Engineering topics

Hidas, Dean

Publications and source records attributed to Hidas, Dean.

5 records

DOE OSTI2025

Ultimate brightness of a medium-energy synchrotron light source at operational beam intensity

Synchrotron light sources are key instruments of modern science, providing unique opportunities for groundbreaking studies in diverse scientific disciplines and driving innovation in numerous scientific and technological fields. Fourth-generation light sources provide unprecedented capabilities in imaging, spectroscopy and diffraction techniques. Ultimate brightness is the key to advancing to a smaller scale, faster response, and higher data measurement and processing rate. The brightness is primarily determined by the electron beam emittance and energy spread at operational intensity. A common feature of fourth-generation synchrotrons is the short length of the electron bunches combined with a very small transverse beam size. Consequently, the high particle density leads to strong collective effects that significantly increase the emittance and limit the achievable brightness at operational beam intensity. In this article, we summarize our studies of the emittance and brightness scaled with the beam energy and intensity, taking into account the effects of intrabeam scattering, beam-impedance interaction and bunch lengthening provided by higher-harmonic RF systems to identify optimal combinations of machine and beam parameters.

36 MATERIALS SCIENCE↗

DOE OSTI2024

Phasing for inline IVU22s at 9.1 keV

This note explores the effects of hard x-ray phasing for two 3m 22mm period inline In-Vacuum Undulators at a photon energy of 9.1 keV. Expectations for current and future low emittance options are given and limitations explored.

43 PARTICLE ACCELERATORS↗

DOE OSTI2024

Brightness for Current NSLS-II In-Vacuum Undulator Technology in Different Lattice Scenarios

In this note the peak and effective magnetic field for In-Vacuum Undulators at NSLS-II is characterized by the well-known Halbach formula. This gives a reasonably good approximation of an IVU of any period and any magnetic gap within the range currently used at NSLS-II (≥ 18mm). This parameterization is then used in conjunction with known stay-clear requirements from the ring aperture definition as well as an absolute minimum of 4.5mm to calculate the maximum achievable brightness at any photon energy by scanning the parameters of period, gap, and length. This maximum achievable brightness is calculated for both devices centered at the lattice center as well as in a center-split configuration for the long and short straight sections of NSLS-II. In addition results are shown for a hypothetical single and center-split long straight section where the horizontal and vertical beta functions for a long straight have been modified to match at 2.5m. These are compared to a hypothetical canted double min-β configuration using the long straight section where the vertical beta function minimum is 1.6m and the horizontal as low as 3.2m. The latter case may provide significant benefit for medium and high photon energy beamlines seeking high brightness.

43 PARTICLE ACCELERATORS↗

DOE OSTI2022

Construction of Cryogen-Free 4.3T Superconducting Wiggler for NSLS-II Ring

With the 3 GeV electron beam energy for the National Synchrotron Light Source II (NSLS-II) ring, only superconducting wigglers (SCW) producing greater than 4T peak field can cover the photon energy range of 20 keV and 200 keV with sufficient number of photons. The High energy Engineering X-ray (HEX) Diffraction beamline, which is primarily funded by the New York State Energy Research and Development Authority (NYSERDA) and NSLS-II, will be equipped with a 1.2m-long SCW with 70 mm period length and 4.3 T on-axis field. This SCW is free from the use of liquid Helium and is cooled only with cryo-coolers. The Electron Beam Chamber (EBC) with vertical aperture of 8 mm is made from 316LN stainless steel and copper plating is applied both surface and +-12.5mm wide from the center in the inner surface. The expected heat load from the electron beam of the NSLS-II ring is estimated to be 10 W/m. Here, we describe the design principles and engineering challenges for the device.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Metrology of a Focusing Capillary Using Optical Ptychography

The focusing property of an ellipsoidal monocapillary has been characterized using the ptychography method with a 405 nm laser beam. The recovered wavefront gives a 12.5×10.4μm 2 focus. The reconstructed phase profile of the focused beam can be used to estimate the height error of the capillary surface. The obtained height error shows a Gaussian distribution with a standard deviation of 1.3 μm. This approach can be used as a quantitative tool for evaluating the inner functional surfaces of reflective optics, complementary to conventional metrology methods.

36 MATERIALS SCIENCE↗