IPAC2019 - Classification: MC2: Photon Sources and Electron Accelerators / A24 Accelerators and Storage Rings, Other

Paper	Title	Page
MOPRB005	Study of Higher-Order Achromat Lattice as an Alternative Option for the SOLEIL Storage Ring Upgrade	586
	R. Nagaoka, A. Bence, P. Brunelle, L. Hoummi, A. Loulergue, A. Nadji, L.S. Nadolski, M.-A. Tordeux, A. Vivoli SOLEIL, Gif-sur-Yvette, France A. Gamelin LAL, Orsay, France
	A ring composed of 20 symmetrical 7BA cells in which of a pair of chromaticity correcting sextupoles placed around horizontal dispersion bumps à la ESRF-EBS was developed as a baseline lattice for the SOLEIL storage ring upgrade (presented at IPAC2018). The strict phase relation between the two dispersion bumps provides an efficient way of optimizing the (on-momentum) nonlinear optics with a limited number of sextupoles. As an alternative, a scheme known as Higher-Order Achromat (HOA) develops a MBA (Multi-Bend Achromat) lattice where chromaticity correcting sextupoles are distributed in each M unit cell with a strict phase relation cell-wise such as to cancel basic geometric and chromatic resonance driving terms. The beam dynamics in a 20-fold 7BA HOA ring is compared with those of the baseline lattice, with focus on off-momentum properties such as Touschek lifetime, which are important for medium energy rings like SOLEIL. The robustness against errors, the reduction of the ring symmetry by introducing 4 longer straight sections, as well as a horizontal dispersion bump to cope with longitudinal on-axis injection scheme are also presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB005
About •	paper received ※ 22 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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MOPRB027	Progress of HEPS Accelerator System Design	633
	P. He, J.S. Cao, F.S. Chen, J. Chen, H. Dong, D.Y. He, Y. Jiao, W. Kang, C.H. Li, J.Y. Li, F. Long, H.H. Lu, X. Qi, Q. Qin, H. Qu, J.Q. Wang, G. Xu, J.H. Yue, J. Zhang, J.R. Zhang, P. Zhang IHEP, Beijing, People’s Republic of China
	The 4th generation ring-based light sources, HEPS (High Energy Photon Source) 7BA lattice has been de-veloped at IHEP. This is 6Gev, 200mA machine which has horizontal emittance Ɛh around 60pm.rad to gain the high brilliance photon beam. this compact lattice design bring so many engineering challenges for accelerator magnets, vacuum components, beam diagnotice, etc. This paper will present the noval lattice design and subsystem design progress.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB027
About •	paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPRB033	Preliminary Research of HOM for 100MHz Superconducting Cavity in the Pre-Research Project of HALS	649
SUSPFO070	use link to see paper's listing under its alternate paper code
	Y.G. Tang, L. Wang, C.-F. Wu USTC/NSRL, Hefei, Anhui, People’s Republic of China
	A 100MHz QWR superconducting cavity is researched in the pre-research project of Hefei Advanced Light Source (HALS). Higher order modes (HOM) damping is a big challenge for synchrotron radiation light source. In this paper, we first apply the novel choke mode structure to the 100MHz QWR (quarter wave resonator) cavity in order to damp the HOM. We identify the main harmful higher order modes. The HOMs in the QWR cavity are suppressed by optimizing the choke dimensions. The broadband HOM impedance spectrum of the cavity was also evaluated by calculating the beam induced wake potential in time domain. The results show that choke mode structure has a good HOM damping effect on the QWR cavity.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB033
About •	paper received ※ 25 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPRB036	Study on Beam-induced heating in injection section of Hefei Light Source	652
	D.R. Xu, W. Xu USTC/NSRL, Hefei, Anhui, People’s Republic of China
	Ceramic chambers distributed with metal belts on the inner surface are installed in the injection section at Hefei Light Source (HLS). Heating on the ceramics chambers has been observed during machine operation. An air compressor is used to cool these chambers due to concerns of overheating during top-up operation mode. To understand the sources of the heating, a series of experiments are performed with various beam currents and bunch filling patterns. The study shows that the heating is mainly caused by the narrow-band impedances of the ceramic chambers and their adjacent vacuum components.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB036
About •	paper received ※ 22 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPRB052	Gamma Factory at CERN: Design of a Proof-of-Principle Experiment	685
