Radiation Physics
Short Summary Revision Notes + Cheat Sheet + MCQs Bundle
Prepared for Stuvia Upload
, Radiation Physics Cheat Sheet
• Photon Interactions: Photoelectric (low energy), Compton (therapy range), Pair Production (>1.02
MeV) • Key Units: Dose = Gray (Gy), Activity = Becquerel (Bq), Dose Equivalent = Sievert (Sv) •
Half-Value Layer (HVL): Reduces beam intensity by 50% • Decay Formula: A = A■e^(−λt) • λ = 0.693 /
T½ • X-ray Production: Bremsstrahlung (most), Characteristic (shell transitions) • LINAC Essentials:
MLC = beam shaping, Waveguide = accelerating electrons • ALARA: Reduce Time, Increase Distance,
Use Shielding
, Radiation Physics – Short Summary Revision Notes
1. Introduction to Radiation Physics
• Ionizing radiation removes electrons from atoms. • Types: α, β, γ, X-rays, neutrons. • Atomic structure:
protons, neutrons, electrons.
2. Radioactivity Basics
• Decay types: alpha, beta minus, beta plus, gamma. • Activity (Bq): decays per second. • Half-life: time
for activity to reduce by half. • Decay law: A = A■e^(−λt)
3. Interaction of Radiation with Matter
• Photoelectric Effect: dominant at low photon energies. • Compton Scattering: dominant in
radiotherapy energies. • Pair Production: occurs above 1.02 MeV. • HVL: Thickness reducing beam
intensity by half.
4. X-ray Production
• Bremsstrahlung: electrons decelerating near nuclei. • Characteristic Radiation: inner-shell vacancy
transitions. • kVp controls beam energy; mA controls beam quantity.
5. Dosimetry
• Absorbed Dose: Gray (Gy). • Equivalent Dose: Sievert (Sv). • LET: energy deposited per unit path
length. • Devices: ion chambers, TLDs, OSL.
6. Beam Quality & LINAC Basics
• Beam hardening filters low-energy photons. • Indicators: HVL, PDD, TMR. • LINAC parts: waveguide,
bending magnet, collimators, MLC.
7. Radiation Protection Fundamentals
• ALARA: minimize time, maximize distance, use shielding. • Dosimeters: TLD badge, OSL badge.
Short Summary Revision Notes + Cheat Sheet + MCQs Bundle
Prepared for Stuvia Upload
, Radiation Physics Cheat Sheet
• Photon Interactions: Photoelectric (low energy), Compton (therapy range), Pair Production (>1.02
MeV) • Key Units: Dose = Gray (Gy), Activity = Becquerel (Bq), Dose Equivalent = Sievert (Sv) •
Half-Value Layer (HVL): Reduces beam intensity by 50% • Decay Formula: A = A■e^(−λt) • λ = 0.693 /
T½ • X-ray Production: Bremsstrahlung (most), Characteristic (shell transitions) • LINAC Essentials:
MLC = beam shaping, Waveguide = accelerating electrons • ALARA: Reduce Time, Increase Distance,
Use Shielding
, Radiation Physics – Short Summary Revision Notes
1. Introduction to Radiation Physics
• Ionizing radiation removes electrons from atoms. • Types: α, β, γ, X-rays, neutrons. • Atomic structure:
protons, neutrons, electrons.
2. Radioactivity Basics
• Decay types: alpha, beta minus, beta plus, gamma. • Activity (Bq): decays per second. • Half-life: time
for activity to reduce by half. • Decay law: A = A■e^(−λt)
3. Interaction of Radiation with Matter
• Photoelectric Effect: dominant at low photon energies. • Compton Scattering: dominant in
radiotherapy energies. • Pair Production: occurs above 1.02 MeV. • HVL: Thickness reducing beam
intensity by half.
4. X-ray Production
• Bremsstrahlung: electrons decelerating near nuclei. • Characteristic Radiation: inner-shell vacancy
transitions. • kVp controls beam energy; mA controls beam quantity.
5. Dosimetry
• Absorbed Dose: Gray (Gy). • Equivalent Dose: Sievert (Sv). • LET: energy deposited per unit path
length. • Devices: ion chambers, TLDs, OSL.
6. Beam Quality & LINAC Basics
• Beam hardening filters low-energy photons. • Indicators: HVL, PDD, TMR. • LINAC parts: waveguide,
bending magnet, collimators, MLC.
7. Radiation Protection Fundamentals
• ALARA: minimize time, maximize distance, use shielding. • Dosimeters: TLD badge, OSL badge.
