Steerable neutrino beam I read a proposal (by real particle physicists) for a steerable neutrino beam source that could feasably destroy nuclear weapons anywhere on the planet from a single location here.
I believe the principle was based on a the greater interaction cross section of the produced neutrinos with unstable nuclei. Such a beam would be able to travel straight through the earth to any desired location. I believe the source was based on a muon storage ring, the decay of which produced the neutrinos.
Any advances or papers related to this that anyone knows of? 
 A: Not a resource suggestion, but the reason why I doubt that you'll find one and much too long for a comment.

While there is nothing intrinsically wrong with the idea it bumps into two practical issues.


*

*The beam intensity needed is prohibitive. 
Right now even performing a neutrino oscillation experiment with a 5000 km baseline requires a beam an order of magnitude more powerful than the most power beam currently funded (and not yet in operation), and a fuel conversion beam would have to be more powerful still.

*A beam strong enough to do the job would have a measurable effect on other material objects in the beams path—objects like people. And given that neutrino beams have significant opening angle you can't prevent them from affecting people if you have a long range.
None of the countries (Canada, Italy, and Japan at a minimum and soon the US) that currently host the emergence points of powerful beams care because the beam doesn't create a measurable dose, but a beam powerful enough to degrade nuclear explosive would do exactly that and the receiving country would presumable (and reasonably) interpret this as an attack on their population.
A: It is a 2003 proposal.

By scattering  neutrons in uranium or plutonium, a sufficiently high-powered beam of neutrinos would destabilise a nuclear bomb. According to Hiroyuki Hagura and Toshiya Sanami at Japan’s KEK High Energy Accelerator Research Organization and Hirotaka Sugawara at the University of Hawaii this would cause the weapon to “melt down” without triggering the chain reaction needed for it to fully detonate.
But the “muon storage ring” generator needed to propose the neutrino beam would need to be 1000 kilometres wide. It would also require 50 gigaWatts of power to operate – the same as used by the entire UK – and would cost an estimated $100 billion to construct.

This could only happen in a very empty region, the Sahara desert or some such.How can such a ring be guarded and kept secret in a populated area? Even if feasible, it makes sense for using against a rogue state (some come to mind) by the UN community.

Weber says the first stage of a generator might be feasible within 10 to 20 years, but he reckons the main problem is that the neutrino beam produced would be just a few metres wide. This means a target would need to be very precisely located beforehand. He adds that the beam would produce dangerous alpha and neutron radiation in any living thing in its path.

And here is the original proposal

We discuss the possibility of utilizing the ultra-high energy neutrino beam (about 1000 TeV) to detect and destroy the nuclear bombs wherever they are and whoever possess them.

....

Our basic idea is to use an extremely high energy neutrino bea
m which penetrates the
earth and interacts just a few meters away from a potentially
concealed nuclear weapon. The
appropriate energy turns out to be about 1000 TeV. This is the
energy where the neutrino
mean free path becomes approximately equal to the diameter o
f the earth. The neutrino
beam produces a hadron shower and the shower hits the plutoni
um or the uranium in the
bomb and causes fission reactions. These reactions will heat
up the bomb and either melt it
down or ignite the nuclear reactions if the explosives alrea
dy surround the plutonium. We
will calculate the intensity of the neutrino beam required a
nd the duration of time which
the whole process will take place for a given intensity

The authors are aware it is a futuristic proposal.
