Содержание
- 2. Basic Radiation Theory and Fundamentals Sources of Ionizing Radiation Biological Effects and Risks of Exposure to
- 3. Basic Radiation Theory & Fundamentals Radiation is simply energy in the form of particles or waves
- 4. Nucleus: Contains Protons (+1 charge) and Neutrons (no charge) Nuclear Diameter ~ 10-15 m Electrons: orbit
- 5. Ionizing versus Non-Ionizing Radiation Ionizing Radiation: Means radiation with sufficient energy to liberate an electron from
- 6. Absorbed The rad (radiation absorbed dose) is the energy deposited per unit mass by Dose ionizing
- 7. Key ‘Dose’ Terms Cont. 1 Sv = 100 rem 1 Gy = 100 rads = 100
- 8. Radioactivity: The spontaneous decomposition or disintegration of unstable atomic nuclei is termed radioactivity. The energy and
- 9. Alpha Particle Massive; +2 charge Beta Particle Some Mass; +/- 1 charge Gamma / X-Ray No
- 10. Photodisintegration X-Ray disappears => liberates a proton, neutron or alpha particle Photoelectric Effect X-Ray disappears =>
- 11. Compton Scatter X-Ray survives => liberates an electron while changing course and losing some energy Pair
- 12. Common Sources of Ionizing Radiation Sources of Background Radiation Exposure Natural Background Medical Diagnosis and Treatment
- 15. CyberKnife M6 Series TomoTherapy H Series Accuray radiation generating machines (RGMs) are capable of creating intense
- 16. Biological Response to Ionizing Radiation – Key Terms Somatic, Stochastic, Deterministic, Heritable Radiation Biology – Mechanisms
- 17. Radiation Biology – Key Terms Somatic Effects: biological effects that occur on the exposed individual Deterministic
- 18. Radiation Causes Ionizations of: ATOMS which may affect MOLECULES which may affect CELLS which may affect
- 19. Radiation Biology – Mechanisms DNA is the Target of Concern (Deoxyribonucleic acid [DNA] encodes the genetic
- 20. Radiation Biology – Affects What can Happen after Direct or Indirect DNA Damage? Detection and Repair
- 21. Radiation Biology – Factors Affecting Biological Response Total Dose Received & Dose Rate Greater total dose
- 22. Acute versus Chronic Exposures Chronic radiation exposures: low doses over long time periods Acute radiation exposures:
- 23. Radiation Risk Radiation Exposure Is Assumed to Increase Cancer Risk Approximately 35 – 45% of all
- 25. The Principles of Radiological Protection Epidemiological Studies Dose Response Models National / International Recommendations & Laws
- 26. Justification – No practice shall be adopted unless its introduction produces a net positive benefit. This
- 27. Epidemiology – the study of patterns, causes, and effects of health and disease conditions in defined
- 29. Epidemiological studies are performed and presented UNSCEAR World Health Organization National and International agencies make recommendations
- 31. Unrestricted Area – Any area that is not controlled for the purposes of radiation safety (offices,
- 32. The developing embryo/fetus, with rapidly dividing cells, is sensitive to many environmental factors including ionizing radiation.
- 33. Member of the Public: means an individual who is not a radiation worker, has not received
- 34. Radiation Protection Policies and Procedures The ALARA Concept (Time, Distance and Shielding) Signs, Labels, and Postings
- 35. The most important policy to remember is … never be inside a test cell or bunker
- 36. ALARA is an acronym for As Low As Reasonably Achievable. Since it is assumed that any
- 37. Reduce Exposures by Minimizing Time & Dose Rate Dose = Dose Rate x Time 500 mrem
- 38. Reduce Exposures by Maximizing Distance
- 39. Inverse Square Law - Example
- 40. Close the Jaws/MLC, Plug Beam, and Beam Down Whenever Possible/Practical Reduce Exposures by Using Shielding Materials
- 41. Some areas require specific authorization or an escort prior to entry. Be aware of and adhere
- 42. Emergency Buttons/Devices Warning Lights Note: Actuating an Emergency Button/Device, or opening the main test cell door/gate,
- 43. Operators must physically enter the test cell, bunker or shielded enclosure to ensure no persons are
- 44. Personnel Monitoring Facility Monitoring Radiation Detectors Radiation Monitoring
- 45. Dosimetry Use is a Requirement for all Radiation Workers Basic Dosimetry Use Guidelines Include: Keep away
- 46. Test Cell/Bunker Commissioning and Routine Leakage Surveys Facility Monitoring Continuous Area Monitoring
- 47. Radiation Leakage Surveys and Area Monitoring Gas Filled Detectors –Ionization Chambers Benefits – rugged, inexpensive, appropriate
- 48. Briefly inspect the instrument for physical damage or excessive wear. Ensure the instrument has been recently
- 49. Management Responsibilities Promote a positive radiation safety culture and ensure adequate resources exist to develop/maintain a
- 50. Limit the radiation dose to involved persons … the first action during any emergency is to
- 51. For more information, visit: http://sharepoint/Radiation Safety/ Procedures, forms, links, contact information, announcements, and more
- 52. Accuray is committed to maintaining a robust radiation safety program. As a result, even our “Radiation
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