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Search Publications by: Lawrence T. Hudson (Assoc)

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Displaying 1 - 25 of 102

X-Ray Spectroscopy and Calibrations in the 50 eV to 60 keV Range

October 12, 2021
Author(s)
J Seely, Uri Feldman, J. Weaver, Lawrence T. Hudson
Spectrometers have been developed to record x-ray spectra in the energy range 50 eV to 60 keV. The dispersion elements are transmission crystals for energies higher than approximately 11 keV, reflection crystals for 1 keV to 20 keV, and transmission

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

February 1, 2021
Author(s)
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 elements of the lanthanide series: praseodymium, neodymium, terbium, and holmium. The spectrometer also

The Molybdenum K-shell X-ray Emission Spectrum

September 18, 2019
Author(s)
Marcus H. Mendenhall, Lawrence T. Hudson, Csilla I. Szabo-Foster, Albert Henins, James P. Cline
Abstract We present newly measured spectra of the X-ray emission of a molybdenum metal anode subject to electron bombardment, using a very high dispersion silicon double-crystal spectrometer. The measurement includes the dipole-allowed KL, KM, and KN

Contemporary x-ray wavelength metrology and traceability

July 3, 2019
Author(s)
Lawrence T. Hudson, James P. Cline, Albert Henins, Marcus H. Mendenhall, Csilla I. Szabo-Foster
We report recent advances in absolute x-ray wavelength metrology in the context of producing modern standard reference data. Primary standard x-ray wavelengths are typically measured with two-crystal (or more) diffraction spectrometers operated in

High x-ray resolving power (up to 4000) utilizing asymmetric diffraction from a quartz transmission crystal measured in the 6 keV to 22 keV energy range

June 27, 2019
Author(s)
Lawrence T. Hudson, John F. Seely, Eric Galtier, Uri Feldman, Albert Henins
A Cauchois type spectrometer utilizing the (203) lattice planes at an oblique angle of 11.53o to the surface of a quartz transmission crystal recorded the Kα and Kβ spectral lines of six elements from Fe to Ag in the 6 keV to 22 keV energy range from a

X-Ray Spectrometer Having 12 000 Resolving Power at 8 keV Energy

May 14, 2018
Author(s)
Lawrence T. Hudson, John F. Seely, Uri Feldman, Albert Henins
An x-ray spectrometer employing a thin (50 μm) silicon transmission crystal was used to record high-resolution Cu Kα spectra from a laboratory x-ray source. The diffraction was from the (331) planes that were at an angle of 13.26° to the crystal surface

A Reassessment of Absolute Energies of X-ray L Lines of Lanthanide Metals

June 28, 2017
Author(s)
Bradley Alpert, W.Bertrand (Randy) Doriese, Gene C. Hilton, Lawrence T. Hudson, Young I. Joe, Kelsey Morgan, Carl D. Reintsema, Dan Schmidt, Daniel Swetz, Csilla Szabo-Foster, Joel Ullom, Joseph Fowler, Galen O'Neil, Douglas Bennett
We introduce a new technique for determining x-ray fluorescence line energies and widths, and we present measurements made with this technique of 22 x-ray L lines from lanthanide-series elements. The technique uses arrays of transition-edge sensors

High-precision measurement of the X-ray Cu K-alpha spectrum

May 12, 2017
Author(s)
Marcus H. Mendenhall, Albert Henins, Lawrence T. Hudson, Csilla I. Szabo-Foster, Donald A. Windover, James P. Cline
The structure of the x-ray emission lines of the Cu Kα complex has been remeasured on a newly commissioned instrument, in a manner directly traceable to the Système Internationale definition of the meter. In this measurement, the region from 8000 to 8100

The Lattice Spacing Variability of Intrinsic Float-Zone Silicon

May 11, 2017
Author(s)
Ernest G. Kessler Jr., Csilla Szabo-Foster, James Cline, Albert Henins, Lawrence T. Hudson, Marcus Mendenhall, Mark D. Vaudin
Precision lattice spacing comparison measurements at the National Institute of Standards and Technology (NIST) provide traceability of x-ray wavelength and powder diffraction standards to the international system of units (SI). Here we both summarize and

Energetic Electrons Driven in the Polarization Direction of an Intense Laser Beam Incident Normal to a Solid Target

June 1, 2016
Author(s)
Lawrence T. Hudson, John F. Seely, Nino R. Pereira, H. Chen, G.J. Williams, R.P. Drake, C.C. Kuranz, C.A. Di Stefano, J. Park
Experiments were performed at the LLNL Titan laser to measure the propagation direction of the energetic electrons that were generated during the interaction of the polarized laser beam with solid targets in the case of normal incidence. The energetic

New x-ray measurements shed light on discrepancy between experiment and QED

December 15, 2014
Author(s)
Lawrence T. Hudson, C T. Chantler, A.T. Payne, M N. Kinnane, John D. Gillaspy, L F. Smale, Albert Henins, J A. Kimpton, E Takacs
Quantum Electro-Dynamics (QED) is the best tested theory of our physical world, yet significant disagreements have emerged between attempts to apply QED to exotic atomic systems. A recent 15 parts-per-million (ppm) experiment on muonic hydrogen, in which

The Metrology of a Rastered Spot of X Rays used in Security Screening

November 6, 2014
Author(s)
Lawrence T. Hudson, Jack L. Glover, Ronaldo Minniti
In recent times, ionizing radiation has been used around the world to screen persons for non- medical purposes, namely to detect bulk explosives or other contraband hidden on the body including materials not registered by metal detectors. In contrast to

Measurement of High-Energy (10 keV to 60 keV) X-Ray Spectral Line Widths with eV Accuracy

August 8, 2014
Author(s)
John F. Seely, Jack L. Glover, Lawrence T. Hudson, Yuri Ralchenko, Nino R. Pereira, U. Feldman, C. D. Stefan
A high resolution crystal spectrometer (HRCS) utilizing a crystal in transmission geometry has been developed and experimentally optimized to measure the line widths of emission lines in the 10 keV to 60 keV energy range with eV accuracy. The spectrometer

High-resolution K-shell spectra from laser excited molybdenum plasma

November 1, 2013
Author(s)
Lawrence T. Hudson, C.I Szabo, P Indelicatio, John F. Seely, T Ma
X-ray spectra from Molybdenum plasmas were recorded by a Cauchois-type cylindrically bent Transmission Crystal Spectrometer (TCS). The absolutely calibrated spectrometer provides an unprecedented resolution of inner shell transitions (K x-ray radiation)