NAPAC2019 - List of Keywords (undulator)

Paper	Title	Other Keywords	Page
MOZBA2	Operational Experience with Superconducting Undulators at APS	operation, photon, vacuum, radiation	57
	K.C. Harkay, L.E. Boon, M. Borland, J.C. Dooling, L. Emery, V. Sajaev, Y.P. Sun ANL, Lemont, Illinois, USA
	Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. APS has been developing superconducting undulators for over a decade. Presently, two planar and one helical device are in operation in the APS storage ring, and a number of devices will be installed in the APS Upgrade ring. All superconducting devices perform with very high reliability and have very minor effect on the storage ring operation. To achieve this, a number of storage ring modifications had to be done, such as introduction of the beam abort system to eliminate device quenches during beam dumps, and lattice and orbit modifications to allow for installation of the small horizontal aperture helical device with magnet coils in the plane of synchrotron radiation.
	Slides MOZBA2 [3.424 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOZBA2
About •	paper received ※ 02 September 2019 paper accepted ※ 19 November 2019 issue date ※ 08 October 2019
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MOZBA3	Strongly Tapered Helical Undulator System for TESSA-266	electron, experiment, laser, permanent-magnet	63
	T.J. Campese, R.B. Agustsson, I.I. Gadjev, A.Y. Murokh RadiaBeam, Santa Monica, California, USA W. Berg, A. Zholents ANL, Lemont, Illinois, USA P.E. Denham, P. Musumeci, Y. Park UCLA, Los Angeles, USA
	Funding: DOE SBIR Award No. DE-SC0017102 RadiaBeam, in collaboration with UCLA and Argonne National Laboratory (ANL), is developing a strongly tapered helical undulator system for the Tapering Enhanced Stimulated Superradiant Amplification experiment at 266 nm (TESSA-266). The experiment will be carried out at the APS LEA facility at ANL and aims at the demonstration of very high energy conversion efficiency in the UV. The undulator system was designed by UCLA, engineered by RadiaBeam, and is presently in fabrication at RadiaBeam. The design is based on a permanent magnet Halbach scheme and includes a short 30 cm long buncher section and four 1 m long undulator sections. The undulator period is fixed at 32 mm and the magnetic field amplitude can be tapered by tuning the gap along the interaction. Each magnet can be individually adjusted by 1.03 mm, offering up to 25% magnetic field tunability with a minimum gap of 5.58 mm. A custom designed 316L stainless steel beampipe runs through the center with a clear aperture of 4.5 mm. This paper discusses the design and engineering of the undulator system, fabrication status, and plans for magnetic measurements, and tuning.
	Slides MOZBA3 [8.942 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOZBA3
About •	paper received ※ 27 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019
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MOZBA4	Recent Developments in High Power High Brightness Double Bunch Self-Seeding at LCLS-II	FEL, photon, electron, simulation	67
	A. Halavanau, F.-J. Decker, Y. Ding, C. Emma, Z. Huang, A.A. Lutman, G. Marcus, C. Pellegrini SLAC, Menlo Park, California, USA
	We discuss the power and spectral characteristics of an X-ray FEL, LCLS-II, operating in a double bunch self-seeding scheme (DBFEL). We show that it can reach very high power levels in the photon energy range of 4-8 keV. We discuss the system implementation on LCLS-II, including the design of a four-bounce crystal monochromator, and linac wakefields effects. Finally, we offer multiple applications of the DBFEL for high-field QED, AMO physics and single particle imaging.
	Slides MOZBA4 [3.175 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOZBA4
About •	paper received ※ 02 September 2019 paper accepted ※ 05 September 2019 issue date ※ 08 October 2019
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MOPLM23	Senis Hall Probe Speed Dependence Issues	wiggler, insertion-device, insertion, coupling	155
	I. Vasserman ANL, Lemont, Illinois, USA
	An extensive test of a Senis 2-axis Hall probe was done at the Advanced Photon Source. Strong dependence of the measurement data on the speed of the sensor is observed. Discussion of the possible reason of such dependence is provided. Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOPLM23
About •	paper received ※ 21 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019
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MOPLO01	A Beam Spreader System for LCLS-II	kicker, septum, FEL, electron	236
	T.G. Beukers, J.W. Amann, Y.M. Nosochkov SLAC, Menlo Park, California, USA
	For the LCLS-II project, the SLAC National Accelerator Laboratory is installing a new superconducting RF linac capable of continuously delivering 4 GeV electron bunches spaced 1.1 microseconds apart. A spreader system is required to distribute the beam between a soft X-ray or hard X-ray undulator, and a beam dump. An additional beam diverter is required in the front end of the linac to divert 100 MeV electrons to a diagnostic line. Both the spreader and diagnostic diversion systems are designed to operate on a bunch by bunch basis via the combination of fast kickers and a Lambertson septum. This paper presents a summary of the optics, kicker, and septum design. Of specific interest is the unique challenge associated with building a high repetition, high stability, spreader capable of diverting a single bunch without disturbing neighboring bunches. Additional discussion includes the application of the spreader technology to the proposed DASEL/S30XL beamline. This beamline will acceptμbunches evenly spaced between the undulator bound bunches, thus requiring a kicker with the same repetition rate as LCLS-II but a pulse width extended to approximately 600 ns.
