IPAC2021 - Classification: MC2: Photon Sources and Electron Accelerators / A08 Linear Accelerators

Paper	Title	Page
TUPAB046	Preliminary design of the Full Energy Linac Injector for the Southern Advanced Photon Source	1454
	X. Liu Institute of High Energy Physics, CAS, Guangdong, People’s Republic of China Y. Jiao, B. Li, S. Wang IHEP, Beijing, People’s Republic of China
	A 4th generation mid-energy range diffraction limited storage ring, named as the Southern Advanced Photon Source (SAPS), is under consideration to be built at the same campus as China Spallation Neutron Source (CSNS), providing a charming one-stop solution for fundamental sciences and industrial applications. While the design of the ring is still under study, a full energy Linac has been proposed as one candidate option for its injector, with the capability of being used as an X-ray Free Electron Laser (XFEL) in the near future. In this paper, an overview of the preliminary design of the Linac is given and simulation results are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB046
About •	paper received ※ 18 May 2021 paper accepted ※ 10 June 2021 issue date ※ 10 August 2021
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TUPAB047	Bunch Compressor Design in the Full Energy Linac Injector for the Southern Advanced Photon Source	1458
	B. Li IHEP CSNS, Guangdong Province, People’s Republic of China Y. Jiao, X. Liu, S. Wang IHEP, Beijing, People’s Republic of China
	A mid-energy fourth-generation storage ring light source named the Southern Advanced Photon Source (SAPS), has been considered to be built neighboring the China Spallation Neutron Source (CSNS). A full energy linac has been proposed as an injector to the storage ring, with the capability to generate high brightness electron beams to feed a Free Electron Laser (FEL) at a later stage. To achieve the high peak current in FELs, space charge, RF structure wakefield, coherent synchrotron radiation (CSR), RF curvature, and the second-order momentum compaction factor should be carefully considered and optimized during the bunch compression processes. In this paper, physic design and simulation results of the bunch compressors are described.
	Poster TUPAB047 [1.918 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB047
About •	paper received ※ 15 May 2021 paper accepted ※ 09 June 2021 issue date ※ 28 August 2021
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TUPAB129	Beam Based Alignment in a Compact THz-FEL Facility	1692
	Q.S. Chen, T. Hu, K.F. Liu, B. Qin, Y.Q. Xiong HUST, Wuhan, People’s Republic of China
	In this paper, we presented the beam based alignment results in a compact THz-FEL facility. The alignment was divided into two sections, the transport line and the optical line. In the transport line, all the five quadrupoles upstream of the undulator were adjusted one by one to fit the electron beam from the traveling wave linac. In the optical line, a set of auxiliary coils were winded on the yokes of the quadrupole downstream of the double bend achromat (DBA) to produce a vertical steering force. Another combined steering magnet, together with the auxiliary coils, corrected the beam orbit in the optical line. With the dispersion free test, the displacement between the magnetic centers of the quads and the beam orbit was less than 0.1mm.
	Poster TUPAB129 [0.673 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB129
About •	paper received ※ 18 May 2021 paper accepted ※ 17 June 2021 issue date ※ 27 August 2021
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TUPAB131	Measurement of Coherent Smith-Purcell Radiation Using Ultra-Short Electron Bunch at T-Acts	1696
	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
	The coherent Smith-Purcell radiation (SPR) emitted as a short electron bunch passes over a periodic metal surface is expected to be applied as a non-destructive beam diagnostic tool. The longitudinal profile of the electron bunch can be deduced by the measured spectrum of the coherent SPR, which is compared with the theoretical one for single electron. There are several theoretical models that explain the SPR mechanism, such as the surface current (SC) model and the van den Berg model. But the difference of estimation in radiation intensity between different models is not trivial, and also the experimental data to evaluate those validity is not enough. At test accelerator, t-ACTS, in Tohoku University we are conducting experimental research on coherent SPR in the terahertz frequency region using an ultra-short electron bunch of about 100 fs. The status and results of the experiment will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB131
About •	paper received ※ 19 May 2021 paper accepted ※ 27 July 2021 issue date ※ 13 August 2021
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TUPAB133	Brazing free RF Pulse Compressor for High Gradient Accelerators	1700
	L. Kankadze, D. Alesini, F. Cardelli, G. Di Raddo, M. Diomede INFN/LNF, Frascati, Italy
	EURPRAXIA@SPARC\_LAB, is a proposal to upgrade the SPARC\_LAB test facility (at LNF, Frascati) to a soft X-ray user facility based on plasma acceleration and high-gradient X-band (11.9942 GHz) accelerating modules. Each module is made up of a group of 4 TW sections assembled on a single girder and fed by one klystron by means of one rf pulse compressor system and a low attenuation circular waveguide network that transports the rf power to the input hybrids of the sections. The pulse compressor is based on a single Barrel Open Cavity (BOC). The BOC use a ’whispering gallery’ mode which has an intrinsically high quality factor and operates in a resonant rotating wave regime. Compared to the conventional SLED scheme it requires a single cavity instead of two cavities and a 3-dB hybrid. A new brazeless mechanical design has been proposed and is described in the present paper together with the electro-magnetic and thermo-mechanical simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB133
About •	paper received ※ 21 May 2021 paper accepted ※ 15 June 2021 issue date ※ 10 August 2021
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TUPAB134	Linac-to-Booster Optimization Procedure Towards High Transmission for the Alba Injector	1703
	R. Muñoz Horta, D. Lanaia, E. Marín, F. Pérez ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	ALBA is a third generation synchrotron light source that consists of 3 accelerators (Linac, Booster and Storage ring) and two transfer lines, Linac-to-Booster (LTB) and Booster-to-Storage (BTS). The ALBA accelerators team has defined a robust procedure that optimizes the beam performance from Linac to Booster in terms of transmission and stability. The implemented beam-based alignment and global orbit correction techniques have been investigated first in simulations and afterwards successfully implemented in the machine.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB134
