, Phys. Rev. 109, 630 (1958); a communication by E. G. Fuller and Evans Hayward to the 1958 Paris Conference, “Photon Scattering and Self Absorption in Lead and Bismuth at 7 Mev”; and their manuscript for Physical Review Letters, “Elastic Scattering of Photons by Tantalum.” All of them give the authors’ affiliation as the National Bureau of Standards in Washington, DC.⁠[4]

In 1961–1962 she was at the Institute for Theoretical Physics in Copenhagen as a Guggenheim Fellow; Raymond W. Hayward spent the same year at the institute.⁠[1][2][3]

In 1966 she was a guest professor at the Institute for Nuclear Physics of Goethe University.⁠[2][1]

In 1969 she was Sir Thomas Lyle Fellow at the University of Melbourne.⁠[2][1]

In August 1970 the National Bureau of Standards issued her Monograph 118, “Photonuclear Reactions,” 46 pages long, with her affiliation given as the bureau’s Center for Radiation Research in Washington, DC. It reviews photonuclear reactions in the approximate energy range 10 to 30 MeV, discusses various sum rules and applies them to experimental data, describes several theories and compares their predictions with experiment, and points out open questions and discrepancies as often as possible; its key words are nuclear hydrodynamics, particle-hole calculations, photon scattering, photonuclear and sum rules.⁠[5]

It was sold by the Superintendent of Documents, U.S. Government Printing Office, for 50 cents; its Library of CongressLibrary of CongressThe Library of Congress is the library of the United States Congress. Founded in 1800 and housed on Capitol Hill in Washington, D.C., it answers reference requests from Congress, the public and other federal agencies.Open the full entry Catalog Card Number is 70-606490.⁠[5]

In 1971 she received the Gold Medal of the Department of Commerce.⁠[2][1]

President Richard NixonRichard NixonRichard Nixon (1913–1994) was an American politician who represented California in the U.S. House and Senate, served as vice president from 1953 to 1961 and was the 37th president of the United States from 1969 to 1974. His administration opened relations with China, signed strategic arms limitation agreements with the Soviet Union and ended U.S. involvement in the Vietnam War; he resigned over the Watergate scandal on August 9, 1974, the only U.S. president to do so.Open the full entry selected her for the General Advisory Committee of the Atomic Energy Commission. The April 1973 issue of Physics Today carried the news that the President had appointed four new members to the committee, describing her as a physicist at the National Bureau of Standards center for radiation research; the other three were Hubert Heffner, chairman of the department of applied physics at Stanford UniversityStanford UniversityStanford University is a research university in California founded by Leland and Jane Stanford in 1885 and opened in 1891.Open the full entry; Michael M. May, associate director-at-large of the Lawrence Livermore Laboratory; and Walter H. Zinn, a retired vice-president of Combustion Engineering, Inc., and former director of Argonne National Laboratory.⁠[1][6]

In 1975 she became a group leader at the bureau: the Physics Today obituary says that she was selected as group leader for the Nuclear Research Group, while the NIST staff profile says that she was promoted to leader of the Neutron Physics Group and served until 1986.⁠[1][2]

The same year she received the Federal Women’s Award (so spelled in both the Physics Today obituary and the NIST staff profile) and was a visiting professor of physics at the University of Toronto.⁠[2][1]

A National Archives blog post gives the award’s name as the Federal Woman’s Award, established by the Civil Service Commission, which announced it in October 1960, to recognize “outstanding achievement by women in the Federal career service,” and discontinued after 1976.⁠[7]

On September 24, 1975, the Office of the White House Press Secretary announced that the President had appointed nine members of the General Advisory Committee to the Energy Research and Development Administration; one of them, Richard S. Morse, president of the MIT Development Foundation, Inc., succeeded Evans Hayward, who had resigned, for the remainder of a term expiring August 1, 1976. The release notes that the committee was formerly the General Advisory Committee to the Atomic Energy Commission and was transferred to the Energy Research and Development Administration by the Energy Reorganization Act of 1974, which created that administration effective January 19, 1975.⁠[8]

