CAREER: Microscale Magnetic Devices for Next Generation Coherent X-Ray Sources

职业：用于下一代相干 X 射线源的微型磁性器件

• 批准号: 1350034
• 负责人: Robert Candler
• 金额: $ 40万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-02-01 至 2020-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1350034&HistoricalAwards=false
• 关键词: CAREER; Microscale; Magnetic; Devices; Next

Overview:This research will explore novel microscale magnetic undulators and quadrupole focusing magnets, enabling unprecedented scaling of x-ray free electron lasers (XFELs). XFELs accelerate a beam of electrons, focus the electron beam using quadrupoles, and convert the electron energy into coherent radiation using the magnetic field of an undulator. Coherent x-rays are used in phase contrast imaging, which offers 1000x better resolution compared to conventional x-ray imaging. Currently, there is only one XFEL in the United States. As such, only a handful of scientists can access it, and potentially high-impact experiments languish as they wait in line for access. Success of this project will lead to broadly accessible XFELs capable of atomic resolution imaging of non-crystalline samples and femtosecond imaging of dynamic processes. In this CAREER project, the PI plans to advance recent innovation in 3D micro-magnet fabrication that his group has pioneered to introduce a new generation of XFELs. To accomplish this overarching goal, the CAREER program will focus on achieving the following goals: (1) Investigate micro-electromagnet quadrupoles that push the limits of focusing for the electron beams used in XFELs. (2) Explore tunable microscale undulators that leverage scaling laws of their sinusoidal magnetic field to create high energy photons from lower energy electron beams. (3) Introduce a lab-scale XFEL that is 1000x smaller than existing XFELs and 1,000,000 times brighter than other coherent x-ray sources of its size.Intellectual Merit :This research will investigate the fundamental limits of electron beam focusing and high-energy photon generation. Conventional quadrupole focusing magnets and undulators are centimeter-scale and individually machined, often by hand. Recent advances in fabrication of 3D electromagnets enable parallel fabrication of large arrays of microscale quadrupoles and undulators. Design optimization techniques will be used to explore novel designs of quadrupoles that focus an electron beam even as the quadrupole is scaled to the limit of the electron beam spot size. Micro-undulators, smaller than any previously built, will access an operating regime where wakefield effects emerge, effects that have not been yet experimentally studied at this scale. If successful, this research will create a new state of the art in high-strength quadrupoles and intense-field, short-period undulators, which will be used to create an XFEL with unmatched brightness among small-scale light sources.Broader Impacts :The proposed research lays the foundation for a new generation of coherent x-ray sources that would revolutionize access to high-speed coherent x-ray imaging for science and medicine. For scientists, intense, ultra-short x-ray pulses have the potential to expand high-speed imaging of biological structure and processes. Imaging of protein structure would become possible for the 40% of proteins that cannot be crystallized, and dynamic processes at the scale of atomic motion could be understood. Also, a 1000x reduction in x-ray dosage made possible by XFELs would diminish concerns about the health effects of medical x-rays, such as for the nearly 40 million mammograms performed in the US each year. The PI plans to create an integrated research, education, and outreach program with the mission of recruiting and retaining underrepresented students in STEM. In collaboration with the CEED diversity center at UCLA, The PI will create a summer design challenge called "Design It, Print It!". In this 6-week design challenge, underrepresented (UR) K-12 students will design, 3D print, and test components to align quadrupoles and undulators. The K-12 students will be guided by an UR undergraduate engineering student, who will also participate in a paid research project during the school year. Four K-12 students and one undergraduate will participate per year, providing an in-depth research experience for twenty K-12 students and five undergraduates during the project. Each year, the PI and undergraduate will also visit the high schools of the K-12 participants to describe their work in 3D printing, reaching ~750 students over the life of the project.

概述：这项研究将探索新型的微观磁性失调器和四极聚焦的磁铁，从而实现X射线游离电子激光器（XFELS）的前所未有的缩放。 Xfels加速了电子束，使用四极杆将电子束聚焦，然后使用Undunator的磁场将电子能量转换为一致的辐射。相干X射线用于相对造影剂成像中，与常规X射线成像相比，该X射线可提供1000倍更好的分辨率。 目前，美国只有一个XFEL。因此，只有少数科学家才能访问它，并且在排队等候访问时可能会进行高影响力的实验。 该项目的成功将导致能够对非晶体样品的原子分辨率成像以及动态过程的飞秒成像进行原子分辨率成像。在这个职业项目中，PI计划推进他的小组率先引入新一代Xfels的3D微型制造的最新创新。为了实现这一总体目标，职业计划将重点放在实现以下目标上：（1）调查微电磁四倍体四倍体，以推动专注于Xfels中使用的电子光束的限制。 （2）探索可调的显微镜起伏器，以利用其正弦磁场的​​缩放定律，从而从低能电子束产生高能光子。 （3）引入一个比现有XFEL小的1000倍的实验室规模XFEL，比其他大小的其他连贯的X射线源高的1,000,000倍。IntlectualFure：这项研究将研究电子光束聚焦和高能量光子的基本限制一代。常规的四极聚焦的磁铁和悬垂器经常是手工的厘米尺度和单独加工的。制造3D电磁体的最新进展可以平行制造大量的显微镜四极杆和起伏器。设计优化技术将用于探索四倍孔的新型设计，即使将四极杆缩放到电子束斑点尺寸的极限，它们将聚焦电子束。 比以前建造的小型构造器将访问韦克菲尔德效果出现的操作制度，这些效果尚未在此规模上进行实验研究。 如果成功的话，这项研究将创造出高强度四极杆和强烈的，短周期的起伏器的新最新状态，将使用小型光源之间的XFEL创建具有无与伦比的亮度的XFEL。拟议的研究为新一代连贯的X射线资源奠定了基础，这些来源将彻底改变获得高速连贯的X射线成像的科学和医学。对于科学家而言，强烈的超短X射线脉冲具有扩展生物结构和过程的高速成像的潜力。对于无法结晶的40％的蛋白质，将有可能对蛋白质结构进行成像，并且可以理解原子运动规模的动态过程。同样，Xfels降低X射线剂量的1000倍将减少对医疗X射线健康影响的担忧，例如每年在美国执行的近4000万次乳房X光检查。 PI计划在STEM中招募和保留代表性不足的学生的任务，创建一项综合的研究，教育和外展计划。与加州大学洛杉矶分校（UCLA）的CEED多样性中心合作，PI将制定一个夏季设计挑战，称为“设计，打印！”。在这项为期6周的设计挑战中，代表性不足（UR）K-12学生将设计，3D打印和测试组件，以使四倍体和未驱动器对齐。 K-12学生将由UR本科工程专业的学生指导，他们还将在学年期间参加一个付费研究项目。该项目期间，四名K-12学生和1名本科生将每年参加，为20个K-12学生和五名本科生提供深入的研究经验。每年，PI和本科生还将访问K-12参与者的高中，描述他们在3D打印中的工作，在该项目的一生中达到750名学生。