NAPAC2016 - Classification: 3: Advanced Acceleration Techniques and Alternative Particle Sources

Paper	Title	Page
TUA2IO01	AWAKE - A Proton Driven Plasma Wakefield Acceleration Experiment at CERN	266
	A. Caldwell MPI-P, München, Germany
	It is the aim of the AWAKE project at CERN to demonstrate the acceleration of electrons in the wake created by a proton beam passing through plasma. The proton beam will be modulated as a result of the transverse two-stream instability into a series ofμbunches that will then drive strong wakefields. The wakefields will then be used to accelerate electrons with GV/m strength fields. The AWAKE experiment is currently being commissioned and first data taking is expected this year. The status of the experimental program is described as well as first thoughts on future steps.
	Slides TUA2IO01 [24.428 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUA2IO01
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUA2IO02	DWFA Staging Results at the Argonne Wakefield Accelerator Facility (AWA)
	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, C. Whiteford, E.E. Wisniewski ANL, Argonne, Illinois, USA S.P. Antipov, C.-J. Jing, J.Q. Qiu Euclid TechLabs, LLC, Solon, Ohio, USA Q. Gao TUB, Beijing, People's Republic of China G. Ha POSTECH, Pohang, Kyungbuk, Republic of Korea N.R. Neveu IIT, Chicago, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy under contract No. DE-AC02-06CH11357. We report on recent Two-Beam-Acceleration (TBA) experiments conducted at the Argonne Wakefield Accelerator Facility (AWA), which used 70 MeV electron bunches to accelerate a 0.5 nC witness bunch in gradients of up to 150 MV/m. The wakefields were generated by the passage of the 15 - 45 nC drive bunches through iris-loaded metallic structures operating at 11.7 GHz. No indication of witness beam quality degradation was observed, and bunch charge was preserved during the acceleration process. Another series of experiments was conducted using two TBA stages, demonstrating acceleration of the witness beam in these two subsequent stages by means of two independent drive bunch trains.
	Slides TUA2IO02 [2.773 MB]
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUA3IO01	Possible Road Maps for High-Energy Collider Based on Advanced Acceleration Techniques
	S. Nagaitsev Fermilab, Batavia, Illinois, USA
	In February 2016, DOE organize a closed workshop to discuss possible roadmaps toward future high-energy linear colliders. Three accelerations techniques were discussed. The purpose of this paper is to summarize the outcome of this workshop.
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUA3IO02	FACET Results and FACET II Perspective
	V. Yakimenko, M.J. Hogan SLAC, Menlo Park, California, USA
	Very short summary of the FACET results followed by plans for FACET II, the facility and the science towards a e⁻/e⁺ PWFA- based collider
	Slides TUA3IO02 [11.297 MB]
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUA4IO01	Staging Results at BELLA and Plans for BELLA
	S. Steinke LBNL, Berkeley, California, USA
	Summary of the staging results obtained at BELLA as well as perspective on facility experiments towards a e⁻/e⁺, LWFA-based collider
	Slides TUA4IO01 [6.105 MB]
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUA4IO02	Eupraxia: A Compact European Plasma Accelerator With Superior Beam Quality
	U. Dorda DESY, Hamburg, Germany
	Plasma wakefield accelerators can sustain multi-GeV/m fields that may allow much smaller accelerators that could be used for a wide range of fundamental and applied research applications. 3 M€ of funding have been awarded to 16 laboratories and universities from 5 EU member states within the European Union's Horizon 2020 programme. They will be joined by 18 associated partners that make additional in-kind commitments. The goal of this ambitious project is to produce a conceptual design report for the worldwide first high energy plasma-based accelerator that can provide industrial beam quality and user areas. It is the important intermediate step between proof-of-principle experiments and ground-breaking, ultra-compact accelerators for science, industry, medicine or the energy frontier. Major elements of the project and the expected timeframe will be discussed.
	Slides TUA4IO02 [7.841 MB]
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPOA12	Interleaving Lattice Design for APS Linac	713
	S. Shin, Y. Sun, A. Zholents ANL, Argonne, Illinois, USA
	In order to realize and test advanced accelerator concepts and hardware, the existing beamline with both old and new components are being reconfigured in Linac Extension Area (LEA) of APS linac. Photo injector, which had been installed in the beginning of APS linac, will provide low emittance electron beam into the LEA. The thermionic RF gun beam for storage ring and photo-cathode RF gun beam for LEA will be operated though the LINAC in an interleaved fashion. In this presentation, technical issues as well as beam dynamics on the design for interleaving operation will be described.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA12
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPOA29	Recent Experiments at NDCX-II: Irradiation of Materials Using Short, Intense Ion Beams	755
	P.A. Seidl, E. Feinberg, Q. Ji, B.A. Ludewigt, A. Persaud, T. Schenkel, M. Silverman, A.A. Sulyman, W.L. Waldron LBNL, Berkeley, California, USA J.J. Barnard, A. Friedman, D.P. Grote LLNL, Livermore, California, USA E.P. Gilson, I. Kaganovich, A.D. Stepanov PPPL, Princeton, New Jersey, USA F. Treffert, M. Zimmer TU Darmstadt, Darmstadt, Germany
