TUPOPT —  Poster Session - Padthai   (14-Jun-22   16:00—18:00)

Paper	Title	Page
TUPOPT005	Status of the Superconducting Soft X-Ray Free-Electron Laser User Facility FLASH	1006
	M. Vogt, C. Gerth, K. Honkavaara, M. Kuhlmann, J. Rönsch-Schulenburg, L. Schaper, S. Schreiber, R. Treusch, J. Zemella DESY, Hamburg, Germany
	The XUV and soft X-ray free-electron laser FLASH at DESY is capable of operating two undulator beamlines simultaneously with up to several thousand bunches per second. It is driven by a normal conducting RF photo-cathode gun and a superconducting L-band linac. FLASH is currently undergoing a substantial refurbishment and upgrade program (FLASH2020+). The first 9-months installation shutdown started in November 2021. Here we report on the operation in 2021 and present main upgrades during the ongoing shutdown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT005
About •	Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 17 June 2022
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TUPOPT006	The New FLASH1 Beamline for the FLASH2020+ Project	1010
	M. Vogt, J. Zemella DESY, Hamburg, Germany
	The 2nd stage of the FLASH2020+ project will be an upgrade of the FLASH1 beamline, downstream of the injector/linac section FLAH0 which is currently being upgraded. The currently existing beamline drives the original planar fixed gap SASE undulators from the TTF-2 setup, a THz undulator that uses the spent electron beam and deflects the e-beam into a dump beamline capable of safely dumping several thousand bunches per second. The updated beamline has been designed for EEHG seeding with 2 modulators, 3 chicanes, and a helical Apple-III undulator beamline as seeding radiator, followed by a transverse deflecting (S-band) structure for longitudinal diagnostics. The separation of the electron beam from the FEL beam will be moved upstream w.r.t. the old design to create more space for the photon diagnostics and will be achieved by a 5 deg double-bend-almost-achromat. To allow enable high power THz radiation output from a moderately compressed seeding beam, a post compressor will be installed. The capability of dumping the the long bunch trains safely may and will not be compromised by the design. This article describes the conceptional and some technical and details of the beamline.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT006
About •	Received ※ 07 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 23 June 2022
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TUPOPT008	An Overview of the T20 Beamline for the LUXE Experiment at the European XFEL	1014
	S.D. Walker, N. Golubeva DESY, Hamburg, Germany
	The Laser Und XFEL Experiment (LUXE) at the EUXFEL aims to explore hitherto unprobed regions of quantum electrodynamics characterised by both high-energy and high-intensity. This will be accomplished by leveraging the electron beam provided by the EUXFEL and an intensely-focussed laser to study electron-photon and photon-photon interactions. The LUXE experiment will be placed in the empty XTD20 tunnel and to this end a new beamline, T20, will need to be installed to deliver one bunch per bunch train to LUXE. The T20 beamline feature a total bend angle of 6.7 degrees, which combined with the very short bunches provided by the EUXFEL raises concerns regarding the deleterious impact of of coherent synchrotron radiation (CSR) on the bunch emittances. As the LUXE experiment has specific beam size requirements at its IP, these effects and the limits on the focus must be characterised. In this paper the T20 beamline design and its final focus are outlined. Furthermore, the impact of collective effects on the beam quality at the LUXE IP are discussed, and finally a means to mitigate the impact of these effects and improve the beam quality at the LUXE IP is shown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT008
About •	Received ※ 13 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 19 June 2022 — Issue date ※ 10 July 2022
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TUPOPT010	Virtual Commissioning of the European XFEL for Advanced User Experiments at Photon Energies Beyond 25 keV Using Low-Emittance Electron Beams	1018
	Y. Chen, F. Brinker, W. Decking, M. Scholz, L. Winkelmann, Z.H. Zhupresenter DESY, Hamburg, Germany
	Funding: The authors acknowledge support from Deutsches Elektronen-Synchrotron DESY (Hamburg, Germany), a member of the Helmholtz Association HGF and European XFEL GmbH (Schenefeld, Germany). Growing interests in ultra-hard X-rays are pushing forward the frontier of commissioning the European X-ray Free-Electron Laser (XFEL) for routine operation towards the sub-ångström regime, where a photon energy of 25 keV (0.5 ångström) is desired. Such X-rays allow for larger penetration depths and enable the investigation of materials in highly absorbing environments. Delivering the requested X-rays to user experiments is of crucial importance for the XFEL development. Unique capabilities of the European XFEL are formed by combining a high energy linac and the long variable-gap undulator systems for generating intense X-rays at 25 keV and pushing the limit even further to 30 keV. However, the FEL performance relies on achievable electron bunch qualities. Low-emittance electron bunch production, and the associated start-to-end modelling of beam physics thus becomes a prerequisite to dig into the XFEL potentials. Here, we present the obtained results from a virtual commissioning of the XFEL for the user experiments at 25 keV and beyond, including the optimized electron bunch qualities at variable accelerating cathode gradients and lasing studies under different conditions. *Appl. Sci. 11(22), 10768 (2021) **Phys. Rev. Accel. Beams 23, 044201(2020) ***NIM A 995, 11 165111 (2021)
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT010
About •	Received ※ 19 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 08 July 2022
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TUPOPT011	Start To End Simulation Study For Oscillator-Amplifier Free-Electron Laser	1022
	H. Sun, Z.H. Zhupresenter SINAP, Shanghai, People’s Republic of China C. Feng, B. Liu SARI-CAS, Pudong, Shanghai, People’s Republic of China Z.H. Zhupresenter DESY, Hamburg, Germany
	External seeding techniques like high-gain harmonic generation (HGHG) and echo-enabled harmonic generation (EEHG) have been proposed and proven to be able to generate fully coherent radiation in the EUV and X-ray range. A big challenge is to combine the advantages of seeding schemes with high repetition rates. Recently, for seeding at a high repetition rate, an optical resonator scheme has been introduced to recirculate the radiation in the modulator to seed the high repetition rate electron bunches. Earlier studies have shown that a resonator-like modulator combined with an amplifier in high gain harmonic generation (HGHG) configuration can be used to generate radiation whose wavelength can reach the water window region. This scheme overcomes the limitation of requiring high repetition rate seed laser systems. In this contribution, we present start-to-end simulation results of a seeded oscillator-amplifier FEL scheme.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT011
About •	Received ※ 07 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 11 June 2022 — Issue date ※ 16 June 2022
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TUPOPT013	Twin Delayed Deep Deterministic Policy Gradient for Free-electron Laser Online Optimization	1025
	M. Cai, C. Feng, L. Tu, Z.T. Zhao, Z.H. Zhupresenter SINAP, Shanghai, People’s Republic of China C. Feng, K.Q. Zhang, Z.T. Zhao SSRF, Shanghai, People’s Republic of China D. Gu SARI-CAS, Pudong, Shanghai, People’s Republic of China
	X-ray free-electron lasers (FEL) have contributed to many frontier applications of nanoscale science which benefit from its extraordinary properties. During FEL commissioning, the beam status optimization especially orbit correction is particularly significant for FEL amplification. For example, the deviation between beam orbit and the magnetic center of undulator can affect the interaction between the electron beam and the FEL pulse. Usually, FEL commissioning requires a lot of effort for multi-dimensional parameters optimization in a time-varying system. Therefore, advanced algorithms are needed to facilitate the commissioning procedure. In this paper, we propose an online method to optimize the FEL power and transverse coherence by using a twin delayed deep deterministic policy gradient (TD3) algorithm. The algorithm exhibits more stable learning convergence and improves learning performance because the overestimation bias of policy gradient methods is suppressed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT013
About •	Received ※ 17 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 22 June 2022
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TUPOPT014	The Status of the SASE3 Variable Polarization Project at the European XFEL	1029
	S. Karabekyan, S. Abeghyan, M. Bagha-Shanjani, S. Casalbuoni, U. Englisch, W. Freund, G. Geloni, J. Grünert, S. Hauf, C. Holz, D. La Civita, J. Laksman, D. Mamchyk, M.P. Planas, F. Preisskorn, S. Serkez, H. Sinn, M. Wuenschel, M. Yakopov, C. Youngman EuXFEL, Schenefeld, Germany P. Altmann, A. Block, W. Decking, L. Fröhlich, O. Hensler, T. Ladwig, D. Lenz, D. Lipka, R. Mattusch, N. Mildner, E. Negodin, J. Prenting, F. Saretzki, M. Schlösser, F. Schmidt-Föhre, E. Schneidmiller, M. Scholz, D. Thoden, T. Wamsat, T. Wilksen, T. Wohlenberg, M.V. Yurkov DESY, Hamburg, Germany J. Bahrdt HZB, Berlin, Germany M. Brügger, M. Calvi, S. Danner, R. Ganter, L. Huber, A. Keller, C. Kittel, X. Liang, S. Reiche, M.S. Schmidt, T. Schmidt, K. Zhang PSI, Villigen PSI, Switzerland D.E. Kim PAL, Pohang, Republic of Korea Y. Li IHEP, People’s Republic of China
