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@INPROCEEDINGS{Simson:827198,
      author       = {Simson, Martin and Dunin-Borkowski, Rafal and Hartmann,
                      Robert and Huth, Martin and Ihle, Sebastian and Jones, Lewys
                      and Kondo, Yukihito and Migunov, Vadim and Nellist, Peter D.
                      and Ritz, Robert and Ryll, Henning and Sagawa, Ryusuke and
                      Schmidt, Julia and Soltau, Heike and Strüder, Lothar and
                      Yang, Hao},
      title        = {{E}xtending the {L}imits of {F}ast {A}cquisition in {TEM}
                      {T}omography and 4{D}-{STEM}},
      address      = {Weinheim, Germany},
      publisher    = {Wiley-VCH Verlag GmbH $\&$ Co. KGaA},
      reportid     = {FZJ-2017-01396},
      pages        = {51 - 52},
      year         = {2016},
      comment      = {European Microscopy Congress 2016: Proceedings},
      booktitle     = {European Microscopy Congress 2016:
                       Proceedings},
      abstract     = {Both transmission electron microscopy (TEM) and scanning
                      transmission electron microscopy (STEM) experiments profit
                      from recording two-dimensional camera images at very high
                      readout speeds. This includes, but is not limited to,
                      tomography in TEM and ptychography in STEM. The pnCCD (S)TEM
                      camera uses a direct detecting, radiation hard pnCCD with a
                      minimum readout speed of 1 000 full frames per second (fps)
                      with a size of 264x264 pixels [1]. It features binning and
                      windowing modes, which allow to further increase the frame
                      rate substantially. For example, 4-fold binning in one
                      direction, i.e. 66x264 pixels, yields a readout speed of 4
                      000 fps. Up to 20 000 fps are possible in windowing modes.
                      Further applications that benefit from the high readout
                      speed range from imaging on the micro- and millisecond
                      timescale to strain analysis or electric and magnetic field
                      mapping.Typical tomographic reconstructions use tilt series
                      of fewer than 100 images which are recorded in 15 to 60
                      minutes with conventional cameras running at speeds below 40
                      fps. The series are recorded by stepwise rotation of the
                      goniometer and taking a camera image after each rotation
                      step. These long acquisition times restrict the acquisition
                      of tomographic series for beam sensitive samples. We have
                      recorded a tilt series containing 3 487 images of an
                      inorganic nanotube in only 3.5 s with the pnCCD camera [2].
                      Due to the high readout speed it was possible to rotate the
                      goniometer continuously over a tilt range of −70 ° to +30
                      ° in an FEI Titan 60–300, operated at 60 keV beam energy.
                      The short acquisition time and the high sensitivity of the
                      camera allowed to reduce the cumulative electron dose to
                      about 8 electrons per Å2, i.e. about an order of magnitude
                      lower than conventionally used for low dose tomography. A 3D
                      reconstruction of the nanowire is shown in Figure 1. The
                      acquisition time was not limited by the readout of the
                      camera, but rather by the rotation speed of the
                      goniometer.Combining the high readout speed with the
                      scanning mode makes 4D-STEM imaging feasible, a powerful
                      imaging technique where a two-dimensional image is recorded
                      for each probe position of a two-dimensional STEM
                      diffraction pattern. With the pnCCD (S)TEM camera, a 4D data
                      cube consisting of 256x256 (i.e. 65 536) probe positions
                      with a 132x264 pixel detector image (using 2-fold binning)
                      for each probe position can be recorded in about 35 s.
                      Several measurements have been performed to prove the
                      capability of the camera for 4D-STEM imaging, including
                      strain analysis, magnetic domain mapping and electron
                      ptychography. The latter is a 4D-STEM technique that was
                      described theoretically already in 1993 [3] but was so far
                      limited experimentally by the low readout speed of existing
                      cameras. In electron ptychography, the intensity
                      distribution in the bright field disk is recorded in 2D for
                      each STEM probe position. In an electron wave-optical
                      approach the phase and amplitude information is extracted
                      from the recorded intensity images. The reconstructed phase
                      image (Figure 2a) shows enhanced image contrast compared to
                      the simultaneously acquired conventional annular dark field
                      image (Figure 2b). Measurements with the pnCCD (S)TEM camera
                      were carried out using a JEOL ARM200-CF to investigate
                      different samples with the ptychographic phase
                      reconstruction technique.In conclusion, the pnCCD camera
                      enables new techniques in TEM and STEM. Various fields of
                      application benefit from recording two-dimensional detector
                      images at high speeds. With its direct detection, high
                      readout speed and radiation hardness the pnCCD (S)TEM camera
                      permits the recording of tomographic tilt series and large
                      4D-STEM data cubes in short times and thus paves the way for
                      new science.},
      month         = {Aug},
      date          = {2016-08-28},
      organization  = {16th European Microscopy Congress (EMC
                       2016), Lyon (France), 28 Aug 2016 - 2
                       Sep 2016},
      cin          = {PGI-5 / ER-C-1},
      cid          = {I:(DE-Juel1)PGI-5-20110106 / I:(DE-Juel1)ER-C-1-20170209},
      pnm          = {143 - Controlling Configuration-Based Phenomena (POF3-143)},
      pid          = {G:(DE-HGF)POF3-143},
      typ          = {PUB:(DE-HGF)8 / PUB:(DE-HGF)7},
      doi          = {10.1002/9783527808465.EMC2016.5295},
      url          = {https://juser.fz-juelich.de/record/827198},
}