	Y. Dutheil, R. Alemany-Fernández, H. Bartosik, N. Biancacci, R. Bruce, P. Czodrowski, V. Fedosseev, B. Goddard, S. Hirlaender, J.M. Jowett, R. Kersevan, M. Kowalska, M. Lamont, D. Manglunki, J. Molson, A.V. Petrenko, M. Schaumann, F. Zimmermann CERN, Geneva, Switzerland S.E. Alden, A. Bosco, S.M. Gibson, L.J. Nevay JAI, Egham, Surrey, United Kingdom A. Apyan ANSL, Yerevan, Armenia E.G. Bessonov LPI, Moscow, Russia A. Bosco, S.M. Gibson, L.J. Nevay Royal Holloway, University of London, Surrey, United Kingdom F. Castelli Università degli Studi di Milano, Milano, Italy F. Castelli, C. Curatolo, L. Serafini INFN-Milano, Milano, Italy K. Kroeger FSU Jena, Jena, Germany A. Martens LAL, Orsay, France V. Petrillo Universita’ degli Studi di Milano, Milano, Italy M. Sapinski, T. Stöhlker GSI, Darmstadt, Germany G. Weber IOQ, Jena, Germany Y.K. Wu FEL/Duke University, Durham, North Carolina, USA
	The Gamma Factory (GF) initiative proposes to create novel research tools at CERN by producing, accelerating and storing highly relativistic partially stripped ion beams in the LHC rings and by exciting their atomic degrees of freedom by lasers, to produce high-energy photon beams. Their intensity would be several orders of magnitude higher than those of the presently operating light sources in the particularly interesting gamma-ray energy domain reaching up to 400 MeV. In this energy domain, the high-intensity photon beams can be used to produce secondary beams of polarized electrons, polarized positrons, polarized muons, neutrinos, neutrons and radioactive ions. Over the years 2017-2018 we have demonstrated that these partially stripped ion beams can be successfully produced, accelerated and stored in the CERN accelerator complex, including the LHC. The next step of the project is to build a proof of principle experiment in the SPS to validate the principal GF concepts. This contribution will present the initial conceptual design of this experiment along with its main challenge - the demonstration of the fast cooling method of partially stripped ion beams.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB052
About •	paper received ※ 19 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPRB057	An Approach to Alleviating Heavy Beam Loading Effect on the Synchrotron Machine Through the Existed Low Level RF Feedback System	697
	L.-H. Chang, F.Y. Chang, M.H. Chang, S.W. Chang, L.J. Chen, F.-T. Chung, Y.T. Li, M.-C. Lin, Z.K. Liu, C.H. Lo, Ch. Wang, M.-S. Yeh, T.-C. Yu NSRRC, Hsinchu, Taiwan
	To pursue the highest brightness and intensity of the synchrotron light, the synchrotron machines are pushed to operate with as high as possible of the beam current. To suppress the heavy beam loading effects, the direct RF feedback is currently widely used. This paper provides an another approach to alleviating the heavy beam loading effects on machine operation. Different from the direct RF feedback technique, this approach need not add additional feedback loop to the existed RF feedback system. Applying a proper angle rotation to the I-Q error signals of the cavity voltage, before entering the existed feedback loop, is the only action required in this approach. The paper will explain the working mechanism and investigate the behaviour of this approach, through an example case, with numerical simulation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB057
About •	paper received ※ 16 April 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019
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MOPRB088	Study of Fluctuations in Undulator Radiation in the IOTA Ring at Fermilab	777
SUSPFO128	use link to see paper's listing under its alternate paper code
	I. Lobach University of Chicago, Chicago, Illinois, USA A. Halavanau, Z. Huang, V. Yakimenko SLAC, Menlo Park, California, USA K. Kim ANL, Argonne, Illinois, USA V.A. Lebedev, S. Nagaitsev, A.L. Romanov, G. Stancari, A. Valishev Fermilab, Batavia, Illinois, USA A.Y. Murokh RadiaBeam, Los Angeles, California, USA T.V. Shaftan BNL, Upton, Long Island, 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. Our study was motivated by the previous experiment . We propose a theoretical model for the experimental data from and in our own experiment we attempted to verify the model in an independent and more systematic way. Moreover, these fluctuations are an interesting subject for a study by itself, since they act as a seed for SASE in FELs. We improve the precision of the measurements from * by subtracting the average signal amplitude using a comb filter with a one-turn IOTA delay, and by using a special algorithm for noise subtraction. We obtain a reasonable agreement between our theoretical model and experiment. Along with repeating the experiment from , which was performed at a constant beam current, we also collect data for fluctuations in undulator light at different beam current values. Lastly, in our experiment we were able to see the transition from Poisson statistics to Super-Poisson statistics for undulator light, whereas in only the latter statistics was observed. * M. Teich et al., PRL, vol. 65, no. 27, p. 3393 (1990).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB088
About •	paper received ※ 14 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019
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MOPRB089	Experimental Study of a Single Electron in a Storage Ring via Undulator Radiation	781