	Funding: This work was supported by the Office of Science of the US Department of Energy under contracts DE-AC0205CH11231 (LBNL), DE-AC52- 07NA27344 (LLNL) and DE-AC02-09CH11466 (PPPL). We present an overview of the performance of the Neutralized Drift Compression Experiment-II (NDCX-II) accelerator at Berkeley Lab, and summarize recent studies of material properties created with nanosecond and millimeter-scale ion beam pulses. The scientific topics being explored include the dynamics of ion induced damage in materials, materials synthesis far from equilibrium, warm dense matter and intense beam-plasma physics. We summarize the improved accelerator performance, diagnostics and results of beam-induced irradiation of thin samples of, e.g., tin and silicon. Bunches with over 3x10¹⁰ ions, 1-mm radius, and 2-30 ns FWHM duration have been created. To achieve these short pulse durations and mm-scale focal spot radii, the 1.2 MeV He⁺ ion beam is neutralized in a drift compression section which removes the space charge defocusing effect during final compression and focusing. Quantitative comparison of detailed particle-in-cell simulations with the experiment play an important role in optimizing accelerator performance; these keep pace with the accelerator repetition rate of ~1/minute.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA29
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPOA33	Novel Metallic Structures for Wakefield Acceleration	762
SUPO25	use link to see paper's listing under its alternate paper code
	X.Y. Lu, M.A. Shapiro, R.J. Temkin MIT/PSFC, Cambridge, Massachusetts, USA
	Funding: US DOE, Office of High Energy Physics Three novel ideas for wakefield acceleration (WFA) of electrons with metallic periodic subwavelength structures will be presented. The first idea is a deep corrugation structure for collinear WFA. A design for the Argonne Wakefield Accelerator is shown. An analytical model is developed and it agrees with the CST wakefield solver. A scaling study has been performed, and ways to increase the gradient will be discussed. The deep corrugation structure can generate a higher gradient than a dielectric tube with the same beam aperture when excited by the same bunch. The second idea is an elliptical structure for two-beam acceleration (TBA). The unit cell is an elliptical cavity, and the drive beam hole and the witness beam hole are located around the two focal points. The TBA process has been calculated and will be presented. The third idea is a metamaterial ‘wagon wheel' structure for a power extractor design. The fundamental mode is a TM mode with a negative group velocity. A power extractor at 11.7 GHz based on the structure can reach a GW power level when a train of 40 nC bunches with 1.3 GHz rep rate are sent in.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA33
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPOA34	Progress on Beam-Plasma Effect Simulations in Muon Ionization Cooling Lattices	765
	J.S. Ellison IIT, Chicago, Illinois, USA P. Snopok Fermilab, Batavia, Illinois, USA P. Snopok Illinois Institute of Technology, Chicago, Illlinois, USA
	Funding: Work supported by the U.S. Department of Energy. New computational tools are essential for accurate modeling and simulation of the next generation of muon-based accelerators. One of the crucial physics processes specific to muon accelerators that has not yet been simulated in detail is beam-induced plasma effect in liquid, solid, and gaseous absorbers. We report here on the progress of developing the required simulation tools and applying them to study the properties of plasma and its effects on the beam in muon ionization cooling channels.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA34
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPOA36	Simulated Measurements of Beam Cooling in Muon Ionization Cooling Experiment	771
SUPO30	use link to see paper's listing under its alternate paper code
	T.A. Mohayai IIT, Chicago, Illinois, USA D.V. Neuffer, D.V. Neuffer, P. Snopok Fermilab, Batavia, Illinois, USA C.T. Rogers STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom P. Snopok Illinois Institute of Technology, Chicago, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Science Graduate Student Research (SCGSR) under contract No. DE-AC05-06OR23100. Cooled muon beams are essential to enable future Neutrino Factory and Muon Collider facilities. The international Muon Ionization Cooling Experiment (MICE) aims to demonstrate muon beam cooling through ionization energy loss in material. A figure of merit for muon beam cooling in MICE is the transverse root-mean-square (RMS) emittance reduction and to measure this, the individual muon positions and momenta are reconstructed using two scintillating-fiber tracking detectors housed in spectrometer solenoid modules. The reconstructed positions and momenta before and after a low-Z absorbing material are then used for constructing the covariance matrix and measuring normalized transverse RMS emittance of MICE muon beam. However, RMS emittance is sensitive to nonlinear effects in beam optics. In this study, the direct measurement of phase-space density as an alternative approach to measuring the muon beam cooling using the novel Kernel Density Estimation (KDE) method, is described.
	Poster WEPOA36 [1.855 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA36
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPOA37	Hybrid Methods for Simulation of Muon Ionization Cooling Channels	775
