Correcting an experimental absorption spectrum for the core level width

Phys. Rev. Accel. Beams

Dallin

et al. 2019

A phase space beam position and size monitor (ps-BPM) system was introduced previously to measure the electron source vertical position and angular motion along with the vertical source size and angular size at a single location in a synchrotron bend magnet beam line. The system was validated experimentally at the Canadian Light Source and demonstrated by a simulation that it is suitable for low-emittance light sources. In this work, the potential practicality of the ps-BPM system is explored with real-case studies. By combining the analysis in the time and frequency domain, information on the beam motion and size can be extracted and identified from both the source and the beam-line optics. Applications of the ps-BPM system at the Canadian Light Source are demonstrated by studying beam vibrations and machine insertion device field changes. Results of these studies provide guidelines for implementing a dedicated ps-BPM system at existing and planned synchrotron facilites.

Section: B Source Size and Divergence Measurementsmentioning

confidence: 99%

Application of a phase space beam position and size monitor for synchrotron radiation source characterization

Phys. Rev. Accel. Beams

Dallin

et al. 2019

“…This energy dispersion is spatially mapped on the detector. The measured K-edge width σ edge on the detector contains contributions from the natural energy width of the K edge [35,36] projected to an angular width σ y 0 K-edge , the angular bandwidth of the monochromator crystal [37], σ y 0 mono , and the electron source size σ y . Assuming all contributions are Gaussian shape functions, the electron source size can be obtained by…”

Section: A System Descriptionmentioning

confidence: 99%

Source size measurement options for low-emittance light sources

Phys. Rev. Accel. Beams

Dallin

et al. 2020

Radiation-based techniques for measuring electron source sizes are widely used as emittance diagnostics at existing synchrotron sources. Three of these techniques, namely, pinhole imaging, double-slit interferometry, and a K-edge filter-based beam position and size monitor system (ps-BPM), are evaluated for measuring source sizes at low-emittance storage rings. Each technique is reviewed with a detailed system description, design optimization, and practical considerations targeted for small source sizes. Pinhole imaging has the simplest setup and gives the beam profile in both transverse dimensions but with limited resolution. Double-slit interferometry has the highest resolution but with a limited detectable size range. The ps-BPM system shows reasonable resolution for monitoring small source sizes and divergence and can give real-time information of the source position and angle. New facilities may consider an integrated system that combines some or all of these techniques.

“…where ð=ÞðEÞ is the energy-dependent mass-attenuation coefficient around the K-edge of the filter, is the concentration and t is the effective filter thickness. The K-edge spectrum depends on the core-level width, which is normally described by a Lorenz function (Babanov et al, 1998). In this work, to be consistent with the experimental results (Samadi et al, 2015), a Gaussian function is used.…”

Section: Simulation Tools and Methodsmentioning

confidence: 88%

“…Table 1 shows the angular width of the barium K-edge in angle, y 0 K edge , with different crystal reflections. For the same energy edge width ( E K edge = 5.6 eV, or a FWHM of 13.2 eV assuming a Gaussian distribution) (Babanov et al, 1998), a crystal with lower reflection indices is preferred.…”

Section: Figurementioning

confidence: 99%

“…The calculated y 0 mono , y 0 K edge and y 0 total values for different filter elements and crystal reflections are summarized in Table 2, where y 0 mono is the fitted Gaussian width of the diffraction profile calculated using XOP (Sá nchez del Río & Dejus, 2011), and y 0 K edge is calculated using equation (11) with E K edge extracted from Fig. 1 in the work by Babanov et al (1998). As the element atomic number goes up, the total contribution from the K-edge width and monochromator width becomes smaller, which implies a better sensitivity for detecting the electron-source size based on equation (2).…”

Section: K-edge Filtermentioning

confidence: 99%

See 1 more Smart Citation

Optimization of a phase-space beam position and size monitor for low-emittance light sources

Chapman

2019

J Synchrotron Radiat

The recently developed vertical phase-space beam position and size monitor (ps-BPM) system has proven to be able to measure the electron-source position, angle, size and divergence simultaneously in the vertical plane at a single location of a beamline. The optimization of the ps-BPM system is performed by ray-tracing simulation to maximize the instrument sensitivity and resolution. The contribution of each element is studied, including the monochromator, the K-edge filter, the detector and the source-to-detector distance. An optimized system is proposed for diffraction-limited storage rings, such as the Advanced Photon Source Upgrade project. The simulation results show that the ps-BPM system can precisely monitor the source position and angle at high speed. Precise measurements of the source size and divergence will require adequate resolution with relatively longer integration time. research papers 1864 Samadi et al. Phase-space beam monitor for low-emittance light sourcesFigure 1Schematic of the ps-BPM system including a Bragg (a) or Laue (b) crystal monochromator, a K-edge filter in (d), and a detector which records both the unfiltered beam side (c) and filtered edge side (d) of the beam.