电离辐射和辐射安全-广州质控班.pptVIP

Welcome to Fluke Biomedical Advantage: Self-paced Training. The topic of this brief training course is how to use the 451B and 451P Radiation Survey Meters. The goal is to keep radiation exposure (dose) as low as reasonably achievable (ALARA). In the specific example of checking background levels of radiation that may be generated in and around a Linear Accelerator, measurements are taken at specific areas with specific limits for the maximum allowable background levels. The background level for employee/clinical staff-occupied areas is different (higher) than for patients awaiting treatment in the patient waiting room(s). The assumption is that whether clinical staff or patients, people are only in the surveyed areas for short periods of time. In other words, the survey does not assume long-term exposure to the background radiation. Such a long-term survey would require time-weighted average exposure (dose) to be determined. One would use personal dosimeters for long-term measurements. Welcome to Fluke Biomedical Advantage: Self-paced Training. The topic of this brief training course is how to use the 451B and 451P Radiation Survey Meters. These are the different types of ion radiation We will not further discuss the Neutron radiation. One would use a 190N survey meter to measure Neutron radiation. * How does one minimize exposure to radiation? There are three important aspects to take care of: Time: Be aware, espacially for radioactive sources, that the radiation is continues. So make the time you are near by the radiation as short as possible Distance: Take notice of the so called Inverse square law: for example 2 meter farther means 4 times less radiation; 3 meter means 9 times less radiation Shielding: Depends on kind of radiation, we will show it to you in the next slide One good way to reduce radiation exposure (dose) is to provide shielding between the source of the radiation and the person or media to be protected. Each of the forms of radiation