	Poster MOPLO01 [1.256 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOPLO01
About •	paper received ※ 27 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019
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TUPLM26	Progress Toward a Laser Amplifier for Optical Stochastic Cooling	laser, radiation, experiment, synchrotron-radiation	434
	A.J. Dick, P. Piot Northern Illinois University, DeKalb, Illinois, USA M.B. Andorf Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Optical Stochastic Cooling (OSC) is a method of beam cooling using optical frequencies which compresses the phase space of the beam by correcting the deviation of each particle’s momentum. A particle bunch passing through an undulator produces radiation which is amplified and provides the corrective energy kick. In this project, we are testing a method of amplifying synchrotron radiation (SR) for the eventual use in OSC. The SR is amplified by passing through a highly-doped Chromium:Zinc Selenide (Cr:ZnSe) crystal which is pumped by a Thulium fiber laser. The SR will be produced by one of the bending magnets of the Advanced Photon Source. The first step is to detect and measure the power of SR using a photo-diode. The gain is then determined by measuring the radiation amplified after the single-pass through the crystal. This serves as a preliminary step to investigate the performance of the amplification of beam-induced radiation fields. The planned experiment is an important step towards achieving active OSC in a proof-of-principle demonstration in IOTA.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLM26
About •	paper received ※ 02 September 2019 paper accepted ※ 13 September 2019 issue date ※ 08 October 2019
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TUPLS03	Advanced Photon Source Upgrade	vacuum, photon, storage-ring, operation	453
	M.E. Szubert, E.R. Anliker, T.J. Bender, J.E. Lerch ANL, Lemont, Illinois, USA
	The Advanced Photon Source Upgrade (APS-U) in-cludes four straight sections equipped with full length Superconducting Undulators (SCUs). These sections require vacuum systems that must span 5.383 meters at nominal length, accommodate the SCU device, and ac-commodate additional magnets for the canted configura-tions. In the direction of the beam, the upstream portion of the vacuum system is a copper chamber doubling as a photon absorber with a design that is manufactured to allow a 13.5 mm canting magnet gap. This portion of the vacuum system operates at room temperature and shad-ows the length of the vacuum chamber that operates within the cryostat at 20K. The vacuum chamber inside the cryostat is a weldment including a machined alumi-num extrusion allowing for an 8mm magnetic gap, stain-less steel thermal insulators, copper shields, and bel-lows/flange assembly. The vacuum system includes an-other room temperature copper chamber and absorber on the downstream end of the straight section. The vacuum system provides Ultra-high Vacuum (UHV) continuity through the straight section, connecting the storage ring vacuum systems.
	Poster TUPLS03 [0.974 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLS03
About •	paper received ※ 26 August 2019 paper accepted ※ 13 September 2019 issue date ※ 08 October 2019
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TUPLS04	Re-Evaluation of the NSLS-II Active Interlock Window	insertion, insertion-device, wiggler, vacuum	456
	R.P. Fliller, III, C. Hetzel, Y. Hidaka, T. Tanabe BNL, Upton, New York, USA
	Funding: This manuscript has been authored by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy The NSLS-II Active Interlock is the system which protects the NSLS-II Storage Ring vacuum chamber from damage due to synchrotron radiation. The Active Interlock measures the beam position and angle at all insertion devices and issues a beam dump if the beam is outside of the pre-defined window. The window is determined by thermal analysis of vacuum apertures and considers the effects of local magnets such as canting magnets, etc. Recently, it was realized that the insertion device correction coils where not considered in the initial evaluation of the envelope. The purpose of these coils is to correct for the orbit deviations caused by imperfections in the insertion devices that steer the beam. The usual effect is to negate any angle induced by the device, however, if the coil is not set properly the beam may have a larger angle than permitted by the Active Interlock even though the angle calculation does not show it. In this paper we discuss the effect of the insertion device coils on the electron beam and the steps taken to account for this effect in the Active Interlock.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLS04
About •	paper received ※ 27 August 2019 paper accepted ※ 16 November 2020 issue date ※ 08 October 2019
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TUPLH01	Status of the Superconducting Undulator Program at the Advanced Photon Source	operation, storage-ring, alignment, photon	490
