View source for Emilio Segrè

{{Short description|Italian-American nuclear physicist and radiochemist (1905–1989)}}
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{{Use British English|date=May 2013}}
{{Use dmy dates|date=June 2020}}
{{redirect|Segrè|Emilio's nephew who is also a physicist|Gino Segrè|other people with the surname|Segre (surname)|other uses|Segre (disambiguation){{!}}Segre}}
{{Infobox scientist
| name              = Emilio Segrè
| image             = Segre.jpg
| caption           = Segrè in 1959
| birth_name        = Emilio Gino Segrè
| birth_date        = {{Birth date|1905|02|01|df=yes}}
| birth_place       = [[Tivoli, Lazio]], [[Kingdom of Italy]]
| death_date        = {{Death date and age|1989|04|22|1905|01|30|df=yes}}
| death_place       = [[Lafayette, California]], U.S.
| citizenship       = {{Plain list|
* Italy (1905–1944)
* United States (1944–1989)
}}
| alma_mater        = [[Sapienza University of Rome]] (''[[laurea]]'', 1928)
| known_for         = {{Plain list|
* Discovering [[technetium]] (1937)
* Discovering [[astatine]] (1940)
* Discovering the [[antiproton]] (1955)
}}
| spouses           = {{Plain list|
* {{Marriage|Elfriede Spiro|1936|1970|reason=died}}
* {{Marriage|Rosa Mines|1972}}
}}
| children          = 3
| relatives         = {{Plain list|
* [[Gino Segrè]] (nephew)
* [[Julie Segre]] (grand-niece)
* [[Kristine Yaffe]] (grand-niece)
}}
| awards            = {{Plain list|
* [[Richtmyer Memorial Award]] (1957)
* [[Nobel Prize in Physics]] (1959)
}}
| fields            = {{Plain list|
* [[Nuclear physics]]
* [[Radiochemistry]]
}}
| work_institutions = {{Plain list|
* Sapienza University of Rome (1932–1936, 1973–1974)
* [[University of Palermo]] <br/> (1936–1938)
* [[University of California, Berkeley]] (1938–1943, 1946–1973)
* [[Los Alamos Laboratory]] <br/> (1943–1946)
}}
| doctoral_advisor  = [[Enrico Fermi]]
| doctoral_students = {{Plain list|
* [[Herbert York]] (1949)
* [[Thomas Ypsilantis]] (1955)
}}
| signature         = Emilio G Segrè signature.svg
}}

'''Emilio Gino Segrè''' ({{IPAc-en|s|ə|ˈ|ɡ|r|eɪ}} {{respell|sə|GRAY}}; {{IPA|it|eˈmiːljo ˈdʒiːno seˈgrɛ|lang}}; 1 February 1905<!-- This is correct! Don't change it! --> – 22 April 1989)<ref>{{Cite web |url=https://www.nobelprize.org/nobel_prizes/physics/laureates/1959/segre-facts.html |title=Emilio Segrè - Facts |website=Nobelprize.org |access-date=20 April 2018}}</ref> was an Italian-American [[nuclear physicist]] and [[radiochemist]] who discovered the elements [[technetium]] and [[astatine]], and the [[antiproton]], a [[subatomic particle|subatomic]] [[antiparticle]], for which he was awarded the [[Nobel Prize in Physics]] in 1959, along with [[Owen Chamberlain]].

Born in [[Tivoli, Italy|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 and while Segrè was visiting the Berkeley Radiation laboratory, [[Benito Mussolini]]'s [[fascist]] government passed [[Italian Racial Laws|antisemitic laws]] barring [[Jew]]s from university positions. As a Jew, Segrè was rendered an indefinite émigré. At the Berkeley Radiation Lab, Lawrence offered him an underpaid 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 nuclear bomb|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 [[University of California, Berkeley|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==
Emilio Gino Segrè was born into a [[Sephardic Jewish]] family in [[Tivoli, Italy|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.{{sfn|Segrè|1993|pp=2–3}} His uncle, Gino Segrè, was a law professor.{{sfn|Segrè|1993|p=6}} He was educated at the ''[[Gymnasium (school)|ginnasio]]'' in Tivoli and, after the family moved to Rome in 1917, the ''ginnasio'' and ''[[Liceo (Italian school)|liceo]]'' in Rome. He graduated in July 1922 and enrolled in the [[University of Rome La Sapienza]] as an [[engineering]] student.{{sfn|Jackson|2002|pp=5–6}}

