Abstract
Organic dosimeters and radiochromic films possess several great benefits, they have great spatial resolution, they are thin and light weight, they give a real time result, inexpensive and their chemical composition makes a good body-tissue analog. When a radiochromic film is exposed to ionizing radiation there would be a change in the optical absorption of the film, allowing it to be measured. This work will focus on the most recent type of molecule used for radiochromic dosimetry- Polydiacetylene (PDA).PDA is a conjugated unbranched polymer formed by the polymerization of diacetylene (DA). PDA have very strong optical properties and is a widely used as an organic sensor. A very common type of DA is 10, 12- Pentacosadiynoic acid (PCDA). It is a fatty acid and a colloid suspension of it is made normally by a vesicle preparation procedure of sonicating and cooling at 4°C. The resulting suspension is not nearly as sensitive for the doses that are used in radiology and radiotherapy and some manipulations are required to improve its sensitivity.The goal of this work is to develop a DA suspension that will be sensitive enough, yet simple enough, so it can be self-fabricated in every lab or clinic. This suspension is as a precursor to forms films or 3D gels.The first chapter of this work shows that two sensitivity improvements can be easily achieved. First improvement is made by simply mixing two common DAs. The second improvement is achieved by crystalizing the suspensions at 25°C (RT) instead of 4°C. Both of those sensitivity improvements are combined to a suspension with 16 times the original sensitivity. This suspension is used as a precursor to form a PVA-DA film.In the second chapter, the PVA-DA film is proven by analyzing its response to gamma radiation, electron radiation, and scintillation light. Also the selected DA suspension is fashioned to a transparent 3D dosimeter.
Original language | English GB |
---|---|
State | Published - 2017 |
Keywords
- Acetylene
- Radiation dosimetry -- Safety measures
- קרינה -- אמצעי בטיחות
- מדידת מנות קרינה
- אציטילן