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Emilio Segrè

Emilio Gino Segrè (1 February 1905 – 22 April 1989)[1] was an Italian-born American physicist and Nobel laureate, who discovered the elements technetium and astatine, and the antiproton, a subatomic antiparticle, for which he was awarded the Nobel Prize in Physics in 1959 along with Owen Chamberlain.

Emilio Segrè
Segrè in 1959
Born
Emilio Gino Segrè

(1905-02-01)1 February 1905
Died22 April 1989(1989-04-22) (aged 84)
CitizenshipItaly (1905–44)
United States (1944–89)
Alma materSapienza University of Rome
Known forDiscovery of antiproton, technetium, and astatine
AwardsNobel Prize in Physics (1959)
Scientific career
InstitutionsLos Alamos National Laboratory
University of California, Berkeley
University of Palermo
Sapienza University of Rome
Columbia University
Doctoral advisorEnrico Fermi
Doctoral studentsThomas Ypsilantis
Herbert York
Signature

Born in Tivoli, near Rome, Segrè studied engineering at the University of Rome La Sapienza before taking up physics in 1927. Segrè was appointed assistant professor of physics at the University of Rome in 1932 and worked there until 1936, becoming one of the Via Panisperna boys. From 1936 to 1938 he was director of the Physics Laboratory at the University of Palermo. After a visit to Ernest O. Lawrence's Berkeley Radiation Laboratory, he was sent a molybdenum strip from the laboratory's cyclotron accelerator in 1937, which was emitting anomalous forms of radioactivity. Using careful chemical and theoretical analysis, Segrè was able to prove that some of the radiation was being produced by a previously unknown element, named technetium, the first artificially synthesized chemical element that does not occur in nature.

In 1938, Benito Mussolini's fascist government passed antisemitic laws barring Jews from university positions. As a Jew, Segrè was rendered an indefinite émigré. At the Berkeley Radiation Lab, Lawrence offered him a job as a research assistant. There, Segrè helped discover the element astatine and the isotope plutonium-239, which was later used to make the Fat Man nuclear bomb dropped on Nagasaki. From 1943 to 1946 he worked at the Los Alamos National Laboratory as a group leader for the Manhattan Project. He found in April 1944 that Thin Man, the proposed plutonium gun-type nuclear weapon, would not work due to the presence of plutonium-240 impurities. In 1944, he became a naturalized citizen of the United States. On his return to Berkeley in 1946, he became a professor of physics and of history of science, serving until 1972. Segrè and Owen Chamberlain co-headed a research group at the Lawrence Radiation Laboratory that discovered the antiproton, for which the two shared the 1959 Nobel Prize in Physics.

Segrè was an active photographer who took many pictures documenting events and people in the history of modern science, which were donated to the American Institute of Physics after his death. The American Institute of Physics named its photographic archive of physics history in his honor.

Early life edit

Emilio Gino Segrè was born into a Sephardic Jewish family in Tivoli, near Rome, on 1 February 1905, the son of Giuseppe Segrè, a businessman who owned a paper mill, and Amelia Susanna Treves. He had two older brothers, Angelo and Marco.[2] His uncle, Gino Segrè, was a law professor.[3] He was educated at the ginnasio in Tivoli and, after the family moved to Rome in 1917, the ginnasio and liceo in Rome. He graduated in July 1922 and enrolled in the University of Rome La Sapienza as an engineering student.[4]

In 1927, Segrè met Franco Rasetti, who introduced him to Enrico Fermi. The two young physics professors were looking for talented students. They attended the Volta Conference at Como in September 1927,[5] where Segrè heard lectures from notable physicists including Niels Bohr, Werner Heisenberg, Robert Millikan, Wolfgang Pauli, Max Planck and Ernest Rutherford. Segrè then joined Fermi and Rasetti at their laboratory in Rome. With the help of the director of the Institute of Physics, Orso Mario Corbino, Segrè was able to transfer to physics,[6] and, studying under Fermi, earned his laurea degree in July 1928,[7] with a thesis on "Anomalous Dispersion and Magnetic Rotation".[4]

After a stint in the Italian Army from 1928 to 1929,[4] during which he was a commissioned as a second lieutenant in the antiaircraft artillery,[8] Segrè returned to the laboratory on Via Panisperna. He published his first article, which summarised his thesis, "On anomalous dispersion in mercury and in lithium", jointly with Edoardo Amaldi in 1928, and another article with him the following year on the Raman effect.[9]

In 1930, Segrè began studying the Zeeman effect in certain alkaline metals. When his progress stalled because the diffraction grating he required to continue was not available in Italy, he wrote to four laboratories elsewhere in Europe asking for assistance and received an invitation from Pieter Zeeman to finish his work at Zeeman's laboratory in Amsterdam. Segrè was awarded a Rockefeller Foundation fellowship and, on Fermi's advice, elected to use it to study under Otto Stern in Hamburg.[10][11] Working with Otto Frisch on space quantization produced results that apparently did not agree with the current theory; but Isidor Isaac Rabi showed that theory and experiment were in agreement if the nuclear spin of potassium was +1/2.[12]

Physics professor edit

Segrè was appointed assistant professor of physics at the University of Rome in 1932 and worked there until 1936, becoming one of the Via Panisperna boys.[13] In 1934, he met Elfriede Spiro, a Jewish woman whose family had come from Ostrowo in West Prussia, but had fled to Breslau when that part of Prussia became part of Poland after World War I. After the Nazi Party came to power in Germany in 1933, she had emigrated to Italy, where she worked as a secretary and an interpreter. At first she did not speak Italian well, and Segrè and Spiro conversed in German, in which he was fluent.[14] The two were married at the Great Synagogue of Rome on 2 February 1936. He agreed with the rabbi to spend the minimal amount on the wedding, giving the balance of what would be spent on a luxury wedding to Jewish refugees from Germany. The rabbi managed to give them many of the trappings of a luxury wedding anyway.[15] The couple had three children: Claudio, born in 1937, Amelia Gertrude Allegra, born in 1937, and Fausta Irene, born in 1945.[16]

 
The Via Panisperna boys in the courtyard of Rome University's Physics Institute in Via Panisperna. Left to right: Oscar D'Agostino, Segrè, Edoardo Amaldi, Franco Rasetti and Enrico Fermi.