About •	paper received ※ 18 May 2021 paper accepted ※ 26 May 2021 issue date ※ 16 August 2021
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WEPAB039	Construction of a Compact Electron Injector Using a Gridded RF Thermionic Gun and a C-Band Accelerator	2687
	T. Inagaki, T. Asaka, T. Hara, T. Hiraiwa, N. Hosoda, E. Iwai, C. Kondo, H. Maesaka, T. Ohshima, H. Tanaka RIKEN SPring-8 Center, Hyogo, Japan H. Dewa, T. Magome, Y. Minagawa, T. Sakurai JASRI/SPring-8, Hyogo-ken, Japan T. Fukui RIKEN SPring-8 Center, Innovative Light Sources Division, Hyogo, Japan S. Hashimoto LASTI, Hyogo, Japan S.I. Inoue, K. Kajimoto, S. Nakata, T. Seno, H. Sumitomo, R. Takesako, S. Tanaka, R. Yamamoto, M. Yoshioka SES, Hyogo-pref., Japan K. Yanagida JASRI, Hyogo, Japan
	A compact and low-cost 1 GeV injector linac was designed and constructed to provide injection beams to the soft X-ray synchrotron radiation facility NewSUBARU instead of the SPring-8 injector system, which will be shutdown. The total length of the injector linac needs to be less than 70 m to fit into the existing tunnel. To this end, an RF electron gun with a gridded thermionic cathode directly attached to a 238 MHz RF cavity was developed and adopted. The 500 keV, 0.6 ns, 1 nC beam emitted from the cavity is compressed to 3 ps by velocity bunching driven by a 476 MHz RF cavity and a S-band RF structure. The short-pulsed beams are accelerated up to 1 GeV with 16 C-band RF structures. In the C-band accelerator section, the klystron output of 50 MW is multiplied 4 times by a pulse compressor and fed to the 4 RF structures to generate a high accelerating field of 31 MV/m. A low-level RF system consisting of a MTCA.4 based high-speed digitizers and RF frontend boards has been constructed. This injector system is used at the 3 GeV SR facility currently under construction in Sendai. In this paper, we report the design outline and the operational performance of the injector system.
	Poster WEPAB039 [2.419 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB039
About •	paper received ※ 20 May 2021 paper accepted ※ 02 July 2021 issue date ※ 24 August 2021
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WEPAB040	Characterization of Low Emittance Electron Beams Generated by Transverse Laser Beam Shaping	2690
	M. Groß, N. Aftab, P. Boonpornprasert, G.Z. Georgiev, J. Good, C. Koschitzki, M. Krasilnikov, X. Li, O. Lishilin, D. Melkumyan, S.K. Mohanty, R. Niemczyk, A. Oppelt, H.J. Qian, G. Shu, F. Stephan, G. Vashchenko DESY Zeuthen, Zeuthen, Germany Y. Chen, G. Loisch DESY, Hamburg, Germany I. Will MBI, Berlin, Germany
	Linac based X-ray free electron laser demand a high beam quality from the electron source, therefore RF photoinjectors are used to generate the electron bunches for state of the art beam brightness. One important figure of merit for these injectors is the transverse emittance of the generated electron beam, which can be minimized by shaping the photocathode laser pulses. Best performance can be achieved with ellipsoidal laser pulses, but 3D shaping is technically challenging. Typically, a quasi-uniform transverse laser profile is truncated from the Gaussian profile generated by the laser with an aperture to reduce the transverse nonlinear space charge forces. This is investigated in detail by optimizing the laser transverse profile at the Photoinjector Test facility at DESY in Zeuthen (PITZ), where photoinjector R&D is conducted for the E-XFEL and FLASH free electron lasers at DESY in Hamburg. In this contribution we present experimental results at high acceleration gradients (up to 60 MV/m) for both 250 pC and 500 pC. For a bunch charge of 500 pC an emittance reduction of about 30% compared to the commonly used transverse flat-top laser distribution was achieved.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB040
About •	paper received ※ 17 May 2021 paper accepted ※ 02 June 2021 issue date ※ 19 August 2021
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WEPAB041	Testing of the Milliampere Booster Prototype Cavity	2693
	R.G. Heine KPH, Mainz, Germany
	The Milliampere Booster (MAMBO) is the injector linac for the Mainz Energy-recovering Superconducting Accelerator MESA. MESA is a multi-turn energy recovery linac with beam energies in the 100 MeV regime currently designed and built at Institut für Kernphysik (KPH) of Johannes Gutenberg-Universität Mainz. The main accelerator consists of two superconducting Rossendorf type modules, while the injector MAMBO relies on normal conducting technolgy. The MAMBO RF cavities are bi-periodic pi/2 structures with 33 cells and 37 cells, respectively. In this paper we present the results of the commissioning and testing of a 13 cell prototype structure.
	Poster WEPAB041 [2.824 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB041
About •	paper received ※ 18 May 2021 paper accepted ※ 23 June 2021 issue date ※ 21 August 2021
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WEPAB042	Linac-200: A New Electron Test Beam Facility at JINR	2697
	M.A. Nozdrin, M. Gostkin, V. Kobets, Y.A. Samofalova, G. Shirkov, A. Trifonov, K. Yunenko, A. Zhemchugov JINR, Dubna, Moscow Region, Russia
	Commissioning of a new electron test beam facility Linac-200 comes to the end at JINR (Dubna, Russia). The core of the facility is a refurbished MEA accelerator from NIKHEF. The key accelerator subsystems including controls, vacuum, precise temperature regulation were redesigned or deeply upgraded. The facility provides electron beams with energy up to 200 MeV while the beam current varying smoothly from 40 mA down to almost zero (single electrons in a bunch). The main goal of the facility is providing test beams for particle detector R&D, studies of novel approaches to the beam diagnostics, and education and training of graduate and postgraduate students. The current status and operation parameters of the facility will be reported.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB042
About •	paper received ※ 18 May 2021 paper accepted ※ 23 June 2021 issue date ※ 23 August 2021
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WEPAB043	Consolidation and Future Upgrades to the CLEAR User Facility at CERN	2700
	L.A. Dyks, P. Korysko Oxford University, Physics Department, Oxford, Oxon, United Kingdom P. Burrows JAI, Oxford, United Kingdom R. Corsini, S. Curt, W. Farabolini, D. Gamba, L. Garolfi, A. Gilardi, E. Granados, G. McMonagle, H. Panuganti CERN, Geneva, Switzerland W. Farabolini CEA-DRF-IRFU, France A. Gilardi University of Napoli Federico II, Napoli, Italy K.N. Sjobak University of Oslo, Oslo, Norway
