Radiation Dosimetry Using Three-Dimensional Optical Random Access Memories

Conference · Mon Aug 20 04:00:00 EDT 2001

OSTI ID:788666

Moscovitch, M ^[1]

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1. ORNL

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 utilizing 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 mm{sup 3}) 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 color change at their intersection (similar to the darkening of light-sensitive sunglasses when exposed to sunlight.) The laser produces color changes in the ORAM, which then reverts to the original color (''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.

• Research Organization: Oak Ridge National Lab., TN (US)
• Sponsoring Organization: US Department of Energy; DOE OFFICE OF DEFENSE NUCLEAR NONPROLIFERATION (US)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 788666
• Report Number(s): P01-111173
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CHARGED PARTICLES
DOSIMETRY
MEMORY DEVICES
NEUTRONS
PERFORMANCE TESTING
PROTONS
RADIATION EFFECTS