The purpose of the shutter is to provide shielding when the neutron beam is not required.

If you can provide shielding, do it, and send whatever weapons you think they'll need.

And all around Shelby could see people in their homes slamming shut large metal sills, covering over their windows to provide shielding from the new arrivals.

Theses are inflatable modules with thick skins that provide shielding, insulation and structure.

A row of shrubs in front provides further shielding.

The entire apparatus is surrounded by layers of lead and polyethylene to provide shielding against background radiation.

We can barely provide shielding for those essential items which are vulnerable.

Paper, or in some cases even air, is enough to provide shielding.

The water cools the fuel and provides shielding from radiation.

Asteroids could serve to provide shielding.