	The CERN Linear Electron Accelerator for Research (CLEAR) at CERN has been operating since 2017 as a dedicated user facility providing beams for a varied range of experiments. CLEAR consists of a 20 m long linear accelerator (linac), able to produce beams from a Cs₂Te photocathode and accelerate them to energies of between 60 MeV and 220 MeV. Following the linac, an experimental beamline is located, in which irradiation tests, wakefield and impedances tudies, plasma lens experiments, beam diagnostics development, and terahertz (THz) emission studies, are performed. In this paper, we present recent upgrades to the entire beamline, as well as the design of future upgrades, such as a dogleg section connecting to an additional proposed experimental beamline. The gain in performance due to these upgrades is presented with a full range of available beam properties documented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB043
About •	paper received ※ 18 May 2021 paper accepted ※ 24 June 2021 issue date ※ 19 August 2021
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WEPAB045	European XFEL High-Power RF System - the First 4 Years of Operation	2708
	M. Bousonville, S. Choroba, T. Grevsmühl, S. Göller, A. Hauberg, V.V. Katalev, K. Machau, V. Vogel, B. Yildirim DESY, Hamburg, Germany
	In 2016, the installation of the European XFEL was completed and its 26 RF stations started operation in 2017. Each RF station consists of a 10 MW-1.3 GHz-multibeam klystron, a HV pulse modulator and a waveguide system to supply the superconducting cavities and the normal-conducting electron gun with RF power. During commissioning and subsequent operation, the RF stations were closely monitored and causes of failures were investigated. For the optimisation of the RF systems, the various RF station failures were evaluated according to their impact on accelerator operation and the measures to eliminate them were prioritised accordingly. This report describes the operation experience and improvements of the high-power RF stations during the first 4 years of operation.
	Poster WEPAB045 [6.887 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB045
About •	paper received ※ 19 May 2021 paper accepted ※ 07 June 2021 issue date ※ 21 August 2021
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WEPAB051	Beam Dynamics for a High Field C-Band Hybrid Photoinjector	2714
	L. Faillace, F. Bosco, M. Carillo, L. Giuliano, M. Migliorati, A. Mostacci, L. Palumbo Sapienza University of Rome, Rome, Italy R.B. Agustsson, I.I. Gadjev, S.V. Kutsaev, A.Y. Murokh RadiaBeam, Marina del Rey, California, USA M. Behtouei, A. Giribono, B. Spataro, C. Vaccarezza INFN/LNF, Frascati, Italy A. Fukasawa, N. Majernik, J.B. Rosenzweig, O. Williams UCLA, Los Angeles, California, USA S.G. Tantawi SLAC, Menlo Park, California, USA
	Funding: This work supported by DARPA GRIT under contract no. 20204571 and partially by INFN National Committee V through the ARYA project. In this paper, we present a new class of a hybrid photoinjector in C-Band. This project is the effort result of a UCLA/Sapienza/INFN-LNF/SLAC/RadiaBeam collaboration. This device is an integrated structure consisting of an initial standing-wave 2.5-cell gun connected to a traveling-wave section at the input coupler. Such a scheme nearly avoids power reflection back to the klystron, removing the need for a high-power circulator. It also introduces strong velocity bunching due to a 90° phase shift in the accelerating field. A relatively high cathode electric field of 120 MV/m produces a ~4 MeV beam with ~20 MW input RF power in a small foot-print. The beam transverse dynamics are controlled with a ~0.27 T focusing solenoid. We show the simulation results of the RF/magnetic design and the optimized beam dynamics that shows 6D phase space compensation at 250 pC. Proper beam shaping at the cathode yields a ~0.5 mm-mrad transverse emittance. A beam waist occurs simultaneously with a longitudinal focus of <400 fs rms and peak current >600 A. We discuss application of this injector to an Inverse-Compton Scattering system and present corresponding start-to-end beam dynamics simulations.
	Poster WEPAB051 [0.827 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB051
About •	paper received ※ 18 May 2021 paper accepted ※ 01 July 2021 issue date ※ 15 August 2021
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WEPAB052	Development of an EO Sampling System for the Analysis of THz Waves Generated by Coherent Cherenkov Radiation	2718
	K. Murakoshi, Y. Koshiba, T. Murakami, K. Sakaue, Y. Tadenuma, P. Wang, M. Washio Waseda University, Tokyo, Japan R. Kuroda AIST, Tsukuba, Japan K. Sakaue The University of Tokyo, Graduate School of Engineering, Bunkyo, Japan
	THz waves, located between microwaves and light waves, have transparency, directionality and fingerprint spectrum of specific materials. Therefore, they are expected to be useful for various applications. We have been studying THz waves generation via Cherenkov radiation with electron beams from a photocathode rf-gun. In our early studies, we have succeeded in the generation of coherent Cherenkov radiation by tilted electron beams using an rf-deflector. Furthermore, we have generated quasi-monochromatic THz waves by spatially modulated electron beams and have succeeded in its measurement by bandpass filters. This study aims to obtain the THz wave form in time domain by electro-optic (EO) sampling, which is an useful detection system for obtaining the information of the electric field and the phase simultaneously with high S/N. In this conference, we report about our probe laser system, results of the time-domain spectroscopy measurement of THz waves by EO sampling, and future prospects.
	Poster WEPAB052 [0.861 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB052
About •	paper received ※ 19 May 2021 paper accepted ※ 07 June 2021 issue date ※ 31 August 2021
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WEPAB054	Electromagnetic and Beam Dynamics Studies of the ThomX LINAC	2721
	M. Alkadi, C. Bruni, M. El Khaldi, M. Jacquet Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France H. Monard IJCLab, ORSAY, France
