James was part of the Laboratory of Metallurgy, University of Chicago, the team directed by Glenn T. Seaborg. The laboratory had large amounts of plutonium (discovered in 1940–41) that was being produced at the Hanford Site to make nuclear weapons. This allowed them to discover two new elements, although the difficulties for study and isolation were great.
In 1944, Seaborg decided to extend the search to heavier elements, and instructed chemists Ralph A. James and Leon O. Morgan to send samples of irradiated plutonium to Albert Ghiorso for analysis. By identifying characteristics of emitted alpha particles they found the new elements.
The New Element Curium (Atomic Number 96). Glenn T. Seaborg, Ralph A. James, & Albert Ghiorso. January 1948.
The New Element Americium (Atomic Number 95).] Glenn T. Seaborg, Ralph A. James, & Leon O.Morgan. NNES PPR (National Nuclear Energy Series, Plutonium Project Record), Vol. 14 B The Transuranium Elements: Research Papers, Paper No. 22.1, McGraw-Hill Book Co., Inc., New York, 1949.
L-Electron Capture and Alpha-Decay in Np235. Ralph A. James, Albert Ghiorso, Donald Orth. Radiation Laboratory, University of California, Berkeley. Phys. Rev. 85, 369 (1952).
Excitation Functions of Proton-Induced Reactions of Nb93. Ralph A. James. Physical Review – January 1954. Vol 93, Number 2, p. 288-290.
Proton Induced Reactions of Thorium—Fission Yield Curves. Howard A. Tewes and Ralph A. James. Department of Chemistry, University of California, Los Angeles. Phys. Rev. 88, 860 (1952).
Cross Sections for Nuclear Reactions Involving Nuclear Isomers. Bruno Linder* and Ralph A. James. Department of Chemistry, UCLA, California. Phys. Rev. 114, 322–325 (1959).
Isomeric States of Nd141 and Sm143. Ralph A. James and Carleton D. Bingham. Department of Chemistry, University of California, Los Angeles. Phys. Rev. 117, 810 (1960).
Estimate of radiation dose to thyroid of the Rongelap children following the Bravo event. Lawrence Radiation Laboratory, 1964.
Calculation of radioactive iodine concentrations in milk and human thyroid as a result of nuclear explosions. Ralph A. James. UCRL 7716. Nuclear Explosions - Peaceful Applications, UC-35. University of California, Lawrence Radiation Laboratory, 1964.
Aaron J. Ihde. The Development of Modern Chemistry. New York: Dover Publications, Inc., 1984. p. 749.
S. G. Thompson, A. Ghiorso, and G. T. Seaborg. The New Element Berkelium (Atomic Number 97).Physical Review, vol. 80, num 5, 1950, pp. 781–789. doi:10.1103/PhysRev.80.781