After marrying, Segrè sought a stable job and became professor of physics and director of the Physics Institute at the University of Palermo. He found the equipment there primitive and the library bereft of modern physics literature, but his colleagues at Palermo included the mathematicians Michele Cipolla and Michele De Franchis, the mineralogist Carlo Perrier and the botanist Luigi Montemartini [it].[17] In 1936 he paid a visit to Ernest O. Lawrence's Berkeley Radiation Laboratory, where he met Edwin McMillan, Donald Cooksey, Franz Kurie, Philip Abelson and Robert Oppenheimer. Segrè was intrigued by the radioactive scrap metal that had once been part of the laboratory's cyclotron. In Palermo, this was found to contain a number of radioactive isotopes. In February 1937, Lawrence sent him a molybdenum strip that was emitting anomalous forms of radioactivity. Segrè enlisted Perrier's help to subject the strip to careful chemical and theoretical analysis, and they were able to prove that some of the radiation was being produced by a previously unknown element.[18] In 1947 they named it technetium, as it was the first artificially synthesized chemical element.[19][20]

Radiation Laboratory edit

In June 1938, Segrè paid a summer visit to California to study the short-lived isotopes of technetium, which did not survive being mailed to Italy. While Segrè was en route, Benito Mussolini's fascist government passed racial laws barring Jews from university positions. As a Jew, Segrè was now rendered an indefinite émigré.[21] The Czechoslovakian crisis prompted Segrè to send for Elfriede and Claudio, as he now feared that war in Europe was inevitable.[22] In November 1938 and February 1939 they made quick trips to Mexico to exchange their tourist visas for immigration visa. Both Segrè and Elfriede held grave fears for the fate of their parents in Italy and Germany.[23]

At the Berkeley Radiation Lab, Lawrence offered Segrè a job as a research assistant—a relatively lowly position for someone who had discovered an element—for US$300 (equivalent to $6,300 in 2022) a month for six months. When Lawrence learned that Segrè was legally trapped in California, he took advantage of the situation to reduce Segrè's salary to $116 a month.[24][25] Working with Glenn Seaborg, Segrè isolated the metastable isotope technetium-99m. Its properties made it ideal for use in nuclear medicine, and it is now used in about 10 million medical diagnostic procedures annually.[26] Segrè went looking for element 93, but did not find it, as he was looking for an element chemically akin to rhenium instead of a rare-earth element, which is what element 93 was.[27] Working with Alexander Langsdorf, Jr., and Chien-Shiung Wu, he discovered xenon-135,[28][29] which later became important as a nuclear poison in nuclear reactors.[30]

Segrè then turned his attention to another missing element on the periodic table, element 85. After he announced how he intended to create it by bombarding bismuth-209 with alpha particles at a Monday meeting Radiation Laboratory meeting, two of his colleagues, Dale R. Corson and Robert A. Cornog carried out his proposed experiment. Segrè then asked whether he could do the chemistry and, with Kenneth Ross MacKenzie, successfully isolated the new element, which is today called astatine.[31][32][33] Segrè and Wu then attempted to find the last remaining missing non-transuranic element, element 61. They had the correct technique for making it, but lacked the chemical methods to separate it.[33] He also worked with Seaborg, McMillan, Joseph W. Kennedy and Arthur C. Wahl to create plutonium-239 in Lawrence's 60-inch (150 cm) cyclotron in December 1940.[34][35]

Manhattan Project edit

 
Segrè's ID badge photo from Los Alamos

The Japanese attack on Pearl Harbor in December 1941 and the subsequent United States declaration of war upon Italy rendered Segrè an enemy alien and cut him off from communication with his parents. Physicists began leaving the Radiation Laboratory to do war work, and Raymond T. Birge asked him to teach classes to the remaining students. This provided a useful supplement to Segrè's income, and he established important friendships and professional associations with some of these students, who included Owen Chamberlain and Clyde Wiegand.[36]

In late 1942, Oppenheimer asked Segrè to join the Manhattan Project at its Los Alamos Laboratory.[37] Segrè became the head of the laboratory's P-5 (Radioactivity) Group, which formed part of Robert Bacher's P (Experimental Physics) Division.[38] For security reasons, he was given the cover name of Earl Seaman.[39] He moved to Los Alamos with his family in June 1943.[40]

Segrè's group set up its equipment in a disused Forest Service cabin in the Pajarito Canyon near Los Alamos in August 1943.[41] His group's task was to measure and catalog the radioactivity of various fission products. An important line of research was determining the degree of isotope enrichment achieved with various samples of enriched uranium. Initially, the tests using mass spectrometry, used by Columbia University, and neutron assay, used by Berkeley, gave different results. Segrè studied Berkeley's results and could find no error, while Kenneth Bainbridge likewise found no fault with New York's. However, analysis of another sample showed close agreement.[42] Higher rates of spontaneous fission were observed at Los Alamos, which Segrè's group concluded were due to cosmic rays, which were more prevalent at Los Alamos due to its high altitude.[41]

The group measured the activity of thorium, uranium-234, uranium-235 and uranium-238, but only had access to microgram quantities of plutonium-239.[41] The first sample plutonium produced in the nuclear reactor at Oak Ridge was received in April 1944. Within days the group observed five times the rate of spontaneous fission as with the cyclotron-produced plutonium.[43] This was not news that the leaders of the project wanted to hear. It meant that Thin Man, the proposed plutonium gun-type nuclear weapon, would not work and implied that the project's investment in plutonium production facilities at the Hanford Site was wasted. Segrè's group carefully checked their results and concluded that the increased activity was due to the plutonium-240 isotope.[44]

In June 1944, Segrè was summoned into Oppenheimer's office and informed that while his father was safe, his mother had been rounded up by the Nazis in October 1943. Segrè never saw either of his parents again. His father died in Rome in October 1944.[45] In late 1944, Segrè and Elfriede became naturalized citizens of the United States.[46] His group, now designated R-4, was given responsibility for measuring the gamma radiation from the Trinity nuclear test in July 1945.[47] The blast damaged or destroyed most of the experiments, but enough data was recovered to measure the gamma rays.[48]