	S. Nagaitsev, A.L. Romanov, G. Stancari Fermilab, Batavia, Illinois, USA A. Arodzero, A.Y. Murokh, M. Ruelas RadiaBeam, Santa Monica, California, USA I. Lobach University of Chicago, Chicago, Illinois, USA T.V. Shaftan BNL, Upton, Long Island, New York, USA
	A single electron orbiting around a ring and emitting single quanta at the rate of about one event per hundred turns could produce a wealth of information about physical processes in large traps (i.e. storage rings) for charged particles. It should be noted that Paul and Penning traps in the 1980s led to the Nobel prize for studying state and motion of single quantum particles, and just recently the Penning trap technique has enabled the measurement of a single proton magnetic moment with an unprecedented precision of 10 decimal places. The information from the storage ring traps could also be used for characterization of a quantum system as well as the "trap" itself, i.e. measuring properties of the storage ring lattice and electron interaction with the laser fields. Although, the interest in single electron quantum processes today is mostly academic in nature, the diagnostics and methodology developed for single electron radiation studies could find subsequent applications in a variety of applied disciplines in quantum technology, including quantum communications and quantum computing.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB089
About •	paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPTS038	BEAM DYNAMICS OF HIGH CHROMATICITY LATTICE FOR IRANIAN LIGHT SOURCE FACILITY (ILSF) STORAGE RING	943
SUSPFO032	use link to see paper's listing under its alternate paper code
	F. Foroughi, S.M. Jazayeri IUST, Narmac, Tehran, Iran E. Ahmadi, S. Dastan, J. Rahighi ILSF, Tehran, Iran
	One of the limiting factors of electron beam lifetime in low emittance storage rings is Head-Tail (HT) insta-bility. Low emittance storage rings typically have a large negative natural chromaticity due to the strong quadru-poles. Above transition large negative natural chroma-ticity leads to large Head-Tail instability which limit the beam lifetime. Since the threshold current of HT insta-bility is directly related to linear chromaticity, increasing the linear chromaticity to slightly positive value is a solution to prevent HT instability. In this paper we in-creased the chromaticity of Iranian Light Source Facility (ILSF) to (+4, +4) and we will investigate the beam dy-namics of ILSF 3GeV storage ring in high chromaticity. For reaching this aim we have used two families of sex-tupoles for chromaticity correction and then optimized them to maximize the dynamic aperture and Touschek lifetime. The beam dynamics of high chromaticity lattice is presented in this paper. Foroughi.farangis@gmail.com
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS038
About •	paper received ※ 29 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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TUPGW039	Error Study and Correction of Hefei Advanced Light Source	1492
	D.R. Xu, Z.H. Bai, W. Li USTC/NSRL, Hefei, Anhui, People’s Republic of China
	Hefei Advanced Light Source (HALS) is a future diffraction limited storage ring. The machine performance under all kinds of magnet errors is a vital component in physical design. In this paper, we present our work on the closed orbit correction, the linear beam optics compensation and the coupling control in HALS. After correction, the dynamical aperture can suffice the injection scheme.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW039
About •	paper received ※ 23 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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THYYPLM1	A Novel Compact High Rep-Rate Gamma Ray Source Based on Strongly Tapered Undulator Interactions
MOPRB108	use link to see paper's listing under its alternate paper code
	N.S. Sudar, P. Musumeci UCLA, Los Angeles, USA A.Y. Murokh RadiaBeam, Los Angeles, California, USA
	Recent experimental efforts have shown strongly tapered undulator interactions to be the most efficient means for exchanging energy between relativistic electron beams and electro-magnetic fields. The Rubicon Inverse Free Electron Laser (IFEL) accelerator demonstrated up to 100 MeV/m acceleration gradients, producing high quality mono-energetic beams. In separate experiments, it was also shown that this acceleration could occur at high rep-rates, and the accelerated beams could be used to produce X-rays through Inverse Compton Scattering (ICS). The Nocibur experiment demonstrated the reverse process, converting 30% of the energy in a relativistic electron beam to coherent radiation. Combining these concepts, we present here a novel scheme where a laser, re-circulated in an optical cavity drives an IFEL interaction, accelerating a 200 MeV beam up to 1 GeV, at which point an ICS interaction can be used to produce gamma rays. This is followed by a Nocibur-like interaction, decelerating the beam below it’s initial energy, replenishing the laser energy absorbed in the acceleration stage as well as compensating for cavity losses.
	Slides THYYPLM1 [5.666 MB]
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Paper

