Characteristics of Photon Beam and Preservation of Coherence in Fourth-Generation Light Sources

Oh, BongHoon; Ko, Jun Ho; Lee, Jaeyu; Jang, G.; Shin, Seunghwan

doi:10.3390/app112411896

Cited by 5 publications

(4 citation statements)

References 14 publications

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“…MGGPO exploiting both SAXP and FXP was used to simultaneously increase the on and off momentum dynamic apertures (DAs) of the Korea-4GSR lattice. Korea-4GSR is a 28-cell low-emittance electron storage ring with hybrid sevenbend achromat optics (Oh et al, 2021). The ring has six sextupoles in each cell, and the ring is assumed to have a periodicity of 14 in terms of sextupole configuration (i.e.…”

Section: Comparison Of Results Of Fixed and Self-adaptive Strategymentioning

confidence: 99%

Nonlinear optimization for a low-emittance storage ring

Oh,

Ko,

Shin

et al. 2024

J Synchrotron Radiat

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A multi-objective genetic algorithm (MOGA) is a powerful global optimization tool, but its results are considerably affected by the crossover parameter ηc. Finding an appropriate ηc demands too much computing time because MOGA needs be run several times in order to find a good ηc. In this paper, a self-adaptive crossover parameter is introduced in a strategy to adopt a new ηc for every generation while running MOGA. This new scheme has also been adopted for a multi-generation Gaussian process optimization (MGGPO) when producing trial solutions. Compared with the existing MGGPO and MOGA, the MGGPO and MOGA with the new strategy show better performance in nonlinear optimization for the design of low-emittance storage rings.

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Section: Comparison Of Results Of Fixed and Self-adaptive Strategymentioning

confidence: 99%

Nonlinear optimization for a low-emittance storage ring

Oh,

Ko,

Shin

et al. 2024

J Synchrotron Radiat

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“…The recent emergence of low-emittance storage ring light sources based on a multibend achromat lattice, known as fourth-generation storage rings (4GSR), deliver orders of magnitude more brilliant X-ray radiation than that previously available from 3rd-generation light sources [16][17][18][19]. The high spatial coherence of the beam promises the possibility to probe fast microscopic dynamics via X-ray photon correlation spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

“…Here, we show that detectors and acquisition systems also exist that can match their anticipated performance. In this work, we demonstrate pulse-resolved hard X-ray photon detection capable of handling the 500 MHz repetition rate of incoming X-rays, which is equivalent to the fill pattern of the upcoming 4GSR in South Korea [19]. The high-speed single-photon detection scheme was implemented at PLS-II of Pohang Accelerator Laboratory.…”

Section: Introductionmentioning

confidence: 99%

Towards a Counting Point Detector for Nanosecond Coherent X-ray Science

et al. 2022

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We present the technical realization of a high-speed hard X-ray single-photon counting-detection scheme based on a commercial avalanche silicon photodiode and high-speed oscilloscope. The development is motivated by the need to perform pulse-resolved photon-correlation and pump-probe studies at synchrotron sources with densely packed pulse patterns that result in high repetition rate pulses on the order of hundreds of MHz. Commissioning experiments are performed at the 1C PAL-KRISS beamline at PLS-II of South Korea operating at a burst mode maximum repetition rate of 500 MHz. In such a high count-rate measurement, detector dead-time can lead to a distortion of counting statistics. We are able to model the counting behavior of our detector under these conditions with a detector dead-time comparable to time between X-ray pulses, implying that nanosecond X-ray photon correlation spectroscopy should be possible at diffraction-limited light sources.

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“…A total of six papers (five research papers and one review paper) are published, which elaborate on the designs and capabilities of emerging storage ring-based synchrotrons, novel X-ray instrumentation, analysis techniques, and measurement protocols. Shin et al presented the characteristics of photon beams expected at Korea's fourth-generation storage ring that employs a multi-bend achromat lattice concept [1]. Dallari et al discussed solutions for acquiring and analyzing an enormous stream of data from 2D detectors that operate at MHz frame rate, which poses a great challenge for performing XPCS experiments at sub-microsecond temporal resolution [2].…”

mentioning

confidence: 99%