IPAC2017 - List of Authors (Conde, M.E.)

Paper	Title	Page
MOPAB137	Validation of a Novel Emittance Diagnostic Method for Beams with Significant Space Charge	451
	R.B. Fiorito, C.P. Welsch, H.D. Zhang Cockcroft Institute, Warrington, Cheshire, United Kingdom M.E. Conde, N.R. Neveu, J.F. Power ANL, Argonne, Illinois, USA O. Mete Apsimon Cockcroft Institute, Lancaster University, Lancaster, United Kingdom A.G. Shkvarunets UMD, College Park, Maryland, USA
	Funding: Work supported by the EU under grant agreement 624890, the STFC Cockcroft Institute Core Grant No. ST/G008248/1. Exact knowledge of beam emittance is of central importance for essentially every accelerator. However, there are only few methods to determine it when the beam has significant space charge. We report on our progress to validate a novel diagnostic method that has been proposed to determine the RMS emittance of an electron beam with space charge. This method uses RMS divergence and beam size data measured at a screen placed in a free drift region for selected values of magnetic focusing strength. A novel algorithm is then used to determine the cross correlation term and consequently the RMS emittance of the beam. Simulations, quadrupole scans, phase space tomography and optical diffraction-dielectric foil radiation interferometry are currently being employed to determine and compare the horizontal (x) and vertical (y) emittances of the 14 MeV witness electron beam at Argonne National Laboratory's Wakefield Accelerator. The results of simulations and current measurements are presented and the advantages of the new technique are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB137
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPIK017	Simultaneous Generation of Drive and Witness Beam for Collinear Wakefield Acceleration	535
	G. Ha POSTECH, Pohang, Kyungbuk, Republic of Korea M.E. Conde, D.S. Doran, W. Gai, J.G. Power ANL, Argonne, Illinois, USA
	Funding: This work is supported by Department of Energy, Office of High Energy Physics, under Contract No. DE-AC02-06CH11357. Generating the drive and witness bunch for collinear wakefield acceleration (CWFA) requires precise control of the longitudinal bunch shape for each bunch as well as the controlling their separation. The emittance exchange (EEX) beamline and a transverse mask can be used to achieve all of these requirements. First, this EEX-based method can independently control the longitudinal bunch shape of each bunches so that the drive bunch is shaped to generate a high transformer ratio while witness bunch is shaped to suppress its energy spread. Second, the timing jitter between the drive and witness bunch poses a serious limitation to the CWFA scheme but the EEX-based method eliminates this since both bunches are generated at the same time and share the exactly same beamline so there are no relative errors. In this paper, we confirm the feasibility of this EEX-based method for simultaneous generation with simulation for CWFA in a dielectric structure.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK017
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAB132	Research Program and Recent Results at the Argonne Wakefield Accelerator Facility (AWA)	2885
	M.E. Conde, S.P. Antipov, D.S. Doran, W. Gai, Q. Gao, G. Ha, C.-J. Jing, W. Liu, N.R. Neveu, J.G. Power, J.Q. Qiu, J.H. Shao, Y.R. Wang, C. Whiteford, E.E. Wisniewski, L.M. Zheng ANL, Argonne, Illinois, USA S.P. Antipov, C.-J. Jing, J.Q. Qiu Euclid TechLabs, LLC, Solon, Ohio, USA Q. Gao, L.M. Zheng TUB, Beijing, People's Republic of China G. Ha POSTECH, Pohang, Kyungbuk, Republic of Korea N.R. Neveu IIT, Chicago, Illinois, USA Y.R. Wang IMP/CAS, Lanzhou, People's Republic of China
	Funding: Work supported by the U.S. Department of Energy under contract No. DE-AC02-06CH11357 We give an overview of the research program at the Argonne Wakefield Accelerator Facility (AWA), including some highlights of recent experiments. The AWA facility is dedicated to the study of beam physics and the development of technology for future particle accelerators. Two independent electron linacs are used to study wakefield acceleration: 70 MeV high charge electron bunches of up to 100 nC are used to drive wakefields, which can be probed by bunches originating from the same linac or from the 15 MeV linac. Recent Two-Beam-Acceleration (TBA) experiments operating at 11.7 GHz reached accelerating gradients of up to 150 MV/m. No indication of witness beam quality degradation was observed, and bunch charge was preserved during the acceleration process. Two identical TBA setups were used in series in order to demonstrate staging capabilities. Dielectric loaded structures operating at 26 GHz are also used in TBA experiments. Another main thrust of the research program consists of exploring and developing techniques to manipulate the phase space of electron bunches. These efforts include bunch shaping and the exchange of emittances in the transverse and the longitudinal phase spaces