Later life edit

In August 1945, a few days before the surrender of Japan and the end of World War II, Segrè received an offer from Washington University in St. Louis of an associate professorship with a salary of US$5,000 (equivalent to $81,300 in 2022). The following month, the University of Chicago also made him an offer. After some prompting, Birge offered $6,500 and a full professorship, which Segrè decided to accept. He left Los Alamos in January 1946 and returned to Berkeley.[49][50]

In the late 1940s, many academics left the University of California, lured away by higher-salary offers and by the University's peculiar loyalty oath requirement. Segrè chose to take the oath and stay, but this did not allay suspicions about his loyalty. Luis Alvarez was incensed that Amaldi, Fermi, Pontecorvo, Rasetti and Segrè had chosen to pursue patent claims against the United States for their pre-war discoveries and told Segrè to let him know when Pontecorvo wrote from Russia. He also clashed with Lawrence over the latter's plan to create a rival nuclear-weapons laboratory to Los Alamos in Livermore, California, in order to develop the hydrogen bomb, a weapon that Segrè felt would be of dubious utility.[51]

Unhappy with his deteriorating relationships with his colleagues and with the poisonous political atmosphere at Berkeley caused by the loyalty oath controversy, Segrè accepted a job offer from the University of Illinois at Urbana–Champaign.[51] The courts ultimately resolved the patent claims in the Italian scientists' favour in 1953, awarding them US$400,000 (equivalent to $4,400,000 in 2022) for the patents related to generating neutrons, which worked out to about $20,000 after legal costs. Kennedy, Seaborg, Wahl and Segrè were subsequently awarded the same amount for their discovery of plutonium, which came to $100,000 after being divided four ways, there being no legal fees this time.[52]

After turning down offers from IBM and the Brookhaven National Laboratory, Segrè returned to Berkeley in 1952.[53] He was elected to the United States National Academy of Sciences that same year.[54] He moved his family from Berkeley to nearby Lafayette, California, in 1955.[55] Working with Chamberlain and others, he began searching for the antiproton, a subatomic antiparticle of the proton.[56] The antiparticle of the electron, the positron had been predicted by Paul Dirac in 1931[57] and then discovered by Carl D. Anderson in 1932.[58] By analogy, it was now expected that there would be an antiparticle corresponding to the proton, but no one had found one, and even in 1955 some scientists doubted that it existed.[59] Using Lawrence's Bevatron set to 6 GeV, they managed to detect conclusive evidence of antiprotons.[56][60] Chamberlain and Segrè were awarded the 1959 Nobel Prize in Physics for their discovery.[61] This was controversial, because Clyde Wiegand and Thomas Ypsilantis were co-authors of the same article, but did not share the prize.[62]

Segrè served on the University's powerful Budget Committee from 1961 to 1965 and was chairman of the Physics Department from 1965 to 1966. He supported Teller's successful bid to separate the Lawrence Berkeley Laboratory from the Lawrence Livermore Laboratory in 1970.[63] He was elected to the American Philosophical Society in 1963.[64] He was one of the trustees of Fermilab from 1965 to 1968. He attended its inauguration with Laura Fermi in 1974.[65] During the 1950s, Segrè edited Fermi's papers. He later published a biography of Fermi, Enrico Fermi: Physicist (1970). He published his own lecture notes as From X-rays to Quarks: Modern Physicists and Their Discoveries (1980) and From Falling Bodies to Radio Waves: Classical Physicists and Their Discoveries (1984). He also edited the Annual Review of Nuclear and Particle Science from 1958 to 1977 and wrote an autobiography, A Mind Always in Motion (1993), which was published posthumously.[66][63]

Elfriede died in October 1970, and Segrè married Rosa Mines in February 1972.[16] He was elected to the American Academy of Arts and Sciences in 1973.[67] That year he reached the University of California's compulsory retirement age. He continued teaching the history of physics.[68] In 1974 he returned to the University of Rome as a professor, but served only a year before reaching the mandatory retirement age.[63] Segrè died from a heart attack at the age of 84 while out walking near his home in Lafayette.[69] Active as a photographer, Segrè took many photos documenting events and people in the history of modern science. After his death Rosa donated many of his photographs to the American Institute of Physics, which named its photographic archive of physics history in his honor. The collection was bolstered by a subsequent bequest from Rosa after her death from an accident in Tivoli in 1997.[63][70][16]

