IPAC2014 - Classification: 02 Synchrotron Light Sources and FELs / A16 Advanced Concepts

Paper	Title	Page
MOXBA01	Challenges in the Design of Diffraction-limited Storage Rings	7
	R.O. Hettel SLAC, Menlo Park, California, USA
	This presentation reviews current developments in the design of ultra-low emittance lattices, the experience and challenges with the operation of low emittance lattices and the main technological problems. Beam dynamics issues and collective effects for ultra low emittance machines are also addressed.
	Slides MOXBA01 [6.969 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOXBA01
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TUZA01	Advanced Concepts and Challenges in Compton Radiation Sources	928
	I. Pogorelsky BNL, Upton, Long Island, New York, USA
	Ongoing developments in Compton radiation sources are aimed toward a diversity of potential applications, ranging from university-scale compact x-ray light sources and metrology tools for EUV lithography, to positron sources for e⁻e⁺ colliders. Novel conceptual approaches are pursued on different routes: One research direction lies in multiplying the source’s repetition rate and increasing its average brightness by placing the point of Compton interaction inside an optical cavity. High-gradient plasma-wakefield accelerators are fast becoming a practical reality, offering a new paradigm to compact all-optical Compton sources operating in x-ray- and gamma-regions. Continuing improvement in the quality of the beam of plasma accelerators promises the achievement of fully coherent Compton x-rays, thereby prompting the evolution of the Compton source to an all-optical free-electron laser.
	Slides TUZA01 [22.419 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUZA01
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TUOCA03	Production of Quasi-monochromatic GeV Photons by Compton Scattering using Undulator X-ray Radiation at SPring-8	941
	H. Ohkuma, A. Mochihashi, M. Oishi, S. Suzuki, K. Tamura JASRI/SPring-8, Hyogo-ken, Japan N. Muramatsu, H. Shimizu Tohoku University, Research Center for Electron Photon Science, Sendai, Japan T. Nakano RCNP, Osaka, Japan
	Funding: This work is supported by JSPS KAKENHI (Grant-in-Aid for Scientific Research) Grant Number 24241035. Backward Compton scattering (BCS) of X-ray photons emitted by undulator and reflected back by a single crystal from the electron beam can produce a quasi-monochromatic gamma-ray beam up to an energy very close to the electron beam energy. The SPring-8 beam diagnostics beamline (BL05SS) is used to inject a reflected undulator X-ray radiation against 8 GeV stored electron beam and to extract a quasi-monochromatic 8 GeV gamma-ray produced by BCS. BL05SS has conditions to do a pilot experiment to obtain the gamma-ray beam using BCS of X-ray photons from existing undulator. Experimental setup including a Bragg mirror system is now under construction. Preliminary reflectivity measurement of a silicon Bragg mirror using around 10keV photons has been done. Status of the experimental preparation and the future outlook is presented.
	Slides TUOCA03 [1.889 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUOCA03
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WEXA01	Low Emittance Upgrade for Existing Mid-size Light Sources
	S. Shin PAL, Pohang, Kyungbuk, Republic of Korea
	Recently, several ideas to upgrade mid-size existing light sources to low emittances have been proposed. In these machines it is more difficult to get down to 100pm level while simultaneously keeping the beam lines as they are. This talk reviews the various ideas to achieve this goal, and presents examples of ongoing projects.
	Slides WEXA01 [3.538 MB]
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WEPRO001	Effect of Beam Dynamics Processes in the Low Energy Ring ThomX	1933
	N. Delerue, C. Bruni, I. Chaikovska, I.V. Drebot, M. Jacquet, A. Variola, Z.F. Zomer LAL, Orsay, France A. Loulergue SOLEIL, Gif-sur-Yvette, France
	Funding: This work is supported by the French "Agence Nationale de la Recherche" as part of the program "investing in the future" under reference ANR-10-EQPX-51 and by grants from Région Ile-de-France. As part of the R&D for the 50 MeV ThomX Compton source project, we have studied the effect of several beam dynamics processes on the evolution of the beam in the ring. The processes studied include among others Compton scattering, intrabeam scattering, coherent synchrotron radiation. We have performed extensive simulations of a full injection/extraction cycle (400000 turns). We show how each of these processes degrades the flux of photons produced and how a feedback system contributes to recovering most of the flux.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO001
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WEPRO002	Studies of Ultrashort THz Pulses at DELTA	1936
	P. Ungelenk, L.-G. Böttger, S. Hilbrich, H. Huck, M. Huck, M. Höner, S. Khan, C. Mai, A. Meyer auf der Heide, R. Molo, H. Rast, A. Schick DELTA, Dortmund, Germany S. Bielawski, C. Evain, M. Le Parquier, E. Roussel, C. Szwaj PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France N. Hiller, V. Judin, J. Raasch, P. Thoma KIT, Karlsruhe, Germany
	Funding: Work supported by the DFG, the BMBF, and the state of NRW. At DELTA, a 1.5-GeV electron storage ring operated as a light source by the Center for Synchrotron Radiation at the TU Dortmund University, coherent ultrashort THz pulses are routinely generated by density-modulated electron bunches. Tracking simulations as well as experimental studies using ultrafast THz detectors and an FT-IR spectrometer aim at understanding the turn-by-turn evolution of the density modulation after an initial laser-electron interaction. Furthermore, intensity-modulated laser pulses are applied to create narrow-band THz radiation. This setup is part of the new short-pulse facility based on coherent harmonic generation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO002