	ThomX is a new generation compact Compton source. The machine is composed of a 50/70 MeV injector linac and a storage ring where an electron bunch collides with a laser pulse accumulated in a Fabry-Perot resonator. The compact source, built at Irene Joliot-Curie Laboratory (IJCLAB) in the Orsay campus of Paris-Saclay University, is designed to produce a total flux of 10¹³ ph/s and a brightness of 1011 ph / (s.mm2.mrad2) in 0.1% of bandwidth with a tunable energy ranging from 45 keV to 90 keV on the X-ray beam axis. The photo-injector is composed of a homemade 2.5 cell photocathode RF-gun, placed between two solenoids. An energy of 5 MeV is reached with a 80 MV/m electric field gradient. During the commissioning phase, a 4.8 m S-band LIL section will be used to achieve a 50 MeV corresponding to a 45 keV X-ray energy. The LIL accelerating section is a quasi-constant gradient traveling wave structure. The energy gain in the section is 45 MeV, corresponding to an average effective accelerating gradient of 10 MV/m for an input RF power of 9 MW. Here we present the electromagnetic and beam dynamics studies of the ThomX LINAC.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB054
About •	paper received ※ 19 May 2021 paper accepted ※ 01 July 2021 issue date ※ 29 August 2021
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WEPAB055	Development of a Linac for Injection of Ultrashort Electron Bunches Into Laser Plasma Electron Accelerators	2725
	S. Masuda, N. Kumagai, T. Masuda, Y. Otake JASRI, Hyogo, Japan Y. Koshiba, S. Otsuka Waseda University, Tokyo, Japan T. Sakai, T. Tanaka LEBRA, Funabashi, Japan K. Sakaue The University of Tokyo, The School of Engineering, Tokyo, Japan
	Funding: This work is supported by JST-Mirai Program Grant Number JPMJMI17A1, Japan. We are developing a C-band linac that produces ultrashort electron bunches as an injector for laser plasma accelerators. A plasma wave excited by a high intense ultrashort laser pulse has a wavelength of the order of 10 to 100 fs and transverse dimensions of the order of 10 to 100 um. To inject the bunch into a proper phase of the plasma wave, a length and transverse sizes of the bunch must be much smaller than the plasma wave structure. A laser triggered photo cathode electron RF-gun and a 2pi/3 mode traveling wave buncher with 24 cells for ultrashort electron bunch production have been developed based on electron beam tracking simulations that show the bunch length is less than 10 fs with a charge of 100 fC at a focus on the plasma wave. The simulations also show that sufficiently small transverse sizes of the bunch at the focus can be obtained by a Q triplet. A highly accurate timing lower than the plasma wavelength (~10fs) is required for the synchronization between the electron bunch injection and the plasma wave excitation. An RF master oscillator with low SSB phase noise (-150dBc/Hz@10MHz) has been developed for the synchronization. We will report present development status.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB055
About •	paper received ※ 19 May 2021 paper accepted ※ 15 July 2021 issue date ※ 29 August 2021
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WEPAB056	Advanced Photoinjector Development at the UCLA SAMURAI Laboratory	2728
	A. Fukasawa, G. Andonian, O. Camacho, C.E. Hansel, G.E. Lawler, W.J. Lynn, N. Majernik, P. Manwani, B. Naranjo, J.B. Rosenzweig, Y. Sakai, O. Williams UCLA, Los Angeles, California, USA Z. Li, R. Robles, S.G. Tantawi SLAC, Menlo Park, California, USA J.I. Mann PBPL, Los Angeles, USA M. Yadav The University of Liverpool, Liverpool, United Kingdom
	Funding: This work was supported by the US Department of Energy under the contract No. DE-SC0017648, DE-SC0009914, and DE-SC0020409, and by National Science Foundation Grant No. PHY-1549132 UCLA has recently constructed SAMURAI, a new radiation bunker and laser infrastructure for advanced accelerator research. In its first phase, we will build a 30 MeV photoinjector with an S-band hybrid gun. The beam dynamics simulation for this beamline showed the generation of the beam with the emittance 2.4 um and the peak current 270 A. FIR-FEL experiments are planned in this beamline. The saturation peak power was expected at 170 MW.
	Poster WEPAB056 [0.939 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB056
About •	paper received ※ 28 May 2021 paper accepted ※ 01 July 2021 issue date ※ 11 August 2021
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THPAB069	Design Concepts for a High-Gradient C-Band Linac	3919
	T.B. Bolin, S.I. Sosa Guitron UNM-ECE, Albuquerque, USA S. Biedron UNM-ME, Albuquerque, New Mexico, USA J.R. Cary Tech-X, Boulder, Colorado, USA M. Dal Forno SLAC, Menlo Park, California, USA
	Funding: This work was performed under Contract No. 89233218CNA000001, supported by the U.S. DOE’s National Nuclear Security Administration, for the operation of Los Alamos National Laboratory (LANL). During the last decade, the production of soft to hard x-rays (up to 25 keV) at XFEL facilities has enabled new developments in a broad range of disciplines. One caveat is that these instruments can require a large amount of real estate. For example, the XFEL driver is typically an electron beam linear accelerator (LINAC) and the need for higher electron beam energies capable of generating higher energy X-rays can require longer linacs; costs quickly become prohibitive, requiring state of art methods. One cost-saving measure is to produce a high accelerating gradient while reducing cavity size. Compact accelerating structures are also high-frequency. Here, we describe design concepts for a high-gradient, cryo-cooled LINAC for XFEL facilities in the C-band regime (~4-8 GHz). We are also exploring C-band for different applications including drivers for security applications. We investigate 2 different traveling wave (TW) geometries optimized for high-gradient operation as modeled with VSim software.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB069
About •	paper received ※ 20 May 2021 paper accepted ※ 02 July 2021 issue date ※ 14 August 2021
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THPAB113	The Extended Operative Range of the LNF LINAC and BTF Facilities	3987
	L.G. Foggetta, M. Belli, B. Buonomo, F. Cardelli, R. Ceccarelli, A. Cecchinelli, R. Clementi, D. Di Giovenale, C. Di Giulio, G. Piermarini, L.A. Rossi, S. Strabioli, R. Zarlenga INFN/LNF, Frascati, Italy
	Funding: These activities has been partially supported by AIDA-2020 Grant Agreement 654168 and ERAD projects. In 2020 the INFN-LNF LINAC and BTF have performed long-term runs for test beams and fixed-target experiments. The scientific needs of these items have been leading our groups to continuous improvements of the LINAC operative range both in pulse time at maximum energy and on the minimum transported energy, until the reset to DAΦNE injections at the beginning of 2021. We will also show the BTF recent developments in the transported beams and the second line installation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB113
About •	paper received ※ 19 May 2021 paper accepted ※ 27 July 2021 issue date ※ 27 August 2021
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Paper