Notes edit

  1. ^ "Emilio Segrè - Facts". Nobelprize.org. Retrieved 20 April 2018.
  2. ^ Segrè 1993, pp. 2–3.
  3. ^ Segrè 1993, p. 6.
  4. ^ a b c Jackson 2002, pp. 5–6.
  5. ^ Fermi 1954, pp. 43–44.
  6. ^ Segrè 1993, pp. 44–49.
  7. ^ Segrè 1993, p. 52.
  8. ^ Segrè 1993, pp. 54–59.
  9. ^ Segrè 1993, pp. 61, 304.
  10. ^ Jackson 2002, pp. 7–8.
  11. ^ Segrè 1993, pp. 64–70.
  12. ^ Segrè 1993, pp. 86–87.
  13. ^ "Emilio Segrè – Biography". The Nobel Foundation. Retrieved 22 May 2013.
  14. ^ Segrè 1993, pp. 96–97.
  15. ^ Segrè 1993, p. 107.
  16. ^ a b c Jackson 2002, p. 7.
  17. ^ Segrè 1993, pp. 104–106.
  18. ^ Jackson 2002, pp. 9–10.
  19. ^ Segrè 1993, pp. 115–118.
  20. ^ Perrier, C.; Segrè, E. (1947). "Technetium: The Element of Atomic Number 43". Nature. 159 (4027): 24. Bibcode:1947Natur.159...24P. doi:10.1038/159024a0. PMID 20279068. S2CID 4136886.
  21. ^ Segrè 1993, pp. 128–132.
  22. ^ Segrè 1993, p. 140.
  23. ^ Segrè 1993, pp. 145–149.
  24. ^ Jackson 2002, pp. 11–12.
  25. ^ Segrè 1993, pp. 147–148.
  26. ^ Hoffman, Ghiorso & Seaborg 2000, p. 15.
  27. ^ Segrè, Emilio (June 1939). "An Unsuccessful Search for Transuranic Elements". Physical Review. 55 (11): 1103–1104. Bibcode:1939PhRv...55.1104S. doi:10.1103/PhysRev.55.1104. ISSN 0031-899X.
  28. ^ Segrè, Emilio; Wu, Chien-Shiung (March 1940). "Some Fission Products of Uranium". Physical Review. 57 (6): 552. Bibcode:1940PhRv...57..552S. doi:10.1103/PhysRev.57.552.3. ISSN 0031-899X.
  29. ^ Wu, Chien-Shiung; Segrè, Emilio (March 1945). "Radioactive Xenons". Physical Review. 67 (5–6): 142–149. Bibcode:1945PhRv...67..142W. doi:10.1103/PhysRev.67.142. ISSN 0031-899X.
  30. ^ Segrè 1993, p. 153.
  31. ^ Jackson 2002, p. 11.
  32. ^ Corson, Dale R.; MacKenzie, Kenneth Ross; Segrè, Emilio (1940). "Artificially radioactive element 85". Physical Review. 58 (8): 672–678. Bibcode:1940PhRv...58..672C. doi:10.1103/PhysRev.58.672. ISSN 0031-899X.
  33. ^ a b Segrè 1993, pp. 155–156.
  34. ^ Seaborg, Glenn T. "An Early History of LBNL: Elements 93 and 94". Advanced Computing for Science Department, Lawrence Berkeley National Laboratory. Retrieved 17 September 2008.
  35. ^ Seaborg, Glenn T. (September 1981). "The plutonium story". Lawrence Berkeley Laboratory, University of California. OSTI 5808140. LBL-13492, DE82 004551.
  36. ^ Segrè 1993, pp. 170–172.
  37. ^ Segrè 1993, pp. 177–180.
  38. ^ Hawkins 1961, p. 101.
  39. ^ Hoddeson et al. 1993, p. 96.
  40. ^ Segrè 1993, p. 186.
  41. ^ a b c Hoddeson et al. 1993, pp. 234–236.
  42. ^ Hawkins 1961, pp. 120–121.
  43. ^ Hoddeson et al. 1993, pp. 236–239.
  44. ^ Hoddeson et al. 1993, pp. 239–244.
  45. ^ Segrè 1993, pp. 195, 214–215.
  46. ^ Segrè 1993, pp. 204–205.
  47. ^ Hoddeson et al. 1993, p. 357.
  48. ^ Hoddeson et al. 1993, p. 375.
  49. ^ Segrè 1993, pp. 206–210.
  50. ^ Jackson 2002, p. 13.
  51. ^ a b Segrè 1993, pp. 234–239.
  52. ^ Segrè 1993, pp. 245–247.
  53. ^ Segrè 1993, p. 240.
  54. ^ "Emilio Segre". www.nasonline.org. Retrieved 14 November 2022.
  55. ^ Segrè 1993, p. 253.
  56. ^ a b Segre, E. (1 July 1960). "Nuclear Properties of Antinucleons". science. 132 (3418): 9–14. Bibcode:1960Sci...132....9S. doi:10.1126/science.132.3418.9. ISSN 0036-8075. PMID 17732394. S2CID 37761659.
  57. ^ Dirac, P. A. M. (1931). "Quantised Singularities in the Quantum Field". Proceedings of the Royal Society. 133 (821): 2–3. Bibcode:1931RSPSA.133...60D. doi:10.1098/rspa.1931.0130.
  58. ^ Anderson, Carl D. (1933). "The Positive Electron". Physical Review. 43 (6): 491–494. Bibcode:1933PhRv...43..491A. doi:10.1103/PhysRev.43.491.
  59. ^ Segrè 1993, pp. 255–257.
  60. ^ Segrè, Emilio (11 December 1959). "Properties of antinucleons – Nobel Lecture" (PDF). The Nobel Foundation. Retrieved 31 May 2013.
  61. ^ "The Nobel Prize in Physics 1959". The Nobel Foundation. Retrieved 31 May 2013.
  62. ^ Jackson 2002, pp. 15–16.
  63. ^ a b c d "Emilio Gino Segrè January 30, 1905–April 22, 1989". National Academy of Sciences biography. Retrieved 2 June 2013.
  64. ^ "APS Member History". search.amphilsoc.org. Retrieved 14 November 2022.
  65. ^ Segrè 1993, pp. 284–287.
  66. ^ Jackson 2002, pp. 17, 25.
  67. ^ "Emilio Gino Segre". American Academy of Arts & Sciences. Retrieved 14 November 2022.
  68. ^ Segrè 1993, p. 288.
  69. ^ Flint, Peter (24 April 1989). "Dr. Emilio G. Segre Is Dead at 84; Shared Nobel for Studies of Atom". The New York Times. Retrieved 31 May 2013.
  70. ^ "Photos of physicists, astronomers and other scientists – Emilio Segrè Visual Archives". American Institute of Physics. Retrieved 13 March 2012.

See also edit

References edit

Bibliography edit

  • E. Segrè (1964). Nuclei and Particles.
  • E. Segrè (1970). Enrico Fermi, Physicist, University of Chicago Press.
  • E. Segrè (1980). From X-rays to Quarks: Modern Physicists and Their Discoveries (Dover Classics of Science & Mathematics), Dover Publications.
  • E. Segrè (1984). From Falling Bodies to Radio Waves: Classical Physicists and Their Discoveries.
  • Segrè, Emilio (1993). A Mind Always in Motion: the Autobiography of Emilio Segrè. Berkeley, California: University of California Press. ISBN 978-0-520-07627-3. OCLC 25629433. Free Online – UC Press E-Books Collection.

