02/07/2015radiation safety - level 51 Radiation safety level 5 Frits Pleiter

02/07/2015radiation safety - level 52 Contents  atomic and nuclear physics(1)  interaction with matter(3) o sources and x-ray equipment (2) o shielding (3) o detection (4) o radiobiology (6) objective risk of radiation (6) subjective risk acceptation (6)  quantities and units(5)  regulations(7) o practical health physics (8 - 10) o waste (11)

02/07/2015radiation safety - level 53 Atomic and nuclear physics atomic structure A Z symbol Z electrons Z protons N neutrons N  Z A = Z + N  2Z proton mass  2000  electron mass atomic mass  nuclear mass electron proton neutron 4 2 He

02/07/2015radiation safety - level 54 Atomic and nuclear physics atomic structure electrons are grouped in shells energy transfer  excitation and ionization  vacancies in shell unit of energy: joule (J) electron volt (eV) 1 eV = 1.6  J electron proton neutron 7 3 Li excitation ionization K L M

02/07/2015radiation safety - level 55 Atomic and nuclear physics atomic structure vacancy is filled  x-ray photon E K = B K – B L Auger electron E KLL = B K – B L – B L low ZAuger emission prevails high Zx-ray emission prevails these are competing processes K L X-ray L K Auger electron

02/07/2015radiation safety - level 56 Atomic and nuclear physics periodic system according to Mendelejev HHe LiBeBCNOFNe NaMgAlSiPSClAr KCaScTiVCrMnFeCoNiCuZnGaGeAsSeBrKr RbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXe CsBa*HfTaWReOsIrPtAuHgTlPbBiPoAtRn FrRa**RfDbSgBhHsMtDsRg *LaCePrNdPmSmEuGdTbDyHoErTmYbLu **AcThPaUNpPuAmCmBkCfEsFmMdNoLr

02/07/2015radiation safety - level 57 Atomic and nuclear physics nuclide chart isotopesequal Z isobarsequal A isomersequal A and Z

02/07/2015radiation safety - level 58 Atomic and nuclear physics mathematical intermezzo addition 8 = 5 + 3addition inverse function 8 = ? + 3  ? = 8 - 3subtraction 8 = 5 + ?  ? = 8 - 5subtraction multiplication 15 = 5  3multiplication inverse function 15 = ?  3  ? = 15 / 3division 15 = 5  ?  ? = 15 / 5division

02/07/2015radiation safety - level 59 Atomic and nuclear physics mathematical intermezzo exponentiation 9 = 3 2 exponentiation there are two inverse functions 9 = ? 2  ? = 2  9root 9 = 3 ?  ? = 3 log(9)logarithm we call 3 the base of the logarithm the "natural" logarithm has base e = we write the natural logarithm as ln(x)

02/07/2015radiation safety - level 510 Atomic and nuclear physics mathematical intermezzo logarithm 2 3  2 5 = = 2 log(2 3 ) 5 = 2 log(2 5 ) 8 = 2 log(2 8 )  = 8 2 log(2 3 ) + 2 log(2 5 ) = 2 log(2 8 ) = 2 log(2 3  2 5 ) in general: x log(a) + x log(b) = x log(a  b) the logarithm makes it possible to multiply with the aid of a ruler

02/07/2015radiation safety - level 511 Atomic and nuclear physics single logarithmic graph paper

02/07/2015radiation safety - level 512 Atomic and nuclear physics double logarithmic graph paper equal distances correspond to equal factors

02/07/2015radiation safety - level 513 Atomic and nuclear physics radioactive decay unit of activity becquerel (Bq) curie (Ci) 1 Bq = 1 decay per second 1 Ci = activity of 1 gram radium = 3.7  Bq the half-life T ½ is the time during which the activitity decreases by a factor of two

02/07/2015radiation safety - level 514 Atomic and nuclear physics prefixes milli(m)10 -3 micro(µ)10 -6 nano(n)10 -9 pico(p) kilo(k)10 3 mega(M)10 6 giga(G)10 9 tera(T)10 12

02/07/2015radiation safety - level 515 Atomic and nuclear physics  - -decay  Z = +1  A = 0

02/07/2015radiation safety - level 516 Atomic and nuclear physics  - -decay average  -energy  E ,max / 3

02/07/2015radiation safety - level 517 Atomic and nuclear physics  + -decay  Z = -1  A = 0  + + e -  2  annihilation E  = m e c 2 = 511 keV

02/07/2015radiation safety - level 518 Atomic and nuclear physics electron capture  Z = -1  A = 0 vacancy in electron shell is filled  x-ray photon Auger electron

02/07/2015radiation safety - level 519 Atomic and nuclear physics  -decay  Z = -2  A = -4  -particle = 4 He nucleus high risk strongly regulated

02/07/2015radiation safety - level 520 Atomic and nuclear physics  -decay and internal conversion  Z = 0  A = 0 excess nuclear energy is released   -photon conversion electron

02/07/2015radiation safety - level 521 Atomic and nuclear physics  -decay and internal conversion these are competing processes conversion electron E K = E  - B K  K = N K / N  x-ray Auger electron K  -ray E  K

02/07/2015radiation safety - level 522 Atomic and nuclear physics nuclear fission A  A 1 + A 2 + neutrons + energy A 1  95 A 2  140 energy  200 MeV examples: U  Rb Cs + 3n U + n  Kr Ba + 2n

02/07/2015radiation safety - level 523 Atomic and nuclear physics decay scheme