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPAB132
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPVA022	RECENT TWO-BEAM ACCELERATION ACTIVITIES AT ARGONNE WAKEFIELD ACCELERATOR FACILITY	3305
	J.H. Shao, S.P. Antipov, M.E. Conde, W. Gai, Q. Gao, G. Ha, W. Liu, N.R. Neveu, J.G. Power, Y.R. Wang, E.E. Wisniewski, L.M. Zheng ANL, Argonne, Illinois, USA C.-J. Jing, J.Q. Qiu Euclid TechLabs, LLC, Solon, Ohio, USA J. Shi, D. Wang TUB, Beijing, People's Republic of China
	The Two-Beam Acceleration (TBA) is a modified approach to the structure-based wakefield acceleration which may meet the luminosity, efficiency, and cost requirement of a future linear collider. Recently, various TBA experiments have been carried out at the Argonne Wakefield Accelerator Facility (AWA). With X-band metallic power extractors and accelerators, a 70 MeV/m average accelerating gradient has been demonstrated in two stages while a 150 MeV/m gradient as well as 300 MW extracted power have been achieved in a single stage. In addition, low cost K-band dielectric power extractor and accelerator have also been developed. The preliminary results show power extraction of 55 MW and an average accelerating gradient of 28 MeV/m.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPVA022
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPAB061	Limiting Effects in the Double EEX Beamline	3858
	G. Ha POSTECH, Pohang, Kyungbuk, Republic of Korea M.E. Conde, D.S. Doran, J.G. Power ANL, Argonne, Illinois, USA
	Funding: This work is supported by Department of Energy, Office of High Energy Physics, under Contract No. DE-AC02-06CH11357. The double emittance exchange (EEX) beamline is suggested to overcome the large horizontal emittance and transverse jitter issues associated with the single EEX beamline while preserving its powerful phase-space manipulation capability. However, the double EEX beamline also has potential limitations due to coherent synchrotron radiation (CSR) and transverse jitter. The former limitation arises because double EEX uses twice as many bending magnets as single EEX which means stronger CSR effects degrading the beam quality. The latter limitation arises because a longitudinal jitter in front of the first EEX beamline is converted into a transverse jitter in the middle section (between the EEX beamlines) which can cause beam loss or beam degradation. In this paper, we numerically explore the effects of these two limitations on the emittance and beam transport.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB061
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPAB062	Preliminary Simulations on Chirpless Bunch Compression using Double-EEX Beamline	3862
	G. Ha POSTECH, Pohang, Kyungbuk, Republic of Korea M.E. Conde, D.S. Doran, W. Gai, J.G. Power ANL, Argonne, Illinois, USA
	Funding: This work is supported by Department of Energy, Office of High Energy Physics, under Contract No. DE-AC02-06CH11357. An emittance exchange (EEX) beamline can be used to compress an electron bunch via its transverse-to-longitudinal exchange mechanism. We are investigating this as an alternative to the normal magnetic chicane bunch compressor. The chicane method requires a longitudinal chirp before the chicane (since it relies on the path length difference of different energies) which results in an unwanted chirp after the compressor. Alternatively, the EEX method uses quadrupole magnets to compress the bunch. In this paper, we present preliminary simulations in preparation for a demonstration of chirp-less bunch compression using an EEX beamline at the Argonne Wakefield Accelerator facility.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB062
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Validation of a Novel Emittance Diagnostic Method for Beams with Significant Space Charge