Title

Page

Study of Higher-Order Achromat Lattice as an Alternative Option for the SOLEIL Storage Ring Upgrade

586

R. Nagaoka, A. Bence, P. Brunelle, L. Hoummi, A. Loulergue, A. Nadji, L.S. Nadolski, M.-A. Tordeux, A. Vivoli
SOLEIL, Gif-sur-Yvette, France
A. Gamelin
LAL, Orsay, France

A ring composed of 20 symmetrical 7BA cells in which of a pair of chromaticity correcting sextupoles placed around horizontal dispersion bumps à la ESRF-EBS was developed as a baseline lattice for the SOLEIL storage ring upgrade (presented at IPAC2018). The strict phase relation between the two dispersion bumps provides an efficient way of optimizing the (on-momentum) nonlinear optics with a limited number of sextupoles. As an alternative, a scheme known as Higher-Order Achromat (HOA) develops a MBA (Multi-Bend Achromat) lattice where chromaticity correcting sextupoles are distributed in each M unit cell with a strict phase relation cell-wise such as to cancel basic geometric and chromatic resonance driving terms. The beam dynamics in a 20-fold 7BA HOA ring is compared with those of the baseline lattice, with focus on off-momentum properties such as Touschek lifetime, which are important for medium energy rings like SOLEIL. The robustness against errors, the reduction of the ring symmetry by introducing 4 longer straight sections, as well as a horizontal dispersion bump to cope with longitudinal on-axis injection scheme are also presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB005

About •

paper received ※ 22 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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MOPRB027

