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http://camilopez.org/mediawiki-1.31.1-wlv/index.php?action=history&feed=atom&title=Experiments_with_gamma_rays Experiments with gamma rays - Revision history 2025-03-16T23:08:39Z Revision history for this page on the wiki MediaWiki 1.31.1 http://camilopez.org/mediawiki-1.31.1-wlv/index.php?title=Experiments_with_gamma_rays&diff=677&oldid=prev Laussy at 17:40, 29 September 2018 2018-09-29T17:40:40Z <p></p> <table class="diff diff-contentalign-left" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 17:40, 29 September 2018</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l28" >Line 28:</td> <td colspan="2" class="diff-lineno">Line 28:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== Sessions ==</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== Sessions ==</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>* On <del class="diffchange diffchange-inline">Wednesday, 3rd of </del>May, [[Inverse Square law with gamma rays, Dudley college (May 2017)|with Dudley Sixth Form college&#039;s students]] (15 students).</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>* On <ins class="diffchange diffchange-inline">3 </ins>May <ins class="diffchange diffchange-inline">2017</ins>, [[Inverse Square law with gamma rays, Dudley college (May 2017)|with Dudley Sixth Form college&#039;s students]] (15 students).</div></td></tr> </table> Laussy http://camilopez.org/mediawiki-1.31.1-wlv/index.php?title=Experiments_with_gamma_rays&diff=309&oldid=prev Laussy at 10:31, 1 June 2017 2017-06-01T10:31:33Z <p></p> <table class="diff diff-contentalign-left" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 10:31, 1 June 2017</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l7" >Line 7:</td> <td colspan="2" class="diff-lineno">Line 7:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* The inverse square law for uncollimated $\gamma$ radiation.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* The inverse square law for uncollimated $\gamma$ radiation.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* The attenuation of radiation in matter.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* The attenuation of radiation in matter.</div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">&lt;center&gt;[[File:Source_ALevelPhysicsDay03.05.1704.jpg|400px]]&lt;/center&gt;</ins></div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== What is radioactivity and where does it come from? ==</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== What is radioactivity and where does it come from? ==</div></td></tr> </table> Laussy http://camilopez.org/mediawiki-1.31.1-wlv/index.php?title=Experiments_with_gamma_rays&diff=293&oldid=prev Laussy at 16:19, 5 May 2017 2017-05-05T16:19:33Z <p></p> <table class="diff diff-contentalign-left" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 16:19, 5 May 2017</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l10" >Line 10:</td> <td colspan="2" class="diff-lineno">Line 10:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== What is radioactivity and where does it come from? ==</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== What is radioactivity and where does it come from? ==</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Radioactivity is everywhere. In the form of decaying C-14 atoms, it is in about one of every other cell of our body, amounting to roughly 4000 disintegrations per second (per person). One finds it in bananas, due to their high level of potassium. In greater amount, we find it from cosmic radiations and, for the main part of the ambient background, from radon. A more useful measure of radiation than the number of disintegration per second (which unit is the Becquerel) is the amount of energy deposited in matter: one Joule in a kg of matter corresponds to one Gray (Gy). Since various types of radiation have varying effects on living tissues, which is what is of greatest concern when measuring radioactivity, one uses a weighted quantity, the effective dose delivered, with units in Sieverts (Sv). Some orders of magnitudes are in order here: the worldwide average dose from background radiation is about 2.4mSv/year. Living within 50 miles of a nuclear power plant yields 0.09$mu$Sv/year, which is considerably less than the single event of eating a banana (0.1$\mu$Sv) or living within 50 miles of a coal power plant (1$\mu$Sv). On average, someone receives a dose of 10$\mu$Sv per day. A chest X-ray delivers 20$\mu$Sv, the extra dose in Tokyo after the Fukushima accident was of about 40$\mu$Sv in the following weeks. A mammogram is 400$\mu$Sv. The legal limit for a US radiation worker is 50mSv per year. Then start the harmful doses: 100mSv a year shows correlation with developing a cancer. Radiation poisoning is felt at about 400mSv if taken over a short time. 4Sv are lethal if no prompt treatment is received. 