Nier, Alfred

Nier, Alfred O. 1939. The isotopic constitution of uranium and the half-lifes of the uranium isotopes. Phys. Rev. 55 150. 

Signer, P., Baur, H., Wieler, R. (1993) Closed system stepped etching An alternative to stepped heating. In Proceedings of the Alfred O. Nier Symposium on Inorganic Mass Spectrometry, D. J. Rokop, Ed., pp. 181-202. U.S. Department of Energy. 

Schwieters, J. B. Bach, P. Proceedings of the 2nd Alfred O. Nier Symposium on Inorganic Mass Spectrometry, Durango, CO, May 1-12, 1994, D. J. Rokop, J. E. Delmore, and L. W. Green, eds., AECL-11342, Chalk River Laboratory, Chalk River, Ontario, Canada, pp. 49-56. 

The first researcher to separate a minute quantity of U-235 from the isotopic mixture of natural uranium was Alfred O, Nier of the University of Minnesota. He sent this miscroscopic quantity of U-235 (about 0.02 micrograms) to Fermi and others at Columbia University. The prediction of Bohr and Wheeler was confirmed in March, 1940. 

Alfred Nier, around 1960. He participated in the development of mass spectrometry, including the instrumentation used in the Mars probes. He provided and mass spectrometers that made possible Boyer s researches with 0 (courtesy of Paul Boyer). 

Even with Szilard and Fermi stalled, fission studies continued at many other American laboratories. Prodded by a late-October letter from Fermi, for example, Alfred Nier at the University of Minnesota finally began preparing to separate enough U235 from U238, using his mass spectroscope, to determine experimentally which isotope is responsible for slow-neutron fission. But to American physicists and administrators in and out of government a bomb of manium seemed a remote possibility at best. However intense their sympathies, the war was still a European war. 

Lawrence Berkeley Laboratory 41. Picture People 42. Rudolf Peierls 43. Smithsonian Institution Science Service Collection, AIP Niels Bohr Library 44. UPI/Bettmann Newsphotos 45. UPI/Bettmann Newsphotos 46. Alfred O. C. Nier 47. Photo by P. Ehrenfest, Weisskopf Collection, AIP Niels Bohr Library 48. Lawrence Berkeley Laboratoiy 49. Picture People 50. UPI/Bettmann Newsphotos 51. Picture People 52. Lawrence Berkeley Laboratory 53. Argonne National Laboratory 54/55. Martin Marietta 56. Philip Abelson 57-61. National Archives 62/63. Norsk Hydro 64-67. Los Alamos National Laboratory 68. Luis W. Alvarez 69. Niels Bohr Institute 70. Fran9oise Ulam 71/72. Los Alamos National Laboratory 73. Oppenheimer Memorial Committee 74. Emilio Segr6 75. Picture People 76. Picture People 77. Mrs. George Kistiakowsky 78-83. Los Alamos National Laboratory 84. AIP Niels Bohr Library 85-96. Los Alamos National Laboratory... 

Alfred O. C. Nier separated a sample oi U235 with his mass-spectrograph Columbia used it to confirm the rare isotope s responsibility for slow-neutron fission. 

Callis EL, Cappis JH (1996) Total evaporation in thermal ionization mass spectrometry, AECL-11342. In Proceedings of the 2nd Alfred O. Nier symposium on inorganic mass spectrometry, Durango, pp 24-26(160 pp)... 

---