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Radiation Detection and Monitoring. Radiation Detection and Monitoring. By: Todd Bailey. Purpose of the four Part Class. Understanding What Radiation is. Effects of Radiation. Purpose of the four Part Class. Using The Radiation Monitor. Maintenance and Limitations .
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Radiation Detection and Monitoring Radiation Detection and Monitoring By: Todd Bailey
Purpose of the four Part Class Understanding What Radiation is Effects of Radiation
Purpose of the four Part Class Using The Radiation Monitor Maintenance and Limitations Easier Then Graduating from Yale
How big is an Atom? • Take one small speck of dust and expand it to the size of earth… • A single Atom would be the size of a city • Alpha particle radiation would be the size of a ping-pong ball
Time for a song http://www.youtube.com/watch?v=TCUK93s1jUY
Ionization • Ionizing radiation: Process of removing electrons from atoms or molecules -Alpha - Beta - Gamma / X-rays - Neutron Ionizing Radiation: Any radiation which is capable of dislodging electrons from atoms thereby producing ions. • Non – ionizing radiation: - radio waves - microwaves - visible light - ultraviolet waves *Most radioactive materials may emit more than one kind of radiation.
There are many kinds of radioactive decay, but three are particularly well known: beta particle alpha particle gamma ray
Alpha Radiation • Range - 2 inches • Shielding - paper, cloth - dead layer of skin • Biological Hazards - not external hazard - internal hazard - easily stopped by dead layer of skin * Alpha radiation will not cause damage from outside the body…
Beta Radiation • Range • up to 30’ • Shielding • thick clothing • ¼ inch aluminum • ¼ inch plastic • Biological Hazard • external hazard to skin and eyes • internal hazard
Gamma Rays/ X-Rays • Range - hundreds of feet • Shielding (dense) - lead - steel - concrete - dirt • Biological Hazard - whole body hazard (external and internal)
Neutron Radiation • Range - hundreds of feet • Shielding - (hydrogen/water) - plastic, concrete, dirt • Biological Hazard - whole body hazard (internal/external hazard)
Back Ground The weather station outside of the Atomic Testing Museum on a hot summer day. Displayed background gamma radiation level is 9.8 μR/hNormal Background 5-25 µR/hr
Radiation Rate • Current Rate • 0 Micro REM/hour • REM is roentgen equivalent in man (or mammal) • Displayed as: • R/hr (REM per Hour) • m R/hr (Milli REM per Hour) • 1,000 m R/hr = R/hr • µ R/hr (Micro REM per Hour) • 1,000,000 µ R/hr = R/hr
Average Annual Absorbed Dose From Naturally-Occurring Stone, brick, concrete 7 mrem Cosmic space radiation 26 mrem Food and water 40 mrem Terrestrial radiation (Continental US) 63 mrem Naturally-occurring radon 200 mrem (0.2 rem)
Average Annual Absorbed Dose From Man-Made Sources Smoke detectors 0.008 mrem (8 μrem) LCD wristwatch 0.06 mrem (60 μrem) Porcelain crowns/dentures 0.07 mrem (70 μrem) Jet plane travel 0.5 mrem per hour in air (Seattle to NY ~ 3.4 mrem) Computer screen/TV 1 mrem X-ray (extremities) 1 mrem X-ray (chest) 6 mrem X-ray (Upper GI) 245 mrem (0.245 rem) Cigarettes (1 pack per day) 1300 mrem (1.3 rem)
Dose Current Dose 48 Micro REM • REM is roentgen equivalent in man (or mammal) • Displayed as: • R (REM) • m R (Milli REM) • 1,000 m R = R • µ R (Micro REM) • 1,000,000 µ R = R
A 21-year-old soldier Nagasaki. Chernobyl Baby
Long Term Effects of Radiation Cancer Genetic Mutations Sterility
Cancer Leukemia Lung cancer Skin cancer Thyroid cancer Multiple myeloma Breast cancer Stomach cancer
Dose Limits OSHA specifies the following exposure limits for emergency workers in radiation fields: 5 rem any work (Dose > 5 rem is on a voluntary basis with knowledge of risks) 10 rem to protect property 25 rem to protect life
Canberra Personal Radiation Detector Gamma detector only – will not detect alpha or beta radiation
Capabilities Measures and records gamma/x-ray dose and rate Multiple user features, data logger, PC download Best uses Personal dosimeter and rate meter Used by decon team
Function Keys • Rate and Dose keys: Display rate or dose • Alarm key: Display “stay time” in minutes • Light key: Power On backlight • Clear/Test key: Perform operational test • On/Off key: Power On and Off Keys have other functions for advanced users
Digital Display Status indicators Units of measure Autoranging digital display
Rate Detection range of 1 µR/hr to 500 R/hr • Total Dose range of 0.1 µR to 999 R • Unit has an initialization time of less than 5 seconds