8Sv are lethal regardless of action taken.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Radioactivity is everywhere. In the form of decaying C-14 atoms, it is in about one of every other cell of our body, amounting to roughly 4000 disintegrations per second (per person). One finds it in bananas, due to their high level of potassium. In greater amount, we find it from cosmic radiations and, for the main part of the ambient background, from radon. A more useful measure of radiation than the number of disintegration per second (which unit is the Becquerel) is the amount of energy deposited in matter: one Joule in a kg of matter corresponds to one Gray (Gy). Since various types of radiation have varying effects on living tissues, which is what is of greatest concern when measuring radioactivity, one uses a weighted quantity, the effective dose delivered, with units in Sieverts (Sv). Some orders of magnitudes are in order here: the worldwide average dose from background radiation is about 2.4mSv/year. Living within 50 miles of a nuclear power plant yields 0.09$<ins class="diffchange diffchange-inline">\</ins>mu$Sv/year, which is considerably less than the single event of eating a banana (0.1$\mu$Sv) or living within 50 miles of a coal power plant (1$\mu$Sv). On average, someone receives a dose of 10$\mu$Sv per day. A chest X-ray delivers 20$\mu$Sv, the extra dose in Tokyo after the Fukushima accident was of about 40$\mu$Sv in the following weeks. A mammogram is 400$\mu$Sv. The legal limit for a US radiation worker is 50mSv per year. Then start the harmful doses: 100mSv a year shows correlation with developing a cancer. Radiation poisoning is felt at about 400mSv if taken over a short time. 4Sv are lethal if no prompt treatment is received. 8Sv are lethal regardless of action taken.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>In [[Wolverhampton]], we have some micrograms of Cs-137 whose relaxations from Cs atoms (in fact Ba atoms following a $\beta$ transition of Cs) provide us with a 370kBq radiosource, that we use for a variety of outreach experiments and demonstrations.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>In [[Wolverhampton]], we have some micrograms of Cs-137 whose relaxations from Cs atoms (in fact Ba atoms following a $\beta$ transition of Cs) provide us with a 370kBq radiosource, that we use for a variety of outreach experiments and demonstrations.</div></td></tr> </table> Laussy http://camilopez.org/mediawiki-1.31.1-wlv/index.php?title=Experiments_with_gamma_rays&diff=292&oldid=prev Laussy at 16:19, 5 May 2017 2017-05-05T16:19:02Z <p></p> <table class="diff diff-contentalign-left" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 16:19, 5 May 2017</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l10" >Line 10:</td> <td colspan="2" class="diff-lineno">Line 10:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== What is radioactivity and where does it come from? ==</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== What is radioactivity and where does it come from? ==</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Radioactivity is everywhere. In the form of decaying C-14 atoms, it is in about one of every other cell of our body, amounting to roughly 4000 disintegrations per second (per person). One finds it in bananas, due to their high level of potassium. In greater amount, we find it from cosmic radiations and, for the main part of the ambient background, from radon. A more useful measure of radiation than the number of disintegration per second (which unit is the Becquerel) is the amount of energy deposited in matter: <del class="diffchange diffchange-inline">1J </del>in kg of matter corresponds to one Gray (Gy). Since various types of radiation have varying effects on living tissues, which is what is of greatest concern when measuring radioactivity, one uses a weighted quantity, the effective dose delivered, with units in Sieverts (Sv). Some orders of magnitudes are in order here: the worldwide average dose from background radiation is about 2.4mSv/year. Living within 50 miles of a nuclear power plant yields 0.09$mu$Sv/year, which is considerably less than the single event of eating a banana (0.1$\mu$Sv) or living within 50 miles of a coal power plant (1$\mu$Sv). On average, someone receives a dose of 10$\mu$Sv per day. A chest X-ray delivers 20$\mu$Sv, the extra dose in Tokyo after the Fukushima accident was of about 40$\mu$Sv in the following weeks. A mammogram is 400$\mu$Sv. The legal limit for a US radiation worker is 50mSv per year. Then start the harmful doses: 100mSv a year shows correlation with developing a cancer. Radiation poisoning is felt at about 400mSv if taken over a short time. 4Sv are lethal if no prompt treatment is received. 8Sv are lethal regardless of action taken.