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Jerry Seidler: What is X-ray Raman Scattering, and What Did Raman Have to Do With It?

X-ray Raman Scattering (XRS, often also called nonresonant inelastic x-ray scattering), is a hard x-ray alternative to soft x-ray NEXAFS. I'll review the basic physics, including the role of momentum transfer to tune selection rules. And I'll explain Raman's involvement, or lack thereof. References: https://journals.aps.org/prb/abstract/10.1103/PhysRevB.74.214117 and https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.105.053202 https://www.youtube.com/watch?v=kuKA81-R7-w

Evan Jahrman Core-to-core X-ray Emission Spectroscopy: Pitfalls and Advantages for Lab-based and Synchrotron Users

Core-to-core X-ray emission spectroscopy (CTC-XES) has not only provided key insights into atomic physics but is extremely well positioned to serve as a major analytical technique for several materials systems in the coming decades. Moreover, CTC-XES frequently serves as an enabling phenomenon for more exotic varieties of synchrotron-based XAFS. I will cover several applications of […]

Adam Hitchcock: Soft X-ray Spectromicroscopy in Scanning Transmission X-ray Microscopes

Soft X-ray scanning transmission microscopy (STXM) is a powerful tool for nanoscale materials analysis, with significant advantages over analytical electron microscopies for studies of radiation sensitive materials. Chemical species identified by near edge X-ray absorption fine structure (NEXAFS) spectra can be mapped quantitatively in 2D and in 3D. STXM instrumentation and methods will be described, […]

Kelsey Morgan: Hot science with cool sensors

The transition-edge sensor (TES) microcalorimeter uses the sharply temperature-dependent resistance of the superconducting transition to measure the energy of X-ray and gamma ray photons. A single TES is a broadband, energy-dispersive area detector capable of eV-scale energy resolution with good quantum efficiency. With an array of hundreds or thousands of sensors, a TES-based spectrometer can […]

Martin McBriarty: Top-Down Approaches to EXAFS Analysis

EXAFS spectra are often modeled using a small number of virtual coordination shells which can vary in coordination number, bond length, and disorder. While this bottom-up approach is generally successful for single-phase samples, it becomes intractable when the element of interest occupies multiple complex coordination states. Such cases may require a top-down approach, in which […]

Steve Heald: Sector 25 at the APS-U: Two new beamlines for advanced spectroscopy

As part of the Advanced Photon Source (APS) Multibend Achromat lattice upgrade two new beamlines for spectroscopy will be constructed on a canted undulator source at Sector 25. The programs at the 20-ID beamline at the APS need to move to sector 25 to make room for a planned long beamline. These will be combined […]

Neil Hyatt: Multimodal microfocus XAS to understand and remediate DU munitions contamination

The talk will show how multimodal microfocus X-ray spectroscopy has been applied to characterize depleted uranium particles from munitions testing to predict and understand their environmental behavior. A combination of spatially resolved XRD, XRF and XAS techniques, combined with laboratory SEM observations, is shown to effectively differentiate DU particulate contamination in near surface and burial […]

Jacinto Sa: Solving chemical mechanisms with X-ray spectroscopy

As a scientist have been always fascinated with how chemical systems react and interact with the natural world. Spectroscopy is a great tool to look at systems in real-time and operation conditions. Hard X-ray photon-in photon-out spectroscopy offers great possibilities due to its chemical sensitivity and speciation as well as high penetration. In this webinar, […]

Yulia Pushkar: X-ray Emission Spectroscopy at X-ray Free Electron Lasers: Limits to Observation of Unperturbed Electronic Structures

Modern free electron lasers provide intense X-ray pulses with 10^12 photons within ~10-100 femtoseconds. Such pulses enable new experimental techniques and provide unique opportunities for investigation of electronic and nuclear dynamics on their intrinsic time-scales. Interaction of ultra-bright, ultra-short X-ray pulses with matter can induce a multitude of nonlinear excitation processes which must be carefully […]