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WEPRO003	Construction of a Laser Compton Scattered Photon Source at cERL	1940
	R. Nagai, R. Hajima, M. Mori, T. Shizuma JAEA, Ibaraki-ken, Japan T. Akagi, Y. Honda, A. Kosuge, J. Urakawa KEK, Ibaraki, Japan
	A nondestructive assay system of isotopes by quasi-monochromatic gamma-rays and nuclear resonance fluorescence is under development in JAEA. The quasi-monochromatic gamma-rays are generated by laser Compton scattering (LCS) based on energy-recovery linac accelerator and laser technologies. In order to demonstrate the accelerator and laser performance required for the gamma-ray source, an LCS experiment is planned at Compact ERL (cERL) at KEK. A mode-locked fiber laser, laser enhancement cavity, beamline, and experimental hatch are under construction for the LCS experiment. Up-to-date construction status is presented in detail.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO003
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WEPRO006	Beam-driven Terahertz Source based on Open Ended Waveguide with a Dielectric Layer	1949
	A.V. Tyukhtin, S.N. Galyamin, V.V. Vorobev Saint-Petersburg State University, Saint-Petersburg, Russia S.P. Antipov Euclid TechLabs, LLC, Solon, Ohio, USA S. Baturin LETI, Saint-Petersburg, Russia
	Funding: Work is supported by the Grant of the President of Russian Federation (MK-273.2013.2) and the Russian Foundation for Basic Research (Grant No. 12-02-31258). Electromagnetic waves with frequencies from 0.1 THz to 10 THz (usually called the Terahertz gap) are of great importance for a number of scientific and practical applications. Different techniques are known allowing generating these frequencies. However, a current trend of physics and industry is to fill this gap with more powerful and efficient sources. For example, recent experiments have shown promising THz generation in dielectric loaded structures. Developing this area, we consider the THz emitting scheme where an ultrarelativistic charge exits the open end of a cylindrical waveguide with a dielectric layer and produces THz waves in a form of Cherenkov radiation. The end of the waveguide is supposed to be either orthogonal to the structure axis or skewed. To obtain THz frequencies from waveguides with centimeter or millimeter radii, we consider high order modes. We present typical field patterns (in the Fraunhofer zone) and show that the aperture of the vacuum channel gives, as a rule, the main contribution. We also give simple expressions for the angle of the main pattern lobe. S. Antipov et al., Appl. Phys. Lett. 100, 132910 (2012).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO006
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WEPRO007	Nanometer Scale Coherent Current Modulation via a Nanotip Cathode Array and Emittance Exchange	1952
	E.A. Nanni, W.S. Graves MIT, Cambridge, Massachusetts, USA P. Piot Fermilab, Batavia, Illinois, USA P. Piot Northern Illinois University, DeKalb, Illinois, USA
	Funding: NSF DMR-1042342, DARPA N66001-11-1-4192 We present PIC simulations of electron bunches with nm scale longitudinal modulation produced using a compact 2-20 MeV LINAC. The modulation is initially imparted in the transverse dimension of the electron bunch with a nano-patterned photo-emitter in a X-band RF gun with 2 MeV exit energy. The electron bunch passes through a 1 m standing wave X-band LINAC which can raise the beam energy up to 20 MeV. The transverse modulation is exchanged into the longitudinal dimension using a double dog-leg emittance exchange setup with a 5 cell RF deflector cavity. The modulation pitch can be tuned by adjusting the spacing of the nano-patterned photo-emitter or magnification of the transverse pitch with electron optics. The electron beam parameters are optimized to produce coherent XFEL radiation upon interacting with a “laser undulator”.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO007
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WEPRO008	A Beam-driven Microwave Undulator for FEL	1956
	A. Kanareykin, C.-J. Jing, P. Schoessow Euclid TechLabs, LLC, Solon, Ohio, USA S. Baturin LETI, Saint-Petersburg, Russia A. Zholents ANL, Argonne, Ilinois, USA
	Funding: DOE SBIR Microwave waveguides can in principle be used for undulators with periods less than 1 cm. Intensive work has been done on the recently proposed design that operates at the HE11 hybrid mode of a corrugated waveguide; successful experimental results have been reported recently [S.Tantawi Talk at POSIPOL 2012]. In this presentation we propose a beam driven design for an undulator based on an electron bunch train powering a microwave or mm waveguide. The drive bunch train propagates towards the undulating beam inside a dielectric loaded structure or corrugated waveguide generating high power RF. The “smart” waveguide design and a proper bunch spacing of the electron drive beam train provide single mode generation of the high magnitude undulating field that gives an undulator parameter in the range of K~1 for a high frequency device.* *A. Zholents, HBEB Workshop, Puerto-Rico, 2013.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO008
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Paper