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Radioactivity is everywhere. In the form of decaying C-14 atoms, it is in about one of every other cell of our body, amounting to roughly 4000 disintegrations per second (per person). One finds it in bananas, due to their high level of potassium. In greater amount, we find it from cosmic radiations and, for the main part of the ambient background, from radon. A more useful measure of radiation than the number of disintegration per second (which unit is the Becquerel) is the amount of energy deposited in matter: <ins class="diffchange diffchange-inline">one Joule </ins>in <ins class="diffchange diffchange-inline">a </ins>kg of matter corresponds to one Gray (Gy). Since various types of radiation have varying effects on living tissues, which is what is of greatest concern when measuring radioactivity, one uses a weighted quantity, the effective dose delivered, with units in Sieverts (Sv). Some orders of magnitudes are in order here: the worldwide average dose from background radiation is about 2.4mSv/year. Living within 50 miles of a nuclear power plant yields 0.09$mu$Sv/year, which is considerably less than the single event of eating a banana (0.1$\mu$Sv) or living within 50 miles of a coal power plant (1$\mu$Sv). On average, someone receives a dose of 10$\mu$Sv per day. A chest X-ray delivers 20$\mu$Sv, the extra dose in Tokyo after the Fukushima accident was of about 40$\mu$Sv in the following weeks. A mammogram is 400$\mu$Sv. The legal limit for a US radiation worker is 50mSv per year. Then start the harmful doses: 100mSv a year shows correlation with developing a cancer. Radiation poisoning is felt at about 400mSv if taken over a short time. 4Sv are lethal if no prompt treatment is received. 8Sv are lethal regardless of action taken.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>In [[Wolverhampton]], we have some micrograms of Cs-137 whose relaxations from Cs atoms (in fact Ba atoms following a $\beta$ transition of Cs) provide us with a 370kBq radiosource, that we use for a variety of outreach experiments and demonstrations.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>In [[Wolverhampton]], we have some micrograms of Cs-137 whose relaxations from Cs atoms (in fact Ba atoms following a $\beta$ transition of Cs) provide us with a 370kBq radiosource, that we use for a variety of outreach experiments and demonstrations.</div></td></tr> </table> Laussy http://camilopez.org/mediawiki-1.31.1-wlv/index.php?title=Experiments_with_gamma_rays&diff=291&oldid=prev Laussy at 16:18, 5 May 2017 2017-05-05T16:18:28Z <p></p> <table class="diff diff-contentalign-left" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 16:18, 5 May 2017</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l10" >Line 10:</td> <td colspan="2" class="diff-lineno">Line 10:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== What is radioactivity and where does it come from? ==</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== What is radioactivity and where does it come from? ==</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Radioactivity is everywhere. In the form of decaying C-14 atoms, it is in about one of every other cell of our body, amounting to roughly 4000 disintegrations per second (per person). One finds it in bananas, due to <del class="diffchange diffchange-inline">the </del>high level of potassium. In greater amount, we find it from cosmic radiations and, for the main part of the ambient background, from radon. A more useful measure of radiation than the number of disintegration per second (which unit is the Becquerel) is the amount of energy deposited in matter: 1J in kg of matter corresponds to one Gray (Gy). Since various types of radiation have varying effects on living tissues, which is what is of greatest concern when measuring radioactivity, one uses a weighted quantity, the effective dose delivered, with units in Sieverts (Sv). Some orders of magnitudes are in order here: the worldwide average dose from background radiation is about 2.4mSv/year. Living within 50 miles of a nuclear power plant yields 0.09$mu$Sv/year, which is considerably less than the single event of eating a banana (0.1$\mu$Sv) or living within 50 miles of a coal power plant (1$\mu$Sv). On average, someone receives a dose of 10$\mu$Sv per day. A chest X-ray delivers 20$\mu$Sv, the extra dose in Tokyo after the Fukushima accident was of about 40$\mu$Sv in the following weeks. A mammogram is 400$\mu$Sv. The legal limit for a US radiation worker is 50mSv per year. Then start the harmful doses: 100mSv a year shows correlation with developing a cancer. Radiation poisoning is felt at about 400mSv if taken over a short time. 4Sv are lethal if no prompt treatment is received. 8Sv are lethal regardless of action taken.