Question: What nationality was the collaborator of Owen Chamberlain in the work for which he received his Nobel prize ?

full_context: Document 1: Emilio Segrè: Emilio Gino Segrè (1 February 1905 – 22 April 1989) was an Italian physicist and Nobel laureate who discovered the elements technetium and astatine, and the antiproton, a sub-atomic antiparticle, for which he was awarded the Nobel Prize in Physics in 1959.
Document 2: Bevatron: The Bevatron was a particle accelerator — specifically, a weak-focusing proton synchrotron — at Lawrence Berkeley National Laboratory, U.S., which began operating in 1954. The antiproton was discovered there in 1955, resulting in the 1959 Nobel Prize in physics for Emilio Segrè and Owen Chamberlain. It accelerated protons into a fixed target, and was named for its ability to impart energies of billions of eV. (Billions of eV Synchrotron.)
Document 3: Enrico Fermi: Enrico Fermi ( ; ] ; 29 September 1901 – 28 November 1954) was an Italian physicist and the creator of the world's first nuclear reactor, the Chicago Pile-1. He has been called the "architect of the nuclear age" and the "architect of the atomic bomb". He was one of the very few physicists in history to excel both theoretically and experimentally. Fermi held several patents related to the use of nuclear power, and was awarded the 1938 Nobel Prize in Physics for his work on induced radioactivity by neutron bombardment and the discovery of transuranic elements. He made significant contributions to the development of quantum theory, nuclear and particle physics, and statistical mechanics.
Document 4: Chien-Shiung Wu: Chien-Shiung Wu (; May 31, 1912 – February 16, 1997) was a Chinese-American experimental physicist who made significant contributions in the field of nuclear physics. Wu worked on the Manhattan Project, where she helped develop the process for separating uranium metal into uranium-235 and uranium-238 isotopes by gaseous diffusion. She is best known for conducting the Wu experiment, which contradicted the hypothetical law of conservation of parity. This discovery resulted in her colleagues Tsung-Dao Lee and Chen-Ning Yang winning the 1957 Nobel Prize in physics, and also earned Wu the inaugural Wolf Prize in Physics a mere two decades later in 1978. Her expertise in experimental physics evoked comparisons to Marie Curie. Her nicknames include "the First Lady of Physics", "the Chinese Madame Curie", and the "Queen of Nuclear Research".
Document 5: Owen Chamberlain: Owen Chamberlain (July 10, 1920 – February 28, 2006) was an American physicist, and Nobel laureate in physics for his discovery, with collaborator Emilio Segrè, of the antiproton, a sub-atomic antiparticle.
Document 6: Charles Thomson Rees Wilson: Charles Thomson Rees Wilson, CH, FRS (14 February 1869 – 15 November 1959) was a Scottish physicist and meteorologist who won the Nobel Prize in Physics for his invention of the cloud chamber.
Document 7: Ray David Owen: Ray David Owen (October 30, 1915 – September 21, 2014) was a teacher and scientist whose discovery of unusual, “mixed,” red blood cell types in cattle twins in 1945 launched the fields of modern immunology and organ transplantation. Owen’s 1945 findings were published in the journal "Science". This observation demonstrated that self was “learned” by the immune system during development and paved the way for research involving induction of immune tolerance and early tissue grafting. When Frank Macfarlane Burnet and Sir Peter Brian Medawar were awarded their 1960 Nobel Prize in Physiology or Medicine for the discovery of acquired immunological tolerance, Owen was not mentioned in the prize. However, in a letter to Owen, Medawar stated that he believed Owen should have also been included in the prize. Owen also led the successful effort to admit women as California Institute of Technology (or Caltech) undergraduates.