	M. Kasa, E.R. Anliker, J.D. Fuerst, E. Gluskin, Q.B. Hasse, Y. Ivanyushenkov, W.G. Jansma, I. Kesgin, Y. Shiroyanagi ANL, Lemont, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. Since 2013 there has been at least one superconducting undulator (SCU) in operation at the Advanced Photon Source (APS), currently there are two planar SCUs and one helical SCU. The combined operational experience of SCUs at the APS is more than 11 years and counting. Through all these years, APS SCUs operated with the predicted or better than predicted radiation performance and with 99% availability. With this demonstrated reliability and experimentally confirmed spectral performance, the APS upgrade project is planning on leveraging the advantages of SCU technology. The present planar SCUs are comprised of ~1.1-m-long magnets, each operated within a 2-m-long cryostat, while the planar SCUs for the upgrade will have two ~1.8-m-long magnets operating within a 5-m-long cryostat. Progress is also being made in other areas of SCU development with work on an arbitrary polarizing SCU, referred to as SCAPE, and a planar SCU wound with Nb₃Sn superconductor. A Nb₃Sn SCU is being designed with two 1.3-m-long magnets within a 5-m-long cryostat, and installation is planned for 2021. Also under development are the alignment and magnetic measurement systems for use with the 5-m-long cryostat.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLH01
About •	paper received ※ 26 August 2019 paper accepted ※ 02 September 2019 issue date ※ 08 October 2019
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TUPLH04	Feasibility Study of Fast Polarization Switching Superconducting Undulator	polarization, simulation, coupling, power-supply	497
	I. Kesgin, Y. Ivanyushenkov, M. Kasa ANL, Lemont, Illinois, USA
	Funding: U.S. Department of Energy, Office of Science, under Contract No. DE-ACO₂-O6CH11357. Polarization switching x-ray probes coupled with high-flux provide a unique tool to unraveling the nature of electronic heterogeneity and drive discovery of novel phases of electronic matter. Superconducting Arbitrary Polarization Emitter (SCAPE) is a new concept for a universal undulator, which offers linear or circular polarization states in one device and is ideal for experiments that require polarization switching. Polarization switching relies on modulating the magnetic field in the undulator. This, however, inevitably incurs losses in superconductors, which need to be mitigated. In this study, feasibility of fast switching SCAPE has been investigated through fabricating and testing several short prototype magnets wound with different superconductors and new design concepts. The losses at different frequencies and field amplitudes are measured and details will be discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLH04
About •	paper received ※ 27 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019
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TUPLH10	Fabrication Progress of a Superconducting Helical Undulator with Superimposed Focusing Gradient for High Efficiency Tapered X-Ray FELs	FEL, quadrupole, vacuum, focusing	509
	S.M. Lynam, R.B. Agustsson, I.I. Gadjev, A.Yu. Smirnov RadiaBeam, Santa Monica, California, USA F.H. O’Shea Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
	Funding: This work is supported by DOE grant no. DE-SC0017072, "Superconducting Helical Undulator with Superimposed Focusing Gradient for High Efficiency Tapered X-Ray FELs" The Advanced Gradient Undulator (AGU) represents a potentially significant advancement in x-ray conversion efficiency for x-ray FELs. This increase in efficiency would have broad implications on the capabilities of x-ray light sources. To achieve this high conversion efficiency, the inner diameter of the undulator coil is a mere 7mm, even with the use of superconducting coils. To accommodate the beamline at the Advanced Photon Source this yields in a chamber with a wall thickness of 0.5mm fabricated from Aluminum. With a period of 2cm and a conductor position tolerance of <100 µm over a length of >80cm at 4.2K, the engineering and fabrication challenges for the undulator alone are substantial. We will discuss these fabrication challenges and present solutions to meet the tolerances required for desired performance, and provide an update on current progress of the construction of a section of the AGU insertion device.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLH10
About •	paper received ※ 28 August 2019 paper accepted ※ 16 November 2020 issue date ※ 08 October 2019
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WEXBA2	Recent Results and Opportunities at the IOTA Facility	electron, experiment, radiation, proton	599
	A.L. Romanov, D.R. Broemmelsiek, K. Carlson, D.J. Crawford, N. Eddy, D.R. Edstrom, J.D. Jarvis, V.A. Lebedev, S. Nagaitsev, J. Ruan, J.K. Santucci, V.D. Shiltsev, G. Stancari, A. Valishev, A. Warner Fermilab, Batavia, Illinois, USA S. Chattopadhyay, S. Szustkowski Northern Illinois University, DeKalb, Illinois, USA Y.K. Kim, N. Kuklev, I. Lobach University of Chicago, Chicago, Illinois, USA
	The Integrable Optics Test Accelerator (IOTA) was recently commissioned as part of the Fermilab Accelerator Science and Technology (FAST) facility. The IOTA ring was briefly operated with electrons at 47 MeV followed by a 6-months run with 100 MeV electrons. The main goal of the first run was to study beam dynamics in the integrable lattices with elliptical nonlinear magnets and in the quasi-integrable case with profiled octupole channel. The flexibility of the IOTA ring allowed a wide range of complementary studies, such as experiments with a single electron; studies of fluctuations in undulator radiation and operation with low emittance beams. Over the next year the proton injector will be installed and two runs carried out. One run will be dedicated to the refinement of nonlinear experiments and another will be dedicated to the proof-of-principle demonstration of Optical Stochastic Cooling.
