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Wang S.,CAS Institute of High Energy Physics | Wang S.,Dongguan Institute of Neutron Science DINS | Fu S.,CAS Institute of High Energy Physics | Fu S.,Dongguan Institute of Neutron Science DINS | And 2 more authors.
IPAC 2016 - Proceedings of the 7th International Particle Accelerator Conference | Year: 2016

CSNS (China Spallation Neutron Source) is a proton accelerator based facility for delivering spallation neutrons to users. The main components are 80-MeV linac, 1.6-GeV RCS and neutron production target. The construction began in 2011, and now construction of the building and accelerator components is well in progress. Most of the components have been tested and installed into the tunnel. The ion source and RFQ have been successfully commissioned. The first DTL tank has successfully completed the beam commissioning, and the beam commissioning for the other three DTL tank will be performed before the end of 2016. The RCS commissioning will start in the beginning of 2017. This presentation provides a complete overview of the status of construction and beam commissioning. Copyright © 2016 CC-BY-3.0 and by the respective authors.


Huang M.-Y.,CAS Institute of High Energy Physics | Huang M.-Y.,Dongguan Institute of Neutron Science DINS | Guo X.-H.,Beijing Normal University | Young B.-L.,Iowa State University | Young B.-L.,CAS Institute of Theoretical Physics
Chinese Physics C | Year: 2016

After considering supernova shock effects, Mikheyev-Smirnov-Wolfenstein effects, neutrino collective effects, and Earth matter effects, the detection of supernova neutrinos at the China Spallation Neutron Source is studied and the expected numbers of different flavor supernova neutrinos observed through various reaction channels are calculated with the neutrino energy spectra described by the Fermi-Dirac distribution and the "beta fit" distribution respectively. Furthermore, the numerical calculation method of supernova neutrino detection on Earth is applied to some other spallation neutron sources, and the total expected numbers of supernova neutrinos observed through different reactions channels are given. © Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Sciences and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.


He C.,Dongguan Institute of Neutron Science DINS | Tao J.,Dongguan Institute of Neutron Science DINS | Ke Y.,Dongguan Institute of Neutron Science DINS | Qiu Y.,Dongguan University of Technology
RSC Advances | Year: 2015

Using a microwave assisting method, we successfully synthesized tungsten carbide nanocrystals with a hexagonal prism shape on graphene (WCP/G). The WCP nanocrystals are 5 nm in size and dominated by (011¯0), (101¯0) and (11¯00) facets with a preferred orientation of [0001]. An intermittent microwave heating (IMH) method is also utilized to load Pd nanoparticles (NPs) onto WCP/G to produce Pd-WCP/G, which displays a significant improvement as a catalyst for formic acid oxidation with peak current density increasing by a factor of 7, and notably enhanced durability. We believe this synthesis method of WCP/G opens new possibilities to research shape-controlled and high-surface-area transition metal carbide nanocrystals (TMCs) and developing them as efficient and low-cost catalysts or catalyst supports in a broad range of sustainable energy technologies. This journal is © The Royal Society of Chemistry.


Jia D.,CAS Beijing National Laboratory for Molecular | Jia D.,University of Chinese Academy of Sciences | Hollingsworth J.V.,University of St. Thomas, Texas | Zhou Z.,CAS Beijing National Laboratory for Molecular | And 4 more authors.
Soft Matter | Year: 2015

The state transition from gel to glass is studied in a biphasic mixture of polystyrene core/poly(N-isopropylacrylamide) shell (CS) microgels and sulfonated polystyrene (PSS) particles. At 35 °C, the interaction between CS microgels is due to short-range van der Waals attraction, while that between PSS particles is from long-range electrostatic repulsion. During the variation of the relative ratio of the two species at a fixed apparent total volume fraction, the mixture exhibits a gel-to-defective gel-to-glass transition. When small amounts of PSS are introduced into the CS gel network, some of them are kinetically trapped, causing a change in its fractal structure, and act as defects to weaken the macroscopic gel strength. An increase of the PSS content in the mixture promotes the switch from the gel to the defective gel, e.g., the typical two-step yielding gel merges into one-step yielding. This phenomenon is an indication that inter-cluster bond breakage coincides with intra-cluster bond fracture. As the relative volume fraction of PSS exceeds a critical threshold, the gel network can no longer be formed; hence, the mixture exhibits characteristics of glass. A state diagram of the biphasic mixture is constructed, and the landscapes of the different transitions will be described in future studies. © The Royal Society of Chemistry.


Zhou Z.,CAS Institute of Chemistry | Zhou Z.,University of Chinese Academy of Sciences | Hollingsworth J.V.,CAS Institute of Chemistry | Hong S.,Beijing University of Chemical Technology | And 6 more authors.
Soft Matter | Year: 2014

A series of microgel particles composed of a polystyrene (PS) core and a thermo-sensitive poly(N-isopropylacrylamide) (PNIPAM) shell with different shell thicknesses were investigated to elucidate the effect of microgel softness on its shear thickening behavior. Since the softness of the microgels increases with decreasing temperature through the volume phase transition effect of PNIPAM shell, the measured softness parameter, n, which is derived from the Zwanzig-Mountain equation, was used to measure and describe the combined influences of temperature and shell thickness. Confocal microscopy is used to investigate the interaction potential between microgel particles with different softness parameters. According to the obtained results, the softness parameter can provide an estimate for the shear thickening behavior of microgel suspensions, at least semi-quantitatively. This journal is © the Partner Organisations 2014.


