IPAC2014 - List of Authors (Schubert, S.G.)

Paper	Title	Page
MOPRI019	In-situ Characterization of K2CsSb Photocathodes	627
SUSPSNE115	use link to see paper's listing under its alternate paper code
	M. Schmeißer, A. Jankowiak, T. Kamps, S.G. Schubert HZB, Berlin, Germany S.G. Schubert BNL, Upton, Long Island, New York, USA
	Funding: Work supported by German Bundesministerium für Bildung und Forschung contract 05K12CB2 PCHB and Land Berlin. Alkali antimonide photocathodes with high quantum efficiency hold the promise of delivering electrons for high-brightness injectors. A drift type spectrometer (momentatron) was attached to the HZB preparation system to allow in-situ characterization within short time after fabrication and possibly identify correlations between growth process and cathode performance parameters.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI019
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MOPRI063	Alkali Antimonide Photocathodes in a Can	745
	J. Smedley, K. Attenkofer, T. Rao, S.G. Schubert BNL, Upton, Long Island, New York, USA I. Ben-Zvi, X. Liang, E.M. Muller, M. Ruiz-Osés Stony Brook University, Stony Brook, USA J. DeFazio PHOTONIS USA Pennsylvanis, Inc., Lancaster, Pennsylvania, USA H.A. Padmore, J.J. Wong LBNL, Berkeley, California, USA J. Xie ANL, Argonne, Illinois, USA
	Funding: Work was supported by the US DOE, under Contracts DE-AC02-05CH11231, DE-AC02-98CH10886, KC0407-ALSJNT-I0013, DE-FG02-12ER41837 and DE-SC0005713. Use of CHESS is supported by NSF award DMR-0936384. The next generation of x-ray light sources will need reliable, high quantum efficiency photocathodes. These cathodes will likely be from the alkali antimonide family, which currently holds the record for highest average current achieved from a photoinjector. In this work, we explore a new option for delivering these cathodes to a machine which requires them: use of sealed commercial vacuum tubes. Several sealed tubes have been introduced into a vacuum system and separated from their housing, exposing the active photocathode on a transport arm suitable for insertion into a photoinjector. The separation has been achieved without loss of QE. These cathodes are compared to those grown via traditional methods, both in terms of QE and in terms of crystalline structure, and found to be similar.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI063
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MOPRO106	Status of the HZB ERL Prototype BERLinPro	340
	M. Abo-Bakr, W. Anders, R. Barday, K.B. Bürkmann-Gehrlein, A. Burrill, V. Dürr, A. Jankowiak, C. Kalus, T. Kamps, G. Klemz, J. Knobloch, J. Kolbe, O. Kugeler, B.C. Kuske, A.N. Matveenko, A. Meseck, A. Neumann, K. Ott, E. Panofski, D. Pflückhahn, J. Rahn, J. Rudolph, M. Schmeißer, S.G. Schubert, O. Schüler, J. Völker, S. Wesch HZB, Berlin, Germany
	Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association. The Berlin Energy Recovery Linac Prototype BERLinPro is to be constructed at the Helmholtz Zentrum site in Berlin. The aim of the project is to expand the required accelerator physics and technology knowledge mandatory for the generation of a high current (100 mA), high brilliance (norm. emittance below 1 mm mrad) cw electron beam. Since the funding decision in October 2010 the project has entered a phase of detailed planning. Hardware specifications have been defined and various components have been ordered. Furthermore, extensive tests of principal superconducting accelerator components successfully demonstrated the envisaged hardware performance. A summary of the most recent activities together with the details of the project timeline for the coming years are given in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO106
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MOPRI018	Influence of Growth Method on K3Sb Photocathode Structure and Performance	624
	S.G. Schubert, T. Kamps, M. Schmeißer HZB, Berlin, Germany K. Attenkofer, J. Smedley BNL, Upton, Long Island, New York, USA E.M. Muller SBU, Stony Brook, New York, USA H.A. Padmore, J.J. Wong LBNL, Berkeley, California, USA M. Ruiz-Osés Stony Brook University, Stony Brook, USA J. Xie ANL, Argonne, Illinois, USA
	Funding: Supported by Director, OoS., OBES of US DOE, Contract DE-AC02-05CH11231, DE-AC02-98CH10886, KC0407-ALSJNTI0013, DE-SC0005713, germ. BMBF, Land Berlin, Helmholtz Assoc.. Use of CHESS by NSF, DMR-0936384. Future high brightness photoelectron sources delivering >100 mA average current call for a new generation of photocathodes. Materials which qualify for this purpose should exhibit low intrinsic emittance, long lifetime and high quantum efficiency at photon energies in the visible range of the spectrum to relax drive laser requirements. A combination of material science techniques are used to determine the influence of the growth parameters on structure and performance of photocathode materials . In-situ XRR, XRD and GiSAXS measurements were performed at the synchrotron radiation sources, NSLS and CHESS. The growth of K3Sb, a precursor material of one of the prime candidates CsK2Sb, was studied intensively to optimize this intermediate growth step in terms of quantum efficiency and roughness. Three methods, a “layer by layer” type and a “super-lattice type” were examined. K3Sb exists in two crystallographic phases, namely cubic and hexagonal. The cubic phase exhibits a higher quantum efficiency at 532 nm than the hexagonal phase and transforms more easily into CsK2Sb, tuning this phase is believed to be one of the key parameters in the CsK2Sb growth.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI018
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MOPRI020	Introducing GunLab – A Compact Test Facility for SRF Photoinjectors	630
SUSPSNE035	use link to see paper's listing under its alternate paper code
	J. Völker, R. Barday, A. Jankowiak, T. Kamps, J. Rudolph, S.G. Schubert, S. Wesch HZB, Berlin, Germany A. Ferrarotto, T. Weis DELTA, Dortmund, Germany V.I. Shvedunov MSU, Moscow, Russia I.Yu. Vladimirov MSU SINP, Moscow, Russia
	Funding: Work supported by German Bundesministerium für Bildung und Forschung (BMBF contract 05K12CB2 PCHB and 05K10PEA), Land Berlin and grants of Helmholtz Association Superconducting radio-frequency photoelectron injectors (SRF photoinjectors) are a promising electron source for high brightness accelerators with high average current and short pulse duration like FELs and ERLs. For the upcoming ERL project BERLinPro we want to test and commission different SRF photoinjectors and examine the beam performance of photocathode materials in an independent test facility. Therefore we designed GunLab to characterize the beam parameters from the SRF photoinjectors in a compact diagnostics beamline. In GunLab we want to investigate the complete 6 dimensional phase space as a function of drive laser and RF setup parameters. In this work we present the design and the estimated performance of GunLab.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI020
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Paper

