Sample Environment for Neutron Scattering at High and Low Temperatures at the McMaster Nuclear Reactor

这项研究工具和仪器拨款申请的目的是获得一种新的温控样品环境，使麦克马斯特核反应堆(MNR)的材料能够进行中子衍射研究。我们建议购买一台闭合循环低温恒温器，它将允许在异常广泛的温度动态范围内进行这些测量。这将使研究人员和他们的高素质人员能够在单一样品环境中研究从很低温度(T~2.7K)到很高温度(T~800K)的材料的结构和磁性。*随着2018年3月白垩河NRU反应堆关闭，MNR成为加拿大唯一用于材料研究的中子束来源。中子是研究材料性质的宝贵工具，它揭示了从原子尺度到介观尺度(几十纳米)关于原子和磁性结构的独特和详细的信息。MNR目前拥有两条中子散射光束线：麦克马斯特准直衍射仪(MAD)和麦克马斯特小角中子散射光束线(MacSANS，将于2019年夏天投入使用)。这两条光束线为加拿大的中子材料研究提供了独特的能力，并有能力为来自全国各地的科学家提供服务，从物理和化学到生物、环境科学和工程等领域。*为了充分利用这些独特的能力，我们需要复杂的样本环境，使我们能够研究感兴趣的材料对各种条件的反应，从低温(量子力学可以产生奇异的和不寻常的物质状态)到远高于室温的高温(材料通常表现出丰富的结构相变，商业和工业感兴趣的材料经常在那里找到它们的应用)。在新材料的物理和化学中的一些非常热门的研究领域，例如热电材料和多铁材料的研究，仅举两例，显示了需要在广泛的温度范围内进行衍射研究的现象。这种新的样品环境将允许在单一平台上跨此温度范围研究我们感兴趣的样品，从而避免从低温仪器更换为高温仪器的复杂情况，并在过程中节省宝贵的光束时间。这项RTI应用程序将资助从先进研究系统公司购买一个新的样品环境，该公司的工作温度范围为2.7K至800K。该建议的仪器与MAD和MacSANS中子衍射仪完全兼容，为在非常广泛的温度范围内对材料进行参数研究开辟了重要的新能力，并为加拿大材料研究人员带来了令人兴奋的新机会。**

The purpose of this Research Tools and Instruments grant application is to acquire a new temperature-controlled sample environment that will enable neutron diffraction studies of materials at the McMaster Nuclear Reactor (MNR). We propose to purchase a closed cycle cryostat which will allow these measurements over an unusually broad dynamic range in temperature. This will allow researchers and their highly qualified personnel to investigate the structural and magnetic properties of materials from very low temperature (T ~ 2.7 K) to very high temperature (T ~ 800 K) in a single sample environment. ******Following the closure of the NRU reactor at Chalk River in March of 2018, the MNR became Canada's only source of neutron beams for materials research. Neutrons are an invaluable tool for studying the properties of materials, revealing unique and detailed information about both atomic and magnetic structure from the atomic scale to the mesoscale (tens of nanometers). The MNR is currently home to two neutron scattering beamlines: the McMaster Alignment Diffractometer (MAD) and the McMaster Small Angle Neutron Scattering beamline (MacSANS, which will become operational in Summer 2019). These two beamlines offer unique capabilities for materials research with neutrons in Canada, and have the capacity to serve scientists from across the country, in fields ranging from Physics and Chemistry, to Biology, Environmental Sciences, and Engineering. ******In order to fully exploit these unique capabilities, we require sophisticated sample environments which will allow us to study how materials of interest respond to conditions ranging from low temperatures (where quantum mechanics can give rise to exotic and unusual states of matter) to high temperatures well above room temperature (and where materials typically display a wealth of structural phase transitions and where materials of commercial and industrial interest often find their applications). A number of very topical research areas in the physics and chemistry of new materials, such as the study of thermoelectric materials and multiferroic materials, to name just two, display phenomena that requires diffraction studies across a broad range of temperatures. This new sample environment will allow our samples of interest to be studied across this range of temperature on a single platform, thus avoiding the complications of changing from a low temperature apparatus to a high temperature apparatus, and saving valuable beam time in the process. This RTI application will fund the purchase of a new sample environment from Advanced Research Systems, Inc. which has an operating temperature range of 2.7 K to 800 K. This proposed apparatus is fully compatible with both the MAD and MacSANS neutron diffraction instruments, opening up important new capabilities for parametric studies of materials over a very broad range of temperatures, and exciting new opportunities for Canadian materials researchers.**