Wu L.,CAS Institute of High Energy Physics | Wu L.,University of Chinese | Wang X.-L.,CAS Institute of High Energy Physics | Wang X.-L.,Dongguan Institute of Neutron Science DINS | And 3 more authors.
Chinese Physics C | Year: 2015

The alignment tolerance of multipoles on a girder is better than ±30 μm in the storage ring of the High Energy Photon Source (HEPS) which will be the next project at IHEP (Institute of High Energy Physics). It is difficult to meet the precision when only using the traditional optical survey method. In order to achieve this goal, a vibrating wire alignment technique with high precision and sensitivity is considered to be used in this project. This paper presents some preliminary research works about theory, scheme design and achievements. © 2015 Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Sciences and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.


Liu J.,University of Chinese Academy of Sciences | Pan C.-Z.,University of Chinese Academy of Sciences | Pan C.-Z.,Chinese Academy of Sciences | Tong J.-F.,CAS Institute of High Energy Physics | And 2 more authors.
Annals of Nuclear Energy | Year: 2015

The thermo-hydraulic analysis including reduction of the height of recirculation zone and stability of the free surface is very important in the design and optimization of ADS windowless spallation targets. In the present study, the Bernoulli equation is used to analyze the entire flow process in the target. Formulae for the height of the recirculation zone and the buffer zone are both obtained explicitly. Furthermore, numerical simulation for the heavy metal lead-bismuth eutectic liquid and vapor with cavitation phase change is also performed, and a novel method to calculate the height of the recirculation zone is put forward. By comparison of the theoretical formulae and numerical results, it is clearly shown that they agree with each other very well, and the heights predicted by the two methods are both determined by their own upstream flow parameters. © 2014 Elsevier Ltd. All rights reserved.


Wang X.-L.,CAS Institute of High Energy Physics | Wang X.-L.,Dongguan Institute of Neutron Science DINS | Dong L.,CAS Institute of High Energy Physics | Dong L.,Dongguan Institute of Neutron Science DINS | And 3 more authors.
Chinese Physics C | Year: 2014

The vibrating wire alignment technique is a method which, by measuring the spatial distribution of a magnetic field, can achieve very high alignment accuracy. The vibrating wire alignment technique can be applied to fiducializing magnets and the alignment of accelerator straight section components, and it is a necessary supplement to conventional alignment methods. This article gives a systematic summary of the vibrating wire alignment technique, including vibrating wire model analysis, system frequency calculation, wire sag calculation, and the relation between wire amplitude and magnetic induction intensity. On the basis of this analysis, this article outlines two existing alignment methods, one based on magnetic field measurement and the other on amplitude and phase measurements. Finally, some basic experimental issues are discussed. © 2014 Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Sciences and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.


Wang P.,CAS Institute of High Energy Physics | Wang P.,Dongguan Institute of Neutron Science DINS | Yang B.,CAS Institute of High Energy Physics | Yang B.,Dongguan Institute of Neutron Science DINS | And 2 more authors.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2015

Bandwidth limiting neutron choppers are indispensable key equipments for the time-of-flight neutron scattering spectrometers of China Spallation Neutron Source (CSNS). The main principle is to chop the neutron beam to limit the neutron wavelength bandwidth at the neutron detector. We have successfully developed a bandwidth limiting neutron chopper for CSNS in the CSNS advance research project II. The transmission rate of the neutron absorbing coating is less than 1 × 10-4 (for 1 angstrom neutron). The phase control accuracy is ±0.084° (±9.4 μs at 25 Hz). The dynamic balance grade is G1.0. Various experimental technical features have met the design requirements, and it also runs stably and reliably during the long-term tests. © 2015 Elsevier B.V. All rights reserved.


Jia D.,CAS Institute of High Energy Physics | Jia D.,Dongguan Institute of Neutron Science DINS | Zuo T.,CAS Institute of High Energy Physics | Zuo T.,Dongguan Institute of Neutron Science DINS | And 5 more authors.
Macromolecules | Year: 2016

The re-entrance of poly(N,N-diethylacrylamide) (PDEA) in D2O/d-ethanol mixtures (i.e., the coil-to-spherical aggregates-to-coil transition) has been observed at 27 °C by small-angle neutron scattering (SANS). PDEA has a lower critical solution temperature (LCST) phase diagram in the D2O-rich region and is soluble in the D2O-poor region for all of the observed temperature ranges. Its spinodal temperature decreases first from 33.5 °C in pure D2O to 26.7 °C in 80% D2O/20% d-ethanol and then increases to 283.1 °C in 50% D2O/50% d-ethanol. With the further decrease of D2O content, PDEA dissolves well, and its phase boundary can no longer be observed by SANS. Therefore, at 27 °C, PDEA dissolves as random coils when the D2O content is higher than 90% and then collapses and aggregates to form the globule phase in 20% D2O/80% d-ethanol; finally, it reswells and behaves as random coils again with excluded volume in the D2O-poor region. The ternary random phase approximation model (RPA) is used to analyze the SANS profiles, and three Flory-Huggins interaction parameters (χPDEA-d-ethanol, χPDEA-D2O, and χd-ethanol-D2O) are obtained. When a small amount of d-ethanol is added to the system, it has a strong interaction with D2O, so it directly gets distributed into the water structure and makes a negative contribution to the dissolution of PDEA (χd-ethanol-D2O is much smaller than χPDEA-d-ethanol and χPDEA-D2O). With the addition of more d-ethanol, its interaction with water becomes weaker, but still stronger than those between PDEA-D2O and PDEA-d-ethanol. Neither d-ethanol nor D2O wants to help the dissolution of PDEA in the first place, until the structure of mixed solvents tends to be pure d-ethanol in the D2O-poor region. © 2016 American Chemical Society.

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