Title

Page

MOPRI019

In-situ Characterization of K2CsSb Photocathodes

627

SUSPSNE115

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

M. Schmeißer, A. Jankowiak, T. Kamps, S.G. Schubert
HZB, Berlin, Germany
S.G. Schubert
BNL, Upton, Long Island, New York, USA

Funding: Work supported by German Bundesministerium für Bildung und Forschung contract 05K12CB2 PCHB and Land Berlin.
Alkali antimonide photocathodes with high quantum efficiency hold the promise of delivering electrons for high-brightness injectors. A drift type spectrometer (momentatron) was attached to the HZB preparation system to allow in-situ characterization within short time after fabrication and possibly identify correlations between growth process and cathode performance parameters.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI019

Export •

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

MOPRI063

Alkali Antimonide Photocathodes in a Can

745

J. Smedley, K. Attenkofer, T. Rao, S.G. Schubert
BNL, Upton, Long Island, New York, USA
I. Ben-Zvi, X. Liang, E.M. Muller, M. Ruiz-Osés
Stony Brook University, Stony Brook, USA
J. DeFazio
PHOTONIS USA Pennsylvanis, Inc., Lancaster, Pennsylvania, USA
H.A. Padmore, J.J. Wong
LBNL, Berkeley, California, USA
J. Xie
ANL, Argonne, Illinois, USA

Funding: Work was supported by the US DOE, under Contracts DE-AC02-05CH11231, DE-AC02-98CH10886, KC0407-ALSJNT-I0013, DE-FG02-12ER41837 and DE-SC0005713. Use of CHESS is supported by NSF award DMR-0936384.
The next generation of x-ray light sources will need reliable, high quantum efficiency photocathodes. These cathodes will likely be from the alkali antimonide family, which currently holds the record for highest average current achieved from a photoinjector. In this work, we explore a new option for delivering these cathodes to a machine which requires them: use of sealed commercial vacuum tubes. Several sealed tubes have been introduced into a vacuum system and separated from their housing, exposing the active photocathode on a transport arm suitable for insertion into a photoinjector. The separation has been achieved without loss of QE. These cathodes are compared to those grown via traditional methods, both in terms of QE and in terms of crystalline structure, and found to be similar.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI063

