Mission Statement

HYSPEC is a versatile spectrometer that allows for ground-breaking investigations of the low-energy, atomic-scale dynamical properties of crystalline solids. Its Bragg focusing optics makes it well suited for measurement of excitations in small single-crystal specimens in a wide range of ancillary sample environments. Full or partial neutron polarization analysis can be deployed to provide unambiguous separation of nuclear and magnetic scattering.

Instrument Description

Developed by a team from leading U.S. universities and national laboratories and an international group of neutron scattering experts, HYPSEC is a new concept in high-flux inelastic neutron spectrometry. It combines the time-of-flight technique used at pulsed sources, such as SNS, with the advantages of crystal spectrometers that use continuous neutrons. The incident neutron beam is monochromated using a Fermi chopper and is then focused by Bragg scattering onto the sample position by either a highly oriented pyrolitic graphite (unpolarized) or a Heusler (polarized) crystal array. Neutrons are detected in a bank of position-sensitive detector tubes that can be positioned over a wide range of scattering angles about the sample axis. The combination of Fermi chopper and Bragg focusing optics, plus a position-sensitive detector bank, leads to a highly flexible instrument in which the energy and wave vector resolution can be independently varied by nearly an order of magnitude. The region around the sample position is designed to accommodate polarization analysis. Two methods of analysing the polarization state of the scattered beam are in development: an in-house designed wide-angle quartz 3He cell to be placed in the uniform magnetic field electromagnet system, and an array of polarizing supermirrors with an m=3 polarizer coating (FeCoV) designed and constructed at the Paul-Scherrer Institut.


  • Unconventional superconductors
  • Lattice and magnetic dynamics in functional materials: ferroelectrics, memory shape alloys, magnetoresistive and magnetocaloric materials
  • Excitations in geometrically frustrated magnets
  • Phase transitions
  • Itinerant Magnets
  • Spin and lattice dynamics in nonostructures
  • Exotic ground states in quantum magnets
  • Quantum critical phenomena


ModeratorCoupled cryogenic hydrogen
Source – Fermi chopper distance37.2 m
Chopper – smaple distance3.2 m
Sample – detector distance4.5 m
Focusing crystals to sample distance1.4 — 1.8m
Incident energy range3.6 — 60 meV
Resolution (elastic scattering)2 — 20% Ei
Detector coverage horizontal2° — 135°
Detector coverage vertical-7° — 7°
Minimum detector angle
Beam Size6 cm x 4 cm unfocused, or 3 cm x 3 cm focused, with fully adjustable motorized slits in the horizontal and vertical directions


HYSPEC is available to users for experiments with unpolarized neutrons. Commissioning for polarized neutrons is under way. Please contact Barry Winn to discuss the feasibility of your experiment before submitting a proposal. More information about writing a proposal.