Title

Page

Preliminary design of the Full Energy Linac Injector for the Southern Advanced Photon Source

1454

X. Liu
Institute of High Energy Physics, CAS, Guangdong, People’s Republic of China
Y. Jiao, B. Li, S. Wang
IHEP, Beijing, People’s Republic of China

A 4th generation mid-energy range diffraction limited storage ring, named as the Southern Advanced Photon Source (SAPS), is under consideration to be built at the same campus as China Spallation Neutron Source (CSNS), providing a charming one-stop solution for fundamental sciences and industrial applications. While the design of the ring is still under study, a full energy Linac has been proposed as one candidate option for its injector, with the capability of being used as an X-ray Free Electron Laser (XFEL) in the near future. In this paper, an overview of the preliminary design of the Linac is given and simulation results are discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB046

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paper received ※ 18 May 2021 paper accepted ※ 10 June 2021 issue date ※ 10 August 2021

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TUPAB047

Bunch Compressor Design in the Full Energy Linac Injector for the Southern Advanced Photon Source

1458

B. Li
IHEP CSNS, Guangdong Province, People’s Republic of China
Y. Jiao, X. Liu, S. Wang
IHEP, Beijing, People’s Republic of China

A mid-energy fourth-generation storage ring light source named the Southern Advanced Photon Source (SAPS), has been considered to be built neighboring the China Spallation Neutron Source (CSNS). A full energy linac has been proposed as an injector to the storage ring, with the capability to generate high brightness electron beams to feed a Free Electron Laser (FEL) at a later stage. To achieve the high peak current in FELs, space charge, RF structure wakefield, coherent synchrotron radiation (CSR), RF curvature, and the second-order momentum compaction factor should be carefully considered and optimized during the bunch compression processes. In this paper, physic design and simulation results of the bunch compressors are described.

Poster TUPAB047 [1.918 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB047

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paper received ※ 15 May 2021 paper accepted ※ 09 June 2021 issue date ※ 28 August 2021

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TUPAB129

Beam Based Alignment in a Compact THz-FEL Facility

1692

Q.S. Chen, T. Hu, K.F. Liu, B. Qin, Y.Q. Xiong
HUST, Wuhan, People’s Republic of China

In this paper, we presented the beam based alignment results in a compact THz-FEL facility. The alignment was divided into two sections, the transport line and the optical line. In the transport line, all the five quadrupoles upstream of the undulator were adjusted one by one to fit the electron beam from the traveling wave linac. In the optical line, a set of auxiliary coils were winded on the yokes of the quadrupole downstream of the double bend achromat (DBA) to produce a vertical steering force. Another combined steering magnet, together with the auxiliary coils, corrected the beam orbit in the optical line. With the dispersion free test, the displacement between the magnetic centers of the quads and the beam orbit was less than 0.1mm.

Poster TUPAB129 [0.673 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB129

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paper received ※ 18 May 2021 paper accepted ※ 17 June 2021 issue date ※ 27 August 2021

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TUPAB131

Measurement of Coherent Smith-Purcell Radiation Using Ultra-Short Electron Bunch at T-Acts

1696

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

The coherent Smith-Purcell radiation (SPR) emitted as a short electron bunch passes over a periodic metal surface is expected to be applied as a non-destructive beam diagnostic tool. The longitudinal profile of the electron bunch can be deduced by the measured spectrum of the coherent SPR, which is compared with the theoretical one for single electron. There are several theoretical models that explain the SPR mechanism, such as the surface current (SC) model and the van den Berg model. But the difference of estimation in radiation intensity between different models is not trivial, and also the experimental data to evaluate those validity is not enough. At test accelerator, t-ACTS, in Tohoku University we are conducting experimental research on coherent SPR in the terahertz frequency region using an ultra-short electron bunch of about 100 fs. The status and results of the experiment will be presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB131

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paper received ※ 19 May 2021 paper accepted ※ 27 July 2021 issue date ※ 13 August 2021

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TUPAB133

Brazing free RF Pulse Compressor for High Gradient Accelerators

1700

L. Kankadze, D. Alesini, F. Cardelli, G. Di Raddo, M. Diomede
INFN/LNF, Frascati, Italy

EURPRAXIA@SPARC\_LAB, is a proposal to upgrade the SPARC\_LAB test facility (at LNF, Frascati) to a soft X-ray user facility based on plasma acceleration and high-gradient X-band (11.9942 GHz) accelerating modules. Each module is made up of a group of 4 TW sections assembled on a single girder and fed by one klystron by means of one rf pulse compressor system and a low attenuation circular waveguide network that transports the rf power to the input hybrids of the sections. The pulse compressor is based on a single Barrel Open Cavity (BOC). The BOC use a ’whispering gallery’ mode which has an intrinsically high quality factor and operates in a resonant rotating wave regime. Compared to the conventional SLED scheme it requires a single cavity instead of two cavities and a 3-dB hybrid. A new brazeless mechanical design has been proposed and is described in the present paper together with the electro-magnetic and thermo-mechanical simulations.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB133

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paper received ※ 21 May 2021 paper accepted ※ 15 June 2021 issue date ※ 10 August 2021

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TUPAB134

Linac-to-Booster Optimization Procedure Towards High Transmission for the Alba Injector

1703

R. Muñoz Horta, D. Lanaia, E. Marín, F. Pérez
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

ALBA is a third generation synchrotron light source that consists of 3 accelerators (Linac, Booster and Storage ring) and two transfer lines, Linac-to-Booster (LTB) and Booster-to-Storage (BTS). The ALBA accelerators team has defined a robust procedure that optimizes the beam performance from Linac to Booster in terms of transmission and stability. The implemented beam-based alignment and global orbit correction techniques have been investigated first in simulations and afterwards successfully implemented in the machine.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB134

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paper received ※ 18 May 2021 paper accepted ※ 26 May 2021 issue date ※ 16 August 2021

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WEPAB039

Construction of a Compact Electron Injector Using a Gridded RF Thermionic Gun and a C-Band Accelerator