	The undulator systems at the European XFEL consist of two hard X-ray systems, SASE1 and SASE2, and one soft X-ray system, SASE3. All three systems are equipped with planar undulators using permanent neodymium magnets. These systems allow the generation of linearly polarized radiation in the horizontal plane. In order to generate variable polarization radiation in the soft X-ray range, an afterburner is currently being implemented behind the SASE3 planar undulator system. It consists of four APPLE-X helical undulators. The project, called SASE 3 Variable Polarization, is close to being put into operation. All four helical undulators have been installed in the tunnel during the 2021-2022 winter shutdown. This paper describes the status of the project and the steps toward its commissioning. It also presents lessons learned during the implementation of the project.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT014
About •	Received ※ 02 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 05 July 2022
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TUPOPT016	Status of the THz@PITZ Project - The Proof-of-Principle Experiment on a THz SASE FEL at the PITZ Facility	1033
	T. Weilbach, P. Boonpornprasert, G.Z. Georgiev, G. Koss, M. Krasilnikov, X.-K. Li, A. Lueangaramwongpresenter, F. Mueller, A. Oppelt, S. Philipp, F. Stephan DESY Zeuthen, Zeuthen, Germany
	Funding: This work was supported by the European XFEL research and development program. In order to allow THz pump/X-ray probe experiments at full bunch repetition rate for users at the European XFEL, the Photo Injector Test Facility at DESYin Zeuthen (PITZ) is building a prototype of an accelerator-based THz source. The goal is to generate THz SASE FEL radiation with a mJ energy level per bunch using an undulator driven by the electron beam from PITZ. Therefore, the existing PITZ beam line is extended into a tunnel annex downstream of the existing accelerator tunnel. The final design of the beam line extension consists of a bunch compressor, a collimation system and a beam dump in the PITZ tunnel. In the tunnel annex one LCLS-I undulator is installed for the production of the THz radiation with a quadrupole triplet in front of it for matching the beam parameters for the FEL process. Behind the undulator two screen stations couple out the THz radiation, for measurements of bunch compression, pulse energy or spatial distribution. A dipole separates the electron from the THz beam and a quadrupole doublet transports the electron beam to the beam dump. The installation progress will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT016
About •	Received ※ 07 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 25 June 2022
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TUPOPT017	Start-to-end Simulations for Bunch Compressor and THz SASE FEL at PITZ	1037
	A. Lueangaramwong, P. Boonpornprasert, M. Krasilnikov, X.-K. Li, F. Stephan DESY Zeuthen, Zeuthen, Germany
	The magnetic bunch compressor was designed as part of a THz accelerator source being developed at the Photo Injector Test facility at DESY in Zeuthen (PITZ) as a prototype for pump-probe experiments at the European XFEL. As an electron bunch is compressed to achieve higher bunch currents for the THz source, the beam dynamics in the bunch compressor was studied by numerical simulations. A start-to-end simulation optimizer including coherent synchrotron radiation (CSR) effects has been developed by combining the use of ASTRA, OCELOT, and GENESIS to support the design of the THz source prototype. In this paper we present simulation results to explore the possibility of improving the performance of the THz FEL at PITZ by using the developed bunch compressor.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT017
About •	Received ※ 18 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 13 June 2022
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TUPOPT018	Fermi 2.0 Future Upgrade Strategy	1041
	L. Giannessi, E. Allaria, L. Badano, F. Bencivenga, C. Callegari, F. Capotondi, D. Castronovo, P. Cinquegrana, M. Coreno, M.B. Danailov, G. De Ninno, P. Delgiusto, A.A. Demidovich, S. Di Mitri, B. Diviacco, W.M. Fawley, M. Ferianis, G. Gaio, F. Gelmetti, G. Kurdi, M. Lonza, M. Malvestuto, M. Manfredda, C. Masciovecchio, I. Nikolov, G. Penco, K.C. Prince, E. Principi, P. Rebernik Ribič, C. Scafuri, N. Shafqat, P. Sigalotti, A. Simoncig, F. Sottocorona, S. Spampinati, C. Spezzani, L. Sturari, M. Trovò, M. Veronese, R. Visintini, M. Zangrando Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy M. Coreno CNR-ISM, Trieste, Italy G. Penn LBNL, Berkeley, California, USA G. Perosa Università degli Studi di Trieste, Trieste, Italy T. Tanaka RIKEN SPring-8 Center, Hyogo, Japan
	FERMI is studying a series of developments to keep the facility in a world-leading position on the base of the requests coming from the user community, the Scientific Advisory Council and the Machine Advisory Committee. The ultimate goal of the development plan consists in doubling the photon energy range and reducing the pulse duration below the characteristic lifetime of the atomic core levels located in the energy range of the source. One of the most promising approaches is the echo-enabled harmonic generation (EEHG) scheme, relying on two external lasers to precisely control the spectro-temporal properties of the FEL pulse. The implementation of EEHG in the double-stage harmonic cascade presently in use on FEL-2, would allow harmonics as high as 120 enabling to generate coherent pulses down to 2 nm starting from UV lasers. An upgrade of FERMI aimed at reaching the oxygen K-edge requires a profound modification of the FEL configurations and of the main components of the machine, including the linac and the undulator lines. The main aspects of the upgrade strategy will be discussed in this presentation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT018
About •	Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 07 July 2022
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TUPOPT019	FERMI FEL-1 Upgrade to EEHG	1044
	C. Spezzani, E. Allaria, L. Badano, D. Castronovo, P. Cinquegrana, M.B. Danailov, R. De Monte, G. De Ninno, P. Delgiusto, A.A. Demidovich, S. Di Mitri, B. Diviacco, M. Ferianis, G. Gaio, F. Gelmetti, L. Giannessi, G. Kurdi, M. Lonza, C. Masciovecchio, I. Nikolov, G. Penco, P. Rebernik Ribič, C. Scafuri, N. Shafqat, P. Sigalotti, F. Sottocorona, S. Spampinati, L. Sturari, M. Trovò, M. Veronese, R. Visintini Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy G. Perosa Università degli Studi di Trieste, Trieste, Italy
	The Fermi free-electron laser (FEL) facility is operating since 2010 providing the user community with ultrashort pulses in the VUV- XUV range. Using the High Gain Harmonic Generation (HGHG) setup, nearly transform-limited pulses with gigawatt peak power are made available. Furthermore, several multicolor and coherent control schemes are possible and highly required from the user community. To meet the request of extending the spectral range over the whole water window, an upgrade strategy of the FERMI facility has recently initiated. During the first phase of the upgrade, the single cascade FEL-1 will be adapted to operate either in Echo Enabled Harmonic Generation (EEHG) or in HGHG. Required modifications can be achieved with limited impact on FERMI operations and will improve FEL-1’s spectral range, spectral quality and flexibility. The second phase includes modification of the FEL-2 setup and will benefit from the experience gained with phase 1. The two phases will proceed in parallel to the linac upgrade aiming at extending the beam energy to 1.8 GeV. We report here details on the upgrade of the FEL-1 foreseen to provide light to users in the new configuration by spring 2023.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT019
About •	Received ※ 07 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 21 June 2022 — Issue date ※ 29 June 2022
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TUPOPT023	Undulator Tapering Studies of an Echo-Enabled Harmonic Generation Based Free-Electron Laser	1047
SUSPMF010	use link to see paper's listing under its alternate paper code
	F. Pannek, W. Hillert University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany S. Ackermann, E. Ferrari, L. Schaper DESY, Hamburg, Germany
	The free-electron laser (FEL) user facility FLASH at DESY is currently undergoing an upgrade which involves the transformation of one of its beamlines to allow for external seeding via so-called Echo-Enabled Harmonic Generation (EEHG). With this seeding technique it will be possible to provide stable, longitudinal coherent and intense radiation in the XUV and soft X-ray regime at high repetition rate. To ensure an efficient FEL amplification process, sustainable energy exchange between the electrons and the electromagnetic field in the undulator is mandatory. Adequate adjustment of the undulator strength along the beamline allows to compensate for electron energy loss and to preserve the resonance condition. The impact of this undulator tapering on the temporal and spectral characteristics on the EEHG FEL radiation at 4 nm is investigated by means of numerical simulations performed with the FEL code GENESIS 1.3, version 4. Different tapering methods are examined and it is shown that specific tapering of the undulator strength allows to exceed the FEL saturation power while maintaining a clear temporal and spectral shape of the FEL pulse.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT023
About •	Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 27 June 2022
