Recommended
Recommended
More Related Content
What's hot
What's hot (20)
Viewers also liked
Viewers also liked (18)
Similar to Radiation types, units, protection
Similar to Radiation types, units, protection (20)
Recently uploaded
Recently uploaded (20)
Radiation types, units, protection
- 1. RADIATION: TYPES, UNITS & PROTECTION. SUFYAN IBRAHIM 4th SEM KASTURBA MEDICAL COLLEGE, MANIPAL.
- 3. Ionizing Radiation • Electromagnetic: X rays, γ rays. • Corpuscular: α particles, β particles, etc. • Cosmic rays. Non-ionizing Radiation • UV rays. • Visible light. • IR rays. • Microwaves. • Radio waves.
- 4. • Ability to penetrate tissues. • Carry KE>10eV . • Deposit its energy within them. • Ionize atoms, molecules • Break chemical bonds, • Very harmful. Ionizing Radiations
- 5. X rays λ<10-9m Solar/Manmade Penetrating ability: Air- 120-240m Tissue- 15-30cm Lead- 0.3mm γ rays λ<10-11m Spontaneous radioactive decay Penetrating ability: Air-400m Tissue- 50cm Lead- 40mm
- 6. α rays 2He4 nucleus. 10x powerful than X, β, γ rays but least penetrating power. Penetrating ability: Air- 4cm Tissue- 0.05mm Lead- 0 Very dangerous if entered into the body(by inhalation or wounds) β rays Electrons or Positrons. More penetrating than α but less than γ rays. Penetrating ability: Air- 6-300cm Tissue- 0.06-4.0mm Lead- 0.005-0.3mm Sometime used in radiotherapy to treat superficial tumors
- 7. NON- IONIZING RADIATIONS EM radiations of longer wavelengths but KE<10eV thus non-ionizing Sufficient energy to change the rotational, vibrational or electronic valence configurations of molecules/atoms Greater the wavelength, lesser the energy(E α 1/λ) Thermal ionization is still possible at far higher energies UV Visible Light IR Microwaves Radio waves Order of Decreasing Energies
- 8. UV Rays 10nm<λ<400nm Sunlight, electric arcs, Hg-vapour lamps Uses: Endogenous Vit D production, Serotonin productiion Bad effects: Suntan, Freckling, Sunburn, Skin cancer
- 9. • Becquerel, Curie, Rutherford, Mache-Einheit Radio-activity • Roentgen, Rad, Rem Potency of Radiation • C/kg, Gray, Sievert SI units R A D I A T I O N U N I T S
- 10. UNITS FOR ACTIVITY(A) • The activity of a radioactive material is the number of nuclear disintegration per unit time • SI Unit(derived) is becquerel(Bq) • One becquerel is defined as the activity of a quantity of radioactive material in which one nucleus decays per second • 1Bq=27pCi [1Ci=3.7×1010 Bq] • 1Rd=2.703 × 10−5Ci [1 million nuclei decay/sec] • 1ME=3.64×10−10 Ci/L
- 11. UNITS FOR EXPOSURE(X) •Roentgen(R) is the measure of the ionization produced in air by X-rays or γ rays and it is used because air ionization can be measured directly •“Amount of radiation absorbed in air at a given point, i.e., number of ions produced in 1mL of air” •SI Unit is Coulomb per kilogram(C/kg) •1R=2.58×10−4 C/kg
- 12. UNITS FOR ABSORBED DOSE(D) •Rad: Amount of radioactive energy absorbed per gram of tissue or any material •SI Unit is Gray(Gy): Dose of ionizing radiation that impart 1 joule of energy to 1 kg of absorbing material •1rad=0.01Gy
- 13. UNITS FOR DOSE EQUIVALENT(H) • Represent the stochastic biological effects of ionizing radiations per unit of energy absorbed • Indicates degree of potential danger for health • H is the product of absorbed dose(D) and quality factor(Q) • Q depends upon density of ionization produced in tissue by the radiation(for X,γ,e-=1, for particle=20) • So, H=D*Q • Units: Rem(Roentgen equivalent in man) and Sievert(Sv) • 1Sv=100rems
- 14. Radiation Protection Radiation Hygiene Prepare Safety Standards Codes for safe operation of Nuclear Power Plants Peaceful use of Atomic Energy ICRP, IAEA and WHO
- 17. REGULATION OF DOSE UPTAKE JUSTIFICATION No unnecessary use of radiation is permitted; The advantages must outweigh the disadvantages. LIMITATION Each individual must be protected against risks that are far too large through individual radiation dose limits. OPTIMIZATION Radiation doses should all be kept ALARA/ALARP