1. Radiation
What is there to fear?

2. Types of radiation Particulate Electromagnetic Alpha particles
Beta particles
Neutrons
Fission Fragments
Electromagnetic
Ionizing
Non-ionizing

3. Particulate Radiation
Alpha particles
Helium nuclei
penetrate < 10 cm in air, 60 m in tissue
stopped by paper
Beta particles
Electrons
Penetrate a few mm into tissue
Neutrons
Fission Fragments

4. Electro-Magnetic Radiation
Penetrating radiation:
X-rays
 rays

5. Radiation Sources Radioactive decay High energy collisions
Particle acceleration
Astrophysical processes

6. Definitions 1 Becquerel (Bq) = 1 disintegration/second (dps)
1 Curie = 3.7 x 1010 dps
1 Röntgen = amount of ionizing radiation that
produces 1 esu/cm3 in dry air
1 rad (Röntgen absorbed dose) = 100 erg/gm
1 Gray (Gy) = 100 rads = 1 Joule/kg
Dose = f R
f = mass absorption coefficient/air
Rem (biological equivalent dose) = rads x QF
QF (quality factor)  # ion pairs / cm
1 Sievert (Sv) = 100 rem

7. Half Life
Time for half the original sample to decay
N = N0 e T1/2 t

8. How Radiation Kills
Ionizing/penetrating radiation breaks chemical bonds
Particles/ionizing radiation deposits energy
Lethal dose: 500 rad kills half

9. Can You Avoid Radiation?
No.

10. The Atom Bomb Runaway fission of U235 or Pu239
U235 + n0 fragments + 2.4n MeV
Pu239 + n0 fragments + 2.9n MeV
MeV: 1.6 x 10-6 erg
100 kg of U235  8x1022 erg ~ 2 MT

11. The Hydrogen Bomb A 3 stage weapon:
Pu239 fission or high explosives compresses D2+H3
D2+H3  He4 + n MeV
n0 release triggers U238 fission in casing
100 kg of D+T  2.3x1023 erg ~ 5 MT