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RADFETs – Space Technology for Terrestrial Applications

RADFETs – Space Technology for Terrestrial Applications

Tyndall’s Radiation Sensing Field Effect Transistors (RADFETs) have originally been developed under European Space Agency’s sponsorship for radiation dose monitoring in space. The need to accurately measure ionising radiation doses is not limited to space exploration, but also exists in clinical environments (radiotherapy and radiology), homeland security domain (e.g. for first responders), nuclear facilities, high energy physics laboratories. All these applications require simple, cost-effective device which can accurately measure radiation doses of interest. Tyndall’s RADFET technology provides the solution.

RADFET is a MOS transistor optimised for radiation sensitivity. RADFET chip is a cube with a side of 0.5mm. Ionising radiation induces charge in the RADFET, which changes one of the basic transistor’s parameters – threshold voltage. Threshold voltage can easily be measured by passing a specified current through the RADFET and measuring a DC voltage at the device output. That DC voltage is indicative of the absorbed radiation dose.


Main advantages of the RADFETs over other dosimeters are:

  • zero or very low power consumption – no need for power during radiation sensing, eliminating cables/wires,
  • small size – smallest active volume of all dosimeters,
  • simple, immediate, non-destructive read-out,
  • low cost – up to 10 times lower than existing solutions,
  • electronic output signal – easy integration with computers and wireless networks.


RADFET-based dosimetry systems can take different forms, e.g.:

  • handheld reader with disposable RADFET patches,
  • handheld reader with built-in RADFET(s),
  • wrist watch type device,
  • badges, staff-cards, flash memories with the RADFETs.


Currently commercially available RADFETs from Tyndall cover a dose range of 1 cGy to > 1000 Gy. Novel patented devices with the minimum detectable dose of between 0.1–1 mGy and below are under development.


Applications (currently available and under development):

  • Radiotherapy (built-in in OneDose and DVS products by Sicel Technologies, US, for QA in RT),
  • High energy physics and nuclear facilities (> 2,000 dosimeters built in the LHC ring at CERN),
  • Accidental personal dosimetry (> 200,000 RADFETs delivered for watch type military device),
  • Radiology (CT scans, dental and ordinary X-rays, interventional cardiology),
  • Personal dosimetry for radiation workers in clinical and industrial environments,
  • Personal dosimetry for general population (e.g. personal monitoring badges, RADFET modules built in mobile phones, etc.).



Tyndall National Institute




Dr. Aleksandar Jaksic


Commercial Contact:

Katrina Bradley

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