New Groundbreaking Scientific Technique Unlocks Mysteries of a 1792 Judd-9 Silver Disme
By Robert Rodriguez

At the 2023 ANS Coinage of the Americas Conference, I presented, on September 22.As a result of our investigations, my colleague, Tony Lopez, and I conclude that the following 1792 Judd-9 silver disme is the Design WorkSurface that was used to design the 1793 half cent. To arrive at this conclusion, our journey of discovery required the most extensive andintensive scientific investigation ever conducted in the field of numismatics that took place over a period of nearly 4 1/2 years.

In this presentation, the numismatic and antiquities communities were introduced to the power and capabilities of synchrotron-radiation-basedX-ray micro-diffraction. At the Argonne National Laboratory's Advanced Photon Source synchrotron, we recovered the first successfulsubsurface metal lattice image from the interior of a coin. Nearly 600 hours of scans were executed that culminated in the recovery of stunningimages of surface features that can no longer be seen or are illegible on the surface. They were recovered from a depth of approximately 50microns using high-intensity X-rays that are about one million times stronger than that which would occur in a doctor's office. Three physicists,Dr. Wenjun Liu, Dr. Jon Tischler and Dr. Ruqing Xu, conducted the scanning investigations.

As an example of this new powerful scientific investigation technique, this remarkable image was recovered from the subsurface of a 1792Judd-9a after a 28-hour scan. The date has not been seen since it was effaced away in 1792.

The presentation may be viewed at the following link: https://www.youtube.com/watch?v=0ap8tHI1QrQ. Our paper will be published later thisyear as part of the proceedings from the 2023 ANS COAC.

We believe this new scientific investigation technique has the ability to unlock mysteries that were thought to be permanently lost. The AdvancedPhoton Source is now undergoing a two-year upgrade program that will make it the premiere synchrotron of its type in the world.

Rob adds: