Innovations in small‐angle X‐ray and neutron scattering (SAXS and SANS) at major X‐ray and neutron facilities offer new characterization tools for researching materials phenomena relevant to advanced ...applications. For SAXS, the new generation of diffraction‐limited storage rings, incorporating multi‐bend achromat concepts, dramatically decrease electron beam emittance and significantly increase X‐ray brilliance over previous third‐generation sources. This results in intense X‐ray incident beams that are more compact in the horizontal plane, allowing significantly improved spatial resolution, better time resolution, and a new era for coherent‐beam SAXS methods such as X‐ray photon correlation spectroscopy. Elsewhere, X‐ray free‐electron laser sources provide extremely bright, fully coherent, X‐ray pulses of <100 fs and can support SAXS studies of material processes where entire SAXS data sets are collected in a single pulse train. Meanwhile, SANS at both steady‐state reactor and pulsed spallation neutron sources has significantly evolved. Developments in neutron optics and multiple detector carriages now enable data collection in a few minutes for materials characterization over nanometre‐to‐micrometre scale ranges, opening up real‐time studies of multi‐scale materials phenomena. SANS at pulsed neutron sources is becoming more integrated with neutron diffraction methods for simultaneous structure characterization of complex materials. In this paper, selected developments are highlighted and some recent state‐of‐the‐art studies discussed, relevant to hard matter applications in advanced manufacturing, energy and climate change.
Selected recent advances in small‐angle X‐ray and neutron scattering are highlighted, together with some of the hard material applications they serve in the areas of manufacturing, energy and climate change. This paper is associated with work presented at the 18th International Conference on Small‐Angle Scattering, Campinas, Brazil, September 2022 (SAS 2022).
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Boron neutron capture therapy (BNCT), advanced cancer treatment utilizing nuclear fission of
B atom in cancer cells, is attracting increasing attention. As
B delivery agent, sodium borocaptate (
BSH,
...B
H
SH ⋅ 2Na), has been used in clinical studies along with L-boronophenylalanine. Recently, this boron cluster has been conjugated with lipids, polymers or nanoparticles to increase selectivity to and retentivity in tumor. In this work, anticancer nanoformulations for BNCT are designed, consisting of poly(glycerol) functionalized detonation nanodiamonds (DND-PG) as a hydrophilic nanocarrier, the boron cluster moiety (
B
H
) as a dense boron-10 source, and phenylboronic acid or RGD peptide as an active targeting moiety. Some hydroxy groups in PG were oxidized to carboxy groups (DND-PG-COOH) to conjugate the active targeting moiety. Some hydroxy groups in DND-PG-COOH were then transformed to azide to conjugate
B
H
through click chemistry. The nanodrugs were evaluated in vitro using B16 murine melanoma cells in terms of cell viability, BNCT efficacy and cellular uptake. As a result, the
B
H
moiety is found to facilitate cellular uptake probably due to its negative charge. Upon thermal neutron irradiation, the nanodrugs with
B
H
moiety exhibited good anticancer efficacies with slight differences with and without targeting moiety.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
We present the first Open Gravitational-wave Catalog, obtained by using the public data from Advanced LIGO's first observing run to search for compact-object binary mergers. Our analysis is based on ...new methods that improve the separation between signals and noise in matched-filter searches for gravitational waves from the merger of compact objects. The three most significant signals in our catalog correspond to the binary black hole mergers GW150914, GW151226, and LVT151012. We assume a common population of binary black holes for these three signals by defining a region of parameter space that is consistent with these events. Under this assumption, we find that LVT151012 has a 97.6% probability of being astrophysical in origin. No other significant binary black hole candidates are found, nor did we observe any significant binary neutron star or neutron star-black hole candidates. We make available our complete catalog of events, including the subthreshold population of candidates.
A new nuclear research reactor, the Jordan Research and Training Reactor (JRTR), has completed its hot commissioning testing and is awaiting the issuance of its operation license. The JRTR is the ...first nuclear reactor to be constructed in Jordan. The JRTR reached its first criticality on April 25th, 2016 and is currently undergoing initial operational testing up to its full rated power. The JRTR is an open-tank-in-pool multi-purpose research reactor with a maximum rated power of 5 MWt, upgradable to 10 MWt, and thermal neutron fluxes of order of 1014 n/cm2. sec in the core region and 1013 n/cm2. sec in the reflector region. The JRTR will provide the following multi-purpose services, both domestically and internationally: education and training, neutron activation analysis, radioisotope production, material irradiation including neutron transmutation doping and various neutron beam research such as in terms of neutron imaging and neutron scattering. In this paper, the general characteristics of the JRTR and its utilization aspects are introduced. Perspectives on the instrumentation plan of the neutron beam tubes of the JRTR are proposed. Having the JRTR to be the first regional scientific research center of excellence in the Middle-East for education, training, and research in nuclear technology applications is highlighted.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
•The UUTR neutron radiography capability is computationally examined regarding the design of tri-layered neutron beamstop prototype intended to be utilized for both imaging and shielding ...purposes.•Augmentations are used to increase computational efficiency in MCNP6 simulations for deeply-penetrating shielding problems by employing adjoint-SN computed weight windows following the CADIS method.•Neutron responses in tally regions of importance within the beamstop design between CADIS-MCNP6 and PENTRAN are in good agreement and differ by less than 8%.
A new neutron radiography facility for the University of Utah TRIGA Reactor (UUTR) is computationally designed to support a multi-purpose irradiation and imaging chamber with a terminal beamstop. Previous efforts from a 3-D MCNP6 UUTR neutron beamport simulation reveals an available neutron flux of 2.5 × 107 ± 1.4 × 105n/cm2/s with an associated dose rate of 5.0 × 105 ± 2.8 × 103 mrem/hr at the end of the beamline system. The shielding required to attenuate the neutron beam and other secondary radiation from reaching the surrounding environment during radiography experiments has been assessed and implemented into MCNP6 Monte Carlo and PENTRAN SN transport code models to assess shield performance and directly compare response solutions between the two methods. In addition, the neutron importance function obtained from adjoint-SN transport is utilized to optimize calculation efficiency in a weight window accelerated PENTRAN-CADIS-MCNP6 model of the irradiation chamber beamstop. Good agreement between adjoint-SN and PENTRAN-CADIS-MCNP6 dose rate calculations is achieved, yielding predicted detector responses within an 8% difference in tally regions of importance. The total neutron dose rate is estimated throughout the entirety of the beamstop prototype, where recommended dimensions and material compositions of the shielding apparatus are provided with supporting analysis.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Multichannel Neutron Collimator for TRT Nemtsev, G. E.; Rodionov, R. N.; Khafizov, R. R. ...
Plasma physics reports,
12/2022, Volume:
48, Issue:
12
Journal Article
Peer reviewed
The project is described of the neutron camera for the tokamak with reactor technologies (TRT). The neutron camera is a multichannel neutron collimator covering the plasma neutron source with ...observation chords. The neutron camera is a system designed for measuring the profile of fusion neutron source in the poloidal cross section of the tokamak. The system conceptual design is proposed, which includes ten measuring channels of collimators that monitor the plasma in the radial direction. For more detailed covering the plasma neutron source with observation lines, it is proposed that the system will also be equipped with several vertical collimators. The channels of collimators are located inside the vacuum chamber ports, being partly introduced into the facility cryostat volume. Such a solution makes it possible to improve the coverage of the plasma volume by observation lines. It is proposed to use stainless steel and high-density borated polyethylene as materials for the collimators. It is planned to use diamond detectors and scintillators based on stilbene and lanthanum chloride as neutron detectors. The plasma neutron source is simulated in this work. Using radiative transport calculations, the neutron fluxes and spectra in the channels of collimators were obtained. The neutron camera of the TRT facility will make it possible to measure the profiles of neutron sources in DD and DT plasmas, as well as the ratios of emission intensities of DD and DT neutrons, neutron spectra, total neutron yields, and other parameters.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A moderator device to produce a uniform thermal neutron field has been designed by Monte Carlo methods using the MCNP6.1 code. It uses a 241Am/9Be neutron source of 111 GBq activity and high-density ...polyethylene (HDPE) moderator. The main tasks developed were to evaluate the geometry of the moderator and to select the neutron source position, in order to optimize the thermal neutrons flux in the irradiation area, and to assess the dose rate. In the system, named FANT (Fuente Ampliada de Neutrones Térmicos), the neutron moderation and backscattering processes are effective to obtain quite uniform thermal fluence rates above 1000 cm−2 s−1 in a cylindrical irradiation chamber of 32 cm diameter and 34 cm length. The device has been built in the neutron measurements hall of the Energy Engineering Department of Universidad Politécnica de Madrid (UPM), performing several measurements to characterize the neutron field and validate the calculations.
FANT can be employed hereafter in different applications requiring a neutron field with a substantial thermal component, like testing and calibration of neutron detectors and neutron dosimeters, or the use NAA (Neutron Activation Analysis) methods for detection of trace substances or materials.
•A thermal neutron source built using a 111 GBq 241Am/9Be source and HDPE moderator.•Designed by Monte Carlo (MCNP6) based on neutron moderation and backscattering.•Effective thermal neutron fluence rates above 1000 cm−2 s−1 and quite uniform.•Cylindrical irradiation chamber of 32 cm diameter and 34 cm length.•Suitable for testing and calibration of neutron instruments, or for NAA.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Half of all of the elements in the Universe that are heavier than iron were created by rapid neutron capture. The theory underlying this astrophysical r-process was worked out six decades ago, and ...requires an enormous neutron flux to make the bulk of the elements
. Where this happens is still debated
. A key piece of evidence would be the discovery of freshly synthesized r-process elements in an astrophysical site. Existing models
and circumstantial evidence
point to neutron-star mergers as a probable r-process site; the optical/infrared transient known as a 'kilonova' that emerges in the days after a merger is a likely place to detect the spectral signatures of newly created neutron-capture elements
. The kilonova AT2017gfo-which was found following the discovery of the neutron-star merger GW170817 by gravitational-wave detectors
-was the first kilonova for which detailed spectra were recorded. When these spectra were first reported
, it was argued that they were broadly consistent with an outflow of radioactive heavy elements; however, there was no robust identification of any one element. Here we report the identification of the neutron-capture element strontium in a reanalysis of these spectra. The detection of a neutron-capture element associated with the collision of two extreme-density stars establishes the origin of r-process elements in neutron-star mergers, and shows that neutron stars are made of neutron-rich matter
.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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