LINAC2018 - List of Authors (Kostin, D.)

Paper	Title	Page
MOPO037	SRF Gun Development at DESY	105
MOOP07	use link to see paper's listing under its alternate paper code
	E. Vogel, S. Barbanotti, I. Hartl, K. Jensch, D. Klinke, D. Kostin, W.-D. Möller, M. Schmökel, J.K. Sekutowicz, S. Sievers, N. Steinhau-Kühl, A.A. Sulimov, J.H. Thie, H. Weise, L. Winkelmann, B. van der Horst DESY, Hamburg, Germany J.A. Lorkiewicz, R. Nietubyć NCBJ, Świerk/Otwock, Poland J. Smedley BNL, Upton, Long Island, New York, USA J. Teichert HZDR, Dresden, Germany M. Wiencek IFJ-PAN, Kraków, Poland
	A future upgrade of the European XFEL (E-XFEL) foresees an additional cw operation mode increasing the flexibility in the photon beam time structure. This mode requires among others a cw operating photo injector. We believe that using an SRF gun is the preferred approach as the beam parameters of normal conducting pulsed guns can be potentially met by SRF guns operating cw. Since more than a decade DESY in collaboration with TJNAF, NCBJ, BNL, HZB and HZDR performs R&D to develop an all superconducting RF gun with a lead cathode. In the frame of E-XFEL cw upgrade feasibility studies, the SRF-gun R&D program gained more attention and support. Within the next few years we would like to demonstrate the performance of the all superconducting injector required for the E-XFEL upgrade. The selected approach offers advantages w.r.t. the cleanliness of the superconducting surface, but requires a complete disassembly of a cryostat and stripping the gun cavity in a clean room to exchange the cathode. Thus it is practical only when the life time of the cathode is at least several months. In this paper we present the actual status of the R&D program, next steps and the longer term plans.
	Slides MOPO037 [1.966 MB]
	Poster MOPO037 [3.774 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO037
About •	paper received ※ 11 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPO038	RF Operation Experience at the European XFEL	109
MOOP09	use link to see paper's listing under its alternate paper code
	J. Branlard, V. Ayvazyan, Ł. Butkowski, M.K. Grecki, M. Hierholzer, M.G. Hoffmann, M. Hoffmann, M. Killenberg, D. Kostin, T. Lamb, L. Lilje, U. Mavrič, M. Omet, S. Pfeiffer, R. Rybaniec, H. Schlarb, Ch. Schmidt, N. Shehzad, V. Vogel, N. Walker DESY, Hamburg, Germany
	After its successful commissioning which took place during the first half of 2017, the European X-ray free electron laser is in now in regular operation delivering photons to users since September 2017. This paper presents an overview on the experience gathered during the first couple of years of operation. In particular, the focus is set on RF operation, maintenance activities, availability and typical failures. A first look on machine performance in terms of RF and beam stability, energy reach, radiation related investigations and microphonics studies will also be presented.
	Slides MOPO038 [2.421 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO038
About •	paper received ※ 11 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPO029	Highlights of the XM-3 Cryomodule Tests at DESY	388
	J. Branlard, V. Ayvazyan, A. Bellandi, J. Eschke, C. Gumus, D. Kostin, K.P. Przygoda, H. Schlarb, J.K. Sekutowicz DESY, Hamburg, Germany W. Cichalewski TUL-DMCS, Łódź, Poland
	To investigate the feasibility of the continuous wave (cw) upgrade of the European XFEL (E-XFEL) DESY, on-going tests are performed on E-XFEL prototype and production cryomodules since 2011. For these studies, DESY’s Cryo-Module Test Bench (CMTB) has been equipped with a 10⁵ kW cw operating IOT in addition to the 10MW pulsed klystron, making CMTB a very flexible test stand, enabling both cw and pulse operation. For these tests, E-XFEL-like LLRF electronics is used to stabilize amplitude and phase of the voltage Vector Sum (VS) of all 8 cavities of the cryomodule under test. The cryomodule most often tested is the pre-series XM-3, unique since it is housing one fine grain niobium and seven large grain niobium cavities. In autumn 2017, additional spacers were installed on all 8 input couplers to increase the maximum reachable loaded quality factor Ql beyond 2·10⁷. With higher Ql, up to 6·10⁷ for 6 cavities and 2.7·10⁷ for 2 cavities, we have investigated the VS stability and SRF-performance of this cryomodule under various conditions of cooling down rate and operation temperature 1.65K, 1.8K and 2K, at gradients up to ca. 18MV/m. The results of these tests are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO029
About •	paper received ※ 11 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

