Equipment: MRI: Track #1 Acquisition of electron spin resonance spectrometer for radiation exposure dating

该主要研究仪器项目（MRI）支持购买电子自旋共振（ESR）光谱仪和独立x射线辐照器，用于内华达州里诺沙漠研究所（DRI）的地质和考古年代测定。ESR定年法是一系列“辐射暴露”定年法中的一种，它依赖于材料中储存的累积辐射剂量来确定其年龄。该家族的其他方法包括光激发发光（OSL）和热释光（TL），这两种方法目前都得到了DRI的支持。ESR测年与OSL和TL相比有两个主要优势：(1)该方法可以应用于更广泛的材料，包括但不限于石英、牙釉质和碳酸盐；(2)其适用的测年范围跨越了过去200万年，远远超过了发光测年方法的能力。重要的是，这台ESR光谱仪的收购将使DRI成为北美仅有的两家拥有ESR测年能力的机构之一，并将大大增加研究合作和创新的机会。这种新仪器还将加强DRI在本科生和研究生研究培训方面的良好记录，并为吸引和培训来自北美各地的地质年代学家提供新的机会。收购Bruker EMXmicro连续波x波段ESR光谱仪和台式x射线辐照仪（x射线剂量ESR版本，Freiberg Instruments）将使许多多学科研究项目能够解决第四纪期间各种沉积环境和时间尺度的问题。这些项目包括：(1)确定新墨西哥州里约热内卢Grande valley第四纪阶地形成的时间尺度和驱动因素；(2)基于湖壳改进放射性碳年代学；(3)大盆地中晚更新世洪积湖的古水文模拟；(4)约束大盆地的长期滑动速率和伸展时间；(5)利用配对ESR和发光分析重建南极沉积物源。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This Major Research Instrumentation Program (MRI) award supports the acquisition of an electron spin resonance (ESR) spectrometer and standalone X-ray irradiator that will be used for geological and archaeological dating at the Desert Research Institute (DRI) in Reno, Nevada. ESR dating is one of a family of ‘radiation exposure’ dating methods that relies on the accumulated radiation dose stored in a material to determine its age. Other methods in the family include optically stimulated luminescence (OSL) and thermoluminescence (TL), both of which are currently supported at DRI. ESR dating offers two main advantages over OSL and TL: (1) the method can be applied to a much wider range of materials including, but not limited to, quartz, tooth enamel, and carbonates, and (2) its applicable dating range spans the last 2 million years, far surpassing the capabilities of luminescence dating methods. Importantly, acquisition of this ESR spectrometer will establish DRI as one of only two North American institutions with ESR dating capabilities and will vastly increase the number of opportunities for research collaboration and innovation. This new instrumentation will also enhance DRI’s strong track record of undergraduate and graduate student research training and provide new opportunities to attract and train geochronologists from across North America.Acquisition of a Bruker EMXmicro continuous wave X-band ESR spectrometer and benchtop X-ray irradiator (X-ray Dose ESR Version, Freiberg Instruments) will enable a number of multi-disciplinary research projects that address questions spanning a variety of depositional environments and timescales over the Quaternary period. Some of these projects include: (1) defining the timescales and drivers of Quaternary terrace formations along the Rio Grande valley, New Mexico, (2) refining radiocarbon chronologies based on lacustrine shells, (3) paleohydrological modeling of mid- to late- Pleistocene pluvial lakes in the Great Basin, (4) constraining long-term slip rates and the timing of extension in the Great Basin, and (5) reconstructing Antarctic sedimentary provenance using paired ESR and luminescence analyses.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.