From 1978 to 1980 she was deputy chief of the bureau’s Nuclear Radiation Division.⁠[2][1]

In 1980 she received the Samuel Wesley Stratton Award of the National Bureau of Standards.⁠[2][1]

From 1982 to 1986 she was a guest professor of experimental physics at the Max Planck Institute (in Mainz, Germany, in the Physics Today obituary; the NIST staff profile gives no place), and in 1985–1986 she was also a senior visiting scientist at the Nuclear Physics Laboratory in Oxford.⁠[2][1]

In 1987 she became a Fellow of the National Bureau of Standards; that year she was also a visiting professor of physics at Duke University and a visiting scientist at the Physics Institute of the University of Lund.⁠[2][1]

In 1990 she retired from NBS/NIST (the National Bureau of Standards had been renamed the National Institute of Standards and Technology in 1988) and continued to collaborate with many scientists; the same year she became an adjunct professor of physics at Duke University.⁠[1][9][2]

In 1995 she was added to the NIST Portrait Gallery of Distinguished Scientists, Engineers, and Administrators. The gallery’s 2020 list gives her tenure as 1950–1990.⁠[1][10]

The May 1996 issue of Physics Today (vol. 49, no. 5, page 88) carried her obituary of Everett Gladding Fuller, signed from the National Institute of Standards and Technology in Gaithersburg, MarylandMarylandMaryland is a Middle Atlantic state of the United States, deeply indented by Chesapeake Bay and bordered by Pennsylvania, Delaware, Virginia, the District of Columbia and West Virginia; its capital is Annapolis and its largest city is Baltimore. One of the original 13 states, it ratified the U.S. Constitution on April 28, 1788, as the seventh state to do so, and had a population of 6,177,224 in the 2020 census (April 1, 2020).Open the full entry.⁠[11]

On December 24, 2001, Raymond W. Hayward died following a heart attack at his home in Bethesda, Maryland.⁠[3]

She died of heart disease at her home in Chevy Chase, Maryland, on March 2, 2020. Her obituary states that she was predeceased by her husband and two sons; colleagues from around the world expressed their condolences and their appreciation for the support and encouragement she had offered for their research.⁠[1]

On October 14, 2021, the Physics Today website published the obituary “Evans Vaughan Hayward” by Allan Carlson, Bert Coursey, Samuel Penner and Vladimir Varlamov. The obituaries section of the magazine’s April 2023 print issue also listed her name with her dates of birth and death.⁠[1][12]

The Physics Today obituary calls her an international leader in photonuclear physics who used beams of electrons, positrons and neutrons from high-energy accelerators to probe nuclear structure; over more than five decades her research interests included precision measurements of photoneutron production cross sections, the scattering and absorption of photons by deformed nuclei, the “nuclear photo-effect in oriented nuclei,” and measurements of electron spectra and of (e,p) and (e,α) reactions. The NIST staff profile lists her research interests as precision measurements of photoneutron production cross sections, the scattering and absorption of photons by deformed nuclei, and “photofission in spatially oriented nuclei.”⁠[1][2]

When the bureau moved from Washington, DC, to Gaithersburg, Maryland, and the 150 MeV linac became available, the much more intense electron beam current allowed her to undertake more difficult experiments. With William Dodge she ran linac experiments testing theories of bremsstrahlung, of real and virtual photon interactions with nuclei and of the elastic scattering of photons; H. William Koch’s recollections of 2006 also describe the work of William Dodge and Evans Hayward on the theory and experiment of bremsstrahlung.⁠[1][13]

In one set of experiments she found that the “giant resonance” of ellipsoidal nuclei peaked at two different energies, corresponding to the major and minor axes of the ellipsoid, and that the relative strengths of the two peaks depended on whether the ellipsoid was oblate or prolate, all as her friend the theorist Mike Danos had predicted. She and Danos shared an office at the bureau for decades; as they became senior staff they were more than once offered separate offices, but they refused. The obituary explains that daily contact with an experimentalist was really useful for a theorist and the reverse was also true, with each learning what was happening in the other’s field.⁠[1]

