Contact

Dr. André Bieberle
Experimental Thermal Fluid Dynamics
a.bieberleAthzdr.de
Phone: +49 351 260 - 2913
Fax: 12913, 2383

Prof. Dr. Uwe Hampel
Head
u.hampel@hzdr.de
Phone: +49 351 260 - 2772
Fax: 12772, 2383

Gamma-ray computed tomography (Gamma-CT)

Motivation

Funktionsprinzip der Gamma-CT
Principle sketch of the high-resolution gamma-ray measurement CT system.

In recent years a transportable and spatial high-resolution gamma-ray computed tomography measurement system was developed and established to determine phase fraction or/and phase interfaces (gas, fluid, solid) in industrial flow apparatus, i.e. axial compressors, pumps, hydrodynamic fluid couplings or thermo hydraulic test facilities. The use of 137Cs (662 keV photons energy) offers the opportunity to penetrate radiological dense material, i.e. aluminum or steel, whereas minor density differences inside the object of investigation can be visualized.

Prinzip

For a CT scan either a relative rotation of the measurement system to the object of investigation is accomplished (classical CT) or a rotation of the object is used (angular resolved CT) to acquire hundreds of radioscopic projections from different angular positions. From this data matrix (sinogram) non-superimposed cross-sectional images can be generated using computed tomography reconstruction algorithms like so called filtered back-projection. With the angular resolved gamma-ray CT all parts in an object, moving with the same rotational speed, can be visualized, i.e. rotating fluid or gas fields.


High resolution gamma-ray detector arc. at the HZDR.

Details

  • Isotopic source (137Cs, E = 662 keV, A = 180 GBq)
  • 320 single scintillation detectors (2 × 8 mm² active area)
  • Spatial resolution about 2 mm
  • Energy resolution about 25 %
  • Interaction probability about 75 % (662 keV)
  • Data transfer via USB 2.0 (fast mode) or Ethernet
  • Fastest readout interval 23 µs (USB 2.0)
  • Thermally stabilised (< 1 K)

Gamma-ray CT @ HZDR

Rückprojektion einer Turbokupplung

Reconstruction of a fluid coupling using the
filtered back projection reconstruction.

Gamma-CT Anlage

Gamma-ray CT measurement system at the HZDR.

Photo Galery / Results

Tomography of a hose pump.

Foto eines Trafos Trafo - Reko

Tomography of a transformator.

Baumscheibe - Foto Baumscheibe - Reko

Tomography of a tree trunk.

Phasenverteilung in einer Turbokupplung

Tomography of a fluid coupling operating in steady state and visualisation of phase distributions in pump and turbine wheel.

Reconstruction of the gas distribution in an axial pump at two-phase operation (64-element detector).

Radiographien eines chemischer Reaktors

Radiography of the fluid distribution in a chemical reactor operating with a stirrer. Different rotational speeds results in different shapes of the used fluid that influences the responsiveness again. (from left: 0 rpm; 125 rpm; 800 rpm)


Publications


2013

2012

2011

2010

2009

2008

2007

2006

2005 und älter




Contact

Dr. André Bieberle
Experimental Thermal Fluid Dynamics
a.bieberleAthzdr.de
Phone: +49 351 260 - 2913
Fax: 12913, 2383

Prof. Dr. Uwe Hampel
Head
u.hampel@hzdr.de
Phone: +49 351 260 - 2772
Fax: 12772, 2383