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 [[Como Conference]] in September 1927,{{sfn|Fermi|1954|pp=43–44}} 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,{{sfn|Segrè|1993|pp=44–49}} and, studying under Fermi, earned his [[Laurea#Former status of the Laurea degree|laurea degree]] in July 1928,{{sfn|Segrè|1993|p=52}} with a thesis on "Anomalous Dispersion and Magnetic Rotation".{{sfn|Jackson|2002|pp=5–6}}

After a stint in the [[Italian Army]] from 1928 to 1929,{{sfn|Jackson|2002|pp=5–6}} during which he was a [[Officer (armed forces)|commissioned]] as a [[second lieutenant]] in the [[antiaircraft artillery]],{{sfn|Segrè|1993|pp=54–59}} 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]].{{sfn|Segrè|1993|pp=61, 304}}

In 1930, Segrè began studying the [[Zeeman effect]] in certain [[alkaline metal]]s. 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]].{{sfn|Jackson|2002|pp=7–8}}{{sfn|Segrè|1993|pp=64–70}} Working with [[Otto Frisch]] on [[Quantization (physics)|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.{{sfn|Segrè|1993|pp=86–87}}

==Physics professor==
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]].<ref name="Nobel">{{cite web |url=https://www.nobelprize.org/nobel_prizes/physics/laureates/1959/segre-bio.html |title=Emilio Segrè – Biography |access-date=22 May 2013 |publisher= The Nobel Foundation }}</ref> 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.{{sfn|Segrè|1993|pp=96–97}} 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.{{sfn|Segrè|1993|p=107}} The couple had three children: Claudio, born in 1937, Amelia Gertrude Allegra, born in 1937, and Fausta Irene, born in 1945.{{sfn|Jackson|2002|p=7}}

[[File:Ragazzi di via Panisperna.jpg|thumb|right|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 {{ill|Luigi Montemartini|it}}.{{sfn|Segrè|1993|pp=104–106}} 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 [[isotope]]s. 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.{{sfn|Jackson|2002|pp=9–10}} In 1947 they named it [[technetium]], as it was the first artificially synthesized [[chemical element]].{{sfn|Segrè|1993|pp=115–118}}<ref name=segre>{{cite journal|doi = 10.1038/159024a0|pmid = 20279068|title = Technetium: The Element of Atomic Number 43|year = 1947|last1 = Perrier|first1 = C.|last2 = Segrè|first2 = E.|journal = Nature|volume = 159|issue = 4027|pages = 24|bibcode = 1947Natur.159...24P |s2cid = 4136886}}</ref>

==Radiation Laboratory==
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 [[Italian Racial Laws|racial laws]] barring Jews from university positions. As a Jew, Segrè was now rendered an indefinite émigré.{{sfn|Segrè|1993|pp=128–132}} The [[German occupation of Czechoslovakia|Czechoslovakian crisis]] prompted Segrè to send for Elfriede and Claudio, as he now feared that war in Europe was inevitable.{{sfn|Segrè|1993|p=140}} 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.{{sfn|Segrè|1993|pp=145–149}}

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 {{USD|300|1939|round=-2}} 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.{{sfn|Jackson|2002|pp=11–12}}{{sfn|Segrè|1993|pp=147–148}} 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.{{sfn|Hoffman|Ghiorso|Seaborg|2000|p=15}} 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.<ref>{{cite journal |journal=[[Physical Review]] |title=An Unsuccessful Search for Transuranic Elements |first=Emilio |last=Segrè |date=June 1939|volume=55 |issue=11 |pages=1103–1104 |issn=0031-899X |doi=10.1103/PhysRev.55.1104 |bibcode = 1939PhRv...55.1104S }}</ref> Working with [[Alexander Langsdorf, Jr.]], and [[Chien-Shiung Wu]], he discovered [[xenon-135]],<ref>{{cite journal |journal=[[Physical Review]] |title = Some Fission Products of Uranium |first1=Emilio |last1=Segrè |first2=Chien-Shiung |last2=Wu |authorlink2=Chien-Shiung Wu |issn=0031-899X |volume = 57 |issue = 6 |page = 552 |date=March 1940 |doi=10.1103/PhysRev.57.552.3 |bibcode = 1940PhRv...57..552S }}</ref><ref>{{cite journal |journal=[[Physical Review]] |title =Radioactive Xenons |first2=Emilio |last2=Segrè |first1=Chien-Shiung |last1=Wu |author-link=Chien-Shiung Wu |volume = 67 |issue = 5–6 |pages = 142–149 |date=March 1945 |issn=0031-899X  |doi = 10.1103/PhysRev.67.142|bibcode = 1945PhRv...67..142W }}</ref> which later became important as a [[nuclear poison]] in [[nuclear reactors]].{{sfn|Segrè|1993|p=153}}