With H. Arenhoevel she developed a theory of the scattering of plane-polarized photons by the giant resonances of nuclei, published as “Scattering of Plane-Polarized Photons by the Giant Resonances of Nuclei” in Phys. Rev. 165, 1170 (1968). Her paper with W. C. Barber and J. Sazama, “Nuclear Scattering of Plane-Polarized Photons,” Phys. Rev. C8, 1065 (1973), described the corresponding experiment: a beam of plane-polarized monochromatic photons was produced from a carbon target in a linac bremsstrahlung beam by resonance fluorescence of the 1⁺ state at 15.1 MeV in carbon-12, and these photons were scattered a second time from natural targets of cadmium, tin, tantalum, tungsten, platinum, gold and bismuth.⁠[1][13]

The Physics Today obituary and H. William Koch’s recollections of 2006 both call the Arenhoevel–Hayward theory “Particularly elegant,” the experiment its “equally elegant” application, and the approach a brute-force method of avoiding the problem caused by x-ray sources with broad energy spectra; Koch adds that it made it possible to study nuclear phenomena at a single energy, in this case 15.1 MeV.⁠[1][13]

Her collaboration with E. Wolynec, M. N. Martins and William Dodge on photonuclear and electronuclear reactions led to publications that the obituary calls well known throughout the world.⁠[1][13]

In describing the experiments of William Dodge and Evans Hayward, Koch’s recollections cite references 42 to 48, which besides the two papers above are: E. Hayward, W. C. Barber and J. J. McCarthy, “Nuclear scattering of plane polarized photons,” Phys. Rev. C10, 2652 (1974); W. R. Dodge, E. Hayward, R. G. Leicht, M. McCord and R. Starr, “Nuclear photon scattering by C12 and O16,” Phys. Rev. C28, 8 (1983); W. R. Dodge, E. Hayward and E. Wolynec, “Experimental Test of Virtual Photon Theory,” Phys. Rev. C28, 150 (1983); M. N. Martins, E. Hayward, G. Lamaze, X. K. Maruyama, F. Schima and E. Wolynec, “Experimental Test of the Bremsstrahlung Cross section,” Phys. Rev. C30, 1855 (1984); and E. Hayward, “Comment on ‘Feasibility of measurement of the electromagnetic polarizability of the bound nucleon,’” Phys. Rev. C40, 467 (1989).⁠[13]

The obituary calls Everett Fuller the world authority on the bibliography of photonuclear reactions; after he retired she continued it. These data formed the basis of the digital database “Photonuclear Data Index,” and the bibliography is now available at the Centre for Photonuclear Experiments Data of the Moscow State University Institute of Nuclear Physics, the National Nuclear Data Center at Brookhaven National Laboratory and the IAEA Nuclear Data Section in Vienna.⁠[1]

The obituary says that she found herself becoming a “committee person” in the 1970s: besides the committee above, she was a member of the Advisory Screening Committee in Physics for the Committee on International Exchange of Persons (Senior Fulbright-Hays Program), reviewing applications for Fulbright Scholarships in physics, and a member of Maryland Governor Mandel’s Science Advisory Council, which assists the governor with scientific problems and with forecasts of future scientific information and their relation to the state of Maryland.⁠[1]

She was a Fellow of the American Physical Society.⁠[2][1]

The obituary notes that she was a woman physicist at a time when very few physicists were women; she knew that she had to excel in her field to be recognized for her work, and she did, and she suffered some level of gender discrimination at various times, even at the National Bureau of Standards. She remarked that she always wore attire that gave a professional appearance so as not to cause distraction during the experiments.⁠[1]

The obituary calls her a natural leader whose peers and direct supervisors recognized her extraordinary accomplishments and the value she brought to the bureau; she travelled widely to take part in experiments at high-energy accelerators and to lecture at academic institutions.⁠[1]

After she had fully retired, she began taking evening classes at American University in politics, international relations, Spanish and Italian; asked why she was taking them, she said that she still wanted to learn.⁠[1]