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TUPOPT024	Recent Developments at SOLARIS National Synchrotron Radiation Centre	1051
	A.I. Wawrzyniak, P. Andryszczak, G. Cios, K. Gula, G.W. Kowalskipresenter, A.M. Marendziak, A. Maximenko, R. Panaś, T. Sobol, M. Szczepaniak, J.J. Wiechecki, M. Wiśniowski, M. Zając NSRC SOLARIS, Kraków, Poland A. Curcio CLPU, Villamayor, Spain H. Lichtenberg Hochschule Niederrhein University of Applied Sciences, Krefeld, Germany
	SOLARIS National Synchrotron Radiation Centre is under constant development of the research infrastructure. In 2018 first users were welcomed at three different experimental stations. Up to now 5 end stations are available at SOLARIS for experiments at 4 beamlines, and 4 new beamlines are under construction. In 2021 new front end for POLYX beamline was installed and de-gassed. Moreover, ASTRA beamline components were installed and first commissioning stage has stared. Additionally, a plasma cleaning station has been designed, built and is currently tested. Apart of the beamlines, up-grades to the linac and storage ring operation have been done. During the COVID-19 pandemic the software for remote injection process was developed and is used on daily basis. The transverse beam emittance measurement on the visible light beamline LUMOS was implemented and gives results that are complementary to the Pinhole beamline. Within this presentation the overview of the recent developments with insight to the details to be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT024
About •	Received ※ 09 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 21 June 2022
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TUPOPT025	Concept of Electron Beam Diagnostics for PolFEL	1055
	A.I. Wawrzyniak, G.W. Kowalskipresenter, A.M. Marendziak, R. Panaś NSRC SOLARIS, Kraków, Poland A. Curcio CLPU, Villamayor, Spain P.J. Czuma, M. Krakówiak, P. Krawczyk, R. Kwiatkowski, S. Mianowski, R. Nietubyc, M. Staszczak, J. Szewiński, M. Terka, M. Wójtowicz NCBJ, Świerk/Otwock, Poland K. Łasocha Jagiellonian University, Kraków, Poland
	PolFEL - Polish Free Electron Laser will be driven by a continuous wave superconducting accelerator consist-ing of low emittance superconducting RF electron gun, four accelerating cryomodules, bunch compressors, beam optics components and diagnostic elements. The acceler-ator will split in three branches leading to undulators pro-ducing VUV, IR and THz radiation, respectively. Two accelerating cryomodules will be installed before a dogleg directing electron bunches towards IR and THz branches. Additional two cryomodules will be placed in the VUV branch accelerating electron bunches up to 185 MeV at 50 kHz repetition rate. Moreover, the electron beam after passing the VUV undulator will be directed to the Inverse Compton Scattering process for high energy photons experiments in a dedicated station. In order to measure and optimise the electron beam parameters along the entire accelerator the main diagnostics components like BPMs, charge monitors, YAG screens, coherent diffrac-tion radiation (CDR) monitors and beam loss monitors are foreseen. Within this presentation the concept of the electron beam diagnostics will be discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT025
About •	Received ※ 09 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 27 June 2022
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TUPOPT026	Design and Status of Fast Orbit Feedback System at SOLARIS	1059
	G.W. Kowalski, K. Gula, R. Panaś, A.I. Wawrzyniak, J.J. Wiechecki NSRC SOLARIS, Kraków, Poland
	SOLARIS storage ring has been built with basic set of diagnostic and feedback systems. FOFB system, as much more advanced and not as critical for startup was envisioned as later addition to the design. Now, we are in the process of implementing this addition. The system’s workhorse is Instrumentation Technologies Libera Brilliance+ with its Fast Acquisition data path and customizable FPGA modules. Feedback algorithm running in hardware provides fast calculations and direct communication with fast power supplies. The hardware installation is almost finished with configuration and software works running in parallel. First measurements of response matrix and proof-of-concept tests were performed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT026
About •	Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 30 June 2022
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TUPOPT027	Numerical Simulation of a Superradiant THz Source at the PITZ Facility	1063
	N. Chaisueb, S. Rimjaem Chiang Mai University, Chiang Mai, Thailand P. Boonpornprasert, M. Krasilnikov, X.-K. Li, A. Lueangaramwong DESY Zeuthen, Zeuthen, Germany S. Rimjaem ThEP Center, Commission on Higher Education, Bangkok, Thailand
	An accelerator-based THz source is under development at the Photo Injector Test Facility at DESY in Zeuthen (PITZ). The facility can produce high brightness electron beams with high charge and small emittance. Currently, a study on development of a tunable high-power THz SASE FEL for supporting THz-pump, X-ray-probe experiments at the European XFEL is underway. An LCLS-I undulator, a magnetic chicane bunch compressor, and THz pulse diagnostics have been installed downstream the previously existing setup of the PITZ beamline. Additional to the SASE FEL, a possibility to generate superradiant THz undulator radiation from short electron bunches is under investigation, which is the focus in this study. Numerical simulations of the superradiant THz radiation by using sub-picosecond electron bunches with energy of 6 - 22 MeV and bunch charge up to 2 nC produced from the PITZ accelerator are performed. The results show that the radiation with a spectral range of 0.5 to 9 THz and a pulse energy in the order of sub-uJ can be obtained. The results from this study can be used as a benchmark for the future development.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT027
About •	Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 07 July 2022
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TUPOPT028	THz Undulator Radiation Based on Super-Radiant Technique at Chiang Mai University	1067
	E. Kongmon IST, Chiang Mai, Thailand N. Chaisueb, S. Rimjaem Chiang Mai University, Chiang Mai, Thailand S. Rimjaem ThEP Center, Commission on Higher Education, Bangkok, Thailand
	A linear accelerator system at the PBP-CMU Electron Linac Laboratory is used as an electron source for generating coherent THz radiation and MIR-FEL. To achieve high power THz radiation, the super-radiant technique using pre-bunched electrons and undulator magnet is utilized. In this study, we investigate the generation of such radiation with comparable properties as the FEL. The beamline composes of a 180-degree magnetic bunch compressor, a 2 m-electromagnet undulator, quadrupole magnets and diagnostic devices. This work includes the undulator design and investigation on properties of electron beam and THz radiation. Based-on the results of beam dynamic study, the optimized electron beams have an energy in a range of 10-16 MeV, a bunch charge of 100 pC, and a bunch length of 300 fs. The radiation with frequency covering from 0.5 to 3 THz yields a peak power of 5.21 MW at 1.15 THz. This information was used as an initial parameter for undulator design by using the CST-EM Studio software. It has 19.5 periods with a period length of 100 mm. The design results show that the maximum magnetic field is 0.2317 T. The results of this study are used as the guideline for construction of the undulator and the THz-FEL beamline.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT028
About •	Received ※ 08 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 27 June 2022
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TUPOPT029	Infrared Free-Electron Laser Project in Thailand	1070
	S. Rimjaem, N. Chaisueb, P. Kitisri, K. Kongmali, E. Kongmon, P. Nanthanasit, S. Pakluea, J. Saisut, S. Sukara, K. Techakaew, C. Thongbai Chiang Mai University, Chiang Mai, Thailand P. Apiwattanakul, P. Jaikaew, W. Jaikla, N. Kangrang Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand M. Jitvisate Suranaree University of Technology, Nakhon Ratchasima, Thailand M.W. Rhodes ThEP Center, Commission on Higher Education, Bangkok, Thailand
	The infrared free-electron laser (IR FEL) project is established at Chiang Mai University in Thailand with the aim to provide experimental stations for users utilizing accelerator-based terahertz (THz) and mid-infrared (MIR) radiation. Main components of the system include a thermionic RF gun, an alpha magnet as a bunch compressor and energy filter, a standing-wave RF linac, a THz transition radiation (THz-TR) station, two magnetic bunch compressors and beamlines for MIR/THz FEL. The system commissioning is ongoing to produce the beams with proper properties. Simulation results suggest that the oscillator MIR-FEL with wavelengths of 9.5-16.6 um and pulse energies of 0.15-0.4 uJ can be produced from 60-pC electron bunches with energy of 20-25 MeV. The super-radiant THz-FEL with frequencies of 1-3 THz and 700 kW peak power can be produced from 10-16 MeV electron bunches with a charge of 50 pC and a length of 200-300 fs. Furthermore, the THz-TR with a spectral range of 0.3-2.5 THz and a pulse power of up to 1.5 MW can be obtained. The MIR/THz FEL will be used as high-brightness light source for pump-probe experiments, while the coherent THz-TR will be used in time-domain spectroscopy.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT029
About •	Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 16 June 2022
