Radioactivity

Radioactivity:

1. Properties of radioactive decay:  spontaneous ( unaffected by external factors)    random   (can not predict when and which one) 

2. Half life        Amount of undecayed atoms     N = N0 * 0.5 ^(t / T1/2)       Amount of decayed atoms

3. Derivation of exponential decay law      Decay constant & half life        Decay constant as probability per unit time      

4. Rate of decay       A(t) = (lambda) * N(t)     Initial rate          Equations  for activity       A = A0 * 0.5 ^(t / T1/2)       A = ln(2) * (N / T 1/2)

5. Radioactive dating by Geiger counter     Age = T1/2 * ln (A0/A)  / ln 2     Radioactive dating by mass spectrometer      Age = T1/2 * ln (N0/N)  / ln 2

1. Geiger counter      Emulsion    Cloud chamber    Bubble chamber       Scintillation      Gamma camera

2. PET    NMR

3. Inverse beta minus decay (neutron transforms into proton end electron)

4. Inverse beta plus decay (proton transforms into neutron end positron)

5. **Dosimetry