Raymond W. Hayward’s obituary relates that the Haywards regularly entertained physicists from all over the world and were famous for the large parties they held when meetings of the American Physical Society were scheduled in Washington, DC.⁠[3]

In the acknowledgments of his recollections of 2006, H. William Koch thanked Randall Caswell, Stephen Seltzer, Evans Hayward and John Hubbell for their help in editing the manuscript.⁠[13]

Her husband, Raymond W. Hayward, born in Omaha, NebraskaNebraskaNebraska is a state of the United States bordered by South Dakota to the north, Iowa and Missouri to the east, Kansas to the south, and Colorado to the southwest, with its panhandle bordering Wyoming to the west; its capital is Lincoln and its largest city is Omaha. It was admitted to the Union on March 1, 1867, as the 37th state, and its population in the 2020 census (April 1, 2020) was 1,961,504.Open the full entry, on July 28, 1921, was a nuclear physicist and an expert in the physics of beta decay in radionuclides. In 1956 he took part in the experiment on the beta decay of cobalt-60 nuclei that demonstrated that parity is not conserved in weak interactions: Chien-Shiung WuChien-Shiung WuChien-Shiung Wu (1912–1997) was a Chinese-born American experimental physicist who spent most of her career at Columbia University and worked on the Manhattan Project. Her cobalt-60 beta-decay experiment of 1956–1957, carried out with collaborators, provided the first experimental proof that parity is not conserved in weak interactions.Open the full entry of Columbia UniversityColumbia UniversityColumbia University, formally Columbia University in the City of New York, is a private research university in New York City and a member of the Ivy League. Founded in 1754 by royal charter from King George II as King's College, it is the oldest institution of higher education in New York State and the fifth oldest in the United States. It was renamed Columbia College in 1784 and adopted the university name and moved to Manhattan's Morningside Heights in 1896. It has 17 schools and four affiliated colleges, with 35,978 students enrolled in fall 2025. Legal scholar Jennifer L. Mnookin became president on July 1, 2026.Open the full entry contacted Ernest AmblerErnest AmblerErnest Ambler (1923–2017) was a British-born American physicist who joined the National Bureau of Standards in 1953 to work in low-temperature physics and was one of the four bureau physicists who carried out the cobalt-60 parity experiment of 1956–1957 with Chien-Shiung Wu. He became the bureau’s acting director in 1975 and its director in 1978, presided over its change into the National Institute of Standards and Technology in 1988 and retired in 1989.Open the full entry in the cryogenic physics section of the National Bureau of Standards, whose chief was Ralph P. HudsonRalph P. HudsonRalph P. Hudson (1924–2016) was a British-born American low-temperature physicist who joined the National Bureau of Standards in 1951, headed its Cryogenic Physics Section and then its Heat Division, and was one of the four bureau physicists who carried out the cobalt-60 parity experiment of 1956–1957 with Chien-Shiung Wu. From 1980 to 1989 he was Director of Publications at the Bureau International des Poids et Mesures in France and editor of the journal Metrologia.Open the full entry, and Raymond W. Hayward and his student Dale D. HoppesDale D. HoppesDale D. Hoppes (born 1928) was a nuclear physicist at the National Bureau of Standards of the United States (later the National Institute of Standards and Technology), where he later led the Radioactivity Group. In 1956–1957, with Chien-Shiung Wu, Ernest Ambler, Raymond W. Hayward and Ralph P. Hudson, he carried out the cobalt-60 beta-decay experiment that showed parity is not conserved in weak interactions.Open the full entry helped design and construct the coincidence system.⁠[3]

In 1957 the Department of Commerce bestowed its Gold Medal on the bureau’s team, and in 1962 Wu and the bureau’s team received the Franklin Institute’s John Price Wetherill Medal for this work.⁠[3]

National Institute of Standards and Technology: Official website: https://www.nist.gov/ (opens in a new window).⁠[14]

Smith College: Official website: https://www.smith.edu/ (opens in a new window).⁠[15]