History of the PorTL System

The three generations
The three generations of Pille

The PorTL portable thermoluminescent dosimetry system is a direct outgrowth of a long line of “Pille” TLD systems developed by the KFKI Atomic Energy Research Institute (KFKI AEKI of the Hungarian Academy of Sciences) in Budapest for use in space radiation research and space crew dosimetry aboard Russian and American spacecraft. Pille (the Hungarian word for “butterfly”) was the first and to date only TLD system designed specifically for use by cosmonauts and astronauts while traveling in space. The original Pille system was developed by KFKI AEKI in the late 1970’s and was used by the first Hungarian cosmonaut, Bertalan Farkas, in 1980 during his flight aboard the Russian Salyut-6 orbital station. This original Pille system continued to be used by Russian cosmonauts aboard Salyut-6 for routine radiation dosimetry until 1983. Since then there have been many improvements and refinements to the Pille system. The second generation Pille system was flown aboard the Salyut-7 orbital station and later transferred to the Russian Mir orbital station, where it was used until the deorbit of Mir in 2001, making this system probably the longest used piece of spaceflight hardware in the history of human spaceflight. During its nearly 20 years of service, the Pille system never malfunctioned.

Bertalan Farkas and the Pille
The hungarian cosmonaut Bertalan Farkas performs measurements with Pille (1980)

The Pille system was first used aboard an American spacecraft by astronaut Sally Ride, the first American woman to fly in space, during her historic Space Shuttle flight in 1984. An improved version of the Pille system was later used by American astronauts traveling aboard the Mir orbital station during the NASA-Mir project in the mid-1990s. Both the Russian space program and NASA currently have Pille systems for space radiation monitoring aboard the International Space Station. Pille dosimeters are routinely carried by cosmonauts and astronauts during EVA (extravehicular activity or space walks) and provide the only measurement of the increased radiation exposure received by the crew while outside the protective shielding provided by the station.

Sally Ride and the Pille
Sally Ride American astronaut uses the Pille (1984)

PorTL is the first TLD system designed and developed by KFKI AEKI specifically for non-space applications. The PorTL system was developed in collaboration with Eril Research, Inc. (USA) specifically for ground-based applications in the areas of radiation protection, homeland security, defense, and health phyisics research and education. The PorTL system benefits from the years of experience gained by KFKI AEKI from the development and use of the Pille system in space, while at the same time taking advantage of the fact it will be used in the more benign environment on the ground in order to decrease the size, mass, and complexity of the detector cells and also reduce the overall cost of the system. The PorTL system also benefits from the latest in microcontroller and electronics technology provided by BL Electronics Bt. (Hungary).

Jim Voss and the Pille
Jim Voss American astronaut uses the Pille