Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Three-dimensional imaging – first insights into magnetic fields

31.03.2008
3-D images are not only useful in medicine; the observation of internal structures is also invaluable in many other fields of scientific investigation.

Recently, researchers from the Hahn-Meitner-Institute (HMI) in Berlin in cooperation with the University of Aplied Science in Berlin have succeeded, for the first time, in a direct, three-dimensional visualisation of magnetic fields inside solid, non-transparent materials. This is announced by Nikolay Kardjilov and colleagues in the current issue of the journal Nature Physics, the on-line contributions to which will be released in advance on the 30th of March at 18.00 London time.


Three-dimensional imaging of magnetic fields with polarized neutrons. Hahn–Meitner Institute

The researchers in the imaging group used neutrons, subatomic particles that have zero net charge, but do have a magnetic moment, making them ideal for investigating magnetic phenomena in magnetic materials. When in an external magnetic field, the neutrons behave like compass needles, all aligning to point on the direction of the field. Neutrons also have an internal angular momentum, often referred to by physicists as spin, a property that causes the needle to rotate around the magnetic field, similar to the way in which the Earth rotates on its axis. When all of the magnetic moments point in the same direction then the neutrons are said to be spin-polarised. If a magnetic sample is irradiated with such neutrons, the magnetic moments of the neutrons will begin to rotate around the magnetic fields they encounter in the sample and the direction of their spin changes.

Kardjilov's group used this phenomenon as a measurement parameter for tomography experiments using two spin polarisers (which only allow the passage of neutrons whose spin points in a specific direction) to polarise and then analyse the neutrons. By detecting changes in the spins, it is possible to “see” the magnetic fields within the sample.

Kardjilov explains this by comparison with a medical CT scan; when a specimen is irradiated with x rays the density of the materials present alters the intensity of the light. "It's the same with our magnetic specimen, which changes the spin rotation of the neutrons", says Nikolay Kardjilov. "The equipment only allows passage of neutrons with a specific spin rotation, and this generates the contrast according to how the magnetic properties are distributed within the specimen. By rotating the specimen we can reconstruct a three-dimensional image."

Since 2005, Nikolay Kardjilov has built up the neutron tomography section at HMI and now his group is the first to use spin rotation as a measurement signal for three-dimensional imaging. Normally, neutron imaging relies on the different levels of absorption of radiation by different materials to produce contrast. The measurement of magnetic signals is a novel concept and its success lies partly in the polarisers and analysers, and the detector system, which have been developed and built by the HMI researchers.

Magnetism is one of the central research fields at HMI. To understand high temperature superconductivity, for example, it is vital to understand how magnetic flux lines are distributed and how these flux lines can be established in the material. With Kardjilov's experimental setup, it is now possible, among other things, to visualise magnetic domains in magnetic crystals three-dimensionally.

At Hahn-Meitner-Institut in Berlin work about 800 employees, among them about 300 scientists. They research properties of materials, develop solar cells of new generation and practice a user facility at research reactor BER II open to the national and international community.

To 1. Januar 2009 the HMI will merge with BESSY, the Berliner Elektronenspeicherring- Gesellschaft für Synchrotronstrahlung becoming together a new research center, the Helmholtz-Zentrum Berlin for materials and energy.

The Hahn-Meitner-Institut Berlin is member of the Helmholtz-Association, the biggest german research organisation. It involves 15 research institutes and 24.000 employees.

contact: HMI
Glienicker Str. 100
14109 Berlin
Dr. Nikolay Kardjilov
Tel.:8062-2298
e-mail: kardjilov@hmi.de
Press and PR:
Dr. Ina Helms
Tel.: 8062-2034
e-mail:ina.helms@hmi.de

Dr. Nikolay Kardjilov | alfa
Further information:
http://www.hmi.de/people/manke/bildernatphys/

More articles from Physics and Astronomy:

nachricht Applicability of dynamic facilitation theory to binary hard disk systems
08.12.2016 | Nagoya Institute of Technology

nachricht Will Earth still exist 5 billion years from now?
08.12.2016 | KU Leuven

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>