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 particle]]s 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]].{{sfn|Jackson|2002|p=11}}<ref>{{cite journal | title = Artificially radioactive element 85 | first1 = Dale R. | last1 = Corson | authorlink1=Dale R. Corson | first2 = Kenneth Ross | last2 =MacKenzie | authorlink2=Kenneth Ross MacKenzie | first3 = Emilio | last3 = Segrè | authorlink3=Emilio Segrè | journal = Physical Review | volume = 58 | pages = 672–678 | year = 1940 |issn=0031-899X | doi = 10.1103/PhysRev.58.672 | issue = 8|bibcode = 1940PhRv...58..672C }}</ref>{{sfn|Segrè|1993|pp=155-156}} 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.{{sfn|Segrè|1993|pp=155–156}} He also worked with Seaborg, McMillan, [[Joseph W. Kennedy]] and [[Arthur C. Wahl]] to create [[plutonium-239]] in Lawrence's {{convert|60|in|cm|adj=on|sp=us}} [[cyclotron]] in December 1940.<ref>{{cite web |url = http://www.lbl.gov/LBL-PID/Nobelists/Seaborg/65th-anniv/14.html |title = An Early History of LBNL: Elements 93 and 94 |access-date = 17 September 2008 |last = Seaborg |first = Glenn T. |author-link = Glenn T. Seaborg |publisher = Advanced Computing for Science Department, Lawrence Berkeley National Laboratory |archive-date = 5 November 2014 |archive-url = https://web.archive.org/web/20141105083122/http://www2.lbl.gov/LBL-PID/Nobelists/Seaborg/65th-anniv/14.html |url-status = dead }}</ref><ref>{{cite web|title=The plutonium story |last= Seaborg |first=Glenn T. |author-link=Glenn T. Seaborg |publisher=Lawrence Berkeley Laboratory, University of California |id=LBL-13492, DE82 004551 |osti= 5808140 |date= September 1981 |url=https://www.osti.gov/biblio/5808140}}</ref>

==Manhattan Project==
[[File:Segre-emilio.jpg|thumb|right|Segrè's ID badge photo from [[Los Alamos National Laboratory|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]].{{sfn|Segrè|1993|pp=170–172}}

In late 1942, Oppenheimer asked Segrè to join the [[Manhattan Project]] at its [[Los Alamos Laboratory]].{{sfn|Segrè|1993|pp=177–180}} Segrè became the head of the laboratory's P-5 (Radioactivity) Group, which formed part of [[Robert Bacher]]'s P (Experimental Physics) Division.{{sfn|Hawkins|1961|p=101}} For security reasons, he was given the cover name of Earl Seaman.{{sfn|Hoddeson|Henriksen|Meade|Westfall|1993|p=96}} He moved to Los Alamos with his family in June 1943.{{sfn|Segrè|1993|p=186}}

Segrè's group set up its equipment in a disused [[United States Forest Service|Forest Service]] cabin in the Pajarito Canyon near Los Alamos in August 1943.{{sfn|Hoddeson|Henriksen|Meade|Westfall|1993|pp=234–236}} His group's task was to measure and catalog the radioactivity of various [[fission product]]s. 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.{{sfn|Hawkins|1961|pp=120–121}} 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.{{sfn|Hoddeson|Henriksen|Meade|Westfall|1993|pp=234–236}}

The group measured the activity of [[thorium]], [[uranium-234]], [[uranium-235]] and [[uranium-238]], but only had access to [[microgram]] quantities of [[plutonium-239]].{{sfn|Hoddeson|Henriksen|Meade|Westfall|1993|pp=234–236}}  The first sample plutonium produced in the [[nuclear reactor]] at [[Oak Ridge National Laboratory|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.{{sfn|Hoddeson|Henriksen|Meade|Westfall|1993|pp=236–239}}  This was not news that the leaders of the project wanted to hear. It meant that [[Thin Man nuclear bomb|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.{{sfn|Hoddeson|Henriksen|Meade|Westfall|1993|pp=239–244}}

