1. FIZIKA Nuclear radiation

2. FIZIKA 2 Radioactivity Dr. Seres István Seres.Istvan@gek.szie.hu Helium nucleus: 2 proton + 2 neutron Components of the nucleus:

3. FIZIKA 3 Radioactivity Dr. Seres István Seres.Istvan@gek.szie.hu Components of the nucleus: Isotopes: same atomic number, dfferent mass number Eg. hydrogen isotopes: - normal hydrogen isotope - deuterium - tricium Eg. carbon: stabil isotope, radioactive isotope Eg. uranium:, radioactive isotopes

4. FIZIKA 4 Radioactivity Dr. Seres István Seres.Istvan@gek.szie.hu Helium nucleus (  particle): 2 protons + 2 neutrons Mass - defects: m  = 6,6447·10 -27 kg, m p = 1,6727·10 -27 kg, m n = 1,6749·10 -27 kg, Nuclear binding energy

5. FIZIKA 5 Radioactivity Dr. Seres István Seres.Istvan@gek.szie.hu Mass-defect: Einstein principle on matter and energy: Binding energy:  = mc 2 = -5·10 -29 ·(3·10 8 ) 2  = 4,5·10 -12 J = 2,8·10 7 eV = 28 MeV· (1 eV = 1,6·10 -19 J) The mass is converted to energy = -5·10 -29 kg Nuclear binding energy

6. FIZIKA 6 Radioactivity Dr. Seres István Seres.Istvan@gek.szie.hu Nuclear physics Nuclear binding energy: Specific binding energy :

7. FIZIKA 7 Radioactivity Dr. Seres István Seres.Istvan@gek.szie.hu Nuclear physics Radioactive decay, fission fusion Specific binding energy (MeV) Mass number (A) -2 -3 -4 -5 -6 -7 -8 -9 0 20 40 60 80 100 120 140 160 180 200 220 240

8. FIZIKA 8 Radioactivity Dr. Seres István Seres.Istvan@gek.szie.hu Radioactive decay Law of radioactivity N N0N0 N 0 /2 T 2T N 0 /4 T – half period

9. FIZIKA 9 Radioactivity Dr. Seres István Seres.Istvan@gek.szie.hu Radioactivity Radiocarbon dating (C 14 ) Examination of metabolism of plants, animals http://c14.arch.ox.ac.uk/calibration.php Pharaos, Shroud of Turin

10. FIZIKA 10 Radioactivity Dr. Seres István Seres.Istvan@gek.szie.hu Aktivity Number of radioactive decay per seconds. SI Unit Bq (Becquerel).

11. FIZIKA 11 Radioactivity Dr. Seres István Seres.Istvan@gek.szie.hu Dozimetry  Absorbed dose: (D) (the absorbed radiative energy by a unit mass) SI unit Gray =J/kg

12. FIZIKA 12 Radioactivity Dr. Seres István Seres.Istvan@gek.szie.hu  alfa radiation (helium nucleus)  beta radiation (electron / pozitron)  gamma radiation (elektromagnetic)

13. FIZIKA 13 Radioactivity Dr. Seres István Seres.Istvan@gek.szie.hu Dozimetry  Dose equivalent (biological dose) H=D·RBE, where RBE= radiobiological equivalent SI unit: Sievert Type and Energy RangeRadiation Weighting Factors X and Gamma rays1 Electrons1 Neutrons (energy dependent)5-20 Protons5 Alpha Particles20

14. FIZIKA 14 Radioactivity Dr. Seres István Seres.Istvan@gek.szie.hu Dozimetry Background radiation The average natural backround radiation is about 1.8 mSv/year + artificial components, - mainly medical imaging (X-ray) and therapy – an average of 0.4 mSv/year, alltogether maximum about 2,5 mSv/year. The miain components of the background radiation: radon in closed buildings (about 0.5 mSv/year), raditaions from the buildings (about 0.4 mSv/year), cosmical radiation (about 0.3 mSv/year), Calium from our own body (about 0.2 mSv/year)

15. FIZIKA 15 Radioactivity Dr. Seres István Seres.Istvan@gek.szie.hu Dozimetry Background radiation

16. FIZIKA 16 Radioactivity Dr. Seres István Seres.Istvan@gek.szie.hu Dozimetry Background Radiation For the professionals working with isotopes (doctors, researchers, etc.) the limit is 25 times bigger than the average background radiation (maximum 50 mSv/year), this is called as dose limit. The dose limit for the population is the double of the average background radiation, such as maximum 5 mSv/year. Lethal Dose : LD 50/30 = 4 – 5 Sv (50% of the people dies without treatment within 30 days

17. FIZIKA 17 Radioactivity Dr. Seres István Seres.Istvan@gek.szie.hu Dozimetry Background radiation radon Fresh air8 Bq/m 3Bq Flats in tropic areas20 Bq/m 3 Drafty room30 Bq/m 3 Flat (worlds average)40 Bq/m 3 Room without ventilation100 Bq/m 3 Hungarian village house130 Bq/m 3 Cellar250 Bq/m 3 Flat in radon areas1000 Bq/m 3 Mine (in vulcanic areas)30 000 Bq/m 3

18. FIZIKA 18 Radioactivity Dr. Seres István Seres.Istvan@gek.szie.hu Dozimetry USA37 Bq/m 3Bq Finland90 Bq/m 3 France62 Bq/m 3 Indonesia12 Bq/m 3 Japan29 Bq/m 3 Hungary55 Bq/m 3 Germany49 Bq/m 3 Sveden108 Bq/m 3 Siria20 Bq/m 3 40 Bq/m 3 activity concentartion is equivalent to about 1mSv/year dose. Background radiation radon

19. FIZIKA 19 Radioactivity Dr. Seres István Seres.Istvan@gek.szie.hu Detecting of nuclear radiation  Cloud chamber http://www.ejf.hu/oktkut/kiallitas/Oldalak/Kodkamra/Kodkamra.htm

20. FIZIKA 20 Radioactivity Dr. Seres István Seres.Istvan@gek.szie.hu  Cloud chamber (Paks, Nuclear Power Plant, Visitor Centre) http://www.tar.hu/fizfoto/fizfoto7.html Detecting of nuclear radiation

21. FIZIKA 21 Radioactivity Dr. Seres István Seres.Istvan@gek.szie.hu Filmdozimeter (staff – doctors, Y-Ray staff) www.sulinet.hu/.../Rab/0/11448/radioakt.htm http://www.euronuclear.org/info/encyclopedia/f/filmdosimeter.htm Detecting of nuclear radiation

22. FIZIKA 22 Radioactivity Dr. Seres István Seres.Istvan@gek.szie.hu Geiger Müller counter (GM tube) http://zope.reaktor.fh-furtwangen.de/portal/human_sciences/alchemie/portal/lectures/gesamttour/geiger/f3.html Detecting of nuclear radiation