scholarly journals The Neutron Imaging Instrument CONRAD—Post-Operational Review

2021 ◽  
Vol 7 (1) ◽  
pp. 11
Author(s):  
Nikolay Kardjilov ◽  
Ingo Manke ◽  
André Hilger ◽  
Tobias Arlt ◽  
Robert Bradbury ◽  
...  
Keyword(s):  
Phase Contrast ◽  
Research Reactor ◽  
Dark Field ◽  
Neutron Imaging ◽  
Neutron Guide ◽  
User Program ◽  
Optical Components ◽  
New Methods ◽  
Cold Source ◽  
Imaging Instrument

The neutron imaging instrument CONRAD was operated as a part of the user program of the research reactor BER-II at Helmholtz-Zentrum Berlin (HZB) from 2005 to 2020. The instrument was designed to use the neutron flux from the cold source of the reactor, transported by a curved neutron guide. The pure cold neutron spectrum provided a great advantage in the use of different neutron optical components such as focusing lenses and guides, solid-state polarizers, monochromators and phase gratings. The flexible setup of the instrument allowed for implementation of new methods including wavelength-selective, dark-field, phase-contrast and imaging with polarized neutrons. In summary, these developments helped to attract a large number of scientists and industrial customers, who were introduced to neutron imaging and subsequently contributed to the expansion of the neutron imaging community.

CONRAD-2: the new neutron imaging instrument at the Helmholtz-Zentrum Berlin

2016 ◽  
Vol 49 (1) ◽  
pp. 195-202 ◽  
Author(s):  
Nikolay Kardjilov ◽  
André Hilger ◽  
Ingo Manke ◽  
Robin Woracek ◽  
John Banhart
Keyword(s):  
Research Reactor ◽  
Cold Neutron ◽  
Transportation Systems ◽  
Neutron Imaging ◽  
Neutron Guide ◽  
Neutron Tomography ◽  
Polarized Beams ◽  
Order Of Magnitude ◽  
Sample Position ◽  
Imaging Instrument

The construction of the new neutron imaging instrument at the BER-2 research reactor of the Helmholtz-Zentrum Berlin has greatly increased the potential of the facility. The redesign of the facility included improvements of the neutron extraction and transportation systems, more effective shielding, and innovative instrumentation. The cold neutron flux at the neutron guide exit was increased by more than one order of magnitude, which allowed for an implementation of methods that require monochromatic or polarized beams, thus enabling the exploitation of nonconventional contrast mechanisms such as phase, diffraction and magnetic contrasts. The improved instrument design also facilitates the development of high-resolution neutron tomography by providing an increased beam intensity at the sample position.

scholarly journals Neutron guide optimisation for a time-of-flight neutron imaging instrument at the European Spallation Source

2015 ◽  
Vol 23 (1) ◽  
pp. 301 ◽  
Author(s):  
A. Hilger ◽  
N. Kardjilov ◽  
I. Manke ◽  
C. Zendler ◽  
K. Lieutenant ◽  
...  
Keyword(s):  
Time Of Flight ◽  
Neutron Imaging ◽  
Neutron Guide ◽  
Spallation Source ◽  
Imaging Instrument

Planning of Energy-Selective Neutron Imaging Instrument at CSNS and its Application Prospect in Materials Science

2016 ◽  
Vol 850 ◽  
pp. 161-166 ◽  
Author(s):  
Jie Chen ◽  
Lun Hua He ◽  
Jun Rong Zhang ◽  
Fang Wei Wang
Keyword(s):  
Neutron Source ◽  
Spatial Resolution ◽  
Materials Science ◽  
Neutron Radiography ◽  
Ccd Camera ◽  
Neutron Imaging ◽  
Crystallographic Structure ◽  
Neutron Guide ◽  
Contrast Imaging ◽  
Imaging Instrument

In order to serve a growing multidisciplinary community beyond the traditional scattering areas, an energy-selective neutron imaging instrument is proposed in the China Spallation Neutron Source (CSNS). The instrument is planned to provide analytical techniques such as state-of-the-art energy-selective neutron imaging, neutron radiography, tomography, polarized neutron imaging, neutron phase contrast imaging, and combined neutron diffraction. Coupled hydrogen moderator (CHM) will be chosen as its neutron source. A flight path of 40 m from moderator to sample will provide good energy resolution better than ~0.4%. Super mirror neutron guide will be used to transport neutron from moderator to aperture selector. Aperture selector with 5 apertures and a set of slits will be used to adjust the neutron beam for different modalities. The best spatial resolution will be 50 μm. Different types of detectors will be needed including high spatial resolution CCD camera, TOF detector, and scintillator detector. With a main emphasis on advanced materials and engineering studies, the instrument will enable 2D/3D mapping of the microstructure, chemical composition, and crystallographic structure (grain size, stress and strain, phase position, texture, and so on). It will also support a broad range of studies in archaeology, biology, biomedicine, geosciences, building technology, manufacturing processes, forensic, and homeland security applications.

