> Based on what?
Potassium 42 can undergo inverse beta decay. Discussions on using tritium to detect neutrinos go all the way back to the 1960s. Also proton collisions are potentially scalable, even though we haven't really economized particle colliders for commercial use yet. I don't think that will always be the case, though.
> You haven't provided any mechanism that would detect that direction.
Yes I have. Smectic phases have distinct layers and a direction in a liquid crystal. I described rotating the liquid crystal (A diaelectric material) in a magnetic field above in order to identify a magic angle where beta decay would be highest due the mechanism listed above. I took optics and am trying to apply optical principles to the detection of neutrinos here. When the crystal lattice is parallel to the neutrino source it would behave functionally transparent to neutrinos. But like magic angle graphene, or polarized lenses, there's an angle where the the likelyhood to collide with an atom in the lattice is maximized. In polarized lenses the distance between the nanomaterial interferes with the wavelength of visible light at 90 degrees, so its not quite the same. But the idea was to design a diffractive material for neutrinos. (still likely a very weakly diffracting material)
> Your decay heat is in the range of tens of megawatts per kilogram, so even if you could produce larger quantities you couldn't store them as a single object. It's also going to saturate every reasonable detector.
I figured it would produce a lot of heat. The liquid crystal has to remain pressurized to remain a liquid crystal. So pressure would have to taken into account and heavily controlled throughout the entire decay process. The whole reaction has to maintain a constant pressure and temperature. So keeping the material at a constant temperature, aka cooling, would also have to be taken into consideration.
Exposing the sample to a strong magnetic field may also help to confine the material and keep the crystal lattice ordered.
Regarding the half life of potassium 42, I figured a shorter half life would mean more events and therefore a stronger possible signal. Of course the noise from the background decay of the sample would be greater than your signal. But in optics its still possible to reconstruct a low resolution image with low quality data. In astrophysics, image stacking is a process that involves combining multiple images of the same object or region of the sky taken over a period of time to improve the overall quality of the final image. Each individual image might suffer from noise, distortions, or imperfections due to factors like atmospheric turbulence, telescope limitations, or sensor noise. But by aligning and averaging/combining these images, the noise tends to cancel out while the signal, such as the light from distant celestial objects, remains, resulting in a clearer and higher-quality final image.
We can apply similar methods to the microscopic as we do to extremely distant objects to produce higher resolution images even despite the noise. Although you make a valid point. The signal to noise ratio may still be so impossibly low that it becomes impractical. Still, choosing a material with a longer half life would mean fewer events and a weaker signal, so if you wanted the highest resolution image possible, it would still be better to choose a material with a shorter half life and to just find ways of separating the signal from the noise.
Also, its questionable whether it will be able to form a liquid crystal while producing so much heat. Still this was mostly food for thought. Also, I forgot that inverse beta decay produces electrons rather than positrons. Which would mean that your signal would also produce an associated gamma emission from annihilating electron-positron pairs. This could futher be used to separate a signal from the noise. So thank you for reminding me about that.