scholarly journals Enhanced position resolution for ZnS:Ag/$$^6$$LiF wavelength shifting fibre thermal neutron detectors

2021 ◽  
Vol 136 (3) ◽  
Author(s):  
Giacomo Mauri ◽  
G. J. Sykora ◽  
E. M. Schooneveld ◽  
N. J. Rhodes
Keyword(s):  
Neutron Scattering ◽  
Interpolation Method ◽  
Reconstruction Algorithms ◽  
Scintillation Light ◽  
Detector Performance ◽  
Position Resolution ◽  
High Position ◽  
Position Reconstruction ◽  
Under Construction ◽  
Scintillator Detectors

AbstractThe high neutron intensity, improvements in neutron delivery and increasingly more complex experiments at neutron scattering facilities, i.e. J-PARC, SNS, ISIS, CSNS and ESS, which is presently under construction, drive the development of neutron scattering instruments and their associated detectors. High position resolution is one of the most demanding detector requirements and is particularly relevant of neutron reflectometry applications. Scintillator detectors using ZnS:Ag/$$^6$$ 6 LiF coupled to wavelength shifting fibre (WLSF) are currently employed in several neutron scattering facilities, including J-PARC, SNS, ISIS and CSNS. For WLSF-based scintillation detectors, the position reconstruction is routinely achieved by determining the combination of fibres that absorb scintillation light. The use of position reconstruction algorithms, analysing light spread in the system, leads to an increase in the position resolution. The optimisation of a centre of gravity interpolation method for linear position-sensitive detectors has been developed, and a factor 2 improvement in position sensitivity has been achieved. The investigation of the light spread over the fibres and the detector performance in correlation with the reconstructed position resolution are discussed.

scholarly journals Status of the two-dimensional, multi-wire proportional chamber detector for the China Spallation Neutron Source

2018 ◽  
Vol 48 ◽  
pp. 1860121 ◽  
Author(s):  
Zhiwen Wen ◽  
Huirong Qi
Keyword(s):  
Neutron Source ◽  
Neutron Detector ◽  
Detection Efficiency ◽  
Spallation Neutron Source ◽  
Two Dimensional ◽  
Large Area ◽  
Position Resolution ◽  
Proportional Chamber ◽  
High Detection Efficiency ◽  
Under Construction

The re-designed two-dimensional, multi-wire proportional chamber (MWPC) detector based on the [Formula: see text]He operation gas has been developed for the multifunctional reflection spectrum detection requirements in China Spallation Neutron Source (CSNS), which is under construction in Guangdong province, China. This efficient thermal neutron detector with large area (200 mm [Formula: see text] 200 mm active area), two-dimensional position sensitive (<2 mm of position resolution), high detection efficiency (>65% in the wavelength of 1.8Å) and good n/[Formula: see text] discrimination would meet some requirements in CSNS The neutron detector consists of a MWPC detector and a high-pressure gas vessel. The wire readout structures of the detector and the gas purity device have been optimized based on previous design and testing. The re-designed MWPC detector with an absorber thickness of 10 mm and 8.5 atm operating gas mixture of [Formula: see text]He and C[Formula: see text]H[Formula: see text] was constructed. Using the non-return valve manufactured by Swagelok, the gas purity device was developed to clean the water and remove gas impurities. The effective cycle time can be up to 50 min per sequence. The performance of the position resolution and the two-dimensional imaging accuracy by the traditional center of gravity readout method was studied with an X-ray radiation source and the neutron source. At the end of this year, the detector will be mounted at CSNS and studied using the neutron source.

APPLICATION OF A ONE-DIMENSIONAL POSITION SENSITIVE CHAMBER ON SYNCHROTRON RADIATION

2014 ◽  
Vol 27 ◽  
pp. 1460142
Author(s):  
HUIRONG QI ◽  
MEI LIU
Keyword(s):  
Synchrotron Radiation ◽  
Low Cost ◽  
Large Area ◽  
Position Resolution ◽  
One Dimensional ◽  
X Ray ◽  
High Position ◽  
Standard Data ◽  
Wire Chamber ◽  
The One

In the last few years, wire chambers have been frequently used for X-ray detection because of their low cost, large area and reliability. X-ray diffraction is an irreplaceable method for powder crystal lattice measurements. A one-dimensional single-wire chamber has been developed in our lab to provide high position resolution for powder diffraction experiments using synchrotron radiation. There are 200 readout strips of 0.5 mm width with a pitch of 1.0 mm in the X direction, and the working gas is a mixture of Ar and CO2 (90/10). The one-dimensional position of the original ionization point is determined by the adjacent strip's distribution information using the center of gravity method. Recently, a study of the detector's performance and diffraction image was completed at the 1W1B laboratory of the Beijing Synchrotron Radiation Facility (BSRF) using a sample of SiO2. Most of the relative errors between the measured values of diffraction angles and existing data were less than 1%. The best position resolution achieved for the detector in the test was 71 μm (σ value) with a 20 μm slit collimator. Finally, by changing the detector height in incremental distances from the center of the sample, the one-dimensional detector achieved a two-dimensional diffraction imaging function, and the results are in good agreement with standard data.

scholarly journals A new neutron detector with a high position resolution for the study of the (p,pn) reaction on rare isotopes

2014 ◽  
Vol 66 ◽  
pp. 11022 ◽  
Author(s):  
Y. Kubota ◽  
M. Sasano ◽  
T. Uesaka ◽  
M. Dozono ◽  
M. Itoh ◽  
...  
Keyword(s):  
Neutron Detector ◽  
Position Resolution ◽  
High Position ◽  
Rare Isotopes

Toward a new lower limit for the minimum scattering vector on the very small angle neutron scattering spectrometer at Laboratoire Léon Brillouin

