scholarly journals Optimization of Performance, Price, and Background of Long Neutron Guides for European Spallation Source

2019 ◽  
Vol 3 (3) ◽  
pp. 16 ◽  
Author(s):  
Sonja Holm-Dahlin ◽  
Martin Andreas Olsen ◽  
Mads Bertelsen ◽  
Jonas Okkels Birk ◽  
Kim Lefmann
Keyword(s):  
Thermal Neutron ◽  
Pulse Shaping ◽  
Systematic Approach ◽  
Cold Neutron ◽  
Good Choice ◽  
Line Of Sight ◽  
Neutron Guide ◽  
General Relevance ◽  
Spallation Source ◽  
Neutron Guides

We describe a systematic approach for the design of long, ballistic cold, and thermal neutron guides for the European Spallation Source (ESS). The guides investigated in this work are 170 m long and are required to have a narrowing point with room for a pulse shaping chopper placed 6 m from the moderator. In addition, most guides avoid line-of-sight from the moderator to the sample. The guides are optimized in order to find a reasonable trade-off between neutronics performance and construction price. The geometries simulated are closely related to the thermal-neutron multi-length-scale diffractometer HEIMDAL and the cold-neutron multi-analyser spectrometer BIFROST. For the cold-neutron guide an inexpensive solution was found that maintains good transport properties, while avoiding line-of-sight. However, for the thermal-neutron guide the losses when avoiding line-of-sight are large and it seems a good choice to stay in line-of-sight, even though this will increase both the shielding costs and fast-neutron background. The results are of general relevance for the understanding of the relation between transport, background, and price of long neutron guides.

scholarly journals Optimization of the Guide Design of MIRACLES, the Neutron Time-of-Flight Backscattering Spectrometer at the European Spallation Source

2021 ◽  
Vol 6 (1) ◽  
pp. 3
Author(s):  
Félix J. Villacorta ◽  
Damián Martín Rodríguez ◽  
Mads Bertelsen ◽  
Heloisa N. Bordallo
Keyword(s):  
Pulse Shaping ◽  
Dynamic Range ◽  
Inelastic Neutron Scattering ◽  
Time Of Flight ◽  
Inelastic Neutron ◽  
Neutron Guide ◽  
Cold Neutrons ◽  
Sample Position ◽  
Spallation Source ◽  
Flux Increase

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.

Instrumentation for Neutron Scattering at the National Institute of Standards and Technology

1994 ◽  
Vol 376 ◽  
Author(s):  
W.A. Kamitakahara ◽  
Jj. Rush ◽  
J.M. Rowe ◽  
Hj. Prask
Keyword(s):  
Neutron Scattering ◽  
Thermal Neutron ◽  
Neutron Beam ◽  
Cold Neutron ◽  
Liquid Hydrogen ◽  
Research Facility ◽  
Cold Source ◽  
Wide Range ◽  
Neutron Guides ◽  
The U.S

ABSTRACTThe National Institute of Standards and Technology (NIST) offers a wide range of neutron beam instruments to the U.S. community. Many of these are of recent construction, and are located in the Cold Neutron Research Facility, a large guide hall with fifteen experimental stations on seven neutron guides. A new liquid hydrogen cold source is being installed. Thermal neutron instruments in the reactor confinement are to be upgraded over the next few years.

scholarly journals ANNI – A pulsed cold neutron beam facility for particle physics at the ESS

2019 ◽  
Vol 219 ◽  
pp. 10003 ◽  
Author(s):  
Torsten Soldner ◽  
Hartmut Abele ◽  
Gertrud Konrad ◽  
Bastian Märkisch ◽  
Florian M. Piegsa ◽  
...  
Keyword(s):  
Neutron Beam ◽  
Particle Physics ◽  
Cold Neutron ◽  
Expected Gain ◽  
Cold Neutron Beam ◽  
Systematic Effects ◽  
Present Design ◽  
Spallation Source ◽  
Pulse Structure ◽  
And Performance

Pulsed beams have tremendous advantages for precision experiments with cold neutrons. In order to minimise and measure systematic effects, they are used at continuous sources in spite of the related substantial decrease in intensity. At the European Spallation Source ESS these experiments will profit from the pulse structure of the source and its 50 times higher peak brightness compared to the most intense reactor facilities, making novel concepts feasible. Therefore, the cold neutron beam facility for particle physics ANNI was proposed as part of the ESS instrument suite. The proposed design has been re-optimised to take into account the present ESS cold moderator layout. We present design considerations, the optimised instrument parameters and performance, and expected gain factors for several reference experiments.

