The Radiation Instrument Development Laboratory (RIDL) was located at 2337 W. 67^th Street in Chicago, IL in 1953. They introduced the Model 15 Scintillation Basic Laboratory as a new concept in scintillation counting. It had a non-overload amplifier, high voltage regulation, and an internal reference tube. The unit could be used with anthracene, sodium iodide, and other crystals as well as thermal neutron crystals. Model 15 has a 500-1,500 volt negative high voltage supply. Model 15A is the same unit but with 500-1,500 volt positive high voltage supply.

Radiation Instrument Development Laboratory Logo 1953

Radiation Instrument Development Laboratory Logo 1950's

Radiation Instrument Development Laboratory Model 15 1953

The Model 98 portable scintillation spectrometer was introduced in 1953. It had a 1-1/2" x 2" thallium activated sodium iodide crystal, amplifier and single channel pulse-height analyzer. The unit weighed 14 lbs. The unit almost completely eliminates the cosmic-ray counts allowing the measurement of very low levels. The pulse height analyzer allows it to measure the energy of the gamma-rays allowing for the identification of the radioactive material. By setting a window for a particular gamma-ray energy, one can determine if that radioisotope is present. By setting to zero, it collects all energies. Crystals up to 5" diameter are available. Alpha, beta and neutron detector are also available.

Radiation Instrument Development Laboratory Scintillator Model 98 1953

Radiation Instrument Development Laboratory Scintillator Model 98 1955

Radiation Instrument Development Laboratory Ad 1953 (left) and 1956 (right)

Radiation Instrument Development Laboratory Model 50-8 Ad 1950's