India Is Building the World's Largest Magnet to Hunt Neutrinos

    a country can print as much money as it wants

Or another way: money is not physical resources, it is a measure of resources. How could printing money increase the physical resources available to a country?

[0] http://www.ino.tifr.res.in/ino//about.php

1) They are looking at atmospheric (cosmic ray) neutrinos, not solar neutrinos like most of the other large underground detectors (SNO, Kamiokande, etc). When cosmic rays (mostly high energy protons) strike nuclei the upper atmosphere, they create a shower of high-energy particles, including neutrinos and anti-neutrinos.

Cosmic rays make an interesting laboratory for some important processes because they have energies that go far higher than anything achievable in accelerators. The LHC has collision energies up to 1.3E13 eV (about 13,000 times the mass of a proton). Cosmic rays have energies at detectable fluxes up to 10E20 eV or and likely useful flux for this kind of experiment at energies a factor of ten or more greater than the LHC is capable of, and they do it for free: all you have to do is build the detector.

2) When high-energy neutrinos or anti-neutrinos interact with the material of the detector, they produce particle and anti-particle showers. How much of each is dependent on the detail of the weak interaction coupling constants and other neutrino properties. So one wants to know in detail how much of each type of particle is created.

There are various ways of doing this, but it is an unfortunate geometric reality that most of the mass in any detector is close to the outside of the volume (this is a pain because most of the background in such detectors comes from the outside, and you typically have to put geometric cuts on that excludes the outer detector volume, losing up to 25% of your detector mass in the process). Because of this, many high-energy particles created by neutrinos in the detector will leave it before they stop, so there is no way to use annihilation radiation to identify the anti-matter (positrons, anti-muons, etc).

Therefore a uniform magnetic field is applied to make the particle tracks curve. By looking at the energy loss in the sensitive (scintillator) layers of the detector the mass and energy can be determined, and the curvature of the track gives the charge, whose sign depends on whether it is a particle or anti-particle.

3) This is a good way for India to approach this problem. I've worked with Indian physicists and they are as good as physicists anywhere. This mine has played a minor role in neutrino physics for many years, and it is the deepest of its kind in the world (SNO was at about 2 km depth, this is over 4). Cosmic ray neutrinos have not been as much studied as they might, and at high energy there is always a change of seeing something odd or unexpected. The technological challenges, while formidable, are likely surmountable and the odds of getting some good physics out of the system are high.