Technician smears phosphorous paste on equipment, St. Louis, Missouri, 1945
Photograph. The first step to render phosphorus radioactive. Official Caption: "(Series of Six) ROME, 6/9/45--Clinical use made of 'Atom Smasher'--Here is a series of pictures the 'Atom Smasher', which does not really break up atoms, but transforms them into an unstable element with radioactive properties similar to radium.--PBS photos--Serviced by Rome OWI ( A List Out)--Approved by appropriate military authority.-o-Here is the first step to render red, or non-crystalline, phosphorus, radioactive. Phosphorus paste is being smeared on the 'target' on which it is to be exposed to the powerful cyclotron beam. 6533A." St. Louis, Missouri, United States. 9 June 1945