	Slides WEXBA2 [12.702 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEXBA2
About •	paper received ※ 31 August 2019 paper accepted ※ 05 September 2019 issue date ※ 08 October 2019
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WEPLM05	Continuous Monitoring of Spectral Features of Electron Beam Orbit Motion at NSLS-II	operation, controls, feedback, cavity	673
	B. Podobedov, A.A. Derbenev, K. Ha, T.V. Shaftan BNL, Upton, New York, USA
	NSLS-II ring is equipped with state-of-the art beam position monitors (BPMs) which are indispensable in all aspects of machine studies and operations. Among other data, they can provide, on demand, up to 10 seconds of fast-acquisition (FA) data, sampled at ~10 kHz. Analysis of these data in time, frequency and spatial domains provides valuable insights into orbit stability, locations of residual noise sources, performance of feedback systems, etc. In addition, changes in FA signal spectral features are often the earliest indicators of potential equipment problems. This is why we recently implemented an Input / Output Controller (IOC) software that runs during regular user operation, and, once a minute, acquires 10 second buffers of FA data from 180 BPMs around the ring. These buffers are processed to determine the amplitudes and frequencies of the strongest spectral peaks as well as some other measures of fast beam orbit noise. Processed results can be monitored in real time and are also archived for offline analysis and troubleshooting. In this paper we discuss the implementation of this system and the insights we gained from it over about two years of operations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLM05
About •	paper received ※ 31 August 2019 paper accepted ※ 02 September 2019 issue date ※ 08 October 2019
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THXBA2	Analysis of Beam Position Monitor Requirements with Bayesian Gaussian Regression	optics, brightness, quadrupole, emittance	912
	Y. Li, R.S. Rainer BNL, Upton, New York, USA W.X. Cheng ANL, Lemont, Illinois, USA Y. Hao FRIB, East Lansing, Michigan, USA
	Funding: This research is supported by U.S. Department of Energy under Contract No. DE-SC0012704, and the NSF under Cooperative Agreement PHY-1102511. With a Bayesian Gaussian regression approach, a systematic method for analyzing a storage ring’s beam position monitor (BPM) system requirements has been developed. The ultimate performance of a ring-based accelerator, based on brightness or luminosity, is determined not only by global parameters, but also by local beam properties at some particular points of interest (POI). BPMs used for monitoring the beam properties, however, can not be located at these points. Therefore, the underlying and fundamental purpose of a BPM system is to predict whether the beam properties at POIs reach their desired values. The prediction process is a regression problem with BPM readings as the training data, but containing random noise. A Bayesian Gaussian regression approach can determine the probability distribution of the predictive errors, which can be used to conversely analyze the BPM system requirements. This approach is demonstrated by using turn-by-turn data to reconstruct a linear optics model, and predict the brightness degradation for a ring-based light source. The quality of BPMs was found to be more important than their quantity in mitigating predictive errors.
	Slides THXBA2 [3.205 MB]
	Poster THXBA2 [7.083 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-THXBA2
About •	paper received ※ 16 August 2019 paper accepted ※ 04 September 2019 issue date ※ 08 October 2019
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THYBA5	Study of Fluctuations in Undulator Radiation in the IOTA Ring at Fermilab	experiment, radiation, electron, wiggler	934
	I. Lobach University of Chicago, Chicago, Illinois, USA A. Halavanau, Z. Huang, V. Yakimenko SLAC, Menlo Park, California, USA K. Kim ANL, Lemont, Illinois, USA V.A. Lebedev, S. Nagaitsev, A.L. Romanov, G. Stancari Fermilab, Batavia, Illinois, USA A.Y. Murokh RadiaBeam, Marina del Rey, California, USA T.V. Shaftan BNL, Upton, New York, USA
	We study turn-by-turn fluctuations in the number of emitted photons in an undulator, installed in the IOTA electron storage ring at Fermilab, with an InGaAs PIN photodiode and an integrating circuit. In this paper, we present a theoretical model for the experimental data from previous similar experiments and in our present experiment, we attempt to verify the model in an independent and a more systematic way. Moreover, in our experiment we consider the regime of very small fluctuation when the contribution from the photon shot noise is significant, whereas we believe it was negligible in the previous experiments. Accordingly, we present certain critical improvements in the experimental setup that let us measure such a small fluctuation.
	Slides THYBA5 [8.048 MB]
	Poster THYBA5 [3.079 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-THYBA5
About •	paper received ※ 24 August 2019 paper accepted ※ 05 September 2019 issue date ※ 08 October 2019
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Paper