Removal of inelastically scattered electrons substantially increases phase contrast on frozen-hydrated molecules

1987 ◽  
Vol 45 ◽  
pp. 652-653
Author(s):  
John P. Langmore ◽  
Brian D. Athey
Keyword(s):  
Electron Diffraction ◽  
Phase Contrast ◽  
Low Dose ◽  
Dark Field ◽  
Biological Structure ◽  
Bright Field ◽  
Low Contrast ◽  
Negative Stain ◽  
The Difference ◽  
Better Than

Although electron diffraction indicates better than 0.3nm preservation of biological structure in vitreous ice, the imaging of molecules in ice is limited by low contrast. Thus, low-dose images of frozen-hydrated molecules have significantly more noise than images of air-dried or negatively-stained molecules. We have addressed the question of the origins of this loss of contrast. One unavoidable effect is the reduction in scattering contrast between a molecule and the background. In effect, the difference in scattering power between a molecule and its background is 2-5 times less in a layer of ice than in vacuum or negative stain. A second, previously unrecognized, effect is the large, incoherent background of inelastic scattering from the ice. This background reduces both scattering and phase contrast by an additional factor of about 3, as shown in this paper. We have used energy filtration on the Zeiss EM902 in order to eliminate this second effect, and also increase scattering contrast in bright-field and dark-field.

Towards 1-Ångstrom-resolution STEM

1993 ◽  
Vol 51 ◽  
pp. 996-997
Author(s):  
H.S. von Harrach ◽  
D.E. Jesson ◽  
S.J. Pennycook
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Phase Contrast ◽  
Spherical Aberration ◽  
A Priori ◽  
Dark Field ◽  
Image Resolution ◽  
Objective Lens ◽  
Annular Dark Field ◽  
First Results

Phase contrast TEM has been the leading technique for high resolution imaging of materials for many years, whilst STEM has been the principal method for high-resolution microanalysis. However, it was demonstrated many years ago that low angle dark-field STEM imaging is a priori capable of almost 50% higher point resolution than coherent bright-field imaging (i.e. phase contrast TEM or STEM). This advantage was not exploited until Pennycook developed the high-angle annular dark-field (ADF) technique which can provide an incoherent image showing both high image resolution and atomic number contrast.This paper describes the design and first results of a 300kV field-emission STEM (VG Microscopes HB603U) which has improved ADF STEM image resolution towards the 1 angstrom target. The instrument uses a cold field-emission gun, generating a 300 kV beam of up to 1 μA from an 11-stage accelerator. The beam is focussed on to the specimen by two condensers and a condenser-objective lens with a spherical aberration coefficient of 1.0 mm.

Imaging sub-micron objects with light microscopy: Visualization of the T-4 bacteriophage

1989 ◽  
Vol 47 ◽  
pp. 834-835
Author(s):  
Malcolm Brown ◽  
Reynolds M. Delgado ◽  
Michael J. Fink
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Focal Plane ◽  
Phase Contrast ◽  
Dark Field ◽  
E Coli ◽  
Polystyrene Beads ◽  
Television Camera ◽  
Transmission Electron ◽  
Universal Microscope

While light microscopy has been used to image sub-micron objects, numerous problems with diffraction-limitations often preclude extraction of useful information. Using conventional dark-field and phase contrast light microscopy coupled with image processing, we have studied the following objects: (a) polystyrene beads (88nm, 264nm, and 557mn); (b) frustules of the diatom, Pleurosigma angulatum, and the T-4 bacteriophage attached to its host, E. coli or free in the medium. Equivalent images of the same areas of polystyrene beads and T-4 bacteriophages were produced using transmission electron microscopy.For light microscopy, we used a Zeiss universal microscope. For phase contrast observations a 100X Neofluar objective (N.A.=1.3) was applied. With dark-field, a 100X planachromat objective (N.A.=1.25) in combination with an ultra-condenser (N.A.=1.25) was employed. An intermediate magnifier (Optivar) was available to conveniently give magnification settings of 1.25, 1.6, and 2.0. The image was projected onto the back focal plane of a film or television camera with a Carl Zeiss Jena 18X Compens ocular.

scholarly journals Multiplexed Plasmonic Nano-Labeling for Bioimaging of Cytological Stained Samples

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3509
Author(s):  
Paule Marcoux-Valiquette ◽  
Cécile Darviot ◽  
Lu Wang ◽  
Andrée-Anne Grosset ◽  
Morteza Hasanzadeh Kafshgari ◽  
...  
Keyword(s):  
Accurate Determination ◽  
Cell Types ◽  
Fine Needle Biopsy ◽  
Dark Field ◽  
Imaging Method ◽  
New Methods ◽  
Formalin Fixed Paraffin ◽  
Dark Field Microscopy ◽  
Formalin Fixed Paraffin Embedded

Reliable cytopathological diagnosis requires new methods and approaches for the rapid and accurate determination of all cell types. This is especially important when the number of cells is limited, such as in the cytological samples of fine-needle biopsy. Immunoplasmonic-multiplexed- labeling may be one of the emerging solutions to such problems. However, to be accepted and used by the practicing pathologists, new methods must be compatible and complementary with existing cytopathology approaches where counterstaining is central to the correct interpretation of immunolabeling. In addition, the optical detection and imaging setup for immunoplasmonic-multiplexed-labeling must be implemented on the same cytopathological microscope, not interfere with standard H&E imaging, and operate as a second easy-to-use imaging method. In this article, we present multiplex imaging of four types of nanoplasmonic markers on two types of H&E-stained cytological specimens (formalin-fixed paraffin embedded and non-embedded adherent cancer cells) using a specially designed adapter for SI dark-field microscopy. The obtained results confirm the effectiveness of the proposed optical method for quantitative and multiplex identification of various plasmonic NPs, and the possibility of using immunoplasmonic-multiplexed-labeling for cytopathological diagnostics.

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