Isotope Data Punch Cards, the "Datadex" (1961-1970)

Isotope Data Punch Cards, the "Datadex"

Manufactured (ca. 1961-1970) by the Scientific Equipment Company of Indianapolis.

Each of the 200 or so punch cards, also known as “keysort” cards, contains the following information for one nuclide: atomic number; half-life; alpha, beta, and gamma energies; and % intensities of any emitted radiation. The data came from the National Academy of Sciences “Nuclear Data Sheets.” To use the Datadex, you simply insert the sorting needle into the appropriate hole on the margin of the cards. For example, to identify nuclides with gamma emissions of 1274 keV, stick the needle into the holes marked 1.250-1.300 MeV. When the needle is lifted, the cards with the indicated range of gamma ray energies drop off. If the unknown emits another gamma ray, a second search is performed on the selected cards.

The idea of using punch cards to store nuclear data and using a needle to sort them was first described in the early 1950s (Lenihan 1952; Bonino 1953), but I believe that the Isotope Data Index was the first commercially available version.

Price: $30 in 1961

Donated by David Allard.


  • Bonino, J.J. and Laing, K.M., Punched-Card Classification of the Nuclides Nucleonics, February, p. 68, 1953.
  • Lenihan, J.M., Isotope Catalog on Punched Cards, British J. Applied Physics, Vol. 3, p.29, 1952.
  • Advertisement, Nucleonics August 1961 p 62.
  • Isotope Datadex Instruction Book, 1962.