Title

Other Keywords

Page

MOZBA2

Operational Experience with Superconducting Undulators at APS

operation, photon, vacuum, radiation

57

K.C. Harkay, L.E. Boon, M. Borland, J.C. Dooling, L. Emery, V. Sajaev, Y.P. Sun
ANL, Lemont, Illinois, USA

Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
APS has been developing superconducting undulators for over a decade. Presently, two planar and one helical device are in operation in the APS storage ring, and a number of devices will be installed in the APS Upgrade ring. All superconducting devices perform with very high reliability and have very minor effect on the storage ring operation. To achieve this, a number of storage ring modifications had to be done, such as introduction of the beam abort system to eliminate device quenches during beam dumps, and lattice and orbit modifications to allow for installation of the small horizontal aperture helical device with magnet coils in the plane of synchrotron radiation.

Slides MOZBA2 [3.424 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOZBA2

About •

paper received ※ 02 September 2019 paper accepted ※ 19 November 2019 issue date ※ 08 October 2019

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MOZBA3

Strongly Tapered Helical Undulator System for TESSA-266

electron, experiment, laser, permanent-magnet

63

T.J. Campese, R.B. Agustsson, I.I. Gadjev, A.Y. Murokh
RadiaBeam, Santa Monica, California, USA
W. Berg, A. Zholents
ANL, Lemont, Illinois, USA
P.E. Denham, P. Musumeci, Y. Park
UCLA, Los Angeles, USA

Funding: DOE SBIR Award No. DE-SC0017102
RadiaBeam, in collaboration with UCLA and Argonne National Laboratory (ANL), is developing a strongly tapered helical undulator system for the Tapering Enhanced Stimulated Superradiant Amplification experiment at 266 nm (TESSA-266). The experiment will be carried out at the APS LEA facility at ANL and aims at the demonstration of very high energy conversion efficiency in the UV. The undulator system was designed by UCLA, engineered by RadiaBeam, and is presently in fabrication at RadiaBeam. The design is based on a permanent magnet Halbach scheme and includes a short 30 cm long buncher section and four 1 m long undulator sections. The undulator period is fixed at 32 mm and the magnetic field amplitude can be tapered by tuning the gap along the interaction. Each magnet can be individually adjusted by 1.03 mm, offering up to 25% magnetic field tunability with a minimum gap of 5.58 mm. A custom designed 316L stainless steel beampipe runs through the center with a clear aperture of 4.5 mm. This paper discusses the design and engineering of the undulator system, fabrication status, and plans for magnetic measurements, and tuning.

Slides MOZBA3 [8.942 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOZBA3

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paper received ※ 27 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019

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MOZBA4

Recent Developments in High Power High Brightness Double Bunch Self-Seeding at LCLS-II

FEL, photon, electron, simulation

67

A. Halavanau, F.-J. Decker, Y. Ding, C. Emma, Z. Huang, A.A. Lutman, G. Marcus, C. Pellegrini
SLAC, Menlo Park, California, USA

We discuss the power and spectral characteristics of an X-ray FEL, LCLS-II, operating in a double bunch self-seeding scheme (DBFEL). We show that it can reach very high power levels in the photon energy range of 4-8 keV. We discuss the system implementation on LCLS-II, including the design of a four-bounce crystal monochromator, and linac wakefields effects. Finally, we offer multiple applications of the DBFEL for high-field QED, AMO physics and single particle imaging.

Slides MOZBA4 [3.175 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOZBA4

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paper received ※ 02 September 2019 paper accepted ※ 05 September 2019 issue date ※ 08 October 2019

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MOPLM23

Senis Hall Probe Speed Dependence Issues

wiggler, insertion-device, insertion, coupling

155

I. Vasserman
ANL, Lemont, Illinois, USA

An extensive test of a Senis 2-axis Hall probe was done at the Advanced Photon Source. Strong dependence of the measurement data on the speed of the sensor is observed. Discussion of the possible reason of such dependence is provided.
Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOPLM23

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paper received ※ 21 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019

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MOPLO01

A Beam Spreader System for LCLS-II

kicker, septum, FEL, electron

236

T.G. Beukers, J.W. Amann, Y.M. Nosochkov
SLAC, Menlo Park, California, USA

For the LCLS-II project, the SLAC National Accelerator Laboratory is installing a new superconducting RF linac capable of continuously delivering 4 GeV electron bunches spaced 1.1 microseconds apart. A spreader system is required to distribute the beam between a soft X-ray or hard X-ray undulator, and a beam dump. An additional beam diverter is required in the front end of the linac to divert 100 MeV electrons to a diagnostic line. Both the spreader and diagnostic diversion systems are designed to operate on a bunch by bunch basis via the combination of fast kickers and a Lambertson septum. This paper presents a summary of the optics, kicker, and septum design. Of specific interest is the unique challenge associated with building a high repetition, high stability, spreader capable of diverting a single bunch without disturbing neighboring bunches. Additional discussion includes the application of the spreader technology to the proposed DASEL/S30XL beamline. This beamline will acceptμbunches evenly spaced between the undulator bound bunches, thus requiring a kicker with the same repetition rate as LCLS-II but a pulse width extended to approximately 600 ns.

