IBIC2019 - List of Authors (Strokov, S.A.)

Paper	Title	Page
TUPP011	Observation of Scintillators Charging Effects at the European XFEL	308
	A.I. Novokshonov, B. Beutner, G. Kube DESY, Hamburg, Germany S.A. Strokov TPU, Tomsk, Russia
	Scintillating screens are widely used for beam profile diagnostics at various kinds of particle accelerators. At modern linac based electron machines with ultrashort bunches as the European XFEL in Hamburg (Germany), scintillators help to overcome the limitation of standard OTR based monitors imposed by the emission of coherent radiation. The XFEL injector section is equipped with four off-axis screens allowing to perform online beam profile diagnostics, i.e. a single bunch out of a bunch train is kicked onto the screen and the profile is analyzed. However, during user operation a decrease of the SASE level was observed in cases that one of the of-axis screens was used. The observation is explained by charging of the scintillator screen: each deflected bunch hitting the screens causes ionization and charging of the screen. The scintillator as good insulator keeps the charge for some time such that the non-deflected part of the bunch-train feels their Coulomb force and experiences a kick, resulting in a drop of the SASE level. This report summarizes the observations at the European XFEL and introduces a simple model for quantification of this effect.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP011
About •	paper received ※ 04 September 2019 paper accepted ※ 07 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Observation of Scintillators Charging Effects at the European XFEL

308

A.I. Novokshonov, B. Beutner, G. Kube
DESY, Hamburg, Germany
S.A. Strokov
TPU, Tomsk, Russia

Scintillating screens are widely used for beam profile diagnostics at various kinds of particle accelerators. At modern linac based electron machines with ultrashort bunches as the European XFEL in Hamburg (Germany), scintillators help to overcome the limitation of standard OTR based monitors imposed by the emission of coherent radiation. The XFEL injector section is equipped with four off-axis screens allowing to perform online beam profile diagnostics, i.e. a single bunch out of a bunch train is kicked onto the screen and the profile is analyzed. However, during user operation a decrease of the SASE level was observed in cases that one of the of-axis screens was used. The observation is explained by charging of the scintillator screen: each deflected bunch hitting the screens causes ionization and charging of the screen. The scintillator as good insulator keeps the charge for some time such that the non-deflected part of the bunch-train feels their Coulomb force and experiences a kick, resulting in a drop of the SASE level. This report summarizes the observations at the European XFEL and introduces a simple model for quantification of this effect.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP011

About •

paper received ※ 04 September 2019 paper accepted ※ 07 September 2019 issue date ※ 10 November 2019

Export •

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