2687

T. Inagaki, T. Asaka, T. Hara, T. Hiraiwa, N. Hosoda, E. Iwai, C. Kondo, H. Maesaka, T. Ohshima, H. Tanaka
RIKEN SPring-8 Center, Hyogo, Japan
H. Dewa, T. Magome, Y. Minagawa, T. Sakurai
JASRI/SPring-8, Hyogo-ken, Japan
T. Fukui
RIKEN SPring-8 Center, Innovative Light Sources Division, Hyogo, Japan
S. Hashimoto
LASTI, Hyogo, Japan
S.I. Inoue, K. Kajimoto, S. Nakata, T. Seno, H. Sumitomo, R. Takesako, S. Tanaka, R. Yamamoto, M. Yoshioka
SES, Hyogo-pref., Japan
K. Yanagida
JASRI, Hyogo, Japan

A compact and low-cost 1 GeV injector linac was designed and constructed to provide injection beams to the soft X-ray synchrotron radiation facility NewSUBARU instead of the SPring-8 injector system, which will be shutdown. The total length of the injector linac needs to be less than 70 m to fit into the existing tunnel. To this end, an RF electron gun with a gridded thermionic cathode directly attached to a 238 MHz RF cavity was developed and adopted. The 500 keV, 0.6 ns, 1 nC beam emitted from the cavity is compressed to 3 ps by velocity bunching driven by a 476 MHz RF cavity and a S-band RF structure. The short-pulsed beams are accelerated up to 1 GeV with 16 C-band RF structures. In the C-band accelerator section, the klystron output of 50 MW is multiplied 4 times by a pulse compressor and fed to the 4 RF structures to generate a high accelerating field of 31 MV/m. A low-level RF system consisting of a MTCA.4 based high-speed digitizers and RF frontend boards has been constructed. This injector system is used at the 3 GeV SR facility currently under construction in Sendai. In this paper, we report the design outline and the operational performance of the injector system.

Poster WEPAB039 [2.419 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB039

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paper received ※ 20 May 2021 paper accepted ※ 02 July 2021 issue date ※ 24 August 2021

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WEPAB040

Characterization of Low Emittance Electron Beams Generated by Transverse Laser Beam Shaping

2690

M. Groß, N. Aftab, P. Boonpornprasert, G.Z. Georgiev, J. Good, C. Koschitzki, M. Krasilnikov, X. Li, O. Lishilin, D. Melkumyan, S.K. Mohanty, R. Niemczyk, A. Oppelt, H.J. Qian, G. Shu, F. Stephan, G. Vashchenko
DESY Zeuthen, Zeuthen, Germany
Y. Chen, G. Loisch
DESY, Hamburg, Germany
I. Will
MBI, Berlin, Germany

Linac based X-ray free electron laser demand a high beam quality from the electron source, therefore RF photoinjectors are used to generate the electron bunches for state of the art beam brightness. One important figure of merit for these injectors is the transverse emittance of the generated electron beam, which can be minimized by shaping the photocathode laser pulses. Best performance can be achieved with ellipsoidal laser pulses, but 3D shaping is technically challenging. Typically, a quasi-uniform transverse laser profile is truncated from the Gaussian profile generated by the laser with an aperture to reduce the transverse nonlinear space charge forces. This is investigated in detail by optimizing the laser transverse profile at the Photoinjector Test facility at DESY in Zeuthen (PITZ), where photoinjector R&D is conducted for the E-XFEL and FLASH free electron lasers at DESY in Hamburg. In this contribution we present experimental results at high acceleration gradients (up to 60 MV/m) for both 250 pC and 500 pC. For a bunch charge of 500 pC an emittance reduction of about 30% compared to the commonly used transverse flat-top laser distribution was achieved.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB040

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paper received ※ 17 May 2021 paper accepted ※ 02 June 2021 issue date ※ 19 August 2021

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WEPAB041

Testing of the Milliampere Booster Prototype Cavity

2693

R.G. Heine
KPH, Mainz, Germany

The Milliampere Booster (MAMBO) is the injector linac for the Mainz Energy-recovering Superconducting Accelerator MESA. MESA is a multi-turn energy recovery linac with beam energies in the 100 MeV regime currently designed and built at Institut für Kernphysik (KPH) of Johannes Gutenberg-Universität Mainz. The main accelerator consists of two superconducting Rossendorf type modules, while the injector MAMBO relies on normal conducting technolgy. The MAMBO RF cavities are bi-periodic pi/2 structures with 33 cells and 37 cells, respectively. In this paper we present the results of the commissioning and testing of a 13 cell prototype structure.

Poster WEPAB041 [2.824 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB041

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paper received ※ 18 May 2021 paper accepted ※ 23 June 2021 issue date ※ 21 August 2021

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WEPAB042

Linac-200: A New Electron Test Beam Facility at JINR

2697

M.A. Nozdrin, M. Gostkin, V. Kobets, Y.A. Samofalova, G. Shirkov, A. Trifonov, K. Yunenko, A. Zhemchugov
JINR, Dubna, Moscow Region, Russia

Commissioning of a new electron test beam facility Linac-200 comes to the end at JINR (Dubna, Russia). The core of the facility is a refurbished MEA accelerator from NIKHEF. The key accelerator subsystems including controls, vacuum, precise temperature regulation were redesigned or deeply upgraded. The facility provides electron beams with energy up to 200 MeV while the beam current varying smoothly from 40 mA down to almost zero (single electrons in a bunch). The main goal of the facility is providing test beams for particle detector R&D, studies of novel approaches to the beam diagnostics, and education and training of graduate and postgraduate students. The current status and operation parameters of the facility will be reported.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB042

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paper received ※ 18 May 2021 paper accepted ※ 23 June 2021 issue date ※ 23 August 2021

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WEPAB043

Consolidation and Future Upgrades to the CLEAR User Facility at CERN

2700

L.A. Dyks, P. Korysko
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
P. Burrows
JAI, Oxford, United Kingdom
R. Corsini, S. Curt, W. Farabolini, D. Gamba, L. Garolfi, A. Gilardi, E. Granados, G. McMonagle, H. Panuganti
CERN, Geneva, Switzerland
W. Farabolini
CEA-DRF-IRFU, France
A. Gilardi
University of Napoli Federico II, Napoli, Italy
K.N. Sjobak
University of Oslo, Oslo, Norway

