and answers
specific Ionization - # of ion pairs formed by a particle per path length
Linear Energy Transfer - the average energy locally deposited in an absorber resulting
from a charged particle per distance of travel
stopping power - the absorbers ability to remove energy from a beam of a charged
particle
Range - inversely related to the stopping power, charged particle is only kinetic, it is
the average depth of penetration before the charged particle loses all of its kinetic
energy
2 energy transfer for alpha particle - ionization and excitation
3 major energy transfer for beta - ionizaton, excitation, and bremsstrahlung
3 major mechanisms by which gamma photon radiation interacts with matter - the
photoelectric Effect(imparts all energy to a valence electron, ionizes)
Compton scattering(imparts some of the energy to the electron, also releases an
scattered photon 200 kev and 5 Mev)
, Pair production(photon is converted to mass, electron and a positron greater than
1.022 Mev)
elastic scattering - neutron strikes a nucleus approximately the same size, cue ball
neutron imparts its kinetic energy to the nucleus
Inelastic Scattering - the neutron hits a large nucleus fort a short time, transfers
energy to a nucleon inside, then exits with a small decrease of energy, the nucleus is
left excited emitting gamma radiation that can cause ionization and excitation
Law of Bergonie and Tribondeau - the radio-sensitivity of a tissue is directly
proportional to its reproductive capacity and inversely proportional to its degree of
differentiation
cells most active in reproducing themselves and cells not fully mature will be most
harmed by radiation
stochastic effects - probability within a population of the effect occuring increases
with dose, without threshold( any low level dose will pose as a problem) CANCER
nonstochastic(deterministic) - threshold dose exist CATARACTS, SKIN ULCURS OR
BURNS, IMPAIRMENT OF FERTILITY
LD 30-50 for humans - 300-500 RADS 3-5 Gray 450
Hematopoietic Syndrom - 200-1000 Rads death will be within 2-6 weeks kills blood
forming cells, organs, and spleen