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#radiotherapy

3 public questions tagged with this topic.

Energy, Intensity and Momentum of EM Waves

Why are gamma rays used in medical applications to treat cancer?

**Momentum of EM wave** p = U/c, U energy, radiation pressure exerts force F = I A/c, small but measurable, comet tail pushed by sunlight, solar sail concept. For E₀=45 V/m, B₀=1.5×10⁻⁷ T, intensity I =0.5×3×10⁸×8.85×10⁻¹²×45²≈2.69 W/m². Gamma rays have very high energy and penetrating power due to their short wavelengths, allowing them to target and destroy cancer cells effectively. Using c = fλ, E₀/B₀ = c, I_d = ε₀ dΦ_E/dt, and spectrum classification λ = c/f, evaluation yields They destroy cancer cells, illustrating EM wave transverse nature and Maxwell's displacement current concept.

Ref: NCERT > Physics Book > Electromagnetic Waves > Energy, Intensity and Momentum of EM Waves

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Ultraviolet, X-rays, Gamma Rays and Their Properties

Gamma rays are used in medicine primarily for what purpose?

**Ultraviolet** λ≈10-400 nm, produced by atomic transitions and Sun, causes fluorescence, sterilization, harmful to eyes/skin, absorbed by ozone layer. **X-rays** λ≈10⁻² to 10 nm, produced by rapid deceleration of energetic electrons in X-ray tube, used in medicine for diagnosis (shadow of bones) and cancer therapy due to high ionization and penetration, detected by photographic film and Geiger counter. The document mentions that gamma rays are used in medicine to destroy cancer cells. Using c = fλ, E₀/B₀ = c, I_d = ε₀ dΦ_E/dt, and spectrum classification λ = c/f, evaluation yields Destroying

Ref: NCERT > Physics Book > Electromagnetic Waves > Ultraviolet, X-rays, Gamma Rays and Their Properties

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Ultraviolet, X-rays, Gamma Rays and Their Properties

Why are X-rays used in medicine to treat certain forms of cancer?

**Gamma rays** λ10¹⁹ Hz, produced by nuclear transitions and radioactive decay, associated with nuclear processes because nuclear energy levels MeV vs atomic eV, highest photon energy, used in cancer treatment due to high penetration and cell damage, also sterilization, astronomy. The document explains that X-rays can damage or destroy living tissues, which makes them useful for targeting and destroying cancer cells. Using c = fλ, E₀/B₀ = c, I_d = ε₀ dΦ_E/dt, and spectrum classification λ = c/f, evaluation yields They destroy cancer cells, illustrating EM wave transverse nature and

Ref: NCERT > Physics Book > Electromagnetic Waves > Ultraviolet, X-rays, Gamma Rays and Their Properties

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