Title

Page

Challenges in the Design of Diffraction-limited Storage Rings

7

R.O. Hettel
SLAC, Menlo Park, California, USA

This presentation reviews current developments in the design of ultra-low emittance lattices, the experience and challenges with the operation of low emittance lattices and the main technological problems. Beam dynamics issues and collective effects for ultra low emittance machines are also addressed.

Slides MOXBA01 [6.969 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOXBA01

Export •

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TUZA01

Advanced Concepts and Challenges in Compton Radiation Sources

928

I. Pogorelsky
BNL, Upton, Long Island, New York, USA

Ongoing developments in Compton radiation sources are aimed toward a diversity of potential applications, ranging from university-scale compact x-ray light sources and metrology tools for EUV lithography, to positron sources for e⁻e⁺ colliders. Novel conceptual approaches are pursued on different routes: One research direction lies in multiplying the source’s repetition rate and increasing its average brightness by placing the point of Compton interaction inside an optical cavity. High-gradient plasma-wakefield accelerators are fast becoming a practical reality, offering a new paradigm to compact all-optical Compton sources operating in x-ray- and gamma-regions. Continuing improvement in the quality of the beam of plasma accelerators promises the achievement of fully coherent Compton x-rays, thereby prompting the evolution of the Compton source to an all-optical free-electron laser.

Slides TUZA01 [22.419 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUZA01

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TUOCA03

Production of Quasi-monochromatic GeV Photons by Compton Scattering using Undulator X-ray Radiation at SPring-8

941

H. Ohkuma, A. Mochihashi, M. Oishi, S. Suzuki, K. Tamura
JASRI/SPring-8, Hyogo-ken, Japan
N. Muramatsu, H. Shimizu
Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
T. Nakano
RCNP, Osaka, Japan