451

R.B. Fiorito, C.P. Welsch, H.D. Zhang
Cockcroft Institute, Warrington, Cheshire, United Kingdom
M.E. Conde, N.R. Neveu, J.F. Power
ANL, Argonne, Illinois, USA
O. Mete Apsimon
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
A.G. Shkvarunets
UMD, College Park, Maryland, USA

Funding: Work supported by the EU under grant agreement 624890, the STFC Cockcroft Institute Core Grant No. ST/G008248/1.
Exact knowledge of beam emittance is of central importance for essentially every accelerator. However, there are only few methods to determine it when the beam has significant space charge. We report on our progress to validate a novel diagnostic method that has been proposed to determine the RMS emittance of an electron beam with space charge. This method uses RMS divergence and beam size data measured at a screen placed in a free drift region for selected values of magnetic focusing strength. A novel algorithm is then used to determine the cross correlation term and consequently the RMS emittance of the beam. Simulations, quadrupole scans, phase space tomography and optical diffraction-dielectric foil radiation interferometry are currently being employed to determine and compare the horizontal (x) and vertical (y) emittances of the 14 MeV witness electron beam at Argonne National Laboratory's Wakefield Accelerator. The results of simulations and current measurements are presented and the advantages of the new technique are discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB137

Export •

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

MOPIK017

Simultaneous Generation of Drive and Witness Beam for Collinear Wakefield Acceleration

535

G. Ha
POSTECH, Pohang, Kyungbuk, Republic of Korea
M.E. Conde, D.S. Doran, W. Gai, J.G. Power
ANL, Argonne, Illinois, USA

Funding: This work is supported by Department of Energy, Office of High Energy Physics, under Contract No. DE-AC02-06CH11357.
Generating the drive and witness bunch for collinear wakefield acceleration (CWFA) requires precise control of the longitudinal bunch shape for each bunch as well as the controlling their separation. The emittance exchange (EEX) beamline and a transverse mask can be used to achieve all of these requirements. First, this EEX-based method can independently control the longitudinal bunch shape of each bunches so that the drive bunch is shaped to generate a high transformer ratio while witness bunch is shaped to suppress its energy spread. Second, the timing jitter between the drive and witness bunch poses a serious limitation to the CWFA scheme but the EEX-based method eliminates this since both bunches are generated at the same time and share the exactly same beamline so there are no relative errors. In this paper, we confirm the feasibility of this EEX-based method for simultaneous generation with simulation for CWFA in a dielectric structure.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK017

Export •

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

WEPAB132

Research Program and Recent Results at the Argonne Wakefield Accelerator Facility (AWA)

2885

M.E. Conde, S.P. Antipov, D.S. Doran, W. Gai, Q. Gao, G. Ha, C.-J. Jing, W. Liu, N.R. Neveu, J.G. Power, J.Q. Qiu, J.H. Shao, Y.R. Wang, C. Whiteford, E.E. Wisniewski, L.M. Zheng
ANL, Argonne, Illinois, USA
S.P. Antipov, C.-J. Jing, J.Q. Qiu
Euclid TechLabs, LLC, Solon, Ohio, USA
Q. Gao, L.M. Zheng
TUB, Beijing, People's Republic of China
G. Ha
POSTECH, Pohang, Kyungbuk, Republic of Korea
N.R. Neveu
IIT, Chicago, Illinois, USA
Y.R. Wang
IMP/CAS, Lanzhou, People's Republic of China

