Freefall 3358
Life problems in low gravity
[!0.987]2019-11-15
How much shielding do we have?
Well, shielding is a little complicated. Higher energy gamma rays have more penetrating power. The thumb rule is 5 cm of lead, 10 cm of steel, or 120 cm of water is one ten-thickness.
A ten-thickness is the amount of material needed to reduce the radiation level to one tenth of the unshielded value.
100 gray, 6 MeV source
5 cm of lead
Radiation level: 10 gray
5 cm of lead
Radiation level: 1 gray
Wow. That much material wrapped around a spaceship would be heavy… and expensive to accelerate… and we don't have much shielding, do we?
Color by George Peterson