LLNL Prototype TLD Badge (ca. 1970)
This is a prototype of the first Lawrence Livermore National Laboratory TLD personnel dosimeter and was designed by Donald E. Jones. The outer ring of holes provide a binary code of the worker's identification number. It was intended to hold three LiF TLD chips in the small depressions seen in the photo below left. Each of the three chips (TLD-100, 600 and 700) had a different enrichment of lithium (different mixes of Li-6 and Li-7). This permitted an estimation of the neutron exposures.
Size: 1 3/8" diameter and 1/8" thick
The following is stamped on three lines on one side of the badge (photo to right): "123456, Rem, Milli E"
Donated by Ron Kathren.
Ron Kathren, personal communication.