Poster MOPLO01 [1.256 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOPLO01

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paper received ※ 27 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019

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TUPLM26

Progress Toward a Laser Amplifier for Optical Stochastic Cooling

laser, radiation, experiment, synchrotron-radiation

434

A.J. Dick, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
M.B. Andorf
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Optical Stochastic Cooling (OSC) is a method of beam cooling using optical frequencies which compresses the phase space of the beam by correcting the deviation of each particle’s momentum. A particle bunch passing through an undulator produces radiation which is amplified and provides the corrective energy kick. In this project, we are testing a method of amplifying synchrotron radiation (SR) for the eventual use in OSC. The SR is amplified by passing through a highly-doped Chromium:Zinc Selenide (Cr:ZnSe) crystal which is pumped by a Thulium fiber laser. The SR will be produced by one of the bending magnets of the Advanced Photon Source. The first step is to detect and measure the power of SR using a photo-diode. The gain is then determined by measuring the radiation amplified after the single-pass through the crystal. This serves as a preliminary step to investigate the performance of the amplification of beam-induced radiation fields. The planned experiment is an important step towards achieving active OSC in a proof-of-principle demonstration in IOTA.

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLM26

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paper received ※ 02 September 2019 paper accepted ※ 13 September 2019 issue date ※ 08 October 2019

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TUPLS03

Advanced Photon Source Upgrade

vacuum, photon, storage-ring, operation

453

M.E. Szubert, E.R. Anliker, T.J. Bender, J.E. Lerch
ANL, Lemont, Illinois, USA

The Advanced Photon Source Upgrade (APS-U) in-cludes four straight sections equipped with full length Superconducting Undulators (SCUs). These sections require vacuum systems that must span 5.383 meters at nominal length, accommodate the SCU device, and ac-commodate additional magnets for the canted configura-tions. In the direction of the beam, the upstream portion of the vacuum system is a copper chamber doubling as a photon absorber with a design that is manufactured to allow a 13.5 mm canting magnet gap. This portion of the vacuum system operates at room temperature and shad-ows the length of the vacuum chamber that operates within the cryostat at 20K. The vacuum chamber inside the cryostat is a weldment including a machined alumi-num extrusion allowing for an 8mm magnetic gap, stain-less steel thermal insulators, copper shields, and bel-lows/flange assembly. The vacuum system includes an-other room temperature copper chamber and absorber on the downstream end of the straight section. The vacuum system provides Ultra-high Vacuum (UHV) continuity through the straight section, connecting the storage ring vacuum systems.

Poster TUPLS03 [0.974 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLS03

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paper received ※ 26 August 2019 paper accepted ※ 13 September 2019 issue date ※ 08 October 2019

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TUPLS04

Re-Evaluation of the NSLS-II Active Interlock Window

insertion, insertion-device, wiggler, vacuum

456

R.P. Fliller, III, C. Hetzel, Y. Hidaka, T. Tanabe
BNL, Upton, New York, USA

Funding: This manuscript has been authored by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy
The NSLS-II Active Interlock is the system which protects the NSLS-II Storage Ring vacuum chamber from damage due to synchrotron radiation. The Active Interlock measures the beam position and angle at all insertion devices and issues a beam dump if the beam is outside of the pre-defined window. The window is determined by thermal analysis of vacuum apertures and considers the effects of local magnets such as canting magnets, etc. Recently, it was realized that the insertion device correction coils where not considered in the initial evaluation of the envelope. The purpose of these coils is to correct for the orbit deviations caused by imperfections in the insertion devices that steer the beam. The usual effect is to negate any angle induced by the device, however, if the coil is not set properly the beam may have a larger angle than permitted by the Active Interlock even though the angle calculation does not show it. In this paper we discuss the effect of the insertion device coils on the electron beam and the steps taken to account for this effect in the Active Interlock.