	J.D. Kunz, P. Snopok IIT, Chicago, Illinois, USA M. Berz MSU, East Lansing, Michigan, USA J.D. Kunz Anderson University, Anderson, USA P. Snopok Fermilab, Batavia, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy COSY Infinity is an arbitrary-order beam dynamics simulation and analysis code. It uses high-order transfer maps of combinations of particle optical elements of arbitrary field configurations. New features have been developed and implemented in COSY to follow charged particles through matter. To study in detail the properties of muons passing through a material, the transfer map approach alone is not sufficient. The interplay of beam optics and atomic processes must be studied by a hybrid transfer map–Monte Carlo approach in which transfer map methods describe the average behavior of the particles including energy loss, and Monte Carlo methods are used to provide small corrections to the predictions of the transfer map, accounting for the stochastic nature of scattering and straggling of particles. This way the vast majority of the dynamics is represented by fast application of the high-order transfer map of an entire element and accumulated stochastic effects. The gains in speed simplify the optimization of muon cooling channels which are usually very computationally demanding. Progress on the development of the required algorithms is reported.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA37
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPOA38	Optically Based Diagnostics for Optical Stochastic Cooling	779
SUPO59	use link to see paper's listing under its alternate paper code
	M.B. Andorf Northern Illinois University, DeKalb, Illinois, USA V.A. Lebedev, P. Piot, J. Ruan Fermilab, Batavia, Illinois, USA
	An Optical Stochastic Cooling (OSC) experiment with electrons is planned in the Integrable Optics Test Accelerator (IOTA) ring currently in construction at Fermilab. OSC requires timing the arrival of an electron and its radiation generated from the upstream pickup undulator into the downstream kicker undulator to a precision on the order of less than a fs. The interference of the pickup and kicker radiation suggests a way to diagnose the arrival time to the required precision.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA38
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPOA42	RF Design of a 1.3-GHz High Average Beam Power SRF Electron Source	789
SUPO42	use link to see paper's listing under its alternate paper code
	N. Sipahi, S. Biedron, S.V. Milton CSU, Fort Collins, Colorado, USA I.V. Gonin, R.D. Kephart, T.N. Khabiboulline, N. Solyak, V.P. Yakovlev Fermilab, Batavia, Illinois, USA
	There is a significant interest in developing high-average power electron sources, particularly those integrated with Superconducting Radio Frequency (SRF) accelerator systems. Even though there are examples of high-average-power electron sources, they are not compact, highly efficient, or available at a reasonable cost. Adapting the recent advances in SRF cavities, RF power sources, and innovative solutions for an SRF gun and cathode system, we have developed a design concept for a compact SRF high-average power electron linac. This design will produce electron beams with energies up to 10 MeV. In this paper, we present the design results of our cathode structure integrated with modified 9-cell accelerating structure.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA42
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPOA44	Accleration System of Beam Brightness Booster	796
	V.G. Dudnikov Muons, Inc, Illinois, USA A.V. Dudnikov BINP SB RAS, Novosibirsk, Russia
	The brightness and intensity of a circulating proton beam now can be increased up to space charge limit by means of charge exchange injection or by an electron cooling but cannot be increased above this limit. Significantly higher brightness can be produced by means of the charge exchange injection with the space charge compensation [1]. The brightness of the space charge compensated beam is limited at low level by development of the electron-proton (e-p) instability [2]. Fortunately, e-p instability can be self-stabilized at a high beam density. A beam brightness booster (BBB) for significant increase of accumulated beam brightness is discussed. Accelerating system with a space charge compensation is proposed and described. The superintense beam production can be simplified by developing of nonlinear nearly integrable focusing system with broad spread of betatron tune and the broadband feedback system for e-p instability suppression . [1] V. Dudnikov, in Proceedings of the Particle Accelerator Conference, Chicago, 2001.. [2] G. Budker, et al., Sov. Atomic Energy 22, 384 (1967);
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA44
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPOA62	The Center for Bright Beams	830
	J.R. Patterson, G.H. Hoffstaetter Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA Y.K. Kim University of Chicago, Chicago, Illinois, USA
	Funding: National Science Foundation award PHY-1549132. The Center for Bright Beams (CBB) is a new National Science Foundation-supported Science and Technology Center. CBB's research goal is to increase the brightness of electron beams while reducing the cost and size of key technologies. To achieve this, it will augment the capabilities of accelerator physicists with those of physical chemists, materials scientists, condensed matter physicists, plasma physicists, and mathematicians. This approach has the potential to increase the brightness of electron sources through better photocathodes, the efficiency and gradient of SRF cavities through deeper understanding of superconducting compounds and their surfaces, and better understanding of beam storage and transport and the associated optics by using new mathematical techniques.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA62
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