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TUPOPT030	Design and Simulation of the MIR-FEL Generation System at Chiang Mai University	1074
SUSPMF012	use link to see paper's listing under its alternate paper code
	S. Sukara, K. Kongmali, S. Rimjaem Chiang Mai University, Chiang Mai, Thailand H. Ohgaki Kyoto University, Kyoto, Japan
	At the PBP-CMU Electron Linac Laboratory, the system to generate MIR-FEL using the electron linac has been developed. In this contribution, the design and simulation results of the MIR-FEL generation system are presented. The system is designed as the oscillator-FEL type consisting of two mirrors and a 1.6-m permanent planar undulator. The middle of the undulator is determined as the laser beam waist position. Both two mirrors are the concave gold-coated copper mirrors placing upstream and downstream the optical cavity, which has a total length of 5.41 m. The FEL is designed to coupling out at a hole with diameter of 2 mm on the upstream mirror. The optical cavity is optimized to obtain high FEL gain and high FEL power using GENESIS 1.3 simulation code. The electron beam with energy of 25 MeV is used in the consideration. As a result, the MIR-FEL with central wavelength of 13.01 ’m is obtained. The optimum upstream and downstream mirror curvatures are 3.091 m and 2.612 m, respectively, which give the Rayleigh length of 0.631 m. This optical cavity yields the power coupling ratio of 1:1000 and the FEL gain of up to 40%. The extracted MIR-FEL peak power in 100 kW scale is obtained at the coupling hole. The construction of the practical MIR-FEL system is conducted based on the results from this study.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT030
About •	Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 01 July 2022
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TUPOPT032	Simulating Beam Transport with Permanent Magnet Chicane for THz Fel	1077
SUSPMF013	use link to see paper's listing under its alternate paper code
	A.C. Fisher, M.P. Lenz, P. Musumeci, A. Ody, Y. Park UCLA, Los Angeles, USA R.B. Agustsson, T.J. Hodgetts, A.Y. Murokh RadiaBeam, Santa Monica, California, USA
	Funding: This work was supported by NSF grant PHY-1734215 and DOE grant No. DE-SC0009914 and DE-SC0021190. The undulator construction has been carried out under SBIR/STTR DE-SC0017102 and DE-SC0018559. Free electron lasers are an attractive option for high average and peak power radiation in the THz gap, a region of the electromagnetic spectrum where radiation sources are scarce, as the required beam and undulator parameters are readily achievable with current technology. However, slippage effects require the FEL to be driven with relatively long and low current electron bunches, limiting amplification gain and output power. Previous work demonstrated that a waveguide could be used to match the radiation and e-beam velocities in a meter-long strongly-tapered helical undulator, resulting in 10\% energy extraction from an ultrashort 200 pC, 5.5 MeV electron beam. We present simulations for a follow-up experiment targeting higher frequencies with improvements to the e-beam transport including a permanent magnet chicane for strong beam compression. FEL simulations show >20\% extraction efficiency from a 125 pC, 7.4 MeV electron beam at 0.32 THz.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT032
About •	Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 28 June 2022
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TUPOPT034	Modelling of X-Ray Volume Excitation of the XLO Gain Medium Using Flash	1081
	P. Manwani, N. Majernik, B. Naranjo, J.B. Rosenzweig UCLA, Los Angeles, California, USA E.C. Galtier, A. Halavanau, C. Pellegrini SLAC, Menlo Park, California, USA
	Funding: This work was performed with the support of the US Department of Energy under Contract No. DE-AC02-76SF00515 and DESC0009914. Plasma dynamics and crater formation of laser excited volumes in solids is a complex process due to thermalization, shockwave formation, varying absorption mechanisms, and a wide range of relevant physics timescales. The properties and interaction of such laser-matter systems can be modeled using an equation of state and opacity based multi-temperature treatment of plasma using a radiation hydrodynamics code. Here, we use FLASH, an adaptive mesh radiation-hydrodynamics code, to simulate the plasma expansion following after the initial energy deposition and thermalization of the column, to benchmark the results of experiments undertaken at UCLA on optical laser ablation. These computational results help develop a quantitative understanding of the material excitation process and enable the optimization of the gain medium delivery system for the x-ray laser oscillator project *. * Halavanau, Aliaksei, et al. "Population Inversion X-Ray Laser Oscillator." Proceedings of the National Academy of Sciences, vol. 117, no. 27, 2020, pp. 15511-15516.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT034
About •	Received ※ 08 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 18 June 2022 — Issue date ※ 24 June 2022
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TUPOPT035	Introduction of Westwood Linear Accelerator Test Facility in University of California Los Angeles	1085
	Y. Sakai, G. Andonian, O. Camacho, A. Fukasawa, G.E. Lawlerpresenter, N. Majernik, P. Manwani, B. Naranjo, J.B. Rosenzweig, O. Williams UCLA, Los Angeles, California, USA
	Funding: U.S. DOE: DE-SC0009914 U.S. DOD: DARPA GRIT Contract 20204571 U.S. DOE: DE-SC0020409 - Cryo RF An electron linear accelerator test facility located on UCLA’s southwest campus in Westwood, SAMURAI, is presently being constructed. A RF-based accelerator consists of a compact, 3 MeV S-band hybrid gun capable of velocity bunching to bunch lengths in the 100s fs range with 100s pC of charge. This beam is accelerated by an 1.5 m S-band linac with a peak output energy of 30 MeV which can be directed to either a secondary beamline or remain on the main beamline for final acceleration by a SLAC 3 m S-band linac to an energy of 80 MeV. Further acceleration by advanced boosters such as a cryo-cooled C-band structure or numerous optical or wakefield methods is under active investigation. In combination with a 3 TW Ti:Sapphire laser, initial proof of principle experiments will be conducted on topics including the ultra-compact x-ray free-electron laser, advanced dielectric wakefield acceleration, bi-harmonic nonlinear inverse Compton scattering, and various radiation detectors. Furthermore, development of a tertiary beamline based on an ultra low emittance, cryo-cooled gun will eventually enable two-beam experiments, expanding the facility’s unique experimental capabilities.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT035
About •	Received ※ 08 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 20 June 2022 — Issue date ※ 24 June 2022
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TUPOPT036	Two and Multiple Bunches with the LCLS Copper Linac	1089
	F.-J. Decker, W.S. Colocho, A. Halavanau, A.A. Lutman, J.P. MacArthur, G. Marcus, R.A. Margraf, J.C. Sheppard, J.J. Turner, S. Vetter SLAC, Menlo Park, California, USA
	Two, four, and even eight bunches were accelerated through the copper linac. Two and four bunches were delivered successfully to photon experiments in both the hard (HXR) and soft (SXR) LCLS x-ray lines. In this paper we will concentrate on the more challenging issues, such as: the BPM deconvolution for both bunches, RF kicks at longer separations, tuning challenges, bridging the communications gap between the photon and electron side, the lower bunch charges for the eight bunch case, and rapid timing scans over several ns. We will describe some of the developed solutions and plans for the rest.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT036
About •	Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 28 June 2022
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TUPOPT037	LCLS Multi-Bunch Improvement Plan: First Results	1092
	A. Halavanau, A.L. Benwell, T.G. Beukers, L.B. Borzenets, F.-J. Deckerpresenter, J. Hugyik, A. Ibrahimov, E.N. Jongewaard, A.K. Krasnykh, A.L. Le, K. Luchini, A.A. Lutman, A. Marinelli, M. Petree, A. Romero, A.V. Sy SLAC, Menlo Park, California, USA
	LCLS copper linac primarily operates in a single bunch mode with a repetition rate of 120 Hz. Presently, several in-house projects and LCLS user experiments require double- and multi-pulse trains of X-rays, with inter-pulse delay spanning between 0.35 and 220 ns. We discuss beam control improvements to the copper linac using ultra-fast stripline kicker, as well as additional photon diagnostics. We especially focus on a case of double-pulse mode, with 218 ns separation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT037
About •	Received ※ 12 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 10 July 2022
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TUPOPT038	FAST-GREENS: A High Efficiency Free Electron Laser Driven by Superconducting RF Accelerator	1094
	P. Musumeci, P.E. Denham, A.C. Fisherpresenter, Y. Park UCLA, Los Angeles, California, USA R.B. Agustsson, T.J. Hodgetts, A.Y. Murokh, M. Ruelas RadiaBeam, Santa Monica, California, USA L. Amoudry Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France D.R. Broemmelsiek, S. Nagaitsev, J. Ruan, J.K. Santucci, G. Stancari, A. Valishev Fermilab, Batavia, Illinois, USA D.L. Bruhwiler, J.P. Edelen, C.C. Hall RadiaSoft LLC, Boulder, Colorado, USA A.H. Lumpkin, A. Zholents ANL, Lemont, Illinois, USA