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Radioactivity is everywhere. In the form of decaying C-14 atoms, it is in about one of every other cell of our body, amounting to roughly 4000 disintegrations per second (per person). One finds it in bananas, due to <ins class="diffchange diffchange-inline">their </ins>high level of potassium. In greater amount, we find it from cosmic radiations and, for the main part of the ambient background, from radon. A more useful measure of radiation than the number of disintegration per second (which unit is the Becquerel) is the amount of energy deposited in matter: 1J in kg of matter corresponds to one Gray (Gy). Since various types of radiation have varying effects on living tissues, which is what is of greatest concern when measuring radioactivity, one uses a weighted quantity, the effective dose delivered, with units in Sieverts (Sv). Some orders of magnitudes are in order here: the worldwide average dose from background radiation is about 2.4mSv/year. Living within 50 miles of a nuclear power plant yields 0.09$mu$Sv/year, which is considerably less than the single event of eating a banana (0.1$\mu$Sv) or living within 50 miles of a coal power plant (1$\mu$Sv). On average, someone receives a dose of 10$\mu$Sv per day. A chest X-ray delivers 20$\mu$Sv, the extra dose in Tokyo after the Fukushima accident was of about 40$\mu$Sv in the following weeks. A mammogram is 400$\mu$Sv. The legal limit for a US radiation worker is 50mSv per year. Then start the harmful doses: 100mSv a year shows correlation with developing a cancer. Radiation poisoning is felt at about 400mSv if taken over a short time. 4Sv are lethal if no prompt treatment is received. 8Sv are lethal regardless of action taken.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>In [[Wolverhampton]], we have some micrograms of Cs-137 whose relaxations from Cs atoms (in fact Ba atoms following a $\beta$ transition of Cs) provide us with a 370kBq radiosource, that we use for a variety of outreach experiments and demonstrations.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>In [[Wolverhampton]], we have some micrograms of Cs-137 whose relaxations from Cs atoms (in fact Ba atoms following a $\beta$ transition of Cs) provide us with a 370kBq radiosource, that we use for a variety of outreach experiments and demonstrations.</div></td></tr> </table> Laussy http://camilopez.org/mediawiki-1.31.1-wlv/index.php?title=Experiments_with_gamma_rays&diff=265&oldid=prev Laussy: /* Sessions */ 2017-05-04T07:44:54Z <p>‎<span dir="auto"><span class="autocomment">Sessions</span></span></p> <table class="diff diff-contentalign-left" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 07:44, 4 May 2017</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l25" >Line 25:</td> <td colspan="2" class="diff-lineno">Line 25:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== Sessions ==</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== Sessions ==</div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">* On Wednesday, 3rd of May, [[Inverse Square law with gamma rays, Dudley college (May 2017)|with Dudley Sixth Form college&#039;s students]] (15 students).</ins></div></td></tr> </table> Laussy http://camilopez.org/mediawiki-1.31.1-wlv/index.php?title=Experiments_with_gamma_rays&diff=264&oldid=prev Laussy at 07:44, 4 May 2017 2017-05-04T07:44:40Z <p></p> <table class="diff diff-contentalign-left" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 07:44, 4 May 2017</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l23" >Line 23:</td> <td colspan="2" class="diff-lineno">Line 23:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Part of the demonstration will involve a presentation and discussion of the risks associated to radioactivity, which either tends to be feared to an irrational degree or on the contrary simply ignored. Teaching about ionising radiations helps people to develop balanced attitudes to the subject, neither blasé nor apprehensive.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Part of the demonstration will involve a presentation and discussion of the risks associated to radioactivity, which either tends to be feared to an irrational degree or on the contrary simply ignored. Teaching about ionising radiations helps people to develop balanced attitudes to the subject, neither blasé nor apprehensive.