AWAKE - A Proton Driven Plasma Wakefield Acceleration Experiment at CERN

266

A. Caldwell
MPI-P, München, Germany

It is the aim of the AWAKE project at CERN to demonstrate the acceleration of electrons in the wake created by a proton beam passing through plasma. The proton beam will be modulated as a result of the transverse two-stream instability into a series ofμbunches that will then drive strong wakefields. The wakefields will then be used to accelerate electrons with GV/m strength fields. The AWAKE experiment is currently being commissioned and first data taking is expected this year. The status of the experimental program is described as well as first thoughts on future steps.

Slides TUA2IO01 [24.428 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUA2IO01

Export •

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

TUA2IO02

DWFA Staging Results at the Argonne Wakefield Accelerator Facility (AWA)

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, C. Whiteford, E.E. Wisniewski
ANL, Argonne, Illinois, USA
S.P. Antipov, C.-J. Jing, J.Q. Qiu
Euclid TechLabs, LLC, Solon, Ohio, USA
Q. Gao
TUB, Beijing, People's Republic of China
G. Ha
POSTECH, Pohang, Kyungbuk, Republic of Korea
N.R. Neveu
IIT, Chicago, Illinois, USA

Funding: Work supported by the U.S. Department of Energy under contract No. DE-AC02-06CH11357.
We report on recent Two-Beam-Acceleration (TBA) experiments conducted at the Argonne Wakefield Accelerator Facility (AWA), which used 70 MeV electron bunches to accelerate a 0.5 nC witness bunch in gradients of up to 150 MV/m. The wakefields were generated by the passage of the 15 - 45 nC drive bunches through iris-loaded metallic structures operating at 11.7 GHz. No indication of witness beam quality degradation was observed, and bunch charge was preserved during the acceleration process. Another series of experiments was conducted using two TBA stages, demonstrating acceleration of the witness beam in these two subsequent stages by means of two independent drive bunch trains.

Slides TUA2IO02 [2.773 MB]

Export •

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

TUA3IO01

Possible Road Maps for High-Energy Collider Based on Advanced Acceleration Techniques

S. Nagaitsev
Fermilab, Batavia, Illinois, USA

In February 2016, DOE organize a closed workshop to discuss possible roadmaps toward future high-energy linear colliders. Three accelerations techniques were discussed. The purpose of this paper is to summarize the outcome of this workshop.

