IPAC2018 - List of Authors (Xiang, R.)

Paper	Title	Page
THPMF039	Study of Magnesium Photocathodes for Superconducting RF Photoinjectors	4142
	R. Xiang, A. Arnold, P.N. Lu, P. Murcek, J. Teichert, H. Vennekate HZDR, Dresden, Germany
	Funding: The work is supported by the German Federal Ministry of Education and Research (BMBF) grant 05K12CR1. The superconducting RF photoinjector (SRF Gun II) has successfully served for the ELBE user facility at HZDR. Nevertheless, the quality of photocathodes is one of the most critical issues in improving the stability and reliability for its application. Magnesium has a comparably low work function (3.6 eV) and shows a quantum efficiency up to 0.3% after laser cleaning. However, the present cleaning process with a high intensity laser beam is time consuming and produces unwanted surface roughness, which leads to a higher thermal emittance. Thermal treatment and Excimer laser cleaning for Mg cathodes are investigated as alternative methods. In this work, the new cleaning procedures are tested and optimized, and the quantum efficiency of Mg samples with different microstructure, composition and suppliers are compared.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF039
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THPMF040	Experiences with the SRF Gun II for User Operation at the ELBE Radiation Source	4145
	J. Teichert, A. Arnold, M. Bawatna, P.E. Evtushenko, M. Gensch, B.W. Green, S. Kovalev, U. Lehnert, P.N. Lu, P. Michel, P. Murcek, H. Vennekate, R. Xiang HZDR, Dresden, Germany
	Funding: The work is supported by the German Federal Ministry of Education and Research (BMBF) grant 05K12CR1. The second version of the superconducting RF pho-toinjector (SRF Gun II) was successfully commissioned at the ELBE radiation source in 2014. The gun features an improved 3.5-cell niobium cavity combined with a super-conducting solenoid integrated in the cryostat. With a Mg photocathode the SRF Gun II is able to generate bunches with up to 200 pC and with sub-ps length in CW mode with 100 kHz pulse frequency for the THz radiation fa-cility at ELBE. In the ELBE linac, the beam is accelerat-ed, gets a proper correlated energy spread, and is com-pressed in a magnetic chicane. Sub-ps pulses are obtained producing coherent diffraction radiation and superradiant undulator radiation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF040
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Study of Magnesium Photocathodes for Superconducting RF Photoinjectors

4142

R. Xiang, A. Arnold, P.N. Lu, P. Murcek, J. Teichert, H. Vennekate
HZDR, Dresden, Germany

Funding: The work is supported by the German Federal Ministry of Education and Research (BMBF) grant 05K12CR1.
The superconducting RF photoinjector (SRF Gun II) has successfully served for the ELBE user facility at HZDR. Nevertheless, the quality of photocathodes is one of the most critical issues in improving the stability and reliability for its application. Magnesium has a comparably low work function (3.6 eV) and shows a quantum efficiency up to 0.3% after laser cleaning. However, the present cleaning process with a high intensity laser beam is time consuming and produces unwanted surface roughness, which leads to a higher thermal emittance. Thermal treatment and Excimer laser cleaning for Mg cathodes are investigated as alternative methods. In this work, the new cleaning procedures are tested and optimized, and the quantum efficiency of Mg samples with different microstructure, composition and suppliers are compared.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF039

Export •

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

THPMF040

Experiences with the SRF Gun II for User Operation at the ELBE Radiation Source

4145

J. Teichert, A. Arnold, M. Bawatna, P.E. Evtushenko, M. Gensch, B.W. Green, S. Kovalev, U. Lehnert, P.N. Lu, P. Michel, P. Murcek, H. Vennekate, R. Xiang
HZDR, Dresden, Germany

Funding: The work is supported by the German Federal Ministry of Education and Research (BMBF) grant 05K12CR1.
The second version of the superconducting RF pho-toinjector (SRF Gun II) was successfully commissioned at the ELBE radiation source in 2014. The gun features an improved 3.5-cell niobium cavity combined with a super-conducting solenoid integrated in the cryostat. With a Mg photocathode the SRF Gun II is able to generate bunches with up to 200 pC and with sub-ps length in CW mode with 100 kHz pulse frequency for the THz radiation fa-cility at ELBE. In the ELBE linac, the beam is accelerat-ed, gets a proper correlated energy spread, and is com-pressed in a magnetic chicane. Sub-ps pulses are obtained producing coherent diffraction radiation and superradiant undulator radiation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF040

Export •

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