The use of chopper spectrometers for cold-to-epithermal neutron scattering at IPNS

Conference · Wed Sep 01 00:00:00 EDT 1993

OSTI ID:10176611

Loong, C K; Donley, L I; Ostrowski, G E; Kleb, R; Hammonds, J P; Soderholm, L; Takahashi, S

A multi-detector chopper spectrometer enables measurements of the scattering function S(Q,E) to be made over a wide range of momentum and energy transfer (Q,E). The application of pulsed-source chopper spectrometers for inelastic measurements at thermal and epithermal energies (50 meV < E < 1000 meV) is well known. Recently at IPNS, we have extended the energy-transfer region down to about 0.5 meV with a resolution of the order of 150 {mu}eV. It is made possible by utilizing the cold-neutron incident spectrum of the 100 K methane moderator in conjunction with a dual beryllium-body rotor system. Neutron incident energies can be changed efficiently over the 4 to 1000 meV region while maintaining an undisturbed sample environment. We describe the operation of the IPNS chopper spectrometers (HRMECS and LRMECS), the instrumental resolution and the background-suppression performance. The capability of measuring inelastic features from 0.5 to 100 meV with an energy resolution of {Delta}E/E{sub 0} = 2.5% is demonstrated by experimental results of crystal-field excitation spectra of a high-Tc superconductor ErBa{sub 2}Cu{sub 3}O{sub 7}. Preliminary data of quasielastic scattering from a room-temperature molten salt AlCl{sub 3}-EMIC are presented.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 10176611
• Report Number(s): ANL/IPNS/CP-78912; CONF-9305177-10; ON: DE93017798
• Resource Relation: Conference: 12. International collaboration of advanced neutron sources meeting (ICANS),Abingdon (United Kingdom),24-28 May 1993; Other Information: PBD: [1993]
• Country of Publication: United States
• Language: English

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43 PARTICLE ACCELERATORS
75 CONDENSED MATTER PHYSICS
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46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
36 MATERIALS SCIENCE
IPNS-I SYNCHROTRON
NEUTRON SPECTROSCOPY
NEUTRON SPECTROMETERS
NEUTRON CHOPPERS
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HIGH-TC SUPERCONDUCTORS
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EXPERIMENTAL FACILITIES AND EQUIPMENT
NUCLEAR TECHNIQUES IN CONDENSED MATTER PHYSICS
NUCLEAR SPECTROSCOPIC INSTRUMENTATION
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