	Funding: This work is supported by DOE grants DE-SC0017102, DE-SC0018559 and DE-SC0009914 In this paper we’ll describe the FAST-GREENS experimental program where a 4 m-long strongly tapered helical undulator with a seeded prebuncher is used in the high gain TESSA regime to convert a significant fraction (up to 10 %) of energy from the 240 MeV electron beam from the FAST linac to coherent 515 nm radiation. We’ll also discuss the longer term plans for the setup where by embedding the undulator in an optical cavity matched with the high repetition rate from the superconducting accelerator (3,9 MHz), a very high average power laser source can be obtained. Eventually, the laser pulses can be redirected onto the relativistic electrons to generate by inverse compton scattering a very high flux of circularly polarized gamma rays for polarized positron production.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT038
About •	Received ※ 09 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 02 July 2022
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TUPOPT039	Characterization of Diamond with Buried Boron-Doped Layer Developed for Q-Switching an X-Ray Optical Cavity	1097
	R.A. Margraf, A. Halavanau, Z. Huang, J. Krzywiński, J.P. MacArthur, G. Marcus, M.L. Ng, A.R. Robert, R. Robles, T. Sato, D. Zhu SLAC, Menlo Park, California, USA Z. Huang, F. Ke, R. Robles, Y. Zhong Stanford University, Stanford, California, USA S.-K. Mo, Y. Zhong LBNL, Berkeley, California, USA P. Pradhan ANL, Lemont, Illinois, USA A.R. Robert MAX IV Laboratory, Lund University, Lund, Sweden M.D. Ynsa UAM, Madrid, Spain
	Funding: This work was supported by the Department of Energy, Laboratory Directed Research and Development program at SLAC National Accelerator Laboratory, under contract DE-AC02-76SF00515. X-ray Free-Electron Laser Oscillators (XFELOs) and X-ray Regenerative Amplifier FELs (XRAFELs) are currently in development to improve longitudinal coherence and spectral brightness of XFELs. These schemes lase an electron beam in an undulator within an optical cavity to produce X-rays. X-rays circulate in the cavity and interact with fresh electron bunches to seed the FEL process over multiple passes, producing progressively brighter and more spectrally pure X-rays. Typically, the optical cavities used are composed of Bragg-reflecting mirrors to provide high reflectivity and spectral filtering. This high reflectivity necessitates special techniques to out-couple X-rays from the cavity to deliver them to users. One method involves "Q-switching" the cavity by actively modifying the reflectivity of one Bragg-reflecting crystal. To control the crystal lattice constant and thus reflectivity, we use an infrared laser to heat a buried boron layer in a diamond crystal. Here, we build on earlier work in Krzywinski et al.* and present the current status of our Q-switching diamond, including implantation with 9 MeV boron ions, annealing, characterization and early tests. *Krzywinski et al., "Q-switching of X-Ray Optical Cavities by using Boron Doped Buried Layer under a Surface of a Diamond Crystal," Proceedings of FEL2019, Hamburg, Germany, TUP033, 2019.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT039
About •	Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 08 July 2022
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TUPOPT044	High-Power Attosecond Pulses via Cascaded Amplification	1101
	P.L. Franz, Z.H. Guo, S. Li, R. Robles Stanford University, Stanford, California, USA D.K. Bohler, D.B. Cesar, X. Cheng, J.P. Cryan, T.D.C. Driver, J.P. Duris, A. Kamalov, S. Li, A. Marinelli, R. Obaid, R. Robles, N.S. Sudar, A.L. Wang, Z. Zhang SLAC, Menlo Park, California, USA
	Funding: This work was supported by US Department of Energy Contracts No. DE-AC02-76SF00. The timescale for electron motion in molecular systems is on the order of hundreds of attoseconds, and thus the time-resolved study of electronic dynamics requires a source of sub-femtosecond x-ray pulses. Here we report the experimental generation of sub-femtosecond duration soft x-ray free electron laser (XFEL) pulses with hundreds of microjoules of energy using fresh-slice amplification in two cascaded stages at the Linac Coherent Light Source. In the first stage, an enhanced self-amplified spontaneous emission (ESASE) pulse is generated using laser-shaping of the electron beam at the photocathode*. The electron bunch is then delayed relative to the pulse by a magnetic chicane, allowing the radiation to slip onto a fresh slice of the bunch, which amplifies the ESASE pulse in the second cascade stage. Angular streaking** characterizes the experimental pulse durations as sub-femtosecond at ~465 eV in the experiment. * Zhang, Z. et al. New J. Phys. 22 (2020) ** Li, S. et al. Optics Express 26.4 (2018): 4531-4547.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT044
About •	Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 21 June 2022
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TUPOPT046	Electron Transport for the LCLS-II-HE Low Emittance Injector	1103
	Y.M. Nosochkov, C. Adolphsen, R. Coy, C.E. Mayes, T.O. Raubenheimer, M.D. Woodley SLAC, Menlo Park, California, USA
	Funding: Work supported by the Department of Energy Contract DE-AC02-76SF00515. The Low Emittance Injector (LEI) is a recent addition to the LCLS-II High Energy (LCLS-II-HE) Project under design at SLAC National Accelerator Laboratory. It will provide a second beam source capable of producing a low emittance electron beam that increases the XFEL photon energy reach to 20 keV. The LEI will include an SRF electron gun, a buncher system, a 1.3 GHz cryomodule, and a beam transport system with a connection to the LCLS-II beamline and a stand-alone diagnostic line. The LEI transport beamlines and diagnostic are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT046
About •	Received ※ 08 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 08 July 2022
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TUPOPT047	Progress Report on Population Inversion X-Ray Laser Oscillator at LCLS	1107
	A. Halavanau, R. Alonso-Mori, A. Aquila, U. Bergmann, F.-J. Decker, F. Fuller, M. Liang, A.A. Lutman, R.A. Margraf, R.H. Paul, C. Pellegrini SLAC, Menlo Park, California, USA R. Ash, N.B. Welke UW-Madison/PD, Madison, Wisconsin, USA A.I. Benediktovitch DESY, Hamburg, Germany S.C. Krusic JSI, Ljubljana, Slovenia N. Majernik, P. Manwani, J.B. Rosenzweig UCLA, Los Angeles, California, USA R. Roblespresenter Stanford University, Stanford, California, USA N. Rohringer Max Planck Institute for the Physics of Complex Systems, Dresden, Germany
	We report the progress in the design and construction of a population inversion x-ray laser oscillator (XLO) using LCLS as an x-ray laser pump, being developed by a SLAC, CFEL, University of Hamburg (Germany), University of Wisconsin, Josef Stefan Institute (Slovenia) and UCLA collaboration. In this proceeding, we will present the latest XLO design and numerical simulations substantiated by our first experimental results. In our next experimental step XLO will be tested on the Coherent X-ray Imaging (CXI) end-station at LCLS as a two pass Regenerative Amplifier operating at the Copper Kα1 photon energy of 8048 eV. When built, XLO will generate fully coherent transform limited pulses with about 50 meV FWHM bandwidth. We expect the XLO will pave the way for new user experiments, e.g. in inelastic x-ray scattering, parametric down conversion, quantum science, x-ray interferometry, and external hard x-ray XFEL seeding.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT047
About •	Received ※ 12 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 24 June 2022
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TUPOPT048	bERLinPro Becomes SEALab: Status and Perspective of the Energy Recovery Linac at HZB	1110
	A. Neumann, B. Alberdi-Esuainpresenter, T. Birke, P. Echevarria, D. Eichel, F. Falkenstern, R. Fleischhauer, A. Frahm, F. Göbel, A. Heugel, F. Hoffmann, H. Huck, T. Kamps, S. Klauke, G. Klemz, J. Kolbe, J. Kühn, B.C. Kuske, J. Kuszynski, S. Mistry, N. Ohm, H. Ploetz, S. Rotterdam, O. Schappeit, G. Schindhelm, C. Schröder, M. Schuster, H. Stein, E. Suljoti, Y. Tamashevich, M. Tannert, J. Ullrich, A. Ushakov, J. Völker, C. Wang HZB, Berlin, Germany T. Kamps HU Berlin, Berlin, Germany
	Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association Since end of the year 2020 the energy recovery linac (ERL) project bERLinPro of Helmholtz-Zentrum Berlin has been officially completed. But what is the status of this facility, the next scientific goals in the framework of accelerator physics at HZB, what are the perspectives? To reflect the continuation of this endeavor and the broadening of applications of this machine from high current SRF based energy recovery concept up to an ultrafast electron diffraction (UED) facility producing shortest electron pulses, the facility is now named Sealab, Superconducting RF Electron Accelerator Laboratory. In this contribution, an overview of lessons learned so far, the status of the machine, the coming set up and commissioning steps with an outlook to midterm and future applications will be given. In summary, Sealab will expand, including the ERL application, and become a general accelerator physics and technology test machine to employ UED as a first study case and will also be an ideal testbed to investigate new control schemes based on digital twins or machine learning methods.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT048
About •	Received ※ 06 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 03 July 2022
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TUPOPT050	Investigation of Polarization Dependent Thomson Scattering in an Energy-Recovering Linear Accelerator on the Example of Mesa	1114
SUSPMF018	use link to see paper's listing under its alternate paper code
	C.L. Lorey, A. Meseck KPH, Mainz, Germany
