Development of High Intensity Cold Neutron Spectrometer with Multichannel Analyzer

多道分析仪高强度冷中子谱仪的研制

• 批准号: 0116585
• 负责人: Collin Broholm
• 金额: --
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-01 至 2008-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0116585&HistoricalAwards=false
• 关键词: Development; Intensity; Cold; Neutron; Spectrometer

This award from the Major Research Instrumentation program to Johns Hopkins University supports the development of a Multi Analyzer Crystal Spectrometer (MACS) for cold neutron spectroscopy. MACS will have two orders of magnitude greater sensitivity than current instrumentation. Located at the NIST cold neutron source, the instrument uses focusing Bragg optics to produce the most intense cold neutron beam worldwide (f108 n/cm2/s for DEi=0.2 meV). The detection system will energy-analyze neutrons scattered into a solid angle more than an order of magnitude greater than conventional instrumentation. The goal of the MACS project is greater insight into nano-scale dynamic phenomena in materials science. It will expand the scope for inelastic neutron scattering from a powerful specialized technique to a versatile probe of dynamic correlations in a wide range of condensed matter. Research enabled by MACS includes direct measurements of interactions in magnetic thin films, determination of spin density wave structure in organic metals, elucidation of spin and charge polarons in oxides, studies of dynamic correlations at pressure and field driven quantum phase transitions, determination of order parameters in weak broken symmetry phases, and studies of impurity generated composite spin. With a different "foot print" in Q-E phase space, MACS will complement the advanced pulsed neutron instrumentation now being developed for the Spallation Neutron Source. The project will provide undergraduate, graduate, and postdoctoral education to produce scientists that are knowledgeable about cutting-edge neutron scattering instrumentation and its use in materials research. Inelastic neutron scattering is a unique probe of nano-scale dynamic phenomena in solids. The experiments are crucial for determining the interactions and understanding the cooperative phenomena that govern the solid state. Unfortunately, current instrumentation limits applicability to cases where large crystalline samples are available. This award from the Major Research Instrumentation program to Johns Hopkins University supports the development of a Multi Analyzer Crystal Spectrometer (MACS) for neutron scattering at the NIST Center for Neutron Research. Through its intense incident beam and its multiplexing detection system, MACS will transform inelastic neutron scattering from a powerful, specialized technique, to a versatile probe of nano-scale dynamics in solids. Research enabled by MACS, includes direct measurements of interactions in magnetic thin films, determination of spin density wave structure in organic metals, elucidation of spin and charge polarons in oxides, and analysis of impurity generated composite spin. Graduate and undergraduate students will be involved, and a post-doc will join for commissioning. The project thus educates scientists who are knowledgeable about cutting-edge neutron scattering instrumentation and its use in materials science. With a different data acquisition protocol, MACS will be complementary to instrumentation now being developed for the Spallation Neutron Source. The capability to probe excitations over a wide range of energies at the SNS and then zoom in using MACS will help scientists develop new materials for the twenty first century.

约翰霍普金斯大学的主要研究仪器计划的这一奖项支持冷中子光谱学的多分析仪晶体光谱仪（MACS）的开发。MACS的灵敏度将比目前的仪器高两个数量级。 该仪器位于NIST冷中子源，使用聚焦布拉格光学器件产生世界上最强的冷中子束（f108 n/cm 2/s，DEi=0.2 meV）。该探测系统将对散射到立体角中的中子进行能量分析，比传统仪器大一个数量级以上。 MACS项目的目标是更深入地了解材料科学中的纳米级动态现象。它将扩展非弹性中子散射的范围，从一个强大的专门技术，以一个多功能的探测器的动态相关性在广泛的凝聚态物质。 MACS的研究包括直接测量磁性薄膜中的相互作用，确定有机金属中的自旋密度波结构，阐明氧化物中的自旋和电荷极化子，研究压力和场驱动量子相变的动态相关性，确定弱对称性破缺相的序参数，以及研究杂质产生的复合自旋。MACS在Q-E相空间中有着不同的“足迹”，它将补充目前正在为Spiritus中子源开发的先进脉冲中子仪器。该项目将提供本科生，研究生和博士后教育，以培养了解尖端中子散射仪器及其在材料研究中的应用的科学家。非弹性中子散射是研究固体中纳米尺度动力学现象的一种独特方法。这些实验对于确定相互作用和理解支配固态的合作现象至关重要。不幸的是，目前的仪器限制了适用性的情况下，大的结晶样品是可用的。 约翰霍普金斯大学的主要研究仪器计划的这一奖项支持NIST中子研究中心开发用于中子散射的多分析仪晶体光谱仪（MACS）。通过其强烈的入射光束和多路复用检测系统，MACS将把非弹性中子散射从一种强大的专业技术转变为固体中纳米尺度动力学的多功能探针。MACS支持的研究包括直接测量磁性薄膜中的相互作用，确定有机金属中的自旋密度波结构，阐明氧化物中的自旋和电荷极化子，以及分析杂质产生的复合自旋。研究生和本科生将参与，博士后将加入委托。因此，该项目教育科学家谁是知识渊博的尖端中子散射仪器及其在材料科学中的使用。 MACS采用不同的数据采集协议，将与目前正在为Sputron中子源开发的仪器相辅相成。在SNS上探测各种能量的激发，然后使用MACS放大的能力将有助于科学家开发二十一世纪的新材料。