Radiation dosimetry using three-dimensional optical random access memories.
The ability to determine particle type and energy plays an important role in the dosimetry of heavy charged particles (HCP) and neutrons. A new approach to radiation dosimetry is presented, which is shown to be capable of particle type and energy discrimination. This method is based on utilising radiation induced changes in the digital information stored on three-dimensional optical random access memories (3D ORAM). 3D ORAM is a small cube (a few mm3) composed of poly(methyl methacrylate) doped with a photochromic dye. and it was originally proposed as a memory device in high speed parallel computers. A Nd:YAG laser system is used to write and read binary information (bits) on the ORAM, which functions as a charged particle detector. Both the read and the write processes use two laser beams that simultaneously strike the material to cause a colour change at their intersection (similar to the darkening of light-sensitive sunglasses when exposed to sunlight.) The laser produces colour changes in the ORAM, which then reverts to the original colour ('bit-flips') at sites where energy is deposited from interaction with incident HCP or neutron-recoil protons. The feasibility of this approach was demonstrated both theoretically and experimentally. Calculations based on track structure theory (TST) predict that when HCP interact with the ORAM material, the local energy deposition is capable of inducing measurable 'bit-flips'. These predictions were recently confirmed experimentally using two types of ORAM systems, one based on spirobenzopyran and the other on anthracene, as the photochromic dyes.
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Related Subject Headings
- Random Allocation
- Radiometry
- Optics and Photonics
- Nuclear Medicine & Medical Imaging
- Models, Theoretical
- Elementary Particles
- Computer Storage Devices
- 5106 Nuclear and plasma physics
- 4206 Public health
- 1117 Public Health and Health Services
Citation
Published In
DOI
EISSN
ISSN
Publication Date
Volume
Issue
Start / End Page
Related Subject Headings
- Random Allocation
- Radiometry
- Optics and Photonics
- Nuclear Medicine & Medical Imaging
- Models, Theoretical
- Elementary Particles
- Computer Storage Devices
- 5106 Nuclear and plasma physics
- 4206 Public health
- 1117 Public Health and Health Services