	Funding: GRK 2128 AccelencE funded by the DFG At the Johannes Gutenberg University (JGU) in Mainz, a new accelerator is currently under construction in order to deliver electron beams of up to 155 MeV to two experiments. The Mainz Energy-recovering Superconducting Accelerator (MESA) will offer two modes of operation, one of which is an energy-recovering (ER) mode. As an ERL, MESA, with it’s high brightness electron beam, is a promising accelerator for supplying a Thomson back scattering based Gamma source. Furthermore, at MESA, the polarization of the electron beam can be set by the injector. The aim of this work is to provide a concept and comprehensive analysis of the merit and practical feasibility of a Thomson backscattering source at MESA under consideration of beam polarization and transversal effects. In this paper, an overview and results of our semi analytical approach to calculate various Thomson back scattering light source scenarios at MESA will be given. Furthermore we will discuss the benefits of using polarized electrons in combination with a polarized laser beam.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT050
About •	Received ※ 08 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 26 June 2022
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TUPOPT051	Reconstruction and Beam-Transport Study of the cERL Dump Line for High-Power IR-FEL Operation	1117
	N. Nakamura, K. Harada, N. Higashi, R. Kato, S. Nagahashi, K.N. Nigorikawa, T. Nogami, T. Obina, H. Sagehashi, H. Sakai, M. Shimada, R. Takai, O.A. Tanakapresenter, Y. Tanimoto, T. Uchiyama, A. Ueda KEK, Ibaraki, Japan
	Funding: This work is supported by a NEDO project "Development of advanced laser processing with intelligence based on high-brightness and high-efficiency laser technologies." A significant FEL pulse energy was successfully generated at the cERL IR-FEL in Burst mode where a macro pulse of about 1 microsecond or less is repeated at the maximum frequency of 5 Hz. In the next step, high-power FEL operation in CW mode should be carried out with energy recovery by increasing electron bunches drastically. However, momentum spread of the electron beam increases due to the FEL-light emission and the space charge effects and may cause serious beam loss by exceeding the momentum acceptance of the cERL downstream of the FEL. Therefore, we reconstructed the dump line in Autumn 2020 in order to greatly increase the momentum acceptance with improvement of the beam-tuning flexibility. Then we performed the beam-transport study of the reconstructed dump line in March 2021 by injecting the beam directly from the injector without passing the recirculation loop. In this paper, we present the reconstructed dump line and the beam-transport study.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT051
About •	Received ※ 16 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 13 June 2022
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TUPOPT052	Proposal for Non-Destructive Electron Beam Diagnostic with Laser-Compton Backscattering at the S-Dalinac	1121
	M.G. Meier, M. Arnold, J. Enders, N. Pietralla TU Darmstadt, Darmstadt, Germany
	Funding: Work supported in part by the state of Hesse within the research cluster ELEMENTS (project ID 500/10.006) and the LOEWE research cluster Nuclear Photonics and by DFG through GRK 2128 "Accelence" and Inst163/308-1 FUGG. To recover a large fraction of energy from the accelerator process in an energy-recovery linac, experiments, secondary-beam production, and beam diagnostics must be non-destructive and/or, hence, feature a low interaction probability with the very intense electron-beam. Laser-Compton backscattering can provide a quasi-monochromatic highly polarized X-ray to γ-ray beam without strongly affecting the electron beam due to the small recoil and the small Compton cross-section. Highest energies of the scattered photons are obtained for photon-scattering angles of \ang{180}, i. e., backscattering. A project at TU Darmstadt foresees to synchronize a highly repetitive high-power laser with the Superconducting DArmstadt electron LINear ACcelerator S\hbox{-}DALINAC, capable of running in energy recovery mode * to realize a laser-Compton backscattering source with photon beam energy up to §I{180}{\kilo\electronvolt}. The source will be first used as a diagnostic tool for determining and monitoring key electron-parameters, in particular energy and the energy spread at the S\hbox{-}DALINAC operation. Results are foreseen to be used for optimizing the design of laser-Compton backscattering sources at energy-recovery linacs. *M. Arnold et al., Phys. Rev. Accel. Beams 23, 020101(2020)
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT052
About •	Received ※ 07 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 24 June 2022
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TUPOPT053	Study of Bunch Length Measurement by Forward Coherent Smith-Purcell Radiation	1125
	H. Yamada, H. Hama, F. Hinode, K. Kanomata, S. Kashiwagi, S. Miura, T. Muto, I. Nagasawa, K. Nanbu, H. Saito, K. Shibata, K. Takahashi Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
	We are currently conducting basic research on the development of a non-destructive real-time bunch length monitor using coherent Smith-Purcell radiation at the t-ACTS test accelerator at the Center for Electron Photon Science, Tohoku University. The angular distribution of coherent Smith-Purcell radiation reflects the longitudinal shape of the electron bunch. Using this, we came up with a method to measure the bunch length from the peak angle of the angular distribution. In this presentation, we mainly report the results of an experiment to determine the bunch length from the peak angle of the angular distribution of coherent Smith-Purcell radiation using a 100 fs electron beam of t-ACTS.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT053
About •	Received ※ 14 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 09 July 2022
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TUPOPT054	Generation of Coherent THz Transition Radiation for Time Domain Spectroscopy at the PBP-CMU Electron Linac Laboratory	1129
SUSPMF019	use link to see paper's listing under its alternate paper code
	S. Pakluea Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand M. Jitvisate Suranaree University of Technology, Nakhon Ratchasima, Thailand S. Rimjaem, J. Saisut, C. Thongbai Chiang Mai University, Chiang Mai, Thailand S. Rimjaem, J. Saisut, C. Thongbai ThEP Center, Commission on Higher Education, Bangkok, Thailand
	The accelerator system at the PBP-CMU Electron Linac Laboratory is used to generate terahertz transition radiation (THz-TR). Due to broad spectrum, it can be used as the light source for THz time-domain spectroscopy (TDS) to measure both the intensity and phase of the THz signal. This contribution presents the generation of the THz-TR produced from 10-20 MeV electron beams and the system preparation for THz TDS. The electron bunches, which are compressed to have a length of femtosecond scale at the experimental station, is used to generate the THz-TR using a 45°-tilted aluminum foil as a radiator. The radiation properties including angular distribution, polarization and radiation spectrum are measured in the accelerator hall and at the TDS station. The radiation spectral range covers up to 2.3 THz with the peak power of 0.5 - 1.25 MW is expected. The effects of electron bunch distribution, divergence of the beam and influence of optical components on the radiation properties were studied. The results show that the considered effects have a significant impact on the TR properties. The Information will be used in the TR characterization that is needed to be interpreted carefully.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT054
About •	Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 27 June 2022 — Issue date ※ 04 July 2022
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TUPOPT057	Using Surrogate Models to Assist Accelerator Tuning at ISIS	1133
	A.A. Saoulis, K.R.L. Baker, H.V. Cavanagh, R.E. Williamson STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom S. Basak, J. Cha, J. Thiyagalingam STFC/RAL/SCD, Didcot, United Kingdom
	Funding: STFC and UKRI High intensity hadron accelerator performance is often dominated by the need to minimise and control beam losses. Operator efforts to tune the machine during live operation are often restricted to local parameter space searches, while existing physics-based simulations are generally too computationally expensive to aid tuning in real-time. To this end, Machine Learning-based surrogate models can be trained on data produced by physics-based simulations, and serve to produce fast, accurate predictions of key beam properties, such as beam phase and bunch shape over time. These models can be used as a virtual diagnostic tool to explore the parameter space of the accelerator in real-time, without making changes on the live machine. At the ISIS Neutron and Muon source, major beam losses in the synchrotron are caused by injection and longitudinal trapping processes, as well as high intensity effects. This paper describes the training and inference performance of a neural network surrogate model of the longitudinal beam dynamics in the ISIS synchrotron, from injection at 70 MeV to 800 MeV extraction, and evaluates the model’s ability to assist accelerator tuning.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT057
About •	Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 03 July 2022
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TUPOPT058	A Machine Learning Approach to Electron Orbit Control at the 1.5 GeV Synchrotron Light Source DELTA	1137
	D. Schirmer DELTA, Dortmund, Germany