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.{{sfn|Segrè|1993|pp=195, 214–215}} In late 1944, Segrè and Elfriede became [[naturalized citizen]]s of the United States.{{sfn|Segrè|1993|pp=204–205}} His group, now designated R-4, was given responsibility for measuring the [[gamma radiation]] from the [[Trinity nuclear test]] in July 1945.{{sfn|Hoddeson|Henriksen|Meade|Westfall|1993|p=357}} The blast damaged or destroyed most of the experiments, but enough data was recovered to measure the gamma rays.{{sfn|Hoddeson|Henriksen|Meade|Westfall|1993|p=375}}

==Later life==
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 {{USD|5000|1945|round=-2}}. 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.{{sfn|Segrè|1993|pp=206–210}}{{sfn|Jackson|2002|p=13}}

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 W. Alvarez|Luis Alvarez]] was incensed that Amaldi, Fermi, [[Bruno Pontecorvo|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.{{sfn|Segrè|1993|pp=234–239}}

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]].{{sfn|Segrè|1993|pp=234–239}} The courts ultimately resolved the patent claims in the Italian scientists' favour in 1953, awarding them {{USD|400000|1952|round=-5}} 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.{{sfn|Segrè|1993|pp=245–247}}

After turning down offers from [[IBM]] and the [[Brookhaven National Laboratory]], Segrè returned to Berkeley in 1952.{{sfn|Segrè|1993|p=240}} He was elected to the United States [[National Academy of Sciences]] that same year.<ref>{{Cite web |title=Emilio Segre |url=http://www.nasonline.org/member-directory/deceased-members/50641.html |access-date=2022-11-14 |website=www.nasonline.org}}</ref> He moved his family from Berkeley to nearby [[Lafayette, California]], in 1955.{{sfn|Segrè|1993|p=253}} Working with Chamberlain and others, he began searching for the [[antiproton]], a [[subatomic particle|subatomic]] [[antiparticle]] of the [[proton]].<ref name="antiproton" /> The antiparticle of the electron, the [[positron]] had been predicted by [[Paul Dirac]] in 1931<ref>{{cite journal |first=P. A. M. |last=Dirac |author-link=Paul Dirac |year=1931 |title=Quantised Singularities in the Quantum Field |pages=2–3 |journal=[[Proceedings of the Royal Society]] |doi=10.1098/rspa.1931.0130|bibcode = 1931RSPSA.133...60D |volume=133 |issue=821 |doi-access=free }}</ref> and then discovered by [[Carl D. Anderson]] in 1932.<ref>{{cite journal |last=Anderson |first=Carl D. |year=1933 |title=The Positive Electron |journal=[[Physical Review]] |volume=43 |issue=6 |pages=491–494 |doi=10.1103/PhysRev.43.491|bibcode = 1933PhRv...43..491A |doi-access=free }}</ref> 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.{{sfn|Segrè|1993|pp=255–257}} Using Lawrence's [[Bevatron]] set to 6&nbsp;GeV, they managed to detect conclusive evidence of antiprotons.<ref name="antiproton">{{cite journal |title=Nuclear Properties of Antinucleons |journal=[[Science (journal)|science]] |date=1 July 1960 |volume=132 |issue=3418|pages=9–14 |doi=10.1126/science.132.3418.9 |pmid=17732394 |issn=0036-8075 |last1=Segre |first1=E. |bibcode = 1960Sci...132....9S |s2cid=37761659 |url=https://digital.library.unt.edu/ark:/67531/metadc893382/ }}</ref><ref>{{cite web |url=https://www.nobelprize.org/nobel_prizes/physics/laureates/1959/segre-lecture.pdf |title=Properties of antinucleons – Nobel Lecture |date=11 December 1959 |last=Segrè |first=Emilio  |publisher=The Nobel Foundation |access-date=31 May 2013 }}</ref> Chamberlain and Segrè were awarded the 1959 [[Nobel Prize in Physics]] for their discovery.<ref>{{cite web |url=https://www.nobelprize.org/nobel_prizes/physics/laureates/1959/ |title=The Nobel Prize in Physics 1959 |publisher=The Nobel Foundation |access-date=31 May 2013 }}</ref> This was controversial, because [[Clyde Wiegand]] and [[Thomas Ypsilantis]] were co-authors of the same article, but did not share the prize.{{sfn|Jackson|2002|pp=15–16}}