Further reading edit

External links edit

  • 1965 Audio Interview with Emilio Segre by Stephane Groueff Voices of the Manhattan Project
  • Oral History transcripts with Emilio G. Segre, American Institute of Physics, Niels Bohr Library and Archives
  • Emilio Segrè on Nobelprize.org   including his Nobel Lecture, 11 December 1959 Properties of Antinucleons

Archival collections edit

  • Emilio Segre lectures and other collected recordings, 1968-1997, Niels Bohr Library & Archives

emilio, segrè, emilio, gino, segrè, february, 1905, april, 1989, italian, born, american, physicist, nobel, laureate, discovered, elements, technetium, astatine, antiproton, subatomic, antiparticle, which, awarded, nobel, prize, physics, 1959, along, with, owe. Emilio Gino Segre 1 February 1905 22 April 1989 1 was an Italian born American physicist and Nobel laureate who discovered the elements technetium and astatine and the antiproton a subatomic antiparticle for which he was awarded the Nobel Prize in Physics in 1959 along with Owen Chamberlain Emilio SegreSegre in 1959BornEmilio Gino Segre 1905 02 01 1 February 1905Tivoli Kingdom of ItalyDied22 April 1989 1989 04 22 aged 84 Lafayette California U S CitizenshipItaly 1905 44 United States 1944 89 Alma materSapienza University of RomeKnown forDiscovery of antiproton technetium and astatineAwardsNobel Prize in Physics 1959 Scientific careerInstitutionsLos Alamos National LaboratoryUniversity of California BerkeleyUniversity of PalermoSapienza University of RomeColumbia UniversityDoctoral advisorEnrico FermiDoctoral studentsThomas YpsilantisHerbert YorkSignatureBorn in Tivoli near Rome Segre studied engineering at the University of Rome La Sapienza before taking up physics in 1927 Segre was appointed assistant professor of physics at the University of Rome in 1932 and worked there until 1936 becoming one of the Via Panisperna boys From 1936 to 1938 he was director of the Physics Laboratory at the University of Palermo After a visit to Ernest O Lawrence s Berkeley Radiation Laboratory he was sent a molybdenum strip from the laboratory s cyclotron accelerator in 1937 which was emitting anomalous forms of radioactivity Using careful chemical and theoretical analysis Segre was able to prove that some of the radiation was being produced by a previously unknown element named technetium the first artificially synthesized chemical element that does not occur in nature In 1938 Benito Mussolini s fascist government passed antisemitic laws barring Jews from university positions As a Jew Segre was rendered an indefinite emigre At the Berkeley Radiation Lab Lawrence offered him a job as a research assistant There Segre helped discover the element astatine and the isotope plutonium 239 which was later used to make the Fat Man nuclear bomb dropped on Nagasaki From 1943 to 1946 he worked at the Los Alamos National Laboratory as a group leader for the Manhattan Project He found in April 1944 that Thin Man the proposed plutonium gun type nuclear weapon would not work due to the presence of plutonium 240 impurities In 1944 he became a naturalized citizen of the United States On his return to Berkeley in 1946 he became a professor of physics and of history of science serving until 1972 Segre and Owen Chamberlain co headed a research group at the Lawrence Radiation Laboratory that discovered the antiproton for which the two shared the 1959 Nobel Prize in Physics Segre was an active photographer who took many pictures documenting events and people in the history of modern science which were donated to the American Institute of Physics after his death The American Institute of Physics named its photographic archive of physics history in his honor Contents 1 Early life 2 Physics professor 3 Radiation Laboratory 4 Manhattan Project 5 Later life 6 Notes 7 See also 8 References 9 Bibliography 10 Further reading 11 External links 11 1 Archival collectionsEarly life editEmilio Gino Segre was born into a Sephardic Jewish family in Tivoli near Rome on 1 February 1905 the son of Giuseppe Segre a businessman who owned a paper mill and Amelia Susanna Treves He had two older brothers Angelo and Marco 2 His uncle Gino Segre was a law professor 3 He was educated at the ginnasio in Tivoli and after the family moved to Rome in 1917 the ginnasio and liceo in Rome He graduated in July 1922 and enrolled in the University of Rome La Sapienza as an engineering student 4 In 1927 Segre met Franco Rasetti who introduced him to Enrico Fermi The two young physics professors were looking for talented students They attended the Volta Conference at Como in September 1927 5 where Segre heard lectures from notable physicists including Niels Bohr Werner Heisenberg Robert Millikan Wolfgang Pauli Max Planck and Ernest Rutherford Segre then joined Fermi and Rasetti at their laboratory in Rome With the help of the director of the Institute of Physics Orso Mario Corbino Segre was able to transfer to physics 6 and studying under Fermi earned his laurea degree in July 1928 7 with a thesis on Anomalous Dispersion and Magnetic Rotation 4 After a stint in the Italian Army from 1928 to 1929 4 during which he was a commissioned as a second lieutenant in the antiaircraft artillery 8 Segre returned to the laboratory on Via Panisperna He published his first article which summarised his thesis On anomalous dispersion in mercury and in lithium jointly with Edoardo Amaldi in 1928 and another article with him the following year on the Raman effect 9 In 1930 Segre began studying the Zeeman effect in certain alkaline metals When his progress stalled because the diffraction grating he required to continue was not available in Italy he wrote to four laboratories elsewhere in Europe asking for assistance and received an invitation from Pieter Zeeman to finish his work at Zeeman s laboratory in Amsterdam Segre was awarded a Rockefeller Foundation fellowship and on Fermi s advice elected to use it to study under Otto Stern in Hamburg 10 11 Working with Otto Frisch on space quantization produced results that apparently did not agree with the current theory but Isidor Isaac Rabi showed that theory and experiment were in agreement if the nuclear spin of potassium was 1 2 12 Physics professor editSegre was appointed assistant professor of physics at the University of Rome in 1932 and worked there until 1936 becoming one of the Via Panisperna boys 13 In 1934 he met Elfriede Spiro a Jewish woman whose family had come from Ostrowo in West Prussia but had fled to Breslau when that part of Prussia became part of Poland