For Co-60 gamma energy, the surface dose is - (i) smaller than Dmax (ii) higher than Dmax (iii) same as Dmax (iv) none of these. The most predominant mode of interaction for megavo... For Co-60 gamma energy, the surface dose is - (i) smaller than Dmax (ii) higher than Dmax (iii) same as Dmax (iv) none of these. The most predominant mode of interaction for megavolt photon beam is - (i) photo-electric effect (ii) Compton effect (iii) pair production (iv) photodisintegration. Tissue air ratio - (i) depends on SSD (ii) does not depend on SSD (iii) does not depend on beam energy (iv) none of these. PDD does not depend on - (i) depth (ii) field size (iii) SSD (iv) none of these. For ortho-voltage X-ray, the reference depth dose is - (i) d=0 cm (ii) d=0.5 cm (iii) d=10 cm (iv) none of these. Radiation exposure varies with distance - (i) directly (ii) indirectly (iii) as inverse square law (iv) none of these.
Understand the Problem
The question involves multiple choice questions related to radiation physics and concepts such as gamma energy, interaction modes, and tissue ratios. It requires understanding of these scientific principles to answer correctly.
Answer
Co-60 surface dose smaller than Dmax, Compton effect for megavolt beams, tissue air ratio depends on SSD, PDD doesn't depend on SSD, ortho-voltage reference depth at 0.5 cm, exposure as inverse square law.
Co-60 gamma energy surface dose is smaller than Dmax, the most predominant interaction mode for megavolt photon beam is the Compton effect, tissue air ratio depends on SSD, PDD does not depend on SSD, ortho-voltage X-ray reference depth dose is at 0.5 cm, and radiation exposure varies as inverse square law.
Answer for screen readers
Co-60 gamma energy surface dose is smaller than Dmax, the most predominant interaction mode for megavolt photon beam is the Compton effect, tissue air ratio depends on SSD, PDD does not depend on SSD, ortho-voltage X-ray reference depth dose is at 0.5 cm, and radiation exposure varies as inverse square law.
More Information
Co-60 units are commonly used in radiotherapy, and understanding dose distribution is key to effective treatment planning. The Compton effect is crucial in radiation therapy due to its dominance in human tissue for megavolt photon beams.
Tips
Always check if SSD is affecting parameters like tissue air ratio or PDD. Remember the inverse square law for calculating radiation exposure limitations.
Sources
- Low Energy Radiation - an overview | ScienceDirect Topics - sciencedirect.com
- Treatment planning with a 2.5 MV photon beam for radiation therapy - pmc.ncbi.nlm.nih.gov
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