Instrument performance on the short and long pulse second SNS target stations

Zhao, Jinkui; Herwig, Kenneth W; Robertson, Lee; Gallmeier, Franz X; Riemer, Bernie

doi:10.1063/1.4823778

Title: Instrument performance on the short and long pulse second SNS target stations

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Abstract

In this work, we investigate the effect of neutron moderator dimensions on the performance of neutron scattering instruments at the Spallation Neutron Source. In a recent study of the planned second target station at the Spallation Neutron Source (SNS) facility [1,2], we have found that the dimensions of a moderator play a significant role in determining its surface brightness. A smaller moderator may be significantly brighter for a smaller viewing area [4]. One of the immediate implications of this finding is that for modern neutron scattering instrument designs, moderator dimensions and brightness have to be incorporated as an integrated optimization parameter. Here, we establish a strategy of matching neutron scattering instruments with moderators using analytical and Monte Carlo techniques. In order to simplify our treatment, we group the instruments into two broad categories, those with natural collimation and those that use neutron guide systems. We found that the cross-sections of the sample and the neutron guide, respectively, are the deciding factors for choosing the moderator. Beam divergence plays no role as long as it is within the reach of practical constraints. Namely, the required divergence is not too large for the guide or sample to be located close enough tomore »« less

Authors:

Zhao, Jinkui ^[1]; Herwig, Kenneth W ^[1]; Robertson, Lee ^[1]; Gallmeier, Franz X ^[1]; Riemer, Bernie ^[1]

ORNL

Publication Date:: Tue Jan 01 00:00:00 EST 2013

Research Org.:: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)

Sponsoring Org.:: USDOE Office of Science (SC)

OSTI Identifier:: 1095668

DOE Contract Number:: DE-AC05-00OR22725

Resource Type:: Journal Article

Journal Name:: Review of Scientific Instruments

Additional Journal Information:: Journal Volume: 84; Journal Issue: 10; Journal ID: ISSN 0034-6748

Country of Publication:: United States

Language:: English

Citation Formats


                    Zhao, Jinkui, Herwig, Kenneth W, Robertson, Lee, Gallmeier, Franz X, and Riemer, Bernie. Instrument performance on the short and long pulse second SNS target stations.  United States: N. p., 2013. 
        Web.  doi:10.1063/1.4823778.

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                    Zhao, Jinkui, Herwig, Kenneth W, Robertson, Lee, Gallmeier, Franz X, & Riemer, Bernie. Instrument performance on the short and long pulse second SNS target stations.  United States.  https://doi.org/10.1063/1.4823778

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                    Zhao, Jinkui, Herwig, Kenneth W, Robertson, Lee, Gallmeier, Franz X, and Riemer, Bernie. 2013.  
        "Instrument performance on the short and long pulse second SNS target stations".  United States.  https://doi.org/10.1063/1.4823778.

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@article{osti_1095668,

  title        = {Instrument performance on the short and long pulse second SNS target stations},

  author       = {Zhao, Jinkui and Herwig, Kenneth W and Robertson, Lee and Gallmeier, Franz X and Riemer, Bernie},

  abstractNote = {In this work, we investigate the effect of neutron moderator dimensions on the performance of neutron scattering instruments at the Spallation Neutron Source. In a recent study of the planned second target station at the Spallation Neutron Source (SNS) facility [1,2], we have found that the dimensions of a moderator play a significant role in determining its surface brightness. A smaller moderator may be significantly brighter for a smaller viewing area [4]. One of the immediate implications of this finding is that for modern neutron scattering instrument designs, moderator dimensions and brightness have to be incorporated as an integrated optimization parameter. Here, we establish a strategy of matching neutron scattering instruments with moderators using analytical and Monte Carlo techniques. In order to simplify our treatment, we group the instruments into two broad categories, those with natural collimation and those that use neutron guide systems. We found that the cross-sections of the sample and the neutron guide, respectively, are the deciding factors for choosing the moderator. Beam divergence plays no role as long as it is within the reach of practical constraints. Namely, the required divergence is not too large for the guide or sample to be located close enough to the moderator on an actual spallation source.},

  doi          = {10.1063/1.4823778},

  url          = {https://www.osti.gov/biblio/1095668},
  journal      = {Review of Scientific Instruments},

  issn         = {0034-6748},

  number       = 10,

  volume       = 84,

  place        = {United States},

  year         = {Tue Jan 01 00:00:00 EST 2013},

  month        = {Tue Jan 01 00:00:00 EST 2013}

}

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