The CERN Linear Electron Accelerator for Research (CLEAR) at CERN has been operating since 2017 as a dedicated user facility providing beams for a varied range of experiments. CLEAR consists of a 20 m long linear accelerator (linac), able to produce beams from a Cs₂Te photocathode and accelerate them to energies of between 60 MeV and 220 MeV. Following the linac, an experimental beamline is located, in which irradiation tests, wakefield and impedances tudies, plasma lens experiments, beam diagnostics development, and terahertz (THz) emission studies, are performed. In this paper, we present recent upgrades to the entire beamline, as well as the design of future upgrades, such as a dogleg section connecting to an additional proposed experimental beamline. The gain in performance due to these upgrades is presented with a full range of available beam properties documented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB043

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paper received ※ 18 May 2021 paper accepted ※ 24 June 2021 issue date ※ 19 August 2021

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WEPAB045

European XFEL High-Power RF System - the First 4 Years of Operation

2708

M. Bousonville, S. Choroba, T. Grevsmühl, S. Göller, A. Hauberg, V.V. Katalev, K. Machau, V. Vogel, B. Yildirim
DESY, Hamburg, Germany

In 2016, the installation of the European XFEL was completed and its 26 RF stations started operation in 2017. Each RF station consists of a 10 MW-1.3 GHz-multibeam klystron, a HV pulse modulator and a waveguide system to supply the superconducting cavities and the normal-conducting electron gun with RF power. During commissioning and subsequent operation, the RF stations were closely monitored and causes of failures were investigated. For the optimisation of the RF systems, the various RF station failures were evaluated according to their impact on accelerator operation and the measures to eliminate them were prioritised accordingly. This report describes the operation experience and improvements of the high-power RF stations during the first 4 years of operation.

Poster WEPAB045 [6.887 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB045

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paper received ※ 19 May 2021 paper accepted ※ 07 June 2021 issue date ※ 21 August 2021

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WEPAB051

Beam Dynamics for a High Field C-Band Hybrid Photoinjector

2714

L. Faillace, F. Bosco, M. Carillo, L. Giuliano, M. Migliorati, A. Mostacci, L. Palumbo
Sapienza University of Rome, Rome, Italy
R.B. Agustsson, I.I. Gadjev, S.V. Kutsaev, A.Y. Murokh
RadiaBeam, Marina del Rey, California, USA
M. Behtouei, A. Giribono, B. Spataro, C. Vaccarezza
INFN/LNF, Frascati, Italy
A. Fukasawa, N. Majernik, J.B. Rosenzweig, O. Williams
UCLA, Los Angeles, California, USA
S.G. Tantawi
SLAC, Menlo Park, California, USA

Funding: This work supported by DARPA GRIT under contract no. 20204571 and partially by INFN National Committee V through the ARYA project.
In this paper, we present a new class of a hybrid photoinjector in C-Band. This project is the effort result of a UCLA/Sapienza/INFN-LNF/SLAC/RadiaBeam collaboration. This device is an integrated structure consisting of an initial standing-wave 2.5-cell gun connected to a traveling-wave section at the input coupler. Such a scheme nearly avoids power reflection back to the klystron, removing the need for a high-power circulator. It also introduces strong velocity bunching due to a 90° phase shift in the accelerating field. A relatively high cathode electric field of 120 MV/m produces a ~4 MeV beam with ~20 MW input RF power in a small foot-print. The beam transverse dynamics are controlled with a ~0.27 T focusing solenoid. We show the simulation results of the RF/magnetic design and the optimized beam dynamics that shows 6D phase space compensation at 250 pC. Proper beam shaping at the cathode yields a ~0.5 mm-mrad transverse emittance. A beam waist occurs simultaneously with a longitudinal focus of <400 fs rms and peak current >600 A. We discuss application of this injector to an Inverse-Compton Scattering system and present corresponding start-to-end beam dynamics simulations.

Poster WEPAB051 [0.827 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB051

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paper received ※ 18 May 2021 paper accepted ※ 01 July 2021 issue date ※ 15 August 2021

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WEPAB052

Development of an EO Sampling System for the Analysis of THz Waves Generated by Coherent Cherenkov Radiation

2718

K. Murakoshi, Y. Koshiba, T. Murakami, K. Sakaue, Y. Tadenuma, P. Wang, M. Washio
Waseda University, Tokyo, Japan
R. Kuroda
AIST, Tsukuba, Japan
K. Sakaue
The University of Tokyo, Graduate School of Engineering, Bunkyo, Japan

THz waves, located between microwaves and light waves, have transparency, directionality and fingerprint spectrum of specific materials. Therefore, they are expected to be useful for various applications. We have been studying THz waves generation via Cherenkov radiation with electron beams from a photocathode rf-gun. In our early studies, we have succeeded in the generation of coherent Cherenkov radiation by tilted electron beams using an rf-deflector. Furthermore, we have generated quasi-monochromatic THz waves by spatially modulated electron beams and have succeeded in its measurement by bandpass filters. This study aims to obtain the THz wave form in time domain by electro-optic (EO) sampling, which is an useful detection system for obtaining the information of the electric field and the phase simultaneously with high S/N. In this conference, we report about our probe laser system, results of the time-domain spectroscopy measurement of THz waves by EO sampling, and future prospects.

Poster WEPAB052 [0.861 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB052

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paper received ※ 19 May 2021 paper accepted ※ 07 June 2021 issue date ※ 31 August 2021

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WEPAB054

Electromagnetic and Beam Dynamics Studies of the ThomX LINAC

2721

M. Alkadi, C. Bruni, M. El Khaldi, M. Jacquet
Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
H. Monard
IJCLab, ORSAY, France

ThomX is a new generation compact Compton source. The machine is composed of a 50/70 MeV injector linac and a storage ring where an electron bunch collides with a laser pulse accumulated in a Fabry-Perot resonator. The compact source, built at Irene Joliot-Curie Laboratory (IJCLAB) in the Orsay campus of Paris-Saclay University, is designed to produce a total flux of 10¹³ ph/s and a brightness of 1011 ph / (s.mm2.mrad2) in 0.1% of bandwidth with a tunable energy ranging from 45 keV to 90 keV on the X-ray beam axis. The photo-injector is composed of a homemade 2.5 cell photocathode RF-gun, placed between two solenoids. An energy of 5 MeV is reached with a 80 MV/m electric field gradient. During the commissioning phase, a 4.8 m S-band LIL section will be used to achieve a 50 MeV corresponding to a 45 keV X-ray energy. The LIL accelerating section is a quasi-constant gradient traveling wave structure. The energy gain in the section is 45 MeV, corresponding to an average effective accelerating gradient of 10 MV/m for an input RF power of 9 MW. Here we present the electromagnetic and beam dynamics studies of the ThomX LINAC.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB054