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.<ref name="nap" /> He was elected to the [[American Philosophical Society]] in 1963.<ref>{{Cite web |title=APS Member History |url=https://search.amphilsoc.org/memhist/search?creator=Emilio+Segr%C3%A8&title=&subject=&subdiv=&mem=&year=&year-max=&dead=&keyword=&smode=advanced |access-date=2022-11-14 |website=search.amphilsoc.org}}</ref> He was one of the trustees of [[Fermilab]] from 1965 to 1968. He attended its inauguration with [[Laura Fermi]] in 1974.{{sfn|Segrè|1993|pp=284–287}} 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.{{sfn|Jackson|2002|pp=17, 25}}<ref name="nap" />

Elfriede died in October 1970, and Segrè married Rosa Mines in February 1972.{{sfn|Jackson|2002|p=7}} He was elected to the [[American Academy of Arts and Sciences]] in 1973.<ref>{{Cite web |title=Emilio Gino Segre |url=https://www.amacad.org/person/emilio-gino-segre |access-date=2022-11-14 |website=American Academy of Arts & Sciences |language=en}}</ref> That year he reached the University of California's compulsory retirement age. He continued teaching the history of physics.{{sfn|Segrè|1993|p=288}} In 1974 he returned to the University of Rome as a professor, but served only a year before reaching the mandatory retirement age.<ref name="nap" /> Segrè died from a [[myocardial infarction|heart attack]] at the age of 84 while out walking near his home in Lafayette.<ref>{{cite news |url=https://www.nytimes.com/1989/04/24/obituaries/dr-emilio-g-segre-is-dead-at-84-shared-nobel-for-studies-of-atom.html |access-date=31 May 2013 |title=Dr. Emilio G. Segre Is Dead at 84; Shared Nobel for Studies of Atom |first=Peter |last=Flint |date=24 April 1989 |newspaper=[[The New York Times]] }}</ref> Active as a [[photography|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.<ref name="nap">{{cite web |url=http://www.nap.edu/readingroom/books/biomems/esegre.html |title=Emilio Gino Segrè January 30, 1905–April 22, 1989 |publisher=National Academy of Sciences biography |access-date=2 June 2013}}</ref><ref>{{cite web | url = http://photos.aip.org/about.jsp | title = Photos of physicists, astronomers and other scientists – Emilio Segrè Visual Archives | publisher = [[American Institute of Physics]] | access-date = 13 March 2012}}</ref>{{sfn|Jackson|2002|p=7}}

==Notes==
{{reflist}}

== See also ==

* [[List of Jewish Nobel laureates]]

==References==
* {{cite book |last=Fermi |first=Laura |author-link=Laura Fermi |year=1954 |title=Atoms in the Family: My Life with Enrico Fermi |url=https://archive.org/details/atomsinfamilymyl00fermrich |url-access=registration |location=Chicago, Illinois |publisher=University of Chicago Press |oclc=537507}}
* {{cite book |last=Hawkins |first=David |year=1961 |title=Manhattan District History: Project Y – The Los Alamos Project. Volume I: Inception until August 1945 |publisher=[[Los Alamos National Laboratory]] |id=LAMS 2532}}
* {{cite book|last1=Hoddeson |first1=Lillian|author-link=Lillian Hoddeson|first2=Paul W. |last2=Henriksen |first3=Roger A. |last3=Meade |first4=Catherine L. |last4=Westfall|author4-link= Catherine Westfall|title=Critical Assembly: A Technical History of Los Alamos During the Oppenheimer Years, 1943–1945 |location=New York |publisher=Cambridge University Press |year=1993 |isbn=978-0-521-44132-2 |oclc=26764320|url-access=registration |url=https://archive.org/details/criticalassembly0000unse }}
* {{cite book |last1=Hoffman |first1=Darleane C. |first2=Albert |last2=Ghiorso |first3=Glenn T. |last3=Seaborg |authorlink3=Glenn T. Seaborg |title = The Transuranium People: The Inside Story |location= London |publisher=Imperial College Press |year=2000 |isbn =978-1-86094-087-3 |oclc=49570028}}
* {{cite book |last=Jackson |first=J. David |author-link=John David Jackson (physicist) |title=Emilio Gino Segrè January 30, 1905–April 22, 1989 |url=http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/segr-emilio.pdf |access-date=17 July 2013 |publisher=[[National Academy of Sciences]] |location=Washington, D.C. |year=2002 |series=Bibliographical Memoirs |oclc=51822510}}

