Half Value Layer		as low as reasonably achievable
TEDE		different types of radiation that produces biological effects
LET		SI equivalent to REM
time		linear energy transfer
distance		Si unit for roentgen; disintegration in air
Shielding		lead barriers
Sievert		total effective dose equivalent
ALARA		principles compare to shielding (thickness)
Coulombs		has no threshold; gets worst with increasing dose
stoichastic		100 Rad equals this
Gray		another name for expressing LET
Quality factor		far away the less radiation dose
RBE		another method of minimizing radiation dose