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Generation of Bremsstrahlung Radiation from Different Low- to High-Z Targets for Medical Applications: A Simulation Approach
Published in Pandit B. Vidyasagar, Sagar S. Jagtap, Omprakash Yemul, Radiation in Medicine and Biology, 2017
Bhushankumar Jagnnath Patil, Vasant Nagesh Bhoraskar, Sanjay Daga Dhole
External beam radiation therapy is also carried out with heavier particles such as neutrons produced by neutron generators and cyclotrons; protons produced by cyclotrons and heavy ions (helium, carbon, nitrogen, argon, neon) produced by Van de Graaff, synchrocyclotrons, pelletrons, and synchrotrons. In case of neutrons, the recoils and nuclear disintegration product contributing to the dose are responsible for a high-energy transfer to the biologically active molecules and destroy them in turn. High relative biological effectiveness (RBE), LET characteristics, and comparatively good dose distribution advantage are the main features of neutron therapy. As the biological effectiveness of neutrons is high, the required tumor dose is about one third the dose required with photons. Therefore, neutron therapy is presently realized in two versions: neutron capture therapy (NCT) and fast neutron therapy (FNT). In NCT, the isotope with large absorption cross section for thermal/epithermal neutrons is introduced into the body mainly through the blood, while FNT uses fast neutron with high penetrability and treats the malignant tumors of the head, neck, dairy gland, osteogenous sarcomas, etc. The limitations have been mainly due to difficulty in generating neutron particles as well as the construction of such treatment facilities [13, 14].
Potentiality of high Z doped PVA polymer as a gamma, neutron and charged particles shielding material
Published in Radiation Effects and Defects in Solids, 2023
G. B. Hiremath, N. H. Ayachit, N. M. Badiger
Radiation protection is very important as gamma rays are rapidly growing in industries, medical applications, nuclear reactors, and research. In fast neutron therapy, proton beam therapy, and hadron beam therapy, fast neutrons, protons, and heavy charged ions are involved for cancer treatment. However, the excessive radiation dose can have serious long term effects on human health (1). Gamma rays and neutrons have an effect on the human body, and shielding materials that are appropriate against nuclear radiation are constantly in demand (2). Normally, lead is used as a shielding material, and because of its toxicity, several investigators are searching for suitable shielding materials which are alternatives to lead. The crack formation, moisture content, and opacity are the limitations of commonly used concretes. And commercial glasses have limitations in cost production for high thickness requirements and due to their heavy weight, they are difficult to handle (3). Nuclear radiation shielding ability of Li2O-Sb2O3-B2O3 and Li2O-CeO2-MoO3-B2O3 glass system with addition of Bi2O3 have been studied recently and observed that with addition of Bi2O3 would improve shielding properties (1,3). Radiation shielding materials are not only required for building structures and also useful in making aprons, transparent windows, space shuttles, to protect medical patients and workers during diagnostic imaging, containers transporting radioactive materials, etc (4). Many materials such as glasses (5–13), alloys (14–17), inorganic compounds (18–21), neutron shielding materials (22), rocks (23,24), concretes (25–27) and polymers (28–32), are being researched for use as shielding materials.