Record in materials research: X-ray microscopy with 1000 tomograms per
second

Date:
September 27, 2021
Source:
Helmholtz-Zentrum Berlin fu"r Materialien und Energie
Summary:
Tomoscopy is an imaging method in which three-dimensional images of
the inside of materials are calculated in rapid succession. Now a
team has achieved a new record: with 1000 tomograms per second, it
is now possible to non-destructively document very fast processes
and developments in materials on the micrometer scale, such as
the burning of a sparkler or the foaming of a metal alloy for the
production of stable lightweight materials.



FULL STORY ==========================================================================
Most people are familiar with computed tomography from medicine: a part of
the body is X-rayed from all sides and a three-dimensional image is then calculated, from which any sectional images can be created for diagnosis.


==========================================================================
Fast 3D-images with synchrotron radiation This method is also very
useful for material analysis, non-destructive quality testing or in
the development of new functional materials. However, to examine such
materials with high spatial resolution and in the shortest possible time,
the particularly intense X-ray light of a synchrotron radiation source
is required. In the synchrotron beam, even rapid changes and processes in material samples can be imaged if it is possible to acquire 3-dimensional images in a very short time sequence.

From 200 to 1000 tomograms per second An HZB team led by Dr Francisco
Garcia Moreno is working on this together with colleagues from the Swiss
Light Source SLS at the Paul Scherrer Institute (PSI), Switzerland. Two
years ago, they managed a record 200 tomograms per second, calling
the method of fast imaging tomoscopy. Now the team has achieved a new
world record: with 1000 tomograms per second, they can now record even
faster processes in materials or during the manufacturing process. This
is achieved without any major compromises in the other parameters: the
spatial resolution is still very good at several micrometres, the field
of view is several square millimetres and continuous recording periods
of up to several minutes are possible.

Rotary table and high speed camera For the X-ray images, the sample is
placed on a high-speed rotary table developed in-house, whose angular
speed can be perfectly synchronised with the camera's acquisition
speed. "We used particularly lightweight components for this rotary
table so that it can reach 500 Hertz rotation speed stably," Garci'a
Moreno explains.



==========================================================================
At the TOMCAT beamline at the SLS, which is specialised in time-resolved
X-ray imaging, PSI physicist Christian Schlepu"tz used a new high-speed
camera and special optics. "This increases the sensitivity very
significantly, so that we can take 40 2D projections in one millisecond,
from which we create a tomogram," Schlepu"tz explains. With the planned
SLS2.0 upgrade, even faster measurements with higher spatial resolution
should be possible from 2025.

Processing the data stream The acquisition of 1000 three-dimensional data
sets per second -- and this over a period of minutes -- generates a huge
data stream, which was initially stored at the PSI. Finally, Dr. Paul
Kamm at HZB was responsible for the further processing and quantitative evaluation of the data. The reconstruction of the raw data into 3D images
was carried out remotely from HZB on the high- performance computers at
PSI, and the results were then transferred to HZB for further analysis.

Sparklers, dendrites and bubbles The team demonstrated the power of
tomoscopy with various examples from materials research: The images
show the extremely rapid changes during the burning of a sparkler, the formation of dendrites during the solidification of casting alloys or
the growth and coalescence of bubbles in a liquid metal foam.

Such metal foams based on aluminium alloys are being investigated as lightweight materials, for example for the construction of electric
cars. The morphology, size and cross-linking of the bubbles are important
to achieve the desired mechanical properties such as strength and
stiffness in large components.

"This method opens a door for the non-destructive study of fast processes
in materials, which is what many research groups and also industry have
been waiting for," says Garci'a Moreno.

========================================================================== Story Source: Materials provided by Helmholtz-Zentrum_Berlin_fu"r_Materialien_und_Energie.

Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Francisco Garci'a-Moreno, Paul Hans Kamm, Tillmann Robert Neu, Felix
Bu"lk, Mike Andreas Noack, Mareike Wegener, Nadine von der Eltz,
Christian Matthias Schlepu"tz, Marco Stampanoni, John Banhart,.

Tomoscopy: Time-Resolved Tomography for Dynamic Processes in
Materials.

Advanced Materials, 2021 DOI: 10.1002/adma.202104659 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/09/210927132039.htm

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