</div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">== Sessions ==</ins></div></td></tr> </table> Laussy http://camilopez.org/mediawiki-1.31.1-wlv/index.php?title=Experiments_with_gamma_rays&diff=262&oldid=prev Laussy: Laussy moved page Inverse Square law investigated with gamma rays to Experiments with gamma rays: more general title 2017-05-04T07:44:00Z <p>Laussy moved page <a href="/wlv/Inverse_Square_law_investigated_with_gamma_rays" class="mw-redirect" title="Inverse Square law investigated with gamma rays">Inverse Square law investigated with gamma rays</a> to <a href="/wlv/Experiments_with_gamma_rays" title="Experiments with gamma rays">Experiments with gamma rays</a>: more general title</p> <table class="diff diff-contentalign-left" data-mw="interface"> <tr class="diff-title" lang="en"> <td colspan="1" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td> <td colspan="1" style="background-color: #fff; color: #222; text-align: center;">Revision as of 07:44, 4 May 2017</td> </tr><tr><td colspan="2" class="diff-notice" lang="en"><div class="mw-diff-empty">(No difference)</div> </td></tr></table> Laussy http://camilopez.org/mediawiki-1.31.1-wlv/index.php?title=Experiments_with_gamma_rays&diff=261&oldid=prev Laussy at 07:41, 4 May 2017 2017-05-04T07:41:03Z <p></p> <table class="diff diff-contentalign-left" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 07:41, 4 May 2017</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l1" >Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td></tr> <tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>= <del class="diffchange diffchange-inline">Inverse Square law </del>with $\gamma$ rays =</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>= <ins class="diffchange diffchange-inline">Experiments </ins>with $\gamma$ rays =</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>$\gamma$ rays are high-energy photons. They typically originate from the spontaneous emission of a nucleon (proton or neutron). Using our Cs-137 source at the [[UoW]], we address the following particular topics surrounding the use of radiosources:</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>$\gamma$ rays are high-energy photons. They typically originate from the spontaneous emission of a nucleon (proton or neutron). Using our Cs-137 source at the [[UoW]], we address the following particular topics surrounding the use of radiosources:</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* The different types of radiation and their main properties, including the existence of background radiation.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* The different types of radiation and their main properties, including the existence of background radiation.</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>* <del class="diffchange diffchange-inline">the </del>randomness of radioactive emission and its associated statistical aspect.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>* <ins class="diffchange diffchange-inline">The </ins>randomness of radioactive emission and its associated statistical aspect.</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>* <del class="diffchange diffchange-inline">the </del>inverse square law for uncollimated $\gamma$ radiation.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>* <ins class="diffchange diffchange-inline">The </ins>inverse square law for uncollimated $\gamma$ radiation<ins class="diffchange diffchange-inline">.</ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">* The attenuation of radiation in matter</ins>.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== What is radioactivity and where does it come from? ==</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== What is radioactivity and where does it come from? ==</div></td></tr> </table> Laussy http://camilopez.org/mediawiki-1.31.1-wlv/index.php?title=Experiments_with_gamma_rays&diff=260&oldid=prev Laussy at 07:27, 4 May 2017 2017-05-04T07:27:49Z <p></p> <table class="diff diff-contentalign-left" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 07:27, 4 May 2017</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l1" >Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>= Inverse Square law with $\gamma$ rays =</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>= Inverse Square law with $\gamma$ rays =</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>$\gamma$ rays are high-energy photons. They <del class="diffchange diffchange-inline">can </del>originate from the spontaneous emission of a nucleon (proton or neutron). Using <del class="diffchange diffchange-inline">such relaxations from </del>Cs <del class="diffchange diffchange-inline">atoms (in fact Ba atoms following a $\beta$ transition of Cs)</del>, we address the following particular topics surrounding the use of radiosources:</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>$\gamma$ rays are high-energy photons. They <ins class="diffchange diffchange-inline">typically </ins>originate from the spontaneous emission of a nucleon (proton or neutron). Using <ins class="diffchange diffchange-inline">our </ins>Cs<ins class="diffchange diffchange-inline">-137 source at the [[UoW]]</ins>, we address the following particular topics surrounding the use of radiosources:</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* The different types of radiation and their main properties, including the existence of background radiation.