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Starter –Sketch in the back of your book the 3 stages of ionisation. Before the photon gets there As it arrives After it has collided Do it. As I could ask any of you !! (Think about the key words). C/W 1 st November 2011
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Starter –Sketch in the back of your book the 3 stages of ionisation Before the photon gets there As it arrives After it has collided Do it. As I could ask any of you!! (Think about the key words)
C/W 1stNovember 2011 Effects of ionising radiation Keywords: gamma rays radioactive X-rays radiographer Objectives: Must – Understand the risk of using x-rays and gamma rays Should – understand the precautions you need to take with x-rays and gamma rays. Could – Understand risk, and perceived risk
Halloween lesson! Come up with the person next to you the top 5 ways you think you are most likely to die (30 seconds)
Odds that an American adult does not want to live to age 120 under any circumstances: 3 to 2 Odds of injury from fireworks: 19,556 to 1 Odds of injury from using a chain saw: 4,464 to 1 Odds of injury from mowing the lawn: 3,623 to 1 Odds of fatally slipping in bath or shower: 2,232 to 1 Odds of drowning in a bathtub: 685,000 to 1 Odds of being killed on a 5-mile bus trip: 500,000,000 to 1 Odds of being killed sometime in the next year in any sort of transportation accident: 77 to 1 Odds of being struck by lightning: 576,000 to 1 Odds of being killed by lightning: 2,320,000 to 1 Odds of dating a supermodel: 88,000 to 1 Odds that a celebrity marriage will last a lifetime: 3 to 1 Odds of being on plane with a drunken pilot: 117 to 1 Odds of dating a millionaire: 215 to 1 Odds of dating a supermodel: 88,000 to 1 Odds of finding a four-leaf clover on first try: 10,000 to 1 Odds of striking it rich on Antiques Roadshow: 60,000 to 1
What conclusions can we draw? people are generally more willing to accept the risk associated with something they choose to do than something that is imposed, and to accept risks that have short-lived effects rather than long-lasting ones People tend to over-estimate the risk of unfamiliar things (like flying as compared with cycling), and of things whose effect is invisible or long-term (like ionising radiation)
What has this got to do with electromagnetic radiation? There are risks involved with this too! Gamma waves – the highest energy
What were the highest energy types of radiation? (Gamma rays are highest, then X-rays)
Radio Micro Infra-Red Light Ultra-Violet X rays Gamma Electromagnetic Spectrum Wavelength () increases Gate XUsually Lets In Most Radiation Can you think of a phrase that would help you remember this order? Low frequency Long wavelength Low energy Least penetrating High frequency Short wavelength High energy Most penetrating x High frequency Short wavelength High energy Most penetrating Low frequency Long wavelength Low energy Least penetrating
Ionisation happens with high energy photons...... Ie x-rays or gamma rays.....you cant just add the energy of lots of infra red rays for example.
We can think of these waves like photons (particles) High energy photons can do more damage, like firing a bullet from a gun, instead of through a stone.
There is radiation around us a lot of the time......Is this a problem?
CT scan (computer tomography) (drawing a map of your insides!) This uses x-rays What are the problems? What are the benefits? Is it worth it?
How can we control our risk of radiation? Think about UV radiation? People that work with radiation like those in hospitals learn to control their risk.
Page 242 question 2, 3, 4, 6 Homework P2_04 task 1 X-rays for thursday
Plenary Write down in the back of your book, the types of electromagnetic radiation you know, in order of most energy to least energy
C/W 18th October 2011 Effects of ionising radiation Keywords: gamma rays radioactive X-rays radiographer Objectives: Must – Understand the risk of using x-rays and gamma rays Should – understand the precautions you need to take with x-rays and gamma rays. Could – Understand risk, and perceived risk