	Machine learning (ML) methods have found their application in a wide range of particle accelerator control tasks. Among other possible use cases, neural networks (NNs) can also be utilized for automated beam position control (orbit correction). ML studies on this topic, which were initially based on simulations, were successfully transferred to real accelerator operation at the 1.5-GeV electron storage ring of the DELTA accelerator facility. For this purpose, classical fully connected multi-layer feed-forward NNs were trained by supervised learning on measured orbit data to apply local and global beam position corrections. The supervised NN training was carried out with various conjugate gradient backpropagation learning algorithms. Afterwards, the ML-based orbit correction performance was compared with a conventional, numerical-based computing method. Here, the ML-based approach showed a competitive orbit correction quality in a fewer number of correction steps.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT058
About •	Received ※ 20 May 2022 — Accepted ※ 16 June 2022 — Issue date ※ 25 June 2022
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TUPOPT059	Machine Learning Methods for Chromaticity Control at the 1.5 GeV Synchrotron Light Source DELTA	1141
	D. Schirmer, A. Althaus, T. Schüngel DELTA, Dortmund, Germany
	In the past, the chromaticity values at the DELTA electron storage ring were manually adjusted using 15 individual sextupole power supply circuits, which are combined into 7 magnet families. To automate and optimize the time-consuming setting process, various machine learning (ML) approaches were investigated. For this purpose, simulations were first performed using a storage ring model and the performance of different neural network (NN) based models was compared. Subsequently, the neural networks were trained with experimental data and successfully implemented for chromaticity correction in real accelerator operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT059
About •	Received ※ 20 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 21 June 2022
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TUPOPT060	EPICS-Based Telegram Integration for Control and Alarm Handling at TEX Facility	1145
	S. Pioli, D. Moriggipresenter LNF-INFN, Frascati, Italy F. Cardelli, P. Ciuffetti, C. Di Giulio INFN/LNF, Frascati, Italy
	We report the status of the development of an High Power RF Laboratory in X-Band called TEX (TEst-stand for X-Band). TEX is part of the LATINO (Laboratory in Advanced Technologies for INnOvation) initiative that is ongoing at the Frascati National Laboratories (LNF) of the Italian Institute for Nuclear Physics (INFN) that covers many different areas focused on particle accelerator technologies. TEX is a RF test facility based on solid-state K400 modulator from ScandiNova with a 50 MW class X-band (11.994 GHz) klystron tube model VKX8311A operating at 50 Hz. TeXbot is a Telegram bot used to notify in asynchronous way event at TEX. The application has been realized making use of framework such as telepot and pysmlib, to interface with Telegram and with EPICS environment respectively. The bot make able the user to subscribe to multiple topic in order to be automatically notified in case of different set up of the machine or when an interlock occurs on a single component. Furthermore the user can request detailed information about subsystem of the accelerator by simply make use of special commands and token in Telegram app.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT060
About •	Received ※ 16 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 21 June 2022
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TUPOPT061	Status and Commissioning of the First X-Band RF Source of the TEX Facility	1148
	F. Cardelli, D. Alesini, M. Bellaveglia, S. Bini, M. Ceccarelli, C. Di Giulio, A. Falone, G. Franzini, A. Gallo, L. Piersanti, L. Sabbatini INFN/LNF, Frascati, Italy B. Buonomo, G. Catuscelli, R. Ceccarelli, A. Cecchinelli, R. Clementi, E. Di Pasquale, A. Liedl, D. Moriggipresenter, G. Piermarini, S. Pioli, S. Quaglia, L.A. Rossi, M. Scampati, G. Scarselletta, S. Strabioli, S. Tocci, R. Zarlenga LNF-INFN, Frascati, Italy
	In 2021 started the commissioning of the TEX (Test stand for X-band) facility at the Frascati National laboratories of INFN. This facility has been founded in the framework of the LATINO (Laboratory in Advanced Technologies for INnOvation) project. The current facility layout includes an high power X-band (11.994 GHz) RF source, realized in collaboration with CERN, which will be used for validation and development of the X-band RF high gradient technology in view of the EuPRAXIA@SPARC_LAB project. The RF source is based on a CPI VKX8311 Klystron and a solid state ScandiNova k400 modulator to generate a maximum RF output power of 50 MW at 50 Hz, that will be mainly used for accelerating structure conditioning and waveguide components testing. In this paper the layout, the installation, commissioning and stability measurements of this source are described in detail. The test stand will be soon operative and ready to test the first X-band accelerating structure prototype.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT061
About •	Received ※ 08 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 10 July 2022
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TUPOPT062	A Data-Driven Anomaly Detection on SRF Cavities at the European XFEL	1152
	A. Sulc, A. Eichler, T. Wilksen DESY, Hamburg, Germany
	Funding: This work was supported by HamburgX grant LFF-HHX-03 to the Center for Data and Computing in Natural Sciences (CDCS) from the Hamburg Ministry of Science, Research, Equalities and Districts. The European XFEL is currently operating with hundreds of superconducting radio frequency cavities. To be able to minimize the downtimes, prevention of failures on the SRF cavities is crucial. In this paper, we propose an anomaly detection approach based on a neural network model to predict occurrences of breakdowns on the SRF cavities based on a model trained on historical data. We used our existing anomaly detection infrastructure to get a subset of the stored data labeled as faulty. We experimented with different training losses to maximally profit from the available data and trained a recurrent neural network that can predict a failure from a series of pulses. The proposed model is using a tailored architecture with recurrent neural units and takes into account the sequential nature of the problem which can generalize and predict a variety of failures that we have been experiencing in operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT062
About •	Received ※ 17 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 24 June 2022
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TUPOPT063	Vsystem to EPICS Control System Transition at the ISIS Accelerators	1156
	I.D. Finch, B.R. Aljamal, K.R.L. Baker, R. Brodie, J.-L. Fernández-Hernando, G.D. Howells, M.F. Leputa, S.A. Medley, A.A. Saoulis STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom A. Kurup Imperial College of Science and Technology, Department of Physics, London, United Kingdom
	The ISIS Neutron and Muon Source at Rutherford Appleton Laboratory is a pulsed source used for research in material and life sciences. A linac and synchrotron accelerate protons to produce neutrons in two spallation targets. The accelerators are currently operated using commercial Vsystem control software. A transition to the EPICS control system is underway, with the end goal of a containerised system preferring the pvAccess protocol. We report the progress of this transition, which is being done without disrupting ISIS operations. We describe a bidirectional interface between Vsystem and EPICS that enables the two control systems to co-exist and interact. This allows us to decouple the transition of controls UI from the associated hardware. Automated conversion of the binary-format Vsystem control screens has been developed that replicates the current interface in EPICS, allowing minimal retraining of operators. We also outline the development of EPICS interfaces to standard and unique-to-ISIS hardware, reuse of and managing continuity of existing long-term data archiving, the development of EPICS interfaces to standard and unique-to-ISIS hardware, and migration of alerts.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT063
About •	Received ※ 25 May 2022 — Accepted ※ 13 June 2022 — Issue date ※ 16 June 2022
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TUPOPT064	Online Optimization of NSLS-II Dynamic Aperture and Injection Transient	1159
	X. Yang, B. Bacha, S. Buda, C. Danneil, A.A. Derbenev, D.J. Durfee, K. Ha, Y. Hidaka, Y. Hu, Y. Lipresenter, D. Padrazo Jr, F. Plassard, T.V. Shaftan, V.V. Smaluk, Y. Tian, G.M. Wang, L.H. Yu BNL, Upton, New York, USA
	The goal of the NSLS-II online optimization project is to improve the beam quality for the user experiments. To increase the beam lifetime and injection efficiency, we have developed a model-independent online optimization of nonlinear beam dynamics using advanced algorithms, such as Robust Conjugate-Gradient Algorithm (RCDS). The optimization objective is the injection efficiency and optimization variables are the sextupole magnet strengths. Using the online optimization technique, we increased the NSLS-II dynamic aperture and reduced the amplitude-dependent tune shift. Recently, the sextupole optimization was successfully applied to double the injection efficiency up to above 90% for the high-chromaticity lattice being developed to improve the beam stability and to in-crease the single-bunch beam intensity. Minimizing the beam perturbation during injection is the second objective in this project, realized by online optimization of the injection kickers. To optimize the full set of kicker parameters, including the trigger timing, amplitude, and pulse width, we upgraded all kicker power supplies with the capability of tunable waveform width. As a result, we have reduced the injection transient by a factor of 29, down to the limit of 60 um.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT064