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* The different types of radiation and their main properties, including the existence of background radiation.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* the randomness of radioactive emission and its associated statistical aspect.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* the randomness of radioactive emission and its associated statistical aspect.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* the inverse square law for uncollimated $\gamma$ radiation.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* the inverse square law for uncollimated $\gamma$ radiation.</div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">== What is radioactivity and where does it come from? ==</ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">Radioactivity is everywhere. In the form of decaying C-14 atoms, it is in about one of every other cell of our body, amounting to roughly 4000 disintegrations per second (per person). One finds it in bananas, due to the high level of potassium. In greater amount, we find it from cosmic radiations and, for the main part of the ambient background, from radon. A more useful measure of radiation than the number of disintegration per second (which unit is the Becquerel) is the amount of energy deposited in matter: 1J in kg of matter corresponds to one Gray (Gy). Since various types of radiation have varying effects on living tissues, which is what is of greatest concern when measuring radioactivity, one uses a weighted quantity, the effective dose delivered, with units in Sieverts (Sv). Some orders of magnitudes are in order here: the worldwide average dose from background radiation is about 2.4mSv/year. Living within 50 miles of a nuclear power plant yields 0.09$mu$Sv/year, which is considerably less than the single event of eating a banana (0.1$\mu$Sv) or living within 50 miles of a coal power plant (1$\mu$Sv). On average, someone receives a dose of 10$\mu$Sv per day. A chest X-ray delivers 20$\mu$Sv, the extra dose in Tokyo after the Fukushima accident was of about 40$\mu$Sv in the following weeks. A mammogram is 400$\mu$Sv. The legal limit for a US radiation worker is 50mSv per year. Then start the harmful doses: 100mSv a year shows correlation with developing a cancer. Radiation poisoning is felt at about 400mSv if taken over a short time. 4Sv are lethal if no prompt treatment is received. 8Sv are lethal regardless of action taken.</ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">In [[Wolverhampton]], we have some micrograms of Cs-137 whose relaxations from Cs atoms (in fact Ba atoms following a $\beta$ transition of Cs) provide us with a 370kBq radiosource, that we use for a variety of outreach experiments and demonstrations.</ins></div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== Safety issues ==</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== Safety issues ==</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:radioactive-cs137-source.png|130px|left]] &#160;</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:radioactive-cs137-source.png|130px|left]] &#160;</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The experiment involve a radioactive source (shown left) and specific safety procedures must be adhered to. We expect maturity and good behaviour from the students. Eating/drinking/applying cosmetics is not allowed during the demonstration and following the staff instructions regarding safety issues and practices in the laboratory are mandatory at all times. Safety instructions <del class="diffchange diffchange-inline">are </del>explained before the demonstration, in particular the procedure to follow in case of an emergency (e.g., fire alarm)<del class="diffchange diffchange-inline">.</del></div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The experiment involve a radioactive source (shown left) and specific safety procedures must be adhered to. We expect maturity and good behaviour from the students. Eating/drinking/applying cosmetics is not allowed during the demonstration and following the staff instructions regarding safety issues and practices in the laboratory are mandatory at all times. Safety instructions <ins class="diffchange diffchange-inline">will be </ins>explained before the demonstration, in particular the procedure to follow in case of an emergency (e.g., fire alarm).