Curved neutron guide of the cold neutron disk-chopper spectrometer at J-PARC

2008 ◽  
Vol 16 (3) ◽  
pp. 81-86 ◽  
Author(s):  
R. Kajimoto ◽  
K. Nakajima ◽  
M. Nakamura ◽  
T. Osakabe ◽  
T. J. Sato ◽  
...  
Keyword(s):  
Cold Neutron ◽  
Neutron Guide

Optimisation of a thermal neutron guide by Monte Carlo simulations

2000 ◽  
Vol 283 (4) ◽  
pp. 436-438 ◽  
Author(s):  
G.R.J Artus ◽  
F Frey ◽  
W Scherer
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Thermal Neutron ◽  
Neutron Guide

scholarly journals MBGEM: a stack of borated GEM detector for high efficiency thermal neutron detection

2021 ◽  
Vol 136 (7) ◽  
Author(s):  
A. Muraro ◽  
G. Claps ◽  
G. Croci ◽  
C. C. Lai ◽  
R. De Oliveira ◽  
...  
Keyword(s):  
Thermal Neutron ◽  
Neutron Detector ◽  
Large Scale ◽  
High Efficiency ◽  
Detection Efficiency ◽  
Neutron Spallation Source ◽  
High Detection Efficiency ◽  
Thermal Neutron Detector ◽  
Spallation Source ◽  
Alpha 7

AbstractA new position-sensitive thermal neutron detector based on boron-coated converters has been developed as an alternative to today’s standard $$^3\mathrm{He}$$ 3 He -based technology for application to thermal neutron scattering. The key elements of the development are the boron-coated GEM foils (Sauli in Nucl Instrum Methods Phys Res Sect A Accel Spectrom Detect Assoc Equip 386:531, 1997) that are used as a multi-layer neutron converter via the $$^{10}\mathrm{B}(n,\alpha )^7\mathrm{Li}$$ 10 B ( n , α ) 7 Li reaction together with an efficient collection of the produced secondary electrons. This paper reports the test performed on a 3 layers converter prototype coupled to a GEMPix detector (Murtas in Radiat Meas 138:106421, 2020), carried out in order to study the possibility to produce a large-scale multi-layer neutron detector capable to reach high detection efficiency with high spatial resolution and able to sustain the high neutron flux expected in the new neutron spallation source under development like the ESS.

scholarly journals Conceptual Design Report, A Replacement Cold Neutron Guide System for HFIR

2020 ◽  
Author(s):  
Matthew Frost ◽  
Garrett Granroth ◽  
Thomas Huegle ◽  
Richard Ibberson ◽  
Lee Robertson
Keyword(s):  
Conceptual Design ◽  
Cold Neutron ◽  
Neutron Guide ◽  
Guide System ◽  
Conceptual Design Report

Neutron Spectrometer Used for Nondestructive Detection of Materials Deep Stress: Status of the Project

2016 ◽  
Vol 723 ◽  
pp. 130-135
Author(s):  
Yang Li ◽  
Yun Xin Wu ◽  
Hai Gong ◽  
Qun Ming Li
Keyword(s):  
Residual Stresses ◽  
Neutron Scattering ◽  
Thermal Neutron ◽  
Research Reactor ◽  
Neutron Guide ◽  
Stress Detection ◽  
Neutron Spectrometer ◽  
Precise Method ◽  
Under Construction ◽  
And Control

The difficulty of materials inner stress detection is a barrier to engineering equipment research. And neutron scattering techniques is now recognized as the most precise method for mapping of inner residual stresses in materials or even components. Nine neutron scattering spectrometers of China Advanced Research Reactor (CARR) has been carried out thermal debugging, another five spectrometers are under construction. The thermal neutron spectrometer mentioned in this paper is one of the five spectrometers to be built in the neutron guide hall. It is anticipated that the instrument will be accomplished and available to users in 2018. The design of the hardware is mentioned. The function of positioning and control of the spectrometer can be carried out by the software. This spectrometer is available for material scientists to accomplish further studies with its function, and provides a good reference for spectrometer designing experts.

Sign in / Sign up

Export Citation Format

Share Document