Development of High Intensity Cold Neutron Spectrometer with Multichannel Analyzer

该奖项由主要研究仪器项目授予约翰霍普金斯大学，用于支持冷中子光谱分析多分析器晶体光谱仪(MACS)的开发。Mac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装置产生世界上最强的冷中子束(F108n/cm2/S，DEI=0.2 MeV)。探测系统将对散布到立体角度的中子进行能量分析，比传统仪器大一个数量级。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。它将把非弹性中子散射的范围从一种强大的专门技术扩展到一种通用的探测器，可以在大范围的凝聚态物质中进行动态关联。由MACS实现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，研究压力下的动态关联和场驱动的量子相变，确定弱破缺对称相中的有序参数，以及研究杂质产生的复合自旋。由于在Q-E相空间有不同的“足迹”，MACS将补充目前正在为散裂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，以培养出精通尖端中子散射仪器及其在材料研究中使用的科学家。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。遗憾的是，目前的仪器设备仅适用于有大块晶体样品的情况。该奖项由主要研究仪器项目授予约翰霍普金斯大学，用于支持NIST中子研究中心开发用于中子散射的多分析器晶体光谱仪(MACS)。通过其强入射光束和多路复用探测系统，MACS将把非弹性中子散射从一种强大的专门技术转变为一种多功能的固体纳米级动力学探测器。由MACS促成的研究，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。将涉及研究生和本科生，一名博士后将加入委托。因此，该项目培养了了解尖端中子散射仪器及其在材料科学中的应用的科学家。有了不同的数据采集协议，Mac将成为目前正在为散裂中子源开发的仪器的补充。在SNS上探测各种能量的激发，然后使用Mac放大的能力，将帮助科学家开发21世纪的新材料。

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.