SEQUOIA: A Newly Operating Chopper Spectrometer at the SNS
- ORNL
- McMaster University
A fine resolution chopper spectrometer (SEQUOIA) recently received first neutronsat the SNS. The commissioning phase of the instrument is underway. SEQUOIA is designedto utilize neutrons of an incident energy (Ei) between 10-2000 meV. A monochromatic beamis provided on a sample, 20 m from the decoupled ambient temperature H2O moderator, byfiltering the white beam with a Fermi chopper located 18 m from the source. After interactingwith the sample, neutrons are detected by an array of 3He linear position sensitive tubes locatedon a vertical cylinder with a radius of 5.5 m. This contribution presents current results from thecommissioning experiments and compares SEQUOIA’s actual and predicted performance. Thesecommissioning experiments include characterization of the beam by monitors, determination ofthe chopper phase offsets, and runs with V and C4H2I2S. The predicted performance is providedby analytical calculations and Monte Carlo simulations.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1001279
- Country of Publication:
- United States
- Language:
- English
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