Minutest absolute magnetic field measurement

December 03, 2015

Every measurement is potentially prone to systematic error. The more sensitive the measurement method, the more important it is to make sure it is also accurate. This is key for example in measuring magnetic fields in state-of-the-art fundamental physics experiments. Now, an international team of physicists has developed an extremely high-precision method for the determination of magnetic fields. The resulting device, they found, has an intrinsic sensitivity that makes it ideal for fundamental physics and cosmology experiments attempting to explain the missing antimatter of the universe. The findings by Hans-Christian Koch from the University of Fribourg, Switzerland, and colleagues have just been published in EPJ D.

The prototype magnetometer the team developed combines the accuracy of a helium (3He) magnetometer with the high sensitivity of a cesium magnetometer. It is also much more convenient than the previously used combination of helium magnetometers and SQUIDs, which requires cooling near absolute zero.

In this paper, the team establishes a theoretical formula describing the ultimately reachable sensitivity of the magnetometer. To do so, they analysed the dependence of the combined magnetometer's sensitivity on the properties of its constituents. They found that the sensitivity can be predicted from parameters characterizing the cesium magnetometers and the helium sample involved in the detection. The team's formula led to predictions that were in excellent agreement with experimental results.

They subsequently calculated the sensitivity of the magnetometer in the envisioned application in an experiment searching for the electric dipole moment of neutrons (nEDM), which are basic constituents of ordinary matter. Observing an nEDM would imply a broken symmetry of the laws of physics, called CP-violation. Such a finding could help to account for the primordial matter-antimatter imbalance at Big Bang stage, leading to the current abundance of matter.
-end-
Reference:

H.-C. Koch, G. Bison, Z. D. Gruji, W. Heil, M. Kasprzak, P. Knowles, A. Kraft, A. Pazgalev, A. Schnabel, J. Voigt, and A. Weis (2015), Investigation of the intrinsic sensitivity of a 3He/Cs magnetometer , Eur. Phys. J. D 69, 262, DOI 10.1140/epjd/e2015-60509-5

Springer

Related Magnetic Fields Articles from Brightsurf:

Physicists circumvent centuries-old theory to cancel magnetic fields
A team of scientists including two physicists at the University of Sussex has found a way to circumvent a 178-year old theory which means they can effectively cancel magnetic fields at a distance.

Magnetic fields on the moon are the remnant of an ancient core dynamo
An international simulation study by scientists from the US, Australia, and Germany, shows that alternative explanatory models such as asteroid impacts do not generate sufficiently large magnetic fields.

Modelling extreme magnetic fields and temperature variation on distant stars
New research is helping to explain one of the big questions that has perplexed astrophysicists for the past 30 years - what causes the changing brightness of distant stars called magnetars.

Could megatesla magnetic fields be realized on Earth?
A team of researchers led by Osaka University discovered a novel mechanism called a ''microtube implosion,'' demonstrating the generation of megatesla-order magnetic fields, which is three orders of magnitude higher than those ever experimentally achieved.

Superconductors are super resilient to magnetic fields
A Professor at the University of Tsukuba provides a new theoretical mechanism that explains the ability of superconductive materials to bounce back from being exposed to a magnetic field.

A tiny instrument to measure the faintest magnetic fields
Physicists at the University of Basel have developed a minuscule instrument able to detect extremely faint magnetic fields.

Graphene sensors find subtleties in magnetic fields
Cornell researchers used an ultrathin graphene ''sandwich'' to create a tiny magnetic field sensor that can operate over a greater temperature range than previous sensors, while also detecting miniscule changes in magnetic fields that might otherwise get lost within a larger magnetic background.

Twisting magnetic fields for extreme plasma compression
A new spin on the magnetic compression of plasmas could improve materials science, nuclear fusion research, X-ray generation and laboratory astrophysics, research led by the University of Michigan suggests.

How magnetic fields and 3D printers will create the pills of tomorrow
Doctors could soon be administering an entire course of treatment for life-threatening conditions with a 3D printed capsule controlled by magnetic fields thanks to advances made by University of Sussex researchers.

Researchers develop ultra-sensitive device for detecting magnetic fields
The new magnetic sensor is inexpensive to make, works on minimal power and is 20 times more sensitive than many traditional sensors.

Read More: Magnetic Fields News and Magnetic Fields Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.