Funding: This work is supported by JSPS KAKENHI (Grant-in-Aid for Scientific Research) Grant Number 24241035.
Backward Compton scattering (BCS) of X-ray photons emitted by undulator and reflected back by a single crystal from the electron beam can produce a quasi-monochromatic gamma-ray beam up to an energy very close to the electron beam energy. The SPring-8 beam diagnostics beamline (BL05SS) is used to inject a reflected undulator X-ray radiation against 8 GeV stored electron beam and to extract a quasi-monochromatic 8 GeV gamma-ray produced by BCS. BL05SS has conditions to do a pilot experiment to obtain the gamma-ray beam using BCS of X-ray photons from existing undulator. Experimental setup including a Bragg mirror system is now under construction. Preliminary reflectivity measurement of a silicon Bragg mirror using around 10keV photons has been done. Status of the experimental preparation and the future outlook is presented.

Slides TUOCA03 [1.889 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUOCA03

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WEXA01

Low Emittance Upgrade for Existing Mid-size Light Sources

S. Shin
PAL, Pohang, Kyungbuk, Republic of Korea

Recently, several ideas to upgrade mid-size existing light sources to low emittances have been proposed. In these machines it is more difficult to get down to 100pm level while simultaneously keeping the beam lines as they are. This talk reviews the various ideas to achieve this goal, and presents examples of ongoing projects.

Slides WEXA01 [3.538 MB]

Export •

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WEPRO001

Effect of Beam Dynamics Processes in the Low Energy Ring ThomX

1933

N. Delerue, C. Bruni, I. Chaikovska, I.V. Drebot, M. Jacquet, A. Variola, Z.F. Zomer
LAL, Orsay, France
A. Loulergue
SOLEIL, Gif-sur-Yvette, France

Funding: This work is supported by the French "Agence Nationale de la Recherche" as part of the program "investing in the future" under reference ANR-10-EQPX-51 and by grants from Région Ile-de-France.
As part of the R&D for the 50 MeV ThomX Compton source project, we have studied the effect of several beam dynamics processes on the evolution of the beam in the ring. The processes studied include among others Compton scattering, intrabeam scattering, coherent synchrotron radiation. We have performed extensive simulations of a full injection/extraction cycle (400000 turns). We show how each of these processes degrades the flux of photons produced and how a feedback system contributes to recovering most of the flux.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO001

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WEPRO002

Studies of Ultrashort THz Pulses at DELTA

1936

P. Ungelenk, L.-G. Böttger, S. Hilbrich, H. Huck, M. Huck, M. Höner, S. Khan, C. Mai, A. Meyer auf der Heide, R. Molo, H. Rast, A. Schick
DELTA, Dortmund, Germany
S. Bielawski, C. Evain, M. Le Parquier, E. Roussel, C. Szwaj
PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France
N. Hiller, V. Judin, J. Raasch, P. Thoma
KIT, Karlsruhe, Germany

Funding: Work supported by the DFG, the BMBF, and the state of NRW.
At DELTA, a 1.5-GeV electron storage ring operated as a light source by the Center for Synchrotron Radiation at the TU Dortmund University, coherent ultrashort THz pulses are routinely generated by density-modulated electron bunches. Tracking simulations as well as experimental studies using ultrafast THz detectors and an FT-IR spectrometer aim at understanding the turn-by-turn evolution of the density modulation after an initial laser-electron interaction. Furthermore, intensity-modulated laser pulses are applied to create narrow-band THz radiation. This setup is part of the new short-pulse facility based on coherent harmonic generation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO002

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WEPRO003

Construction of a Laser Compton Scattered Photon Source at cERL

1940

R. Nagai, R. Hajima, M. Mori, T. Shizuma
JAEA, Ibaraki-ken, Japan
T. Akagi, Y. Honda, A. Kosuge, J. Urakawa
KEK, Ibaraki, Japan

A nondestructive assay system of isotopes by quasi-monochromatic gamma-rays and nuclear resonance fluorescence is under development in JAEA. The quasi-monochromatic gamma-rays are generated by laser Compton scattering (LCS) based on energy-recovery linac accelerator and laser technologies. In order to demonstrate the accelerator and laser performance required for the gamma-ray source, an LCS experiment is planned at Compact ERL (cERL) at KEK. A mode-locked fiber laser, laser enhancement cavity, beamline, and experimental hatch are under construction for the LCS experiment. Up-to-date construction status is presented in detail.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO003

