Iridium Neutron Reflector
The Iridium Neutron Reflector is a nuclear reactor component that reflects neutron pulses from nearby fuel rods.
Unlike the basic and thick versions, the iridium version is completely indestructible, no matter how many neutron pulses you fire at it! And considering how much it costs to make one of these things, you know what? You deserve it, my friend. Go on. Bask in the knowledge that you have reached the pinnacle of neutron reflecting technology. Also, bask in the radiation.
Horizontal or vertical, it all comes out the same in the end.