IPAC2014 - List of Authors (Qiao, S.)

Paper	Title	Page
WEPRO038	Possibility for Quasi-periodic Knot-APPLE Undulator	2026
	S. Sasaki, A. Miyamoto HSRC, Higashi-Hiroshima, Japan N. Kawata, T. Mitsuyasu Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan S. Qiao SIMIT, Shanghai, People's Republic of China
	An intense on-axis radiation power from an undulator is a serious problem especially for a low-photon-energy beamline in a facility with high or medium energy storage ring. This problem may be solved by using a Figure-8, a Pera, or a Knot undulator configuration,. However, these schemes are useless for variably polarizing undulators such as an APPLE undulator and other similar variations since such devices are not capable for reducing on-axis power density in the linear mode. In these circumstances, we have completed a conceptual magnet design of Knot-APPLE udulator which is capable to generate elliptically polarized radiation as well as linearly polarized radiation. This pure permanent magnet device is equipped with a motion mechanism of APPLE undulator. In this paper, we present detailed magnet design feature, magnetic field distributions, and radiation properties including variations of polarization in comparisons with other exotic devices. In addition, a possibility to introduce a quasi-periodicity in this type of undulator is considered in order to achieve further reduction of second and third harmonic radiation intensities. S. Sasaki, "Undulators, wigglers and their applications," p.237-243 (Ed. by H. Onuki and P. Elleaume, Taylor & Francis Inc, New York, 2003). **S. Qiao, et. al, Rev. Sci. Instrum., 80, 085108 (2009).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO038
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Paper

Title

Page

Possibility for Quasi-periodic Knot-APPLE Undulator

2026

S. Sasaki, A. Miyamoto
HSRC, Higashi-Hiroshima, Japan
N. Kawata, T. Mitsuyasu
Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan
S. Qiao
SIMIT, Shanghai, People's Republic of China

An intense on-axis radiation power from an undulator is a serious problem especially for a low-photon-energy beamline in a facility with high or medium energy storage ring. This problem may be solved by using a Figure-8, a Pera, or a Knot undulator configuration*,**. However, these schemes are useless for variably polarizing undulators such as an APPLE undulator and other similar variations since such devices are not capable for reducing on-axis power density in the linear mode. In these circumstances, we have completed a conceptual magnet design of Knot-APPLE udulator which is capable to generate elliptically polarized radiation as well as linearly polarized radiation. This pure permanent magnet device is equipped with a motion mechanism of APPLE undulator. In this paper, we present detailed magnet design feature, magnetic field distributions, and radiation properties including variations of polarization in comparisons with other exotic devices. In addition, a possibility to introduce a quasi-periodicity in this type of undulator is considered in order to achieve further reduction of second and third harmonic radiation intensities.
*S. Sasaki, "Undulators, wigglers and their applications," p.237-243 (Ed. by H. Onuki and P. Elleaume, Taylor & Francis Inc, New York, 2003).
**S. Qiao, et. al, Rev. Sci. Instrum., 80, 085108 (2009).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO038

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)