Export •

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

WEPRO006

Beam-driven Terahertz Source based on Open Ended Waveguide with a Dielectric Layer

1949

A.V. Tyukhtin, S.N. Galyamin, V.V. Vorobev
Saint-Petersburg State University, Saint-Petersburg, Russia
S.P. Antipov
Euclid TechLabs, LLC, Solon, Ohio, USA
S. Baturin
LETI, Saint-Petersburg, Russia

Funding: Work is supported by the Grant of the President of Russian Federation (MK-273.2013.2) and the Russian Foundation for Basic Research (Grant No. 12-02-31258).
Electromagnetic waves with frequencies from 0.1 THz to 10 THz (usually called the Terahertz gap) are of great importance for a number of scientific and practical applications. Different techniques are known allowing generating these frequencies. However, a current trend of physics and industry is to fill this gap with more powerful and efficient sources. For example, recent experiments have shown promising THz generation in dielectric loaded structures*. Developing this area, we consider the THz emitting scheme where an ultrarelativistic charge exits the open end of a cylindrical waveguide with a dielectric layer and produces THz waves in a form of Cherenkov radiation. The end of the waveguide is supposed to be either orthogonal to the structure axis or skewed. To obtain THz frequencies from waveguides with centimeter or millimeter radii, we consider high order modes. We present typical field patterns (in the Fraunhofer zone) and show that the aperture of the vacuum channel gives, as a rule, the main contribution. We also give simple expressions for the angle of the main pattern lobe.
* S. Antipov et al., Appl. Phys. Lett. 100, 132910 (2012).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO006

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WEPRO007

Nanometer Scale Coherent Current Modulation via a Nanotip Cathode Array and Emittance Exchange

1952

E.A. Nanni, W.S. Graves
MIT, Cambridge, Massachusetts, USA
P. Piot
Fermilab, Batavia, Illinois, USA
P. Piot
Northern Illinois University, DeKalb, Illinois, USA

Funding: NSF DMR-1042342, DARPA N66001-11-1-4192
We present PIC simulations of electron bunches with nm scale longitudinal modulation produced using a compact 2-20 MeV LINAC. The modulation is initially imparted in the transverse dimension of the electron bunch with a nano-patterned photo-emitter in a X-band RF gun with 2 MeV exit energy. The electron bunch passes through a 1 m standing wave X-band LINAC which can raise the beam energy up to 20 MeV. The transverse modulation is exchanged into the longitudinal dimension using a double dog-leg emittance exchange setup with a 5 cell RF deflector cavity. The modulation pitch can be tuned by adjusting the spacing of the nano-patterned photo-emitter or magnification of the transverse pitch with electron optics. The electron beam parameters are optimized to produce coherent XFEL radiation upon interacting with a “laser undulator”.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO007

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WEPRO008

A Beam-driven Microwave Undulator for FEL

1956

A. Kanareykin, C.-J. Jing, P. Schoessow
Euclid TechLabs, LLC, Solon, Ohio, USA
S. Baturin
LETI, Saint-Petersburg, Russia
A. Zholents
ANL, Argonne, Ilinois, USA

Funding: DOE SBIR
Microwave waveguides can in principle be used for undulators with periods less than 1 cm. Intensive work has been done on the recently proposed design that operates at the HE11 hybrid mode of a corrugated waveguide; successful experimental results have been reported recently [S.Tantawi Talk at POSIPOL 2012]. In this presentation we propose a beam driven design for an undulator based on an electron bunch train powering a microwave or mm waveguide. The drive bunch train propagates towards the undulating beam inside a dielectric loaded structure or corrugated waveguide generating high power RF. The “smart” waveguide design and a proper bunch spacing of the electron drive beam train provide single mode generation of the high magnitude undulating field that gives an undulator parameter in the range of K~1 for a high frequency device.*
*A. Zholents, HBEB Workshop, Puerto-Rico, 2013.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO008

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