Progress of HEPS Accelerator System Design

633

P. He, J.S. Cao, F.S. Chen, J. Chen, H. Dong, D.Y. He, Y. Jiao, W. Kang, C.H. Li, J.Y. Li, F. Long, H.H. Lu, X. Qi, Q. Qin, H. Qu, J.Q. Wang, G. Xu, J.H. Yue, J. Zhang, J.R. Zhang, P. Zhang
IHEP, Beijing, People’s Republic of China

The 4th generation ring-based light sources, HEPS (High Energy Photon Source) 7BA lattice has been de-veloped at IHEP. This is 6Gev, 200mA machine which has horizontal emittance Ɛh around 60pm.rad to gain the high brilliance photon beam. this compact lattice design bring so many engineering challenges for accelerator magnets, vacuum components, beam diagnotice, etc. This paper will present the noval lattice design and subsystem design progress.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB027

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paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPRB033

Preliminary Research of HOM for 100MHz Superconducting Cavity in the Pre-Research Project of HALS

649

SUSPFO070

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

Y.G. Tang, L. Wang, C.-F. Wu
USTC/NSRL, Hefei, Anhui, People’s Republic of China

A 100MHz QWR superconducting cavity is researched in the pre-research project of Hefei Advanced Light Source (HALS). Higher order modes (HOM) damping is a big challenge for synchrotron radiation light source. In this paper, we first apply the novel choke mode structure to the 100MHz QWR (quarter wave resonator) cavity in order to damp the HOM. We identify the main harmful higher order modes. The HOMs in the QWR cavity are suppressed by optimizing the choke dimensions. The broadband HOM impedance spectrum of the cavity was also evaluated by calculating the beam induced wake potential in time domain. The results show that choke mode structure has a good HOM damping effect on the QWR cavity.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB033

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paper received ※ 25 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPRB036

Study on Beam-induced heating in injection section of Hefei Light Source

652

D.R. Xu, W. Xu
USTC/NSRL, Hefei, Anhui, People’s Republic of China

Ceramic chambers distributed with metal belts on the inner surface are installed in the injection section at Hefei Light Source (HLS). Heating on the ceramics chambers has been observed during machine operation. An air compressor is used to cool these chambers due to concerns of overheating during top-up operation mode. To understand the sources of the heating, a series of experiments are performed with various beam currents and bunch filling patterns. The study shows that the heating is mainly caused by the narrow-band impedances of the ceramic chambers and their adjacent vacuum components.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB036

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paper received ※ 22 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPRB052

Gamma Factory at CERN: Design of a Proof-of-Principle Experiment

685

Y. Dutheil, R. Alemany-Fernández, H. Bartosik, N. Biancacci, R. Bruce, P. Czodrowski, V. Fedosseev, B. Goddard, S. Hirlaender, J.M. Jowett, R. Kersevan, M. Kowalska, M. Lamont, D. Manglunki, J. Molson, A.V. Petrenko, M. Schaumann, F. Zimmermann
CERN, Geneva, Switzerland
S.E. Alden, A. Bosco, S.M. Gibson, L.J. Nevay
JAI, Egham, Surrey, United Kingdom
A. Apyan
ANSL, Yerevan, Armenia
E.G. Bessonov
LPI, Moscow, Russia
A. Bosco, S.M. Gibson, L.J. Nevay
Royal Holloway, University of London, Surrey, United Kingdom
F. Castelli
Università degli Studi di Milano, Milano, Italy
F. Castelli, C. Curatolo, L. Serafini
INFN-Milano, Milano, Italy
K. Kroeger
FSU Jena, Jena, Germany
A. Martens
LAL, Orsay, France
V. Petrillo
Universita’ degli Studi di Milano, Milano, Italy
M. Sapinski, T. Stöhlker
GSI, Darmstadt, Germany
G. Weber
IOQ, Jena, Germany
Y.K. Wu
FEL/Duke University, Durham, North Carolina, USA

