skip to main content

Title: Analysis and simulation of a small-angle neutron scattering instrument on a 1 MW long pulse spallation source

We studied the design and performance of a small-angle neutron scattering (SANS) instrument for a proposed 1 MW, 60 Hz long pulsed spallation source at the Los Alamos Neutron Science Center (LANSCE). An analysis of the effects of source characteristics and chopper performance combined with instrument simulations using the LANSCE Monte Carlo instrument simulations package shows that the T{sub 0} chopper should be no more than 5 m from the source with the frame overlap and frame definition choppers at 5.6 and greater than 7 m, respectively. The study showed that an optimal pulse structure has an exponential decaying tail with {tau} {approx} 750 {mu}s. The Monte Carlo simulations were used to optimize the LPSS SANS, showing that an optimal length is 18 m. The simulations show that an instrument with variable length is best to match the needs of a given measurement. The performance of the optimized LPSS instrument was found to be comparable with present world standard instruments.
Authors:
; ;
Publication Date:
OSTI Identifier:
464176
Report Number(s):
LA-UR--97-548; CONF-9606223--6
ON: DE97004703; TRN: 97:009992
DOE Contract Number:
W-7405-ENG-36
Resource Type:
Conference
Resource Relation:
Conference: 5. world conference on neutron radiography, Berlin (Germany), 17-20 Jun 1996; Other Information: PBD: 1996
Research Org:
Los Alamos National Lab., NM (United States)
Sponsoring Org:
USDOE Assistant Secretary for Human Resources and Administration, Washington, DC (United States)
Country of Publication:
United States
Language:
English
Subject:
44 INSTRUMENTATION, INCLUDING NUCLEAR AND PARTICLE DETECTORS; 07 ISOTOPE AND RADIATION SOURCE TECHNOLOGY; NEUTRON DETECTORS; SMALL ANGLE SCATTERING; DESIGN; NEUTRON SOURCES; NEUTRON DETECTION; PULSED NEUTRON TECHNIQUES; MONTE CARLO METHOD