Advancing instrumentation to monitor radiation dose

Radiation dosimetry, or evaluation of the radiation dose absorbed by a person, has applications in monitoring occupational exposures, for assessing biomedical therapies, secondary (scatter-dependent) dose during radiation therapy, and even exposure of individuals on board commercial flights and of astronauts in space. A large international consortium of eight full and six associate partners is training early-stage researchers (ESRs) on relevant topics with EU support of the project ARDENT (Advanced Radiation Dosimetry European Network Training initiative).

The project is intended to strengthen international cooperation and European research, promote technology transfer to industry, and prepare a new generation of scientists for an increasingly important career in radiation dosimetry. The focus is on gas detectors, solid-state detectors and track detectors (based on different speeds with which tracks of nuclear particles are etched relative to bulk materials). Researchers are developing and testing instrumentation for measuring energy distributions and dosimetric quantities in complex radiation fields and in monoenergetic particle beams used in cancer therapy.

All 15 ESRs have been successfully recruited and have been involved in an extensive research and training program. They come from 10 countries and about one fourth of them are women, a rather respectable number given female representation in the field overall. For each ESR, a project document keeps track of training courses, experimental activities, conferences and presentations, scientific publications, public outreach and secondments. The project web site provides details on the project and its results.

In a fortuitous addition to the original plan, the European Space Agency (ESA) has offered secondments using the Geant4 simulator to study the response of the TimePix chip. TimePix is a hybrid semiconductor particle-tracking pixel detector for direct energy measurement of various types of radiation. The Geant4 is a toolkit for simulating the passage of particles through matter. Both were developed through collaborations at the European Organization for Nuclear Research (CERN) in Switzerland.

Several projects focus around development and applications of Timepix. A novel detector, GEMPix, built coupling two CERN technologies (GEM and Timepix) has been developed with potential applications in medical dosimetry, microdosimetry and in the measurements of low energy photon emitters for the characterization of radioactive waste.

A 4D phantom able to mimic the movement of a human thorax during breathing was developed, able to simulate the lungs, bones and tissue motion within a human torso and the 3D movement of a tumor inside it, as a function of time. It includes the possibility to insert passive and active detectors to precisely measure the delivered dose to a moving tumor in conventional radiation therapy and, in future, in advanced hadrontherapy centers.

ARDENT is conducting cutting-edge research in radiation dosimetry with an emphasis on industrial applications via its four industrial partners. The project trained a next generation of researchers in a key research area, fostered private sector development and strengthened international collaboration for a lasting legacy.