MOPO037

SRF Gun Development at DESY

105

MOOP07

use link to see paper's listing under its alternate paper code

E. Vogel, S. Barbanotti, I. Hartl, K. Jensch, D. Klinke, D. Kostin, W.-D. Möller, M. Schmökel, J.K. Sekutowicz, S. Sievers, N. Steinhau-Kühl, A.A. Sulimov, J.H. Thie, H. Weise, L. Winkelmann, B. van der Horst
DESY, Hamburg, Germany
J.A. Lorkiewicz, R. Nietubyć
NCBJ, Świerk/Otwock, Poland
J. Smedley
BNL, Upton, Long Island, New York, USA
J. Teichert
HZDR, Dresden, Germany
M. Wiencek
IFJ-PAN, Kraków, Poland

A future upgrade of the European XFEL (E-XFEL) foresees an additional cw operation mode increasing the flexibility in the photon beam time structure. This mode requires among others a cw operating photo injector. We believe that using an SRF gun is the preferred approach as the beam parameters of normal conducting pulsed guns can be potentially met by SRF guns operating cw. Since more than a decade DESY in collaboration with TJNAF, NCBJ, BNL, HZB and HZDR performs R&D to develop an all superconducting RF gun with a lead cathode. In the frame of E-XFEL cw upgrade feasibility studies, the SRF-gun R&D program gained more attention and support. Within the next few years we would like to demonstrate the performance of the all superconducting injector required for the E-XFEL upgrade. The selected approach offers advantages w.r.t. the cleanliness of the superconducting surface, but requires a complete disassembly of a cryostat and stripping the gun cavity in a clean room to exchange the cathode. Thus it is practical only when the life time of the cathode is at least several months. In this paper we present the actual status of the R&D program, next steps and the longer term plans.

Slides MOPO037 [1.966 MB]

Poster MOPO037 [3.774 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO037

About •

paper received ※ 11 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019

Export •

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

MOPO038

RF Operation Experience at the European XFEL

109

MOOP09

use link to see paper's listing under its alternate paper code

J. Branlard, V. Ayvazyan, Ł. Butkowski, M.K. Grecki, M. Hierholzer, M.G. Hoffmann, M. Hoffmann, M. Killenberg, D. Kostin, T. Lamb, L. Lilje, U. Mavrič, M. Omet, S. Pfeiffer, R. Rybaniec, H. Schlarb, Ch. Schmidt, N. Shehzad, V. Vogel, N. Walker
DESY, Hamburg, Germany

After its successful commissioning which took place during the first half of 2017, the European X-ray free electron laser is in now in regular operation delivering photons to users since September 2017. This paper presents an overview on the experience gathered during the first couple of years of operation. In particular, the focus is set on RF operation, maintenance activities, availability and typical failures. A first look on machine performance in terms of RF and beam stability, energy reach, radiation related investigations and microphonics studies will also be presented.

Slides MOPO038 [2.421 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO038

About •

paper received ※ 11 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019

Export •

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

TUPO029

Highlights of the XM-3 Cryomodule Tests at DESY

388

J. Branlard, V. Ayvazyan, A. Bellandi, J. Eschke, C. Gumus, D. Kostin, K.P. Przygoda, H. Schlarb, J.K. Sekutowicz
DESY, Hamburg, Germany
W. Cichalewski
TUL-DMCS, Łódź, Poland

To investigate the feasibility of the continuous wave (cw) upgrade of the European XFEL (E-XFEL) DESY, on-going tests are performed on E-XFEL prototype and production cryomodules since 2011. For these studies, DESY’s Cryo-Module Test Bench (CMTB) has been equipped with a 10⁵ kW cw operating IOT in addition to the 10MW pulsed klystron, making CMTB a very flexible test stand, enabling both cw and pulse operation. For these tests, E-XFEL-like LLRF electronics is used to stabilize amplitude and phase of the voltage Vector Sum (VS) of all 8 cavities of the cryomodule under test. The cryomodule most often tested is the pre-series XM-3, unique since it is housing one fine grain niobium and seven large grain niobium cavities. In autumn 2017, additional spacers were installed on all 8 input couplers to increase the maximum reachable loaded quality factor Ql beyond 2·10⁷. With higher Ql, up to 6·10⁷ for 6 cavities and 2.7·10⁷ for 2 cavities, we have investigated the VS stability and SRF-performance of this cryomodule under various conditions of cooling down rate and operation temperature 1.65K, 1.8K and 2K, at gradients up to ca. 18MV/m. The results of these tests are presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO029

About •

paper received ※ 11 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019

Export •

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