Australian Nuclear Research and Education Network | Virtual Seminar Series 2025

Published in the Research School of Physics Event Horizon
Vol50 Issue24 16–20 June 2025

Abstract
Experimental nuclear physics, radiation medicine including radiation therapy and diagnostic imaging, safe exploitation of nuclear energy with development of Small Modular Reactor (SMR) and transport reactors as placed in submarines, space exploration and possible radiation accident require radiation measurements and sophisticated radiation detectors for that.

The Centre for Medical Radiation Physics (CMRP) is developing a wide range of innovative semiconductor radiation detectors and their applications for dosimetry during the last three decades.

In medical dosimetry, the main challenges arises from many strict and sometimes conflicting requirements, such as need of small detectors do not perturbing the radiation field while measure steep dose gradients, ability to work in high dose rate like in FLASH therapy,while provide real time dosimetry.

To address these challenges at CMRP developed the family of semiconductor detectors providing submillimeter spatial and high temporal resolution in dose mapping for quality assurance (QA) in MV X-ray therapy and brachytherapy, synchrotron microbeam radiation therapy (MRT) and particle therapy, and implement them successfully to clinical practice. Recent development of the semiconductor detector for Very High Energy Electron (VHEE) FLASH therapy able accurate dosimetry of instantaneous dose up to 20Gy delivered with the dose rate of 108Gy/s. New opportunities with innovative semiconductor detectors based on organic semiconductors and amorphous silicon, and allowing fabrication of wearable 2D dosimeters for QA in radiation therapy and operational under accumulated doses up to 108cGy will be discussed.

CMRP initiated concept of solid state microdosimetry related to stochastic energy deposition by charged particles on a micron scale level, developed and brought it to clinical application in proton and heavy ion therapy, and space radiation field characterization for radiation protection of astronauts. Silicon On Insulator (SOI) detectors for microdosimetry led to new domain of QA in particle therapy -Radiobiological Efficiency (RBE) verification along with traditional absorbed dose verification that is leading to more accurate cancer treatment.

Neutron dosimetry, which has been a niche area, could see renewed importance with the potential rise of compact nuclear reactors. These reactors, being small and relatively inexpensive, could be installed in remote and developing regions, increasing the need for reliable neutron dosimetry solutions. CMRP is addressing lack of skills in this area in Australia. Recently developed semiconductor neutron detectors were used successfully for characterization of neutron field at the DINGO neutron imaging beam line at ANSTO Australian Centre for Neutron Scattering aiming as a future standard neutron field for biological and dosimetry research as well as for dosimetry in accelerator based Boron Neutron Capture Therapy. Personal low cost wearable fast neutron dose equivalent meter for reactor personnel which is based on a silicon segmented detector will be presented.
With gained experience at CMRP in development of semiconductor detectors for dosimetry, their applications and commercialisation make CMRP as world leader and training hub in a field for ANREN.

Meeting ID: 850 2724 7072
Password: 143640

ANREN is a network of tertiary academics and professional staff involved in conducting or supportingnuclear research and education in Australia. To join the network or for more information, email elizabeth.williams@anu.edu.au