after World War I After the Nazi Party came to power in Germany in 1933 she had emigrated to Italy where she worked as a secretary and an interpreter At first she did not speak Italian well and Segre and Spiro conversed in German in which he was fluent 14 The two were married at the Great Synagogue of Rome on 2 February 1936 He agreed with the rabbi to spend the minimal amount on the wedding giving the balance of what would be spent on a luxury wedding to Jewish refugees from Germany The rabbi managed to give them many of the trappings of a luxury wedding anyway 15 The couple had three children Claudio born in 1937 Amelia Gertrude Allegra born in 1937 and Fausta Irene born in 1945 16 nbsp The Via Panisperna boys in the courtyard of Rome University s Physics Institute in Via Panisperna Left to right Oscar D Agostino Segre Edoardo Amaldi Franco Rasetti and Enrico Fermi After marrying Segre sought a stable job and became professor of physics and director of the Physics Institute at the University of Palermo He found the equipment there primitive and the library bereft of modern physics literature but his colleagues at Palermo included the mathematicians Michele Cipolla and Michele De Franchis the mineralogist Carlo Perrier and the botanist Luigi Montemartini it 17 In 1936 he paid a visit to Ernest O Lawrence s Berkeley Radiation Laboratory where he met Edwin McMillan Donald Cooksey Franz Kurie Philip Abelson and Robert Oppenheimer Segre was intrigued by the radioactive scrap metal that had once been part of the laboratory s cyclotron In Palermo this was found to contain a number of radioactive isotopes In February 1937 Lawrence sent him a molybdenum strip that was emitting anomalous forms of radioactivity Segre enlisted Perrier s help to subject the strip to careful chemical and theoretical analysis and they were able to prove that some of the radiation was being produced by a previously unknown element 18 In 1947 they named it technetium as it was the first artificially synthesized chemical element 19 20 Radiation Laboratory editIn June 1938 Segre paid a summer visit to California to study the short lived isotopes of technetium which did not survive being mailed to Italy While Segre was en route Benito Mussolini s fascist government passed racial laws barring Jews from university positions As a Jew Segre was now rendered an indefinite emigre 21 The Czechoslovakian crisis prompted Segre to send for Elfriede and Claudio as he now feared that war in Europe was inevitable 22 In November 1938 and February 1939 they made quick trips to Mexico to exchange their tourist visas for immigration visa Both Segre and Elfriede held grave fears for the fate of their parents in Italy and Germany 23 At the Berkeley Radiation Lab Lawrence offered Segre a job as a research assistant a relatively lowly position for someone who had discovered an element for US 300 equivalent to 6 300 in 2022 a month for six months When Lawrence learned that Segre was legally trapped in California he took advantage of the situation to reduce Segre s salary to 116 a month 24 25 Working with Glenn Seaborg Segre isolated the metastable isotope technetium 99m Its properties made it ideal for use in nuclear medicine and it is now used in about 10 million medical diagnostic procedures annually 26 Segre went looking for element 93 but did not find it as he was looking for an element chemically akin to rhenium instead of a rare earth element which is what element 93 was 27 Working with Alexander Langsdorf Jr and Chien Shiung Wu he discovered xenon 135 28 29 which later became important as a nuclear poison in nuclear reactors 30 Segre then turned his attention to another missing element on the periodic table element 85 After he announced how he intended to create it by bombarding bismuth 209 with alpha particles at a Monday meeting Radiation Laboratory meeting two of his colleagues Dale R Corson and Robert A Cornog carried out his proposed experiment Segre then asked whether he could do the chemistry and with Kenneth Ross MacKenzie successfully isolated the new element which is today called astatine 31 32 33 Segre and Wu then attempted to find the last remaining missing non transuranic element element 61 They had the correct technique for making it but lacked the chemical methods to separate it 33 He also worked with Seaborg McMillan Joseph W Kennedy and Arthur C Wahl to create plutonium 239 in Lawrence s 60 inch 150 cm cyclotron in December 1940 34 35 Manhattan Project edit nbsp Segre s ID badge photo from Los AlamosThe Japanese attack on Pearl Harbor in December 1941 and the subsequent United States declaration of war upon Italy rendered Segre an enemy alien and cut him off from communication with his parents Physicists began leaving the Radiation Laboratory to do war work and Raymond T Birge asked him to teach classes to the remaining students This provided a useful supplement to Segre s income and he established important friendships and professional associations with some of these students who included Owen Chamberlain and Clyde Wiegand 36 In late 1942 Oppenheimer asked Segre to join the Manhattan Project at its Los Alamos Laboratory 37 Segre became the head of the laboratory s P 5 Radioactivity Group which formed part of Robert Bacher s P Experimental Physics Division 38 For security reasons he was given the cover name of Earl Seaman 39 He moved to Los Alamos with his family in June 1943 40 Segre s group set up its equipment in a disused Forest Service cabin in the Pajarito Canyon near Los Alamos in August 1943 41 His group s task was to measure and catalog the radioactivity of various fission products An important line of research was determining the degree of isotope enrichment achieved with various samples of enriched uranium Initially the tests using mass spectrometry used by Columbia University and neutron assay used by Berkeley gave different results Segre studied Berkeley s results and could find no error while Kenneth Bainbridge likewise found no fault with New York s However analysis of another sample showed close agreement 42 Higher rates of spontaneous fission were observed at Los Alamos which Segre s group concluded were due to cosmic rays which were more prevalent at Los Alamos due to its high altitude 41 The group measured the activity of thorium uranium 234 uranium 235 and uranium 238 but only had access to microgram quantities of plutonium 239 41 The first sample plutonium produced in the nuclear reactor at Oak Ridge was received in April 1944 Within days the group observed five times the rate