LA Notebook, J-3 (April 12, 1945 to June 1945)

This is a laboratory notebook from the Los Alamos Scientific Laboratory, labeled J-3, covering April 12, 1945 through June 1945. The archival description calls it a logbook of measurements made on prepared sample sources for alpha activity. Alpha activity is a form of radiation given off by heavy elements, and the phrase points to counting work done on samples that staff had already processed. The description does not state which element the samples contained.

On the question of what was being measured, the description offers a guess rather than an answer. It says the entries may be plutonium or polonium analysis data. It also notes one feature of how the notebook was kept: the coding in it refers to analyst names. People who worked on the measurements appear as codes rather than by name, so matching entries to individuals would take a separate key.

Almost nothing in this scan reads as text. The pages come through as faint handwriting, ruled columns and stray digits, with no entry legible enough to quote or tabulate. Anyone who wants the measurements themselves will need the original pages or a cleaner scan. The record is indexed under the Manhattan Project, the wartime U.S. atomic bomb program, the Trinity event, plutonium, polonium, radionuclides and human tissue studies.