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

MOPRO106

Status of the HZB ERL Prototype BERLinPro

340

M. Abo-Bakr, W. Anders, R. Barday, K.B. Bürkmann-Gehrlein, A. Burrill, V. Dürr, A. Jankowiak, C. Kalus, T. Kamps, G. Klemz, J. Knobloch, J. Kolbe, O. Kugeler, B.C. Kuske, A.N. Matveenko, A. Meseck, A. Neumann, K. Ott, E. Panofski, D. Pflückhahn, J. Rahn, J. Rudolph, M. Schmeißer, S.G. Schubert, O. Schüler, J. Völker, S. Wesch
HZB, Berlin, Germany

Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association.
The Berlin Energy Recovery Linac Prototype BERLinPro is to be constructed at the Helmholtz Zentrum site in Berlin. The aim of the project is to expand the required accelerator physics and technology knowledge mandatory for the generation of a high current (100 mA), high brilliance (norm. emittance below 1 mm mrad) cw electron beam. Since the funding decision in October 2010 the project has entered a phase of detailed planning. Hardware specifications have been defined and various components have been ordered. Furthermore, extensive tests of principal superconducting accelerator components successfully demonstrated the envisaged hardware performance. A summary of the most recent activities together with the details of the project timeline for the coming years are given in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO106

Export •

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

MOPRI018

Influence of Growth Method on K3Sb Photocathode Structure and Performance

624

S.G. Schubert, T. Kamps, M. Schmeißer
HZB, Berlin, Germany
K. Attenkofer, J. Smedley
BNL, Upton, Long Island, New York, USA
E.M. Muller
SBU, Stony Brook, New York, USA
H.A. Padmore, J.J. Wong
LBNL, Berkeley, California, USA
M. Ruiz-Osés
Stony Brook University, Stony Brook, USA
J. Xie
ANL, Argonne, Illinois, USA

Funding: Supported by Director, OoS., OBES of US DOE, Contract DE-AC02-05CH11231, DE-AC02-98CH10886, KC0407-ALSJNTI0013, DE-SC0005713, germ. BMBF, Land Berlin, Helmholtz Assoc.. Use of CHESS by NSF, DMR-0936384.
Future high brightness photoelectron sources delivering >100 mA average current call for a new generation of photocathodes. Materials which qualify for this purpose should exhibit low intrinsic emittance, long lifetime and high quantum efficiency at photon energies in the visible range of the spectrum to relax drive laser requirements. A combination of material science techniques are used to determine the influence of the growth parameters on structure and performance of photocathode materials . In-situ XRR, XRD and GiSAXS measurements were performed at the synchrotron radiation sources, NSLS and CHESS. The growth of K3Sb, a precursor material of one of the prime candidates CsK2Sb, was studied intensively to optimize this intermediate growth step in terms of quantum efficiency and roughness. Three methods, a “layer by layer” type and a “super-lattice type” were examined. K3Sb exists in two crystallographic phases, namely cubic and hexagonal. The cubic phase exhibits a higher quantum efficiency at 532 nm than the hexagonal phase and transforms more easily into CsK2Sb, tuning this phase is believed to be one of the key parameters in the CsK2Sb growth.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI018

Export •

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

MOPRI020

Introducing GunLab – A Compact Test Facility for SRF Photoinjectors

630

SUSPSNE035

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

J. Völker, R. Barday, A. Jankowiak, T. Kamps, J. Rudolph, S.G. Schubert, S. Wesch
HZB, Berlin, Germany
A. Ferrarotto, T. Weis
DELTA, Dortmund, Germany
V.I. Shvedunov
MSU, Moscow, Russia
I.Yu. Vladimirov
MSU SINP, Moscow, Russia

Funding: Work supported by German Bundesministerium für Bildung und Forschung (BMBF contract 05K12CB2 PCHB and 05K10PEA), Land Berlin and grants of Helmholtz Association
Superconducting radio-frequency photoelectron injectors (SRF photoinjectors) are a promising electron source for high brightness accelerators with high average current and short pulse duration like FELs and ERLs. For the upcoming ERL project BERLinPro we want to test and commission different SRF photoinjectors and examine the beam performance of photocathode materials in an independent test facility. Therefore we designed GunLab to characterize the beam parameters from the SRF photoinjectors in a compact diagnostics beamline. In GunLab we want to investigate the complete 6 dimensional phase space as a function of drive laser and RF setup parameters. In this work we present the design and the estimated performance of GunLab.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI020

Export •

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