About •	Received ※ 18 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 16 June 2022
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TUPOPT065	Dispersion-Free Steering Beam Based Alignment at SwissFEL	1163
	E. Ferrari, M. Calvi, R. Ganter, C. Kittel, E. Prat, S. Reichepresenter, T. Schietinger PSI, Villigen PSI, Switzerland C. Kittel University of Malta, Information and Communication Technology, Msida, Malta
	Micron-level alignment of the undulator line is required for successful operation of linear accelerator based high gain free electron lasers to produce powerful radiation at X-rays’ wavelengths. Such precision in the straightness of the trajectory allows for an optimal transverse superposition between the electrons and the photon beam. This is extremely challenging and can only be achieved via beam-based techniques. In this paper we will report on the dispersion-free steering approach implemented at SwissFEL, that helped achieving improved performance for both the hard and soft X-ray beamlines.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT065
About •	Received ※ 16 May 2022 — Accepted ※ 16 June 2022 — Issue date ※ 23 June 2022
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TUPOPT066	KEK LUCX Facility Laser-to-RF&RF-to-RF Stability Study and Optimization	1167
SUSPMF098	use link to see paper's listing under its alternate paper code
	K. Popov Sokendai, Ibaraki, Japan A. Aryshev, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan
	KEK LUCX facility* is a linear accelerator devoted to the beam instrumentation R&Ds for present and future accelerator systems and colliders including ILC. According to the ILC TDR**, it is necessary to achieve RF-gun Laser-to-RF&RF-to-RF phase stability of 0.35°(RMS) and amplitude stability of 0.07%(RMS) with implementation of the Digital LLRF feedback based on commercially available FPGA board and digital trigger system. As the first step to achieve ILC stability level at KEK-LUCX facility, present Laser-to-RF&RF-to-RF phase and amplitude jitters were measured using time- and frequency-domain techniques. After that, jitter influence on beam parameters after RF-gun and main solenoid magnet was simulated with ASTRA tracking code*** and results were cross-checked during LUCX facility beam operation. Finally, stable digital trigger system and digital LLRF feedback based on SINAP EVG&EVR and RedPitaya SIGNALlab-250 modules were implemented. This report demonstrates the results of Laser-to-RF&RF-to-RF phase and amplitude jitter measurements cross-checked with ASTRA simulation and real beam parameters measurements before and after LUCX facility stabilization. References *A. Aryshev et al., Appl. Phys. Lett. 111, 033508 (2017). **International Linear Collider Reference Design Report, ILC-REPORT-2007-001, 2007. ***https://www.desy.de/~mpyflo/
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT066
About •	Received ※ 08 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 03 July 2022
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TUPOPT067	Development of a Trigger Distribution System Based on MicroTCA.4	1171
	H. Maesaka, N. Hosoda, T. Inagaki, E. Iwai, T. Ohshima RIKEN SPring-8 Center, Hyogo, Japan N. Hosoda, T. Inagaki, E. Iwai, H. Maesaka, T. Ohshima JASRI, Hyogo, Japan
	We developed a MicroTCA.4 (MTCA.4) module to generate and distribute trigger timing signals. This module has 16 LVDS inputs and 16 LVDS outputs each on the front panel and the Zone 3 connector, and 8 M-LVDS I/O’s for MTCA.4 backplane. The trigger timing of each output can be precisely adjusted with the interval of 238 MHz or 509 MHz clocks by a 24-bit counter. The timing can also be fine-tuned by ~80 ps tap delay. This module has additional 5 optical transceivers, one for receiving trigger signals from upstream and four for fanouts to downstream. A master module distributes trigger signals, trigger counts, and event data through optical links. Slave modules generate trigger output signals with appropriate delays based on the event data and the local setting for each output channel. The timing jitter was measured to be 40 ps std, which is significantly smaller than the clock period of 238 MHz or 509 MHz. This system can also distribute an alarm signal received by a slave module to take data at a faulty situation. Trigger systems with this module have been utilized in SPring-8, SACLA, and NewSUBARU and stably synchronize various accelerator components with sufficient timing accuracy.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT067
About •	Received ※ 08 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 20 June 2022
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TUPOPT068	Transverse and Longitudinal Modulation of Photoinjection Pulses at FLUTE	1174
	M. Nabinger, A.-S. Müller, M.J. Nasse, C. Sax, J. Schaeferpresenter, C. Widmann, C. Xu KIT, Eggenstein-Leopoldshafen, Germany
	Funding: Supported by the Doctoral School "Karlsruhe School of Elementary and Astroparticle Physics: Science and Technology" (KSETA). To generate the electrons to be accelerated, a photoinjection laser is used at the linac-based test facility FLUTE (Ferninfrarot Linac- Und Test Experiment) at the Karlsruhe Institute of Technology (KIT). The properties of the laser pulse, such as intensity, laser spot size or temporal profile, are the first parameters to influence the characteristics of the electron bunches. In order to control the initial parameters of the electrons in the most flexible way possible, the laser optics at FLUTE are therefore supplemented by additional setups that allow transverse and longitudinal laser pulse shaping by using so-called Spatial Light Modulators (SLMs). In the future, the control of the SLMs will be integrated into a Machine Learning (ML) supported feedback system for the optimization of the electron bunch properties. In this contribution the first test experiments and results on laser pulse shaping at FLUTE on the way to this project are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT068
About •	Received ※ 07 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 22 June 2022
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TUPOPT069	Preparation and Characterization of BTO-BFO Multiferroic Ceramics as Electrical Controllable Fast Phase Shifting Component	1178
	N.W. Martirosyan, A. Grigoryan, Kh.Gh. Kirakosyan, V. Sahakyan, A. Sargsyan CANDLE SRI, Yerevan, Armenia A. Grigoryan YSU, Yerevan, Armenia G.S. Karoyan, R.H. Khazaryan, M.M. Mkrtchian, T. Vandunts NPUA, Yerevan, Armenia
	A rich variety of dielectric, optical, acoustic/piezoelectric, ferromagnetic properties of ferroelectric and multiferroic composite materials open a new perspective for the development of modern accelerators with new principle of electron acceleration and control system. These properties may be controlled by external electric fields. In particular, the production of electric field controlling ultrafast facilities for 0.7-20 GHz RF phase shifting and amplitude modulation where a very short response time of <10 nsec is required . A Self-propagating High-temperature Synthesis (SHS) technology for obtaining ceramic materials, based on (1-x)BiFeO3-xBaTiO3 compositions with various dopant (MgO, MnO, etc.), has been developed. The general parameters of the SHS process (temperature and propagation velocity of the combustion front) are measured. The dependences of microstructure (grain size, density, and porosity), as well as electro physical properties of the sintered samples on compaction and sintering thermodynamic variables, such as the pressing pressure and duration, sintering temperature, sintering duration and atmosphere, heating and cooling rates, are experimentally investigated. * https://doi.org/10.3390/coatings11010066 ** Appl. Phys. Let., V.101, p. 232903-5, 2012 *** A. Kanareykin & et al. FERROELECTRIC BASED HIGH POWER TUNER FOR L-BAND ACCELERATOR APPLICATIONS. IPAC2013
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT069
About •	Received ※ 31 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 11 June 2022 — Issue date ※ 12 June 2022
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TUPOPT070	Surrogate Modelling of the FLUTE Low-Energy Section	1182
	C. Xu, E. Bründermann, A.-S. Müller, A. Santamaria Garcia, J. Schaeferpresenter KIT, Karlsruhe, Germany
	Funding: Supported by the Helmholtz Association (Autonomous Accelerator, ZT-I-PF-5-6) and the DFG-funded Doctoral School "Karlsruhe School of Elementary and Astroparticle Physics: Science and Technology". Numerical beam dynamics simulations are essential tools in the study and design of particle accelerators, but they can be prohibitively slow for online prediction during operation or for systematic evaluations of new parameter settings. Machine learning-based surrogate models of the accelerator provide much faster predictions of the beam properties and can serve as a virtual diagnostic or to augment data for reinforcement learning training. In this paper, we present the first results on training a surrogate model for the low-energy section at the Ferninfrarot Linac- und Test-Experiment (FLUTE).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT070
About •	Received ※ 30 May 2022 — Accepted ※ 15 June 2022 — Issue date ※ 05 July 2022
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