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arXiv · 1308.0172

Purified SASE undulator configuration to enhance the performance of the soft x-ray beamline at the European XFEL

Svitozar Serkez·Vitali Kocharyan·Evgeni Saldin·Igor Zagorodnov·Gianluca Geloni
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Abstract

The purified SASE (pSASE) undulator configuration recently proposed at SLAC promises an increase in the output spectral density of XFELs. In this article we study a straightforward implementation of this configuration for the soft x-ray beamline at the European XFEL. A few undulator cells, resonant at a subharmonic of the FEL radiation, are used in the middle of the exponential regime to amplify the radiation, while simultaneously reducing the FEL bandwidth. Based on start-to-end simulations, we show that with the proposed configuration the spectral density in the photon energy range between 1.3 keV and 3 keV can be enhanced of an order of magnitude compared to the baseline mode of operation. This option can be implemented into the tunable-gap SASE3 baseline undulator without additional hardware, and it is complementary to the self-seeding option with grating monochromator proposed for the same undulator line, which can cover the photon energy range between about 0.26 keV and 1 keV.

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Svitozar Serkez, Vitali Kocharyan, Evgeni Saldin, Igor Zagorodnov, Gianluca Geloni. 2013-08-01. Purified SASE undulator configuration to enhance the performance of the soft x-ray beamline at the European XFEL. https://arxiv.org/abs/1308.0172

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