Resolution of time-of-flight small-angle neutron diffractometers

1987 ◽  
Vol 20 (4) ◽  
pp. 273-279 ◽  
Author(s):  
R. P. Hjelm
Keyword(s):  
Small Angle ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Time Of Flight ◽  
Simple Method ◽  
Neutron Diffractometer ◽  
Reduction Methods ◽  
Measurement Strategies ◽  
Pulsed Neutron ◽  
Pulsed Neutron Source

A simple method of calculating the resolution of small-angle neutron data from diffractometers which use time-of-flight techniques has been derived in terms of the variances of the time and spatial channels of the measurement. The method is used to calculate the resolution in scattering-vector space of scattering intensity from a simulated isotropic scatterer on the small-angle neutron diffractometer at the Intense Pulsed Neutron Source at Argonne National Laboratory. The effects of the various instrumental geometries, time-of-flight measurement strategies and data reduction methods that can be chosen by the experimenter are considered. It is found that the best resolution is obtained with weighted constant Δt/t time-of-flight data acquisition schemes, with the detector placed in the beam in such a way that the highest possible angular range is accessed.

The Time-of-Flight Small-Angle Neutron Diffractometer (SAD) at IPNS, Argonne National Laboratory

1997 ◽  
Vol 30 (3) ◽  
pp. 280-293 ◽  
Author(s):  
P. Thiyagarajan ◽  
J. E. Epperson ◽  
R. K. Crawford ◽  
J. M. Carpenter ◽  
T. E. Klippert ◽  
...  
Keyword(s):  
Small Angle ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Time Of Flight ◽  
Neutron Diffractometer

Correspondent's Report: The Intense Pulsed Neutron Source at Argonne National Laboratory

Neutron News ◽  
2004 ◽  
Vol 15 (3) ◽  
pp. 1-1
Author(s):  
Raymond Teller ◽  
James Richardson ◽  
John Carpenter
Keyword(s):  
Neutron Source ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Pulsed Neutron ◽  
Pulsed Neutron Source

Comparison of Small-Angle Neutron Scattering of δ' Precipitation in an Al–Li Alloy at a High-Flux Reactor and at a Pulsed-Neutron Source

1997 ◽  
Vol 30 (5) ◽  
pp. 602-606 ◽  
Author(s):  
G. Albertini ◽  
F. Carsughi ◽  
R. Coppola ◽  
R. K. Heenan ◽  
M. Stefanon
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Size Distribution Function ◽  
Data Sets ◽  
Flux Reactor ◽  
Average Size ◽  
Pulsed Neutron ◽  
Pulsed Neutron Source ◽  
Good Agreement

Two different small-angle neutron scattering (SANS) facilities, the D11 camera at the Institut Laue–Langevin (ILL, Grenoble, France) and the LOQ time-of-flight diffractometer at the Rutherford Appleton Laboratory (RAL, Didcot, Oxon, England), were used in the investigations of δ′-Al3Li precipitation at 463 K in Al–Li 3% alloy. The results obtained from the steady-state reactor and from the pulsed source by using two different data-acquisition techniques and two different procedures for data analysis are compared. The SANS curves for the same set of samples investigated using the two different instruments are in good agreement within the experimental uncertainties. A check was also made on the metallurgically relevant quantities, namely the average size and the size-distribution function of the δ′ precipitates at the various stages of the ageing process, obtained from the two sets of SANS curves by applying the same numerical method. Good agreement was found between the results from the two data sets.

scholarly journals Determination of an Effective Detector Position for Pulsed-Neutron-Source Alpha Measurement by Time-Dependent Monte Carlo Neutron Transport Simulations

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Sang Hoon Jang ◽  
Hyung Jin Shim
Keyword(s):  
Monte Carlo ◽  
Neutron Source ◽  
Neutron Transport ◽  
Signal Amplitude ◽  
Time Dependent ◽  
Convergence Time ◽  
Simple Method ◽  
Detector Position ◽  
Pulsed Neutron ◽  
Pulsed Neutron Source

A simple method using the time-dependent Monte Carlo (TDMC) neutron transport calculation is presented to determine an effective detector position for the prompt neutron decay constant (α) measurement through the pulsed-neutron-source (PNS) experiment. In the proposed method, the optimum detector position is searched by comparing amplitudes of detector signals at different positions when their α estimates by the slope fitting are converged. The developed method is applied to the Pb-Bi-zoned ADS experimental benchmark at Kyoto University Critical Assembly. The α convergence time estimated by the TDMC PNS simulation agrees well with the experimental results. The α convergence time map and the corresponding signal amplitude map predicted by the developed method show that polyethylene moderator regions adjacent to fuel region are better positions than other candidates for the PNS α measurement.

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