verbatim): In this SBIR phase I proposal, we will develop a new radiation dosimetry technique for use in the ionizing radiation industry. Radiation is frequently used to sterilize biomedical polymers, and improve through crosslinking, the properties of these implants. Polymer irradiation often requires dose levels beyond 200 kGray. Electron beam operators thus need dosimeters with this range and fast response times for on-the-fly dose rate adjustment. Photochromic dyes, the most commonly used dosimetry system, saturate at 50 kGray, often take 5-6 hours to stabilize, and show aging. By making use of the radiolytic reactions in poly(ethylene) undergoing ionizing radiation, a reliable marker for radiation dose can be obtained. Our approach focuses on a specific radiolytic reaction that scales with radiation dose, and is easily measured with infrared absorption. This proposal will involve the design and fabrication of a prototype small enough, and simple enough, to use at a radiation facility with no special training. The thin dosimetry targets will be flexible (and therefore conformable), resilient, tolerant of contamination and damage (therefore ideal for industrial applications in laboratories or on production floors) and will have a response time on the order of minutes. They will also be immune to aging and have considerably higher dosage ranges than other current dosimetry techniques.
The proposed dosimeter design will provide a simple, low cost, technique capable of replacing, and improving on, current state-of-the-art radiation dosimetry approaches. The reader will be useable with little or no training. It will therefore be invaluable in any radiation facility that must have fast response dosimeters (such as beam-lines requiring variable doses), in high dose applications (such as orthopaedic implant fabrication), in applications requiring directional irradiation (such as the wire coating industry) and in environments where surface contamination may be an issue.