of spontaneous fission as with the cyclotron produced plutonium 43 This was not news that the leaders of the project wanted to hear It meant that Thin Man the proposed plutonium gun type nuclear weapon would not work and implied that the project s investment in plutonium production facilities at the Hanford Site was wasted Segre s group carefully checked their results and concluded that the increased activity was due to the plutonium 240 isotope 44 In June 1944 Segre was summoned into Oppenheimer s office and informed that while his father was safe his mother had been rounded up by the Nazis in October 1943 Segre never saw either of his parents again His father died in Rome in October 1944 45 In late 1944 Segre and Elfriede became naturalized citizens of the United States 46 His group now designated R 4 was given responsibility for measuring the gamma radiation from the Trinity nuclear test in July 1945 47 The blast damaged or destroyed most of the experiments but enough data was recovered to measure the gamma rays 48 Later life editIn August 1945 a few days before the surrender of Japan and the end of World War II Segre received an offer from Washington University in St Louis of an associate professorship with a salary of US 5 000 equivalent to 81 300 in 2022 The following month the University of Chicago also made him an offer After some prompting Birge offered 6 500 and a full professorship which Segre decided to accept He left Los Alamos in January 1946 and returned to Berkeley 49 50 In the late 1940s many academics left the University of California lured away by higher salary offers and by the University s peculiar loyalty oath requirement Segre chose to take the oath and stay but this did not allay suspicions about his loyalty Luis Alvarez was incensed that Amaldi Fermi Pontecorvo Rasetti and Segre had chosen to pursue patent claims against the United States for their pre war discoveries and told Segre to let him know when Pontecorvo wrote from Russia He also clashed with Lawrence over the latter s plan to create a rival nuclear weapons laboratory to Los Alamos in Livermore California in order to develop the hydrogen bomb a weapon that Segre felt would be of dubious utility 51 Unhappy with his deteriorating relationships with his colleagues and with the poisonous political atmosphere at Berkeley caused by the loyalty oath controversy Segre accepted a job offer from the University of Illinois at Urbana Champaign 51 The courts ultimately resolved the patent claims in the Italian scientists favour in 1953 awarding them US 400 000 equivalent to 4 400 000 in 2022 for the patents related to generating neutrons which worked out to about 20 000 after legal costs Kennedy Seaborg Wahl and Segre were subsequently awarded the same amount for their discovery of plutonium which came to 100 000 after being divided four ways there being no legal fees this time 52 After turning down offers from IBM and the Brookhaven National Laboratory Segre returned to Berkeley in 1952 53 He was elected to the United States National Academy of Sciences that same year 54 He moved his family from Berkeley to nearby Lafayette California in 1955 55 Working with Chamberlain and others he began searching for the antiproton a subatomic antiparticle of the proton 56 The antiparticle of the electron the positron had been predicted by Paul Dirac in 1931 57 and then discovered by Carl D Anderson in 1932 58 By analogy it was now expected that there would be an antiparticle corresponding to the proton but no one had found one and even in 1955 some scientists doubted that it existed 59 Using Lawrence s Bevatron set to 6 GeV they managed to detect conclusive evidence of antiprotons 56 60 Chamberlain and Segre were awarded the 1959 Nobel Prize in Physics for their discovery 61 This was controversial because Clyde Wiegand and Thomas Ypsilantis were co authors of the same article but did not share the prize 62 Segre served on the University s powerful Budget Committee from 1961 to 1965 and was chairman of the Physics Department from 1965 to 1966 He supported Teller s successful bid to separate the Lawrence Berkeley Laboratory from the Lawrence Livermore Laboratory in 1970 63 He was elected to the American Philosophical Society in 1963 64 He was one of the trustees of Fermilab from 1965 to 1968 He attended its inauguration with Laura Fermi in 1974 65 During the 1950s Segre edited Fermi s papers He later published a biography of Fermi Enrico Fermi Physicist 1970 He published his own lecture notes as From X rays to Quarks Modern Physicists and Their Discoveries 1980 and From Falling Bodies to Radio Waves Classical Physicists and Their Discoveries 1984 He also edited the Annual Review of Nuclear and Particle Science from 1958 to 1977 and wrote an autobiography A Mind Always in Motion 1993 which was published posthumously 66 63 Elfriede died in October 1970 and Segre married Rosa Mines in February 1972 16 He was elected to the American Academy of Arts and Sciences in 1973 67 That year he reached the University of California s compulsory retirement age He continued teaching the history of physics 68 In 1974 he returned to the University of Rome as a professor but served only a year before reaching the mandatory retirement age 63 Segre died from a heart attack at the age of 84 while out walking near his home in Lafayette 69 Active as a photographer Segre took many photos documenting events and people in the history of modern science After his death Rosa donated many of his photographs to the American Institute of Physics which named its photographic archive of physics history in his honor The collection was bolstered by a subsequent bequest from Rosa after her death from an accident in Tivoli in 1997 63 70 16 Notes edit Emilio Segre Facts Nobelprize org Retrieved 20 April 2018 Segre 1993 pp 2 3 Segre 1993 p 6 a b c Jackson 2002 pp 5 6 Fermi 1954 pp 43 44 Segre 1993 pp 44 49 Segre 1993 p 52 Segre 1993 pp 54 59 Segre 1993 pp 61 304 Jackson 2002 pp 7 8 Segre 1993 pp 64 70 Segre 1993 pp 86 87 Emilio Segre Biography The Nobel Foundation Retrieved 22 May 2013 Segre 1993 pp 96 97 Segre 1993 p 107 a b c Jackson 2002 p 7 Segre 1993 pp 104 106 Jackson 2002 pp 9 10 Segre 1993 pp 115 118 Perrier C Segre E 1947 Technetium The Element of Atomic Number 43 Nature 159 4027 24 Bibcode 1947Natur 159 24P doi 10 1038 159024a0 PMID 20279068 S2CID 4136886 Segre 1993 pp 128 132 Segre 1993 p 140 Segre 1993 pp 145 149 Jackson 2002 pp 11 12 Segre 1993 pp 147 148 Hoffman Ghiorso amp Seaborg 2000 p 15 Segre Emilio June 1939 An Unsuccessful