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Bradley Alpert (Fed)

Research interests center on algorithms for scientific computation. As a numerical analyst, develops algorithms for solution of integral equations and partial differential equations. Expertise includes fast multipole methods, high-order quadrature techniques, special functions of mathematical physics, harmonic-analysis-based methods, wavelets, signal processing, and machine learning. Research applications include computational electromagnetics, including time-domain methods and nonreflecting boundary conditions.  Recent work in computational methods for thermophysical equations of state and data analysis for low-temperature superconducting transition-edge sensors.


Absolute energies and emission line shapes of the x-ray lines of lanthanide metals

Joseph Fowler, Galen O'Neil, Bradley K. Alpert, Douglas Bennett, Edward V. Denison, William Doriese, Gene Hilton, Lawrence T. Hudson, Young I. Joe, Kelsey Morgan, Daniel Schmidt, Daniel Swetz, Csilla I. Szabo-Foster, Joel Ullom
We use an array of transition-edge sensors, cryogenic microcalorimeters with 4 eV energy resolution, to measure the x-ray emission-line profiles of four

Approaches to the Optimal Nonlinear Analysis of Microcalorimeter Pulses

Joseph W. Fowler, Christine G. Pappas, Bradley K. Alpert, William B. Doriese, Galen C. O'Neil, Joel N. Ullom, Daniel S. Swetz
We consider how to analyze microcalorimeter pulses for quantities that are nonlinear in the data, while preserving the signal-to-noise advantages of linear


X-Ray Spectrometer

NIST Inventors
Joel Ullom, Galen O'Neil, Luis Miaja Avila, Kevin L. Silverman, Daniel Swetz, Ralph Jimenez, W.Bertrand (Randy) Doriese, Gene C. Hilton, Carl D. Reintsema, Dan Schmidt and Bradley Alpert
Patent Description Presently, there are no commercial tools for x-ray absorption and emission spectroscopy with picosecond time resolution. Additionally, there are no table-top tools for x-ray emission spectroscopy with picosecond time resolution. Previously, x-ray emission spectroscopy with this
Created May 31, 2018, Updated June 15, 2021