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLS04

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paper received ※ 27 August 2019 paper accepted ※ 16 November 2020 issue date ※ 08 October 2019

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TUPLH01

Status of the Superconducting Undulator Program at the Advanced Photon Source

operation, storage-ring, alignment, photon

490

M. Kasa, E.R. Anliker, J.D. Fuerst, E. Gluskin, Q.B. Hasse, Y. Ivanyushenkov, W.G. Jansma, I. Kesgin, Y. Shiroyanagi
ANL, Lemont, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
Since 2013 there has been at least one superconducting undulator (SCU) in operation at the Advanced Photon Source (APS), currently there are two planar SCUs and one helical SCU. The combined operational experience of SCUs at the APS is more than 11 years and counting. Through all these years, APS SCUs operated with the predicted or better than predicted radiation performance and with 99% availability. With this demonstrated reliability and experimentally confirmed spectral performance, the APS upgrade project is planning on leveraging the advantages of SCU technology. The present planar SCUs are comprised of ~1.1-m-long magnets, each operated within a 2-m-long cryostat, while the planar SCUs for the upgrade will have two ~1.8-m-long magnets operating within a 5-m-long cryostat. Progress is also being made in other areas of SCU development with work on an arbitrary polarizing SCU, referred to as SCAPE, and a planar SCU wound with Nb₃Sn superconductor. A Nb₃Sn SCU is being designed with two 1.3-m-long magnets within a 5-m-long cryostat, and installation is planned for 2021. Also under development are the alignment and magnetic measurement systems for use with the 5-m-long cryostat.

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLH01

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paper received ※ 26 August 2019 paper accepted ※ 02 September 2019 issue date ※ 08 October 2019

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TUPLH04

Feasibility Study of Fast Polarization Switching Superconducting Undulator

polarization, simulation, coupling, power-supply

497

I. Kesgin, Y. Ivanyushenkov, M. Kasa
ANL, Lemont, Illinois, USA

Funding: U.S. Department of Energy, Office of Science, under Contract No. DE-ACO₂-O6CH11357.
Polarization switching x-ray probes coupled with high-flux provide a unique tool to unraveling the nature of electronic heterogeneity and drive discovery of novel phases of electronic matter. Superconducting Arbitrary Polarization Emitter (SCAPE) is a new concept for a universal undulator, which offers linear or circular polarization states in one device and is ideal for experiments that require polarization switching. Polarization switching relies on modulating the magnetic field in the undulator. This, however, inevitably incurs losses in superconductors, which need to be mitigated. In this study, feasibility of fast switching SCAPE has been investigated through fabricating and testing several short prototype magnets wound with different superconductors and new design concepts. The losses at different frequencies and field amplitudes are measured and details will be discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLH04

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paper received ※ 27 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019

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TUPLH10

Fabrication Progress of a Superconducting Helical Undulator with Superimposed Focusing Gradient for High Efficiency Tapered X-Ray FELs

FEL, quadrupole, vacuum, focusing

509

S.M. Lynam, R.B. Agustsson, I.I. Gadjev, A.Yu. Smirnov
RadiaBeam, Santa Monica, California, USA
F.H. O’Shea
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

Funding: This work is supported by DOE grant no. DE-SC0017072, "Superconducting Helical Undulator with Superimposed Focusing Gradient for High Efficiency Tapered X-Ray FELs"
The Advanced Gradient Undulator (AGU) represents a potentially significant advancement in x-ray conversion efficiency for x-ray FELs. This increase in efficiency would have broad implications on the capabilities of x-ray light sources. To achieve this high conversion efficiency, the inner diameter of the undulator coil is a mere 7mm, even with the use of superconducting coils. To accommodate the beamline at the Advanced Photon Source this yields in a chamber with a wall thickness of 0.5mm fabricated from Aluminum. With a period of 2cm and a conductor position tolerance of <100 µm over a length of >80cm at 4.2K, the engineering and fabrication challenges for the undulator alone are substantial. We will discuss these fabrication challenges and present solutions to meet the tolerances required for desired performance, and provide an update on current progress of the construction of a section of the AGU insertion device.

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLH10

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paper received ※ 28 August 2019 paper accepted ※ 16 November 2020 issue date ※ 08 October 2019

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WEXBA2

Recent Results and Opportunities at the IOTA Facility

electron, experiment, radiation, proton

599

A.L. Romanov, D.R. Broemmelsiek, K. Carlson, D.J. Crawford, N. Eddy, D.R. Edstrom, J.D. Jarvis, V.A. Lebedev, S. Nagaitsev, J. Ruan, J.K. Santucci, V.D. Shiltsev, G. Stancari, A. Valishev, A. Warner
Fermilab, Batavia, Illinois, USA
S. Chattopadhyay, S. Szustkowski
Northern Illinois University, DeKalb, Illinois, USA
Y.K. Kim, N. Kuklev, I. Lobach
University of Chicago, Chicago, Illinois, USA

The Integrable Optics Test Accelerator (IOTA) was recently commissioned as part of the Fermilab Accelerator Science and Technology (FAST) facility. The IOTA ring was briefly operated with electrons at 47 MeV followed by a 6-months run with 100 MeV electrons. The main goal of the first run was to study beam dynamics in the integrable lattices with elliptical nonlinear magnets and in the quasi-integrable case with profiled octupole channel. The flexibility of the IOTA ring allowed a wide range of complementary studies, such as experiments with a single electron; studies of fluctuations in undulator radiation and operation with low emittance beams. Over the next year the proton injector will be installed and two runs carried out. One run will be dedicated to the refinement of nonlinear experiments and another will be dedicated to the proof-of-principle demonstration of Optical Stochastic Cooling.

