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Technische Universität Müchen

This New Metal Box Could Help Take Physics Beyond The Standard Model

14 MAY 2015

Researchers in Germany have created a shield that can cut magnetic fields more than a million-fold, and they've used it to create one of the most exciting metal boxes on the planet right now.


The 4.1-cubic-metre space has the weakest magnetic field in our Solar System, and it will allow scientists to finally conduct the high-precision experiments that could reveal physics beyond the Standard Model.

The Standard Model of particle physics, also known as 'The Theory of Almost Everything', is the best set of equations we have to explain the behaviour and interactions of the fundamental particles in the Universe.

But although the model has served us well, there are a whole lot of gaps, such as the fact that the Standard Model doesn't explain gravity, or why matter and antimatter from the Big Bang didn't annihilate each other completely. It also can't predict the behaviour of particles at very high energies.

Large-scale experiments such as the Large Hadron Collider are helping to improve our understanding in these areas, but are limited by the natural and artificial magnetic fields on Earth, which have the unfortunate habit of easily penetrating all kinds of matter.

But now, researchers from Technische Universität Müchen (TUM) in Germany have managed to eliminate magnetic fields to previously unheard-of levels, opening up a whole new world of experiments. In fact, their box's magnetic field is even weaker than the average ambient magnetic field experienced in the interstellar medium between galaxies.

"Precision experiments are able to probe nature up to energy scales which might not be accessible by current and next generation collider experiments," Tobias Lins, a doctoral student who worked on the magnetic shield, said in a press release. This is because the existence of exotic new particles could be detected by tiny alterations in the properties of already known particles, but we currently can't track those changes because of the background 'noise' from magnetic fields.

The shield, which involves several layers of a specially made, highly magnetic nickel-and-iron alloy, acts like a sponge that absorbs and redirects a magnetic field. The researchers describe its design and performance in the Journal of Applied Physics.

91740 webAstrid Eckert/Technische Universität Müchen

"The apparatus might be compared to cuboid Russian nesting dolls," said Lins. "Like the dolls, most layers can be used individually and with an increasing number of layers the inside is more and more protected."

They're already planning to use their shield to determine the charge distribution in neutrons - referred to by physicists as the electric dipole moment. Essentially what they're looking for is the brief moment when a neutron has a tiny magnetic charge - generally a neutron is electrically neutral because its three quarks cancel each other out. If they find that this moment lasts for longer than predicted by the Standard Model, it could suggest the existence of a new particle.

"This kind of measurement would be of fundamental significance in particle physics and swing wide open the door to physics beyond the Standard Model of particle physics," explained the team leader, Peter Fierlinger, in a statement.

The team also wants to use the shield to search for the long-theorised, but never detected, magnetic monopoles using a SQUID detector, which can detect extremely subtle magnetic fields.

Both of these experiments, as well as the many others that can now be conducted inside this small, metal box, could take us into a brave new world of physics, and we can't wait to see some results. We've said it before, and we'll say it again: what an incredible time to be alive.

probingtheseTechnische Universität Müchen