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

To boost the science case of MIRACLES, the time-of-flight backscattering spectrometer at the European Spallation Source (ESS), an optimized neutron guide system, is proposed. This systematic study resulted in an enhancement in the transport of cold neutrons, compared with the previous conceptual design, with wavelengths ranging from λ = 2 Å to 20 Å along the 162.5-m distance from source to sample. This maintained the undisturbed main focus of the instrument, viz, to carry out quasielastic and inelastic neutron scattering (QENS and INS) experiments on a large dynamic range and for both energy-gain and energy-loss sides. To improve the collection of cold neutrons from the source and direct them to the sample position, the vertical geometry was adjusted to an adapted version of a ballistic elliptical profile. Its horizontal geometry was conceived to: (i) keep the high-resolution performance of the instrument, and (ii) minimize the background originating from fast and thermal neutrons. To comply with the first requirement, a narrow guide section at the pulse shaping chopper position has been implemented. To fulfil the second, a curved guide segment has been chosen to suppress neutrons with wavelengths λ < 2 Å. Subsequent tailoring of the phase space provided an efficient transport of cold neutrons along the beamline to reach a 3 × 3 cm2 sample. Finally, additional calculations were performed to present a potential upgrade, with the exchange of the final segment, to focus on samples of approximately 1 × 1 cm2; the proposal anticipates a flux increase of 70% in this 1 cm2 sample area.

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.850.161 ◽

2016 ◽

Vol 850 ◽

pp. 161-166 ◽

Cited By ~ 1

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.

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The Neutron Imaging Instrument CONRAD—Post-Operational Review

Journal of Imaging ◽

10.3390/jimaging7010011 ◽

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.

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

Journal of Applied Crystallography ◽

10.1107/s1600576715023353 ◽

2016 ◽

Vol 49 (1) ◽

pp. 195-202 ◽

Cited By ~ 43

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.

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A new time-of-flight small-angle scattering instrument at the Helmholtz-Zentrum Berlin: V16/VSANS

Journal of Applied Crystallography ◽

10.1107/s1600576713030227 ◽

2014 ◽

Vol 47 (1) ◽

pp. 237-244 ◽

Cited By ~ 20

Author(s):

Karsten Vogtt ◽

Miriam Siebenbürger ◽

Daniel Clemens ◽

Christian Rabe ◽

Peter Lindner ◽

...

Keyword(s):

Momentum Transfer ◽

Small Angle ◽

Soft Matter ◽

Scattering Length ◽

Time Of Flight ◽

Small Angle Scattering ◽

Neutron Guide ◽

Macromolecular Assemblies ◽

Angle Scattering ◽

The Individual

Small-angle scattering methods have become routine techniques for the structural characterization of macromolecules and macromolecular assemblies like polymers, (block) copolymers or micelles in the spatial range from a few to hundreds of nanometres. Neutrons are valuable scattering probes, because they offer freedom with respect to scattering length density contrast and isotopic labelling of samples. In order to gain maximum benefit from the allotted experiment time, the instrumental setup must be optimized in terms of statistics of scattered intensity, resolution and accessible range in momentum transferQ. The new small-angle neutron scattering instrument V16/VSANS at the Helmholtz-Zentrum in Berlin, Germany, augments neutron guide collimation and pinhole optics with time-of-flight data recording and flexible chopper configuration. Thus, the availableQrange and the respective instrumental resolution in the intermediate and high momentum transfer regions can be adjusted and balanced to the individual experimental requirements. This renders V16/VSANS a flexible and versatile instrument for soft-matter research.

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