</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>&#160;</div></td><td colspan="2">&#160;</td></tr> <tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">Transfer of the radio-source from its storage locker are made by one of the university radiation protection officers. The demonstration is conducted in a properly equipped and maintained laboratory (in the Rosalind Franklin building). </del></div></td><td colspan="2">&#160;</td></tr> <tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">The demonstration is carried out and supervised at all times by a qualified Physicist, with a Diploma of Advanced Studies in Corpuscular Physics and experience in overlooking laboratory sessions with university students handling similar radiosources. It uses our Cs-137 370kBq sealed source, from the last generation in design for safe handling, experimentation, storage and security. &#039;&#039;Sealing&#039;&#039; means that the radioactive material is permanently fixed in a capsule designed to prevent release and dispersal of the radioactive material under the most severe conditions which are likely to be encountered in normal use and handling. Spreading of Cs is the most dangerous aspect of this common radioactive element, that is one of the most common waste in nuclear incidents (Tchernobyl and Fukushimas) or contaminating agent following nuclear-weapon tests. The sealing of our source means that Cs is confined and that the risks associated to its dispersion in the surroundings are eliminated. Students should maintain at a distance from the setup (a meter) during the demonstration, in particular, they should not be in contact with the source itself or its support. They are given the opportunity to participate actively and taking data, without having to interact with the radiosource. The exposure of students and staff are kept considerably below the legal dose limits (similar to that delivered by ambient radioactivity).</del></div></td><td colspan="2">&#160;</td></tr> <tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>&#160;</div></td><td colspan="2">&#160;</td></tr> <tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">Part of the demonstration involves a presentation and discussion of the risks associated to radioactivity, which either tends to be feared to an irrational degree or on the contrary simply ignored. Teaching about ionising radiations helps people to develop balanced attitudes to the subject, neither blasé nor apprehensive</del>.</div></td><td colspan="2">&#160;</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">== Sessions ==</del></div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">Transfer of the radio-source from its storage locker will be made by the university radiation protection officer. The demonstration will be conducted in a properly equipped and maintained laboratory (in the Rosalind Franklin building). </ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">The demonstration will be carried out at all times by a qualified Physicist, with a Diploma of Advanced Studies in Corpuscular Physics and experience in overlooking laboratory sessions with University students handling similar radiosources. It will use a Cs-137 370kBq sealed source, from the last generation in design for safe handling, experimentation, storage and security. &#039;&#039;Sealing&#039;&#039; means that the radioactive material is permanently fixed in a capsule designed to prevent release and dispersal of the radioactive material under the most severe conditions which are likely to be encountered in normal use and handling. Spreading of Cs is the most dangerous aspect of this common radioactive element, that is one of the most common waste in nuclear incidents (Tchernobyl and Fukushimas) or contaminating agent following nuclear-weapon tests. The sealing of our source means that Cs is confined and that the risks associated to its dispersion in the surroundings are eliminated. Students should maintain at a distance from the setup (a meter) during the demonstration, in particular, they should not be in contact with the source itself or its support. They will be given the opportunity to participate actively and taking data, without having to interact with the radiosource. The exposure of students and staff will be kept considerably below the legal dose limits (much less than is delivered by ambiant radioactivity).</ins></div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">* On Wednesday, 3rd </del>of <del class="diffchange diffchange-inline">May</del>, <del class="diffchange diffchange-inline">[[Inverse Square law with gamma rays</del>, <del class="diffchange diffchange-inline">Dudley college (May 2017)|with Dudley Sixth Form college&#039;s students]] (15 students)</del>.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">Part of the demonstration will involve a presentation and discussion </ins>of <ins class="diffchange diffchange-inline">the risks associated to radioactivity</ins>, <ins class="diffchange diffchange-inline">which either tends to be feared to an irrational degree or on the contrary simply ignored. Teaching about ionising radiations helps people to develop balanced attitudes to the subject</ins>, <ins class="diffchange diffchange-inline">neither blasé nor apprehensive</ins>.</div></td></tr> </table> Laussy