==Bibliography==
* E. Segrè (1964). ''Nuclei and Particles.''
* E. Segrè (1970). ''Enrico Fermi, Physicist'', University of Chicago Press.
** [http://plunkettlakepress.com/amaim.html eBook published by] [[Plunkett Lake Press]] (2016). {{ASIN| B01M30L2QS}}.
* 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''.
* {{cite book |first=Emilio |last=Segrè |year=1993 |title=A Mind Always in Motion: the Autobiography of Emilio Segrè |publisher=University of California Press |location=Berkeley, California |isbn=978-0-520-07627-3 |oclc=25629433|url-access=registration |url=https://archive.org/details/mindalwaysinmoti00segr }} [http://publishing.cdlib.org/ucpressebooks/view?docId=ft700007rb Free Online – UC Press E-Books Collection].
** [http://plunkettlakepress.com/amaim.html eBook published by] [[Plunkett Lake Press]] (2016). {{ASIN|B01M3S03Q0}}.

==Further reading==
* [https://www.osti.gov/biblio/4422363-formation-year-element-from-deuteron-bombardment-sup-sup Segrè, 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 [[United States Atomic Energy Commission|Atomic Energy Commission]]).
* [https://www.osti.gov/biblio/910247-spontaneous-fission Segrè, E. "Spontaneous Fission", (22 November 1950)], Radiation Laboratory, [[Lawrence Berkeley National Laboratory]], [[United States Department of Energy]] (through predecessor agency the [[United States Atomic Energy Commission|Atomic Energy Commission]]).
* Segrè, E. (1953) ''Experimental Nuclear Physics''.
* [https://www.osti.gov/biblio/915069-observation-antiprotons Segrè, E; et.al. "Observation of Antiprotons", (19 October 1955)], Radiation Laboratory, [[Lawrence Berkeley National Laboratory]], [[United States Department of Energy]] (through predecessor agency the [[United States Atomic Energy Commission|Atomic Energy Commission]]).
* [https://www.osti.gov/biblio/915070-antiprotons  Segrè, E; et.al. "Antiprotons", (29 November 1955)], Radiation Laboratory, [[Lawrence Berkeley National Laboratory]], [[United States Department of Energy]] (through predecessor agency the [[United States Atomic Energy Commission|Atomic Energy Commission]]).
* [https://www.osti.gov/biblio/914470-antiproton-nucleon-annihilation-process-antiprotoncollaboration-experiment Segrè, 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 [[United States Atomic Energy Commission|Atomic Energy Commission]]).
* [https://www.osti.gov/biblio/914473-experiments-antiprotons-antiproton-nucleon-crosssections  Segrè, 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 [[United States Atomic Energy Commission|Atomic Energy Commission]]).

==External links==
{{Commons}}
*[http://manhattanprojectvoices.org/oral-histories/emilio-segr%C3%A8s-interview 1965 Audio Interview with Emilio Segre by Stephane Groueff] Voices of the Manhattan Project
*[https://www.aip.org/history-programs/oral-histories/search?search_api_views_fulltext=Segr%C3%A8 Oral History transcripts with Emilio G. Segre, American Institute of Physics, Niels Bohr Library and Archives]
* {{Nobelprize}} including his Nobel Lecture, 11 December 1959 ''Properties of Antinucleons''

=== Archival collections ===

* [https://libserv.aip.org/ipac20/ipac.jsp?session=16L131033431H.350891&menu=search&aspect=power&npp=10&ipp=20&spp=20&profile=rev-all&ri=11&source=%7E%21horizon&index=.GW&term=EMILIO+SEGR%C3%88+LECTURES+AND+OTHER+COLLECTED+RECORDINGS%2C+1968-1997&x=8&y=11&aspect=power Emilio Segre lectures and other collected recordings, 1968-1997, Niels Bohr Library & Archives]
{{Manhattan Project}}
{{Nobel Prize in Physics Laureates 1951–1975}}
{{1959 Nobel Prize winners}}
{{Time Persons of the Year 1951–1975}}
{{New Mexico during World War II}}
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