The Gamma Factory (GF) initiative proposes to create novel research tools at CERN by producing, accelerating and storing highly relativistic partially stripped ion beams in the LHC rings and by exciting their atomic degrees of freedom by lasers, to produce high-energy photon beams. Their intensity would be several orders of magnitude higher than those of the presently operating light sources in the particularly interesting gamma-ray energy domain reaching up to 400 MeV. In this energy domain, the high-intensity photon beams can be used to produce secondary beams of polarized electrons, polarized positrons, polarized muons, neutrinos, neutrons and radioactive ions. Over the years 2017-2018 we have demonstrated that these partially stripped ion beams can be successfully produced, accelerated and stored in the CERN accelerator complex, including the LHC. The next step of the project is to build a proof of principle experiment in the SPS to validate the principal GF concepts. This contribution will present the initial conceptual design of this experiment along with its main challenge - the demonstration of the fast cooling method of partially stripped ion beams.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB052

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paper received ※ 19 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPRB057

An Approach to Alleviating Heavy Beam Loading Effect on the Synchrotron Machine Through the Existed Low Level RF Feedback System

697

L.-H. Chang, F.Y. Chang, M.H. Chang, S.W. Chang, L.J. Chen, F.-T. Chung, Y.T. Li, M.-C. Lin, Z.K. Liu, C.H. Lo, Ch. Wang, M.-S. Yeh, T.-C. Yu
NSRRC, Hsinchu, Taiwan

To pursue the highest brightness and intensity of the synchrotron light, the synchrotron machines are pushed to operate with as high as possible of the beam current. To suppress the heavy beam loading effects, the direct RF feedback is currently widely used. This paper provides an another approach to alleviating the heavy beam loading effects on machine operation. Different from the direct RF feedback technique, this approach need not add additional feedback loop to the existed RF feedback system. Applying a proper angle rotation to the I-Q error signals of the cavity voltage, before entering the existed feedback loop, is the only action required in this approach. The paper will explain the working mechanism and investigate the behaviour of this approach, through an example case, with numerical simulation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB057

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paper received ※ 16 April 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

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MOPRB088

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

777

SUSPFO128

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

I. Lobach
University of Chicago, Chicago, Illinois, USA
A. Halavanau, Z. Huang, V. Yakimenko
SLAC, Menlo Park, California, USA
K. Kim
ANL, Argonne, Illinois, USA
V.A. Lebedev, S. Nagaitsev, A.L. Romanov, G. Stancari, A. Valishev
Fermilab, Batavia, Illinois, USA
A.Y. Murokh
RadiaBeam, Los Angeles, California, USA
T.V. Shaftan
BNL, Upton, Long Island, 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. Our study was motivated by the previous experiment *. We propose a theoretical model for the experimental data from * and in our own experiment we attempted to verify the model in an independent and more systematic way. Moreover, these fluctuations are an interesting subject for a study by itself, since they act as a seed for SASE in FELs. We improve the precision of the measurements from * by subtracting the average signal amplitude using a comb filter with a one-turn IOTA delay, and by using a special algorithm for noise subtraction. We obtain a reasonable agreement between our theoretical model and experiment. Along with repeating the experiment from *, which was performed at a constant beam current, we also collect data for fluctuations in undulator light at different beam current values. Lastly, in our experiment we were able to see the transition from Poisson statistics to Super-Poisson statistics for undulator light, whereas in * only the latter statistics was observed.
* M. Teich et al., PRL, vol. 65, no. 27, p. 3393 (1990).

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB088

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paper received ※ 14 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

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MOPRB089

Experimental Study of a Single Electron in a Storage Ring via Undulator Radiation

781

S. Nagaitsev, A.L. Romanov, G. Stancari
Fermilab, Batavia, Illinois, USA
A. Arodzero, A.Y. Murokh, M. Ruelas
RadiaBeam, Santa Monica, California, USA
I. Lobach
University of Chicago, Chicago, Illinois, USA
T.V. Shaftan
BNL, Upton, Long Island, New York, USA

