Radiation Damage Threshold in Various Materials, including Fused Silica Glass

Nuclear particles, mainly neutrons, are of particular concern in settings such as research accelerators, as they are generally present in large quantities. Neutrons passing through materials transfer some of their energy to the atoms of the irradiated material. They may even eject some of them from their normal positions in the materials. The cumulative result is manifested in significant modifications of the physical properties of irradiated materials. These properties include physical dimensions, strength and hardness, conductivity of heat and electricity, magnetism, resistance to corrosion, and many others.

While all materials are affected to some extent by ionizing radiation, predicting the radiation hardness of a specific material is a complex task. The material relative sensitivity is a function of multiple factors, including the type of ionizing radiation, the dose, and the dose rate. The Handbook of Accelerator Physics and Engineering provides a good summary of the subject matter [1]. Electronic components that are based on semiconductors are known to be especially sensitive to radiation. Electron-hole pairs, generated by the radiation flux, accumulate at material interfaces, where they create havoc with the device performance.  Most organic materials are also known to be strongly affected by ionizing radiation, although Teflon and PEEK have been shown to be somewhat more resistant to some radiation. Many mixed composition glasses will darken when exposed to ionizing radiation. In sharp contrast, pure fused silica glass is known to be exceptionally tolerant of most ionizing radiation. [2]

References

  1. “Handbook of Accelerator Physics and Engineering”, Second ed. , edited by Alexander Wu Chao, Karl Hubert Mess, Maury Tigner, and Frank Zimmermann, World Scientific Publishing, (2013) ISBN 978-981-4415-84-2
  2. B. Brichard, P. Borgermans, A. Fernandez Fernandez, K. Lammens, and M. Decreton, “Radiation Effect in Silica Optical Fiber Exposed to Intense Mixed Neutron–Gamma Radiation Field”, IEEE Trans. On Nucl. Science, 48, 2069 (2001).