2008 ◽  
Vol 41 (1) ◽  
pp. 161-166 ◽  
Author(s):  
Annie Brûlet ◽  
Vincent Thévenot ◽  
Didier Lairez ◽  
Sébastien Lecommandoux ◽  
Willy Agut ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Pixel Size ◽  
Resolution Function ◽  
Incident Wavelength ◽  
Under Construction ◽  
Very High ◽  
Good Agreement ◽  
Small Pixel

The main characteristics of the very small angle neutron scattering spectrometer (VSANS) under construction at the Laboratoire Léon Brillouin are a multibeam pinhole collimator converging onto an image plate detector. By combining tiny collimation (diaphragms of around 1 or 2 mm in diameter) with the small pixel size of the detector (0.15 × 0.15 mm), very high resolution measurements can be achieved. The resolution function of the instrument contains a contribution from gravity, which is reduced by the intermediate masks of the collimator. Owing to the relatively short length of the VSANS instrument (around 14 m), this effect remains weak, in good agreement with the predictions. With a prototype multibeam collimator, an incident wavelength of 0.9 nm and the detector located at 6 m from the sample, it is possible to accessqvalues as low as 4 × 10−3 nm−1with very highqresolution. Promising preliminary experiments with highqresolution are reported, which open up new fields to the SANS technique.

Single-crystal neutron diffractometry — Recent developments and trends

2003 ◽  
Vol 218 (2) ◽  
Author(s):  
H. A. Graf
Keyword(s):  
Neutron Scattering ◽  
Single Crystal ◽  
Magnetic Order ◽  
The United States ◽  
Range Magnetic Order ◽  
Scattering Center ◽  
Recent Developments ◽  
Spallation Source ◽  
Under Construction ◽  
Long Range Magnetic Order

AbstractAn overview is given over recent developments and trends in single-crystal neutron diffractometry. Special emphasis is put on instrumental developments which have considerably enhanced the efficiency of neutron scattering experiments over the last years by improving monochromator and/or detector systems. Not discussed are developments in the field of polarised neutrons. Examples from the Berlin Neutron Scattering Center (BENSC) are given for the measurement of short-range magnetic order using the flat-cone diffractometer E2 of BENSC and of the study of long-range magnetic order making use of a high-field cryomagnet at BENSC. The perspectives of neutron diffractometry within the next 5 to 10 years are discussed with view on the new powerful spallation sources SNS (under construction in the United States), JSNS (under construction in Japan) and ESS, the European Spallation Source, planned to be constructed in Europe.

Development of hybrid MSGC detectors with high position and time-of-flight resolution for neutron scattering experiments at ESS

2002 ◽  
Author(s):  
Christian Schulz ◽  
Burckhard Gebauer ◽  
Guenter Richter ◽  
Bernhard Namaschk ◽  
Lev N. Balykov ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Time Of Flight ◽  
High Position

Use Of A Capillary X-Ray Focused Beam To Investigate The Chemical Composition Of CdZnTe Wafers With High Resolution CdZnTe Detectors

1997 ◽  
Vol 487 ◽  
Author(s):  
P. Fougères ◽  
Ch. Burggraf ◽  
Chr. Burggraf ◽  
J. M. Koebel ◽  
C. Koenig ◽  
...  
Keyword(s):  
High Resolution ◽  
High Sensitivity ◽  
X Rays ◽  
Position Resolution ◽  
X Ray ◽  
High Position ◽  
Cdznte Detector ◽  
Cdznte Detectors ◽  
Focused Beam ◽  
New System

AbstractThe control of the concentration of Zn and its fluctuation in the high pressure Bridgman grown CdZnTe crystals is part of our characterization work on the ternary grown ingots grown in house. In order to reach both high sensitivity and high position resolution, we have developed a new system consisting of a X-ray generator, coupled to a focusing X-ray capillary, delivering intense beams in the micron scale, since the intensity gain is around a factor of 100 compared to conventional methods.The characteristic X-rays are measured through a high resolution CdZnTe detector (225 eV at 5.9 keV FWHM) cooled by a Peltier system. The results of our investigations on different kinds of crystals will be discussed.

On-the-Fly Treatment of Discrete Representation Thermal Neutron Scattering Data in RMC Code

2020 ◽  
Author(s):  
Lei Zheng ◽  
Kaiwen Li ◽  
Kan Wang
Keyword(s):  
Elastic Scattering ◽  
Neutron Scattering ◽  
Thermal Neutron ◽  
Interpolation Method ◽  
Beryllium Oxide ◽  
Scattering Data ◽  
Computational Time ◽  
Discrete Representation ◽  
Thermal Region ◽  
Thermal Neutron Scattering

Abstract A proper treatment of thermal neutron scattering data is required for the high-fidelity neutronics calculation of thermal reactors. Monte Carlo codes typically use an S(α, β) treatment to describe scattering events in the thermal region if the S(α, β) data is available for the material. The S(α,β) model stores a large majority of scattering physics and can handle thermal scattering process accurately. In neutronic-thermohydraulic coupling calculations, the temperature effect on nuclear data must be treated properly. The on-the-fly sampling method or the on-the-fly interpolation method are typically used in thermal region. In this paper, the on-the-fly interpolation method for the discrete representation S(α,β) data was introduced. The two-dimensional linear-linear interpolation was used to calculate the scattering cross sections and the secondary information for inelastic scattering, coherent elastic scattering and incoherent elastic scattering. The implemented on-the-fly capability was tested by a series of benchmarks that contain various thermal materials, including light water, beryllium and beryllium oxide. The integral kinf eigenvalues, the efficiency and the fine energy spectra of the on-the-fly treatment capacity were compared with those of the references. Results show that the on-the-fly treatment capability has high accuracy, and the computational time increases up to 20%.

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