Slides WEXBA2 [12.702 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEXBA2

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paper received ※ 31 August 2019 paper accepted ※ 05 September 2019 issue date ※ 08 October 2019

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WEPLM05

Continuous Monitoring of Spectral Features of Electron Beam Orbit Motion at NSLS-II

operation, controls, feedback, cavity

673

B. Podobedov, A.A. Derbenev, K. Ha, T.V. Shaftan
BNL, Upton, New York, USA

NSLS-II ring is equipped with state-of-the art beam position monitors (BPMs) which are indispensable in all aspects of machine studies and operations. Among other data, they can provide, on demand, up to 10 seconds of fast-acquisition (FA) data, sampled at ~10 kHz. Analysis of these data in time, frequency and spatial domains provides valuable insights into orbit stability, locations of residual noise sources, performance of feedback systems, etc. In addition, changes in FA signal spectral features are often the earliest indicators of potential equipment problems. This is why we recently implemented an Input / Output Controller (IOC) software that runs during regular user operation, and, once a minute, acquires 10 second buffers of FA data from 180 BPMs around the ring. These buffers are processed to determine the amplitudes and frequencies of the strongest spectral peaks as well as some other measures of fast beam orbit noise. Processed results can be monitored in real time and are also archived for offline analysis and troubleshooting. In this paper we discuss the implementation of this system and the insights we gained from it over about two years of operations.

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLM05

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paper received ※ 31 August 2019 paper accepted ※ 02 September 2019 issue date ※ 08 October 2019

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THXBA2

Analysis of Beam Position Monitor Requirements with Bayesian Gaussian Regression

optics, brightness, quadrupole, emittance

912

Y. Li, R.S. Rainer
BNL, Upton, New York, USA
W.X. Cheng
ANL, Lemont, Illinois, USA
Y. Hao
FRIB, East Lansing, Michigan, USA

Funding: This research is supported by U.S. Department of Energy under Contract No. DE-SC0012704, and the NSF under Cooperative Agreement PHY-1102511.
With a Bayesian Gaussian regression approach, a systematic method for analyzing a storage ring’s beam position monitor (BPM) system requirements has been developed. The ultimate performance of a ring-based accelerator, based on brightness or luminosity, is determined not only by global parameters, but also by local beam properties at some particular points of interest (POI). BPMs used for monitoring the beam properties, however, can not be located at these points. Therefore, the underlying and fundamental purpose of a BPM system is to predict whether the beam properties at POIs reach their desired values. The prediction process is a regression problem with BPM readings as the training data, but containing random noise. A Bayesian Gaussian regression approach can determine the probability distribution of the predictive errors, which can be used to conversely analyze the BPM system requirements. This approach is demonstrated by using turn-by-turn data to reconstruct a linear optics model, and predict the brightness degradation for a ring-based light source. The quality of BPMs was found to be more important than their quantity in mitigating predictive errors.

Slides THXBA2 [3.205 MB]

Poster THXBA2 [7.083 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-THXBA2

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paper received ※ 16 August 2019 paper accepted ※ 04 September 2019 issue date ※ 08 October 2019

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THYBA5

Study of Fluctuations in Undulator Radiation in the IOTA Ring at Fermilab

experiment, radiation, electron, wiggler

934

I. Lobach
University of Chicago, Chicago, Illinois, USA
A. Halavanau, Z. Huang, V. Yakimenko
SLAC, Menlo Park, California, USA
K. Kim
ANL, Lemont, Illinois, USA
V.A. Lebedev, S. Nagaitsev, A.L. Romanov, G. Stancari
Fermilab, Batavia, Illinois, USA
A.Y. Murokh
RadiaBeam, Marina del Rey, California, USA
T.V. Shaftan
BNL, Upton, New York, USA

We study turn-by-turn fluctuations in the number of emitted photons in an undulator, installed in the IOTA electron storage ring at Fermilab, with an InGaAs PIN photodiode and an integrating circuit. In this paper, we present a theoretical model for the experimental data from previous similar experiments and in our present experiment, we attempt to verify the model in an independent and a more systematic way. Moreover, in our experiment we consider the regime of very small fluctuation when the contribution from the photon shot noise is significant, whereas we believe it was negligible in the previous experiments. Accordingly, we present certain critical improvements in the experimental setup that let us measure such a small fluctuation.

Slides THYBA5 [8.048 MB]

Poster THYBA5 [3.079 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-THYBA5

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paper received ※ 24 August 2019 paper accepted ※ 05 September 2019 issue date ※ 08 October 2019

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