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paper received ※ 19 May 2021 paper accepted ※ 01 July 2021 issue date ※ 29 August 2021

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WEPAB055

Development of a Linac for Injection of Ultrashort Electron Bunches Into Laser Plasma Electron Accelerators

2725

S. Masuda, N. Kumagai, T. Masuda, Y. Otake
JASRI, Hyogo, Japan
Y. Koshiba, S. Otsuka
Waseda University, Tokyo, Japan
T. Sakai, T. Tanaka
LEBRA, Funabashi, Japan
K. Sakaue
The University of Tokyo, The School of Engineering, Tokyo, Japan

Funding: This work is supported by JST-Mirai Program Grant Number JPMJMI17A1, Japan.
We are developing a C-band linac that produces ultrashort electron bunches as an injector for laser plasma accelerators. A plasma wave excited by a high intense ultrashort laser pulse has a wavelength of the order of 10 to 100 fs and transverse dimensions of the order of 10 to 100 um. To inject the bunch into a proper phase of the plasma wave, a length and transverse sizes of the bunch must be much smaller than the plasma wave structure. A laser triggered photo cathode electron RF-gun and a 2pi/3 mode traveling wave buncher with 24 cells for ultrashort electron bunch production have been developed based on electron beam tracking simulations that show the bunch length is less than 10 fs with a charge of 100 fC at a focus on the plasma wave. The simulations also show that sufficiently small transverse sizes of the bunch at the focus can be obtained by a Q triplet. A highly accurate timing lower than the plasma wavelength (~10fs) is required for the synchronization between the electron bunch injection and the plasma wave excitation. An RF master oscillator with low SSB phase noise (-150dBc/Hz@10MHz) has been developed for the synchronization. We will report present development status.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB055

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paper received ※ 19 May 2021 paper accepted ※ 15 July 2021 issue date ※ 29 August 2021

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WEPAB056

Advanced Photoinjector Development at the UCLA SAMURAI Laboratory

2728

A. Fukasawa, G. Andonian, O. Camacho, C.E. Hansel, G.E. Lawler, W.J. Lynn, N. Majernik, P. Manwani, B. Naranjo, J.B. Rosenzweig, Y. Sakai, O. Williams
UCLA, Los Angeles, California, USA
Z. Li, R. Robles, S.G. Tantawi
SLAC, Menlo Park, California, USA
J.I. Mann
PBPL, Los Angeles, USA
M. Yadav
The University of Liverpool, Liverpool, United Kingdom

Funding: This work was supported by the US Department of Energy under the contract No. DE-SC0017648, DE-SC0009914, and DE-SC0020409, and by National Science Foundation Grant No. PHY-1549132
UCLA has recently constructed SAMURAI, a new radiation bunker and laser infrastructure for advanced accelerator research. In its first phase, we will build a 30 MeV photoinjector with an S-band hybrid gun. The beam dynamics simulation for this beamline showed the generation of the beam with the emittance 2.4 um and the peak current 270 A. FIR-FEL experiments are planned in this beamline. The saturation peak power was expected at 170 MW.

Poster WEPAB056 [0.939 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB056

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paper received ※ 28 May 2021 paper accepted ※ 01 July 2021 issue date ※ 11 August 2021

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THPAB069

Design Concepts for a High-Gradient C-Band Linac

3919

T.B. Bolin, S.I. Sosa Guitron
UNM-ECE, Albuquerque, USA
S. Biedron
UNM-ME, Albuquerque, New Mexico, USA
J.R. Cary
Tech-X, Boulder, Colorado, USA
M. Dal Forno
SLAC, Menlo Park, California, USA

Funding: This work was performed under Contract No. 89233218CNA000001, supported by the U.S. DOE’s National Nuclear Security Administration, for the operation of Los Alamos National Laboratory (LANL).
During the last decade, the production of soft to hard x-rays (up to 25 keV) at XFEL facilities has enabled new developments in a broad range of disciplines. One caveat is that these instruments can require a large amount of real estate. For example, the XFEL driver is typically an electron beam linear accelerator (LINAC) and the need for higher electron beam energies capable of generating higher energy X-rays can require longer linacs; costs quickly become prohibitive, requiring state of art methods. One cost-saving measure is to produce a high accelerating gradient while reducing cavity size. Compact accelerating structures are also high-frequency. Here, we describe design concepts for a high-gradient, cryo-cooled LINAC for XFEL facilities in the C-band regime (~4-8 GHz). We are also exploring C-band for different applications including drivers for security applications. We investigate 2 different traveling wave (TW) geometries optimized for high-gradient operation as modeled with VSim software.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB069

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paper received ※ 20 May 2021 paper accepted ※ 02 July 2021 issue date ※ 14 August 2021

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THPAB113

The Extended Operative Range of the LNF LINAC and BTF Facilities

3987

L.G. Foggetta, M. Belli, B. Buonomo, F. Cardelli, R. Ceccarelli, A. Cecchinelli, R. Clementi, D. Di Giovenale, C. Di Giulio, G. Piermarini, L.A. Rossi, S. Strabioli, R. Zarlenga
INFN/LNF, Frascati, Italy

Funding: These activities has been partially supported by AIDA-2020 Grant Agreement 654168 and ERAD projects.
In 2020 the INFN-LNF LINAC and BTF have performed long-term runs for test beams and fixed-target experiments. The scientific needs of these items have been leading our groups to continuous improvements of the LINAC operative range both in pulse time at maximum energy and on the minimum transported energy, until the reset to DAΦNE injections at the beginning of 2021. We will also show the BTF recent developments in the transported beams and the second line installation.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB113

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paper received ※ 19 May 2021 paper accepted ※ 27 July 2021 issue date ※ 27 August 2021

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