Search for Transuranic Elements Physical Review 55 11 1103 1104 Bibcode 1939PhRv 55 1104S doi 10 1103 PhysRev 55 1104 ISSN 0031 899X Segre Emilio Wu Chien Shiung March 1940 Some Fission Products of Uranium Physical Review 57 6 552 Bibcode 1940PhRv 57 552S doi 10 1103 PhysRev 57 552 3 ISSN 0031 899X Wu Chien Shiung Segre Emilio March 1945 Radioactive Xenons Physical Review 67 5 6 142 149 Bibcode 1945PhRv 67 142W doi 10 1103 PhysRev 67 142 ISSN 0031 899X Segre 1993 p 153 Jackson 2002 p 11 Corson Dale R MacKenzie Kenneth Ross Segre Emilio 1940 Artificially radioactive element 85 Physical Review 58 8 672 678 Bibcode 1940PhRv 58 672C doi 10 1103 PhysRev 58 672 ISSN 0031 899X a b Segre 1993 pp 155 156 Seaborg Glenn T An Early History of LBNL Elements 93 and 94 Advanced Computing for Science Department Lawrence Berkeley National Laboratory Retrieved 17 September 2008 Seaborg Glenn T September 1981 The plutonium story Lawrence Berkeley Laboratory University of California OSTI 5808140 LBL 13492 DE82 004551 Segre 1993 pp 170 172 Segre 1993 pp 177 180 Hawkins 1961 p 101 Hoddeson et al 1993 p 96 Segre 1993 p 186 a b c Hoddeson et al 1993 pp 234 236 Hawkins 1961 pp 120 121 Hoddeson et al 1993 pp 236 239 Hoddeson et al 1993 pp 239 244 Segre 1993 pp 195 214 215 Segre 1993 pp 204 205 Hoddeson et al 1993 p 357 Hoddeson et al 1993 p 375 Segre 1993 pp 206 210 Jackson 2002 p 13 a b Segre 1993 pp 234 239 Segre 1993 pp 245 247 Segre 1993 p 240 Emilio Segre www nasonline org Retrieved 14 November 2022 Segre 1993 p 253 a b Segre E 1 July 1960 Nuclear Properties of Antinucleons science 132 3418 9 14 Bibcode 1960Sci 132 9S doi 10 1126 science 132 3418 9 ISSN 0036 8075 PMID 17732394 S2CID 37761659 Dirac P A M 1931 Quantised Singularities in the Quantum Field Proceedings of the Royal Society 133 821 2 3 Bibcode 1931RSPSA 133 60D doi 10 1098 rspa 1931 0130 Anderson Carl D 1933 The Positive Electron Physical Review 43 6 491 494 Bibcode 1933PhRv 43 491A doi 10 1103 PhysRev 43 491 Segre 1993 pp 255 257 Segre Emilio 11 December 1959 Properties of antinucleons Nobel Lecture PDF The Nobel Foundation Retrieved 31 May 2013 The Nobel Prize in Physics 1959 The Nobel Foundation Retrieved 31 May 2013 Jackson 2002 pp 15 16 a b c d Emilio Gino Segre January 30 1905 April 22 1989 National Academy of Sciences biography Retrieved 2 June 2013 APS Member History search amphilsoc org Retrieved 14 November 2022 Segre 1993 pp 284 287 Jackson 2002 pp 17 25 Emilio Gino Segre American Academy of Arts amp Sciences Retrieved 14 November 2022 Segre 1993 p 288 Flint Peter 24 April 1989 Dr Emilio G Segre Is Dead at 84 Shared Nobel for Studies of Atom The New York Times Retrieved 31 May 2013 Photos of physicists astronomers and other scientists Emilio Segre Visual Archives American Institute of Physics Retrieved 13 March 2012 See also editList of Jewish Nobel laureatesReferences editFermi Laura 1954 Atoms in the Family My Life with Enrico Fermi Chicago Illinois University of Chicago Press OCLC 537507 Hawkins David 1961 Manhattan District History Project Y The Los Alamos Project Volume I Inception until August 1945 Los Alamos National Laboratory LAMS 2532 Hoddeson Lillian Henriksen Paul W Meade Roger A Westfall Catherine L 1993 Critical Assembly A Technical History of Los Alamos During the Oppenheimer Years 1943 1945 New York Cambridge University Press ISBN 978 0 521 44132 2 OCLC 26764320 Hoffman Darleane C Ghiorso Albert Seaborg Glenn T 2000 The Transuranium People The Inside Story London Imperial College Press ISBN 978 1 86094 087 3 OCLC 49570028 Jackson J David 2002 Emilio Gino Segre January 30 1905 April 22 1989 PDF Bibliographical Memoirs Washington D C National Academy of Sciences OCLC 51822510 Retrieved 17 July 2013 Bibliography editE Segre 1964 Nuclei and Particles E Segre 1970 Enrico Fermi Physicist University of Chicago Press eBook published by Plunkett Lake Press 2016 ASIN B01M30L2QS E Segre 1980 From X rays to Quarks Modern Physicists and Their Discoveries Dover Classics of Science amp Mathematics Dover Publications E Segre 1984 From Falling Bodies to Radio Waves Classical Physicists and Their Discoveries Segre Emilio 1993 A Mind Always in Motion the Autobiography of Emilio Segre Berkeley California University of California Press ISBN 978 0 520 07627 3 OCLC 25629433 Free Online UC Press E Books Collection eBook published by Plunkett Lake Press 2016 ASIN B01M3S03Q0 Further reading editSegre E et al Formation of the 50 Year Element 94 from Deuteron Bombardment of U238 June 1942 Argonne National Laboratory United States Department of Energy through predecessor agency the Atomic Energy Commission Segre E Spontaneous Fission 22 November 1950 Radiation Laboratory Lawrence Berkeley National Laboratory United States Department of Energy through predecessor agency the Atomic Energy Commission Segre E 1953 Experimental Nuclear Physics Segre E et al Observation of Antiprotons 19 October 1955 Radiation Laboratory Lawrence Berkeley National Laboratory United States Department of Energy through predecessor agency the Atomic Energy Commission Segre E et al Antiprotons 29 November 1955 Radiation Laboratory Lawrence Berkeley National Laboratory United States Department of Energy through predecessor agency the Atomic Energy Commission Segre E et al The Antiproton Nucleon Annihilation Process Antiproton Collaboration Experiment 10 September 1956 Radiation Laboratory Lawrence Berkeley National Laboratory United States Department of Energy through predecessor agency the Atomic Energy Commission Segre E et al Experiments on Antiprotons Antiproton Nucleon Cross Sections 22 July 1957 Radiation Laboratory Lawrence Berkeley National Laboratory United States Department of Energy through predecessor agency the Atomic Energy Commission External links edit nbsp Wikimedia Commons has media related to Emilio Segre 1965 Audio Interview with Emilio Segre by Stephane Groueff Voices of the Manhattan Project Oral History transcripts with Emilio G Segre American Institute of Physics Niels Bohr Library and Archives Emilio Segre on Nobelprize org nbsp including his Nobel Lecture 11 December 1959 Properties of AntinucleonsArchival collections edit Emilio Segre lectures and other collected recordings 1968 1997 Niels Bohr Library amp Archives Portals nbsp World War II nbsp Nuclear technology nbsp Physics nbsp History of science nbsp United States nbsp Biography nbsp Italy Retrieved from https en wikipedia org w index php title Emilio Segre amp oldid 1176078206, wikipedia, wiki, book, books, library,

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