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NG7 PHADES
Instrument purpose
To serve as a highly flexible neutron beam test station for development of 3He neutron spin filters, prototyping of new instrument components, detector development, and precise alignment of single crystal samples.
The NCNR Advantage
- Rapid-Response Development: Instruments in the NCNR user program are highly oversubscribed and are tightly scheduled, frequently many months in advance. Time on PHADES is typically allocated for short-duration tests, calibrations, and alignments, and is available on short notice. This makes PHADES an ideal location for researchers to validate complex sample structures and test new instrument technologies ahead of their experiments.
- Specialized Polarized 3He Infrastructure: As the primary development station for the NCNR's spin-filter program, it offers unique capabilities for development and testing of novel 3He spin filters under real-world beam conditions.
Research Domains
- Instrument Development: Testing of technologies including polarization devices, detectors, neutron optics, choppers, and velocity selectors.
- Crystallography: Preliminary alignment and quality assessment of single crystals (HKL mapping).
What You Can Measure
- Crystal Mosaicity: Precise measurement of the angular spread of crystal planes.
- Detector Response: Spatial and temporal resolution mapping of new detector prototypes.
- Polarization Decay: Long-term monitoring of 3He spin relaxation in the presence of a neutron beam.
Technical Specifications
| Parameter | Specification |
|---|---|
| Source Type | Cold Neutron Guide (NG7) |
| Monochromator | Pyrolytic Graphite (PG 002), take-off angle 75° |
| Wavelength (λ) | 4.10 Å (Fixed monochromatic) |
| Energy (E) | 4.87 meV |
| Neutron Flux | ~ 4 x 106 n/cm2/s (Post-2026 upgrade) |
| Angular Range (2θ) | -7° to +150° |
| Max Sample Load | 100 kg (on variable-height optical table) |
Specialized Sample Environments
PHADES has flexible instrument features that facilitate a wide range of sample environments
- Variable Optical Table: A 25 cm x 75 cm optical table that can be adjusted in height or removed entirely to accommodate larger sample environments.
- Huber Goniometer: Standard 4-circle goniometer with ± 22° tilt and ± 10 mm translation for precise crystal positioning.
- Auxiliary Utilities: Integrated air and water lines to support high-power electromagnets or specialized cooling systems.
- Flexible Flight Path: A secondary spectrometer that can translate over 1 m, providing space for oversized prototype hardware.
Expertise & Support
- Infrastructure Support: The PHADES instrument responsible works with the NCNR 3He spin filter and detector teams, providing access to core technology developers.
- Crystal Alignment Assistance: On-site scientists provide specialized HKL alignment software and hands-on training for users prepping for diffraction experiments.
- Prototyping Collaboration: The station is often used for joint research projects between NIST and academic partners to develop "first-of-its-kind" neutron optical devices.
Access & Resources
Planning Tools
Live Data
Submit a Proposal
Instrument Contacts
Created June 9, 2026, Updated August 27, 2026