Radiation is the natural enemy of atomically precise technology.


There are several forms of radiation: alpha radiation, beta r., gamma r., UV r., neutron r., and radiation of more exotic particles. The problem with radiation is that if it's quanta carry high enough energies (and interact strongly enough with atoms - neutrinos do not) they can break chemical covalent bonds and kick atoms around. As some remote analogy radiation can be imagined as a bully who sends flying pieces of different size and speed into your beautifully crafted castle made out of magnetic balls.

With non atomically precise manufacturing this is not so much of a problem since there's chaos everywhere anyway. Non atomically precise Metals produced by a thermodynamic melt and cast process instead of mechanosynthesis (that is all macroscopic pieces of metals of today 2016) for example are full of defects. Some of these (step defects) are even desired for mechanical plasticity. Radiation does displace atoms in todays metals too but omnidirectional metallic bonds can reconnect better than covalent bonds forming basically the original crystal lattice with displaced but qualitatively equivalent defects. Of course if the radiation becomes hard and intense enough todays metal will take damage too. E.g. through transmutation of elements and larger scale material migration, changes of grains, ... .

## Means of coping with high energy radiation

(wiki-TODO: elaborate)

• redundancy (mandatory)
• shielding (for some forms of radiation (e.g. UV)
• self repair (optional but most effective)
• bulky design with polycyclic bond-meshes (avoidance of soft nanomachinery components)

All radiation with longer wavelength and lower frequency than UV have not enough energy to break your average chemical bond. So they are safe for use inside atomically precise technology systems.

Radiation damage that just manage to break a single bond can often be self healing in diamondoid systems since the surrounding 3D mesh of bonds can keep the partners in place till they reform their bond (related: semi diamondoid structures).

For protection of nano-machinery against UV radiation a thin protective shell of aluminum was proposed [todo: find source - Nanosystems?]. Since metallic aluminium might have too much surface diffusion at room-temperature (?) conductive diamondoid materials might be preferable. Of interest are essentially those that give metallic reflectiveness - the same materials that give metallic reflectiveness.

Especially cross-hatched conductive nanotubes might work exceptionally well (one direction only would let through polarized light) because of their electrical conductivity that even surpasses copper. (related: management of wires and sheets) Rectennas for UV wavelengths might work too.

(TODO: investigate absorption of UV photons in advanced AP structures - conditions that free electrons capture before bond ones do)

# Atomically precise technology in nuclear reactors

Since radiation is very high in nuclear reactors atomically precise technology might have a hard time to operate in these conditions.

Warning! you are moving into more speculative areas.

Contiuous off site microcomponent disposal and remechanosynthisation from bottom up (less efficient than normal microcomponent recycling) is essential and full structural replacement over a short period of time is essential too.

(TODO: inverstigate feasability: expactable damage rate (easy); feasible exchange rate; power and volume for repair mechanosynthesis)

# Notes

Heavy ions in dense heavy metals can produce massive damage like can be seen here: (Wikipedia: Collision cascade) This is very different than a typical hit in an AP system though.