A single electron orbiting around a ring and emitting single quanta at the rate of about one event per hundred turns could produce a wealth of information about physical processes in large traps (i.e. storage rings) for charged particles. It should be noted that Paul and Penning traps in the 1980s led to the Nobel prize for studying state and motion of single quantum particles, and just recently the Penning trap technique has enabled the measurement of a single proton magnetic moment with an unprecedented precision of 10 decimal places. The information from the storage ring traps could also be used for characterization of a quantum system as well as the "trap" itself, i.e. measuring properties of the storage ring lattice and electron interaction with the laser fields. Although, the interest in single electron quantum processes today is mostly academic in nature, the diagnostics and methodology developed for single electron radiation studies could find subsequent applications in a variety of applied disciplines in quantum technology, including quantum communications and quantum computing.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB089

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paper received ※ 15 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPTS038

BEAM DYNAMICS OF HIGH CHROMATICITY LATTICE FOR IRANIAN LIGHT SOURCE FACILITY (ILSF) STORAGE RING

943

SUSPFO032

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

F. Foroughi, S.M. Jazayeri
IUST, Narmac, Tehran, Iran
E. Ahmadi, S. Dastan, J. Rahighi
ILSF, Tehran, Iran

One of the limiting factors of electron beam lifetime in low emittance storage rings is Head-Tail (HT) insta-bility. Low emittance storage rings typically have a large negative natural chromaticity due to the strong quadru-poles. Above transition large negative natural chroma-ticity leads to large Head-Tail instability which limit the beam lifetime. Since the threshold current of HT insta-bility is directly related to linear chromaticity, increasing the linear chromaticity to slightly positive value is a solution to prevent HT instability. In this paper we in-creased the chromaticity of Iranian Light Source Facility (ILSF) to (+4, +4) and we will investigate the beam dy-namics of ILSF 3GeV storage ring in high chromaticity. For reaching this aim we have used two families of sex-tupoles for chromaticity correction and then optimized them to maximize the dynamic aperture and Touschek lifetime. The beam dynamics of high chromaticity lattice is presented in this paper.
Foroughi.farangis@gmail.com

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS038

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paper received ※ 29 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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TUPGW039

Error Study and Correction of Hefei Advanced Light Source

1492

D.R. Xu, Z.H. Bai, W. Li
USTC/NSRL, Hefei, Anhui, People’s Republic of China

Hefei Advanced Light Source (HALS) is a future diffraction limited storage ring. The machine performance under all kinds of magnet errors is a vital component in physical design. In this paper, we present our work on the closed orbit correction, the linear beam optics compensation and the coupling control in HALS. After correction, the dynamical aperture can suffice the injection scheme.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW039

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paper received ※ 23 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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THYYPLM1

A Novel Compact High Rep-Rate Gamma Ray Source Based on Strongly Tapered Undulator Interactions

MOPRB108

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N.S. Sudar, P. Musumeci
UCLA, Los Angeles, USA
A.Y. Murokh
RadiaBeam, Los Angeles, California, USA

Recent experimental efforts have shown strongly tapered undulator interactions to be the most efficient means for exchanging energy between relativistic electron beams and electro-magnetic fields. The Rubicon Inverse Free Electron Laser (IFEL) accelerator demonstrated up to 100 MeV/m acceleration gradients, producing high quality mono-energetic beams. In separate experiments, it was also shown that this acceleration could occur at high rep-rates, and the accelerated beams could be used to produce X-rays through Inverse Compton Scattering (ICS). The Nocibur experiment demonstrated the reverse process, converting 30% of the energy in a relativistic electron beam to coherent radiation. Combining these concepts, we present here a novel scheme where a laser, re-circulated in an optical cavity drives an IFEL interaction, accelerating a 200 MeV beam up to 1 GeV, at which point an ICS interaction can be used to produce gamma rays. This is followed by a Nocibur-like interaction, decelerating the beam below it’s initial energy, replenishing the laser energy absorbed in the acceleration stage as well as compensating for cavity losses.

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