19 Apr 7 Fundamental Forces, Radiation Doses, Medical Applications Actual Presented

Smart Women in Physics Together: Undergraduate Mentoring ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Today: Radiation Dose Definitions, Medical Applications, PET scan 3-D rendering Source: wikipedia

Small group exercise! ,[object Object],[object Object],[object Object],?

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Measuring the amount of radioactivity or dose ,[object Object],[object Object],[object Object],[object Object],[object Object]

There are rigorous ways to characterize the source of radiation ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

There are two main units of radioactivity ,[object Object],[object Object],[object Object],[object Object],Marie Curie Nobel prizes in Physics and Chemistry Henri Becquerel Nobel Prize in Physics Example: 1 kilogram of “typical” soil has 400 Bq of Potassium-40 -- or 11 nanocuries

Radioactive decay is a random process P P P P P P P P P P P P P P P P P P U P P U P P P P U P U U P P P P P P S S S S S U P U U P P P P P U U P U P P U P S S S S S S S U P U U P P P U P U U P U U P U P S S S S S S S S S 10 days 20 days 30 days Example: Phosphorus-32 decay into Sulfur-32

Half-life is the average amount of time for ½ of the atoms to decay ,[object Object],[object Object],[object Object],[object Object],[object Object]

Radioactivity (becquerels) and Half-life are inversely related ,[object Object],[object Object],[object Object],[object Object]

Clicker Question—Half life / radioactivity ,[object Object],[object Object],[object Object],[object Object],[object Object]

Clicker Question—Half life / radioactivity ,[object Object],[object Object],[object Object],[object Object],[object Object],Shorter half-life = higher radioactivity If the half-life is infinite, it is not radioactive

The energy per emitted particle indicates how deeply it can penetrate materials and how much damage it can do ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],Mega = 10^6 or 1 million

Clicker question—classifying radiation ,[object Object],[object Object],[object Object],[object Object]

Clicker question—classifying radiation ,[object Object],[object Object],[object Object],[object Object],There are many other things you would need to know: What type of radiation do each emit? Is there any shielding in between?

Results of homework assignment

A few homework responses Adrian: If I became a luddite and lived in a hut in the woods at sea level I might save myself 80 mrem or so. Laura: Only 2.010 mrem or 0.6 % of my annual radiation exposure can be attributed to man made sources David: Unavoidable background radiation is from food and water, there is absolutely nothing I can do to change that.

Classifying the radiation dose is very complicated ,[object Object],[object Object],[object Object],[object Object],[object Object]

Radiation doses ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Some relevant radiation dose values ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Medical applications of radiation Destruction: Radiation Therapy Imaging: X-rays Imaging: Positron emission tomography Imaging: Gastrointestinal imaging

Positron emission tomography (PET scanning)

Radiation Therapy ,[object Object],[object Object],[object Object],[object Object]

Some slides about cancer radiation therapy http://youtube.com/watch?v=ZtENJI1K1hA&feature=related

Clicker Question—Acute Radiation Dose ,[object Object],[object Object],[object Object]

Clicker Question—Acute Radiation Dose ,[object Object],[object Object],[object Object],The information is not specific enough. If it happens over the whole body in a short time, then probably YES… However, if it happens over 100 years, then probably not. Also if localized, also will not die There is no easy way to put a concrete number on radiation dose

Ionizing radiation almost NEVER makes something turn radioactive! ,[object Object],[object Object],[object Object],[object Object],The person does NOT become radioactive … his nuclei are unchanged Nuclear reaction Releases ionizing radiation Causes Chemical reactions

Clicker question--transmutation ,[object Object],[object Object],[object Object],[object Object]

Clicker question--transmutation ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Protons and neutrons are made of quarks Quark model of a proton www2.cnrs.fr/presse/communique/709.htm “ Up” quarks charge = + 2/3 each “ Down” quark -1/3 charge Arpad Horvath Quark model of neutron

Quarks and Leptons are the constituent parts of matter. Murray Gell-Mann Nobel Prize 1969 There are six quarks Up Charmed Top Down Strange Bottom Charge = +2/3 Charge = -1/3 Similarly, there are six leptons Increasing mass Electron Muon Tau Electron neutrino Muon neutrino Tau neutrino Antimatter consists of the 6 anti-particle quarks and 6 anti-particle leptons

Under normal conditions, quarks do not exist in free space. Fermilab particle accelerator Billion-dollar physics experiments were required to detect quarks for fleeting instants in time

Beta-decay can transform a neutron into a proton Quarks (Electron) It is a decay of a “down quark” into an “up quark”

Clicker question--Quarks ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Clicker question--Quarks ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],+2/3 +2/3 -1/3 Take home message about quarks: Nucleons are composed of three quarks. Particle Physicists can predict a lot about matter from the quark / lepton models, Including some radioactive decay properties

19 Apr 7 Fundamental Forces, Radiation Doses, Medical Applications Actual Presented

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19 Apr 7 Fundamental Forces, Radiation Doses, Medical Applications Actual Presented