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Updated: Jan 27, 2026
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Measuring the Time-Evolution of Nanoscale Materials with Stopped-Flow and Small-Angle Neutron Scattering
Published on: August 6, 2021
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Upgrade to the MAPS neutron time-of-flight chopper spectrometer
R A Ewings1, J R Stewart1, T G Perring1
1ISIS Pulsed Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, United Kingdom.
The Review of Scientific Instruments
|April 1, 2019
Summary
The Multi-Angle Particle Spectrometer (MAPS) chopper spectrometer was upgraded to enhance neutron flux and reduce background. Performance exceeds expectations, significantly improving scientific capabilities.
Area of Science:
- Neutron scattering
- Spectroscopy
- Materials science
Background:
- The MAPS spectrometer at ISIS has operated since 1999.
- Its detector technology influenced global chopper spectrometer design.
- Operational experience informed the need for upgrades.
Purpose of the Study:
- To detail three parallel upgrades to the MAPS instrument.
- To assess the impact of these upgrades on instrument performance.
- To demonstrate enhanced scientific capabilities through commissioning examples.
Main Methods:
- Replacement of primary beamline collimation with supermirror neutron guides.
- Installation of a disk chopper.
- Modification of water moderator poisoning geometry.
- Comparison of pre- and post-upgrade performance with Monte Carlo simulations.
Main Results:
- Substantial increase in neutron flux.
- More flexible use of repetition rate multiplication.
- Reduction in background noise.
- Instrument performance meets or exceeds simulation expectations.
Conclusions:
- The upgrades significantly enhance the MAPS instrument's performance.
- Improved flux and reduced background expand scientific possibilities.
- The upgraded MAPS spectrometer offers advanced capabilities for research.
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