Funding: Work supported by the U.S. Department of Energy under contract No. DE-AC02-06CH11357
We give an overview of the research program at the Argonne Wakefield Accelerator Facility (AWA), including some highlights of recent experiments. The AWA facility is dedicated to the study of beam physics and the development of technology for future particle accelerators. Two independent electron linacs are used to study wakefield acceleration: 70 MeV high charge electron bunches of up to 100 nC are used to drive wakefields, which can be probed by bunches originating from the same linac or from the 15 MeV linac. Recent Two-Beam-Acceleration (TBA) experiments operating at 11.7 GHz reached accelerating gradients of up to 150 MV/m. No indication of witness beam quality degradation was observed, and bunch charge was preserved during the acceleration process. Two identical TBA setups were used in series in order to demonstrate staging capabilities. Dielectric loaded structures operating at 26 GHz are also used in TBA experiments. Another main thrust of the research program consists of exploring and developing techniques to manipulate the phase space of electron bunches. These efforts include bunch shaping and the exchange of emittances in the transverse and the longitudinal phase spaces

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPAB132

Export •

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

WEPVA022

RECENT TWO-BEAM ACCELERATION ACTIVITIES AT ARGONNE WAKEFIELD ACCELERATOR FACILITY

3305

J.H. Shao, S.P. Antipov, M.E. Conde, W. Gai, Q. Gao, G. Ha, W. Liu, N.R. Neveu, J.G. Power, Y.R. Wang, E.E. Wisniewski, L.M. Zheng
ANL, Argonne, Illinois, USA
C.-J. Jing, J.Q. Qiu
Euclid TechLabs, LLC, Solon, Ohio, USA
J. Shi, D. Wang
TUB, Beijing, People's Republic of China

The Two-Beam Acceleration (TBA) is a modified approach to the structure-based wakefield acceleration which may meet the luminosity, efficiency, and cost requirement of a future linear collider. Recently, various TBA experiments have been carried out at the Argonne Wakefield Accelerator Facility (AWA). With X-band metallic power extractors and accelerators, a 70 MeV/m average accelerating gradient has been demonstrated in two stages while a 150 MeV/m gradient as well as 300 MW extracted power have been achieved in a single stage. In addition, low cost K-band dielectric power extractor and accelerator have also been developed. The preliminary results show power extraction of 55 MW and an average accelerating gradient of 28 MeV/m.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPVA022

Export •

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

THPAB061

Limiting Effects in the Double EEX Beamline

3858

G. Ha
POSTECH, Pohang, Kyungbuk, Republic of Korea
M.E. Conde, D.S. Doran, J.G. Power
ANL, Argonne, Illinois, USA

Funding: This work is supported by Department of Energy, Office of High Energy Physics, under Contract No. DE-AC02-06CH11357.
The double emittance exchange (EEX) beamline is suggested to overcome the large horizontal emittance and transverse jitter issues associated with the single EEX beamline while preserving its powerful phase-space manipulation capability. However, the double EEX beamline also has potential limitations due to coherent synchrotron radiation (CSR) and transverse jitter. The former limitation arises because double EEX uses twice as many bending magnets as single EEX which means stronger CSR effects degrading the beam quality. The latter limitation arises because a longitudinal jitter in front of the first EEX beamline is converted into a transverse jitter in the middle section (between the EEX beamlines) which can cause beam loss or beam degradation. In this paper, we numerically explore the effects of these two limitations on the emittance and beam transport.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB061

Export •

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

THPAB062

Preliminary Simulations on Chirpless Bunch Compression using Double-EEX Beamline

3862

G. Ha
POSTECH, Pohang, Kyungbuk, Republic of Korea
M.E. Conde, D.S. Doran, W. Gai, J.G. Power
ANL, Argonne, Illinois, USA

Funding: This work is supported by Department of Energy, Office of High Energy Physics, under Contract No. DE-AC02-06CH11357.
An emittance exchange (EEX) beamline can be used to compress an electron bunch via its transverse-to-longitudinal exchange mechanism. We are investigating this as an alternative to the normal magnetic chicane bunch compressor. The chicane method requires a longitudinal chirp before the chicane (since it relies on the path length difference of different energies) which results in an unwanted chirp after the compressor. Alternatively, the EEX method uses quadrupole magnets to compress the bunch. In this paper, we present preliminary simulations in preparation for a demonstration of chirp-less bunch compression using an EEX beamline at the Argonne Wakefield Accelerator facility.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB062

Export •

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