Document 8: Meitnerium: Meitnerium is a chemical element with symbol Mt and atomic number 109. It is an extremely radioactive synthetic element (an element not found in nature that can be created in a laboratory). The most stable known isotope, meitnerium-278, has a half-life of 7.6 seconds, although the unconfirmed meitnerium-282 may have a longer half-life of 67 seconds. The GSI Helmholtz Centre for Heavy Ion Research near Darmstadt, Germany, first created this element in 1982. It is named for Lise Meitner.
Document 9: Robert Hofstadter: Robert Hofstadter (February 5, 1915 – November 17, 1990) was an American physicist. He was the joint winner of the 1961 Nobel Prize in Physics (together with Rudolf Mössbauer) "for his pioneering studies of electron scattering in atomic nuclei and for his consequent discoveries concerning the structure of nucleons".
Document 10: Ernest Lawrence: Ernest Orlando Lawrence (August 8, 1901 – August 27, 1958) was a pioneering American nuclear scientist and winner of the Nobel Prize in Physics in 1939 for his invention of the cyclotron. He is known for his work on uranium-isotope separation for the Manhattan Project, as well as for founding the Lawrence Berkeley National Laboratory and the Lawrence Livermore National Laboratory.
Document 11: Lawrencium: Lawrencium is a synthetic chemical element with symbol Lr (formerly Lw) and atomic number 103. It is named in honor of Ernest Lawrence, inventor of the cyclotron, a device that was used to discover many artificial radioactive elements. A radioactive metal, lawrencium is the eleventh transuranic element and is also the final member of the actinide series. Like all elements with atomic number over 100, lawrencium can only be produced in particle accelerators by bombarding lighter elements with charged particles. Twelve isotopes of lawrencium are currently known; the most stable is Lr with a half-life of 11 hours, but the shorter-lived Lr (half-life 2.7 minutes) is most commonly used in chemistry because it can be produced on a larger scale.
Document 12: Cockcroft–Walton generator: The Cockcroft–Walton (CW) generator, or multiplier, is an electric circuit that generates a high DC voltage from a low-voltage AC or pulsing DC input. It was named after the British and Irish physicists John Douglas Cockcroft and Ernest Thomas Sinton Walton, who in 1932 used this circuit design to power their particle accelerator, performing the first artificial nuclear disintegration in history. They used this voltage multiplier cascade for most of their research, which in 1951 won them the Nobel Prize in Physics for "Transmutation of atomic nuclei by artificially accelerated atomic particles". Less well known is the fact that the circuit was discovered much earlier, in 1919, by Heinrich Greinacher, a Swiss physicist. For this reason, this doubler cascade is sometimes also referred to as the Greinacher multiplier. Cockcroft–Walton circuits are still used in particle accelerators. They also are used in everyday electronic devices that require high voltages, such as X-ray machines, television sets, microwave ovens and photocopiers.
Document 13: Ettore Majorana: Ettore Majorana ( ; ] ; born on 5 August 1906 – probably died after 1959) was an Italian theoretical physicist who worked on neutrino masses. On March 25, 1938, he disappeared under mysterious circumstances while going by ship from Palermo to Naples. The Majorana equation and Majorana fermions are named after him.
Document 14: Murray Gell-Mann: Murray Gell-Mann ( ; born September 15, 1929) is an American physicist who received the 1969 Nobel Prize in physics for his work on the theory of elementary particles. He is the Robert Andrews Millikan Professor of Theoretical Physics Emeritus at the California Institute of Technology, a Distinguished Fellow and co-founder of the Santa Fe Institute, Professor in the Physics and Astronomy Department of the University of New Mexico, and the Presidential Professor of Physics and Medicine at the University of Southern California.
Document 15: Glenn T. Seaborg: Glenn Theodore Seaborg ( ; April 19, 1912February 25, 1999) was an American chemist whose involvement in the synthesis, discovery and investigation of ten transuranium elements earned him a share of the 1951 Nobel Prize in Chemistry. His work in this area also led to his development of the actinide concept and the arrangement of the actinide series in the periodic table of the elements.
ground_truth: Italian