Export •

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

TUA3IO02

FACET Results and FACET II Perspective

V. Yakimenko, M.J. Hogan
SLAC, Menlo Park, California, USA

Very short summary of the FACET results followed by plans for FACET II, the facility and the science towards a e⁻/e⁺ PWFA- based collider

Slides TUA3IO02 [11.297 MB]

Export •

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

TUA4IO01

Staging Results at BELLA and Plans for BELLA

S. Steinke
LBNL, Berkeley, California, USA

Summary of the staging results obtained at BELLA as well as perspective on facility experiments towards a e⁻/e⁺, LWFA-based collider

Slides TUA4IO01 [6.105 MB]

Export •

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

TUA4IO02

Eupraxia: A Compact European Plasma Accelerator With Superior Beam Quality

U. Dorda
DESY, Hamburg, Germany

Plasma wakefield accelerators can sustain multi-GeV/m fields that may allow much smaller accelerators that could be used for a wide range of fundamental and applied research applications. 3 M€ of funding have been awarded to 16 laboratories and universities from 5 EU member states within the European Union's Horizon 2020 programme. They will be joined by 18 associated partners that make additional in-kind commitments. The goal of this ambitious project is to produce a conceptual design report for the worldwide first high energy plasma-based accelerator that can provide industrial beam quality and user areas. It is the important intermediate step between proof-of-principle experiments and ground-breaking, ultra-compact accelerators for science, industry, medicine or the energy frontier. Major elements of the project and the expected timeframe will be discussed.

Slides TUA4IO02 [7.841 MB]

Export •

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

WEPOA12

Interleaving Lattice Design for APS Linac

713

S. Shin, Y. Sun, A. Zholents
ANL, Argonne, Illinois, USA

In order to realize and test advanced accelerator concepts and hardware, the existing beamline with both old and new components are being reconfigured in Linac Extension Area (LEA) of APS linac. Photo injector, which had been installed in the beginning of APS linac, will provide low emittance electron beam into the LEA. The thermionic RF gun beam for storage ring and photo-cathode RF gun beam for LEA will be operated though the LINAC in an interleaved fashion. In this presentation, technical issues as well as beam dynamics on the design for interleaving operation will be described.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA12

Export •

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

WEPOA29

Recent Experiments at NDCX-II: Irradiation of Materials Using Short, Intense Ion Beams

755

P.A. Seidl, E. Feinberg, Q. Ji, B.A. Ludewigt, A. Persaud, T. Schenkel, M. Silverman, A.A. Sulyman, W.L. Waldron
LBNL, Berkeley, California, USA
J.J. Barnard, A. Friedman, D.P. Grote
LLNL, Livermore, California, USA
E.P. Gilson, I. Kaganovich, A.D. Stepanov
PPPL, Princeton, New Jersey, USA
F. Treffert, M. Zimmer
TU Darmstadt, Darmstadt, Germany

Funding: This work was supported by the Office of Science of the US Department of Energy under contracts DE-AC0205CH11231 (LBNL), DE-AC52- 07NA27344 (LLNL) and DE-AC02-09CH11466 (PPPL).
We present an overview of the performance of the Neutralized Drift Compression Experiment-II (NDCX-II) accelerator at Berkeley Lab, and summarize recent studies of material properties created with nanosecond and millimeter-scale ion beam pulses. The scientific topics being explored include the dynamics of ion induced damage in materials, materials synthesis far from equilibrium, warm dense matter and intense beam-plasma physics. We summarize the improved accelerator performance, diagnostics and results of beam-induced irradiation of thin samples of, e.g., tin and silicon. Bunches with over 3x10¹⁰ ions, 1-mm radius, and 2-30 ns FWHM duration have been created. To achieve these short pulse durations and mm-scale focal spot radii, the 1.2 MeV He⁺ ion beam is neutralized in a drift compression section which removes the space charge defocusing effect during final compression and focusing. Quantitative comparison of detailed particle-in-cell simulations with the experiment play an important role in optimizing accelerator performance; these keep pace with the accelerator repetition rate of ~1/minute.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA29

Export •

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

WEPOA33

Novel Metallic Structures for Wakefield Acceleration

762

SUPO25

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

X.Y. Lu, M.A. Shapiro, R.J. Temkin
MIT/PSFC, Cambridge, Massachusetts, USA

Funding: US DOE, Office of High Energy Physics
Three novel ideas for wakefield acceleration (WFA) of electrons with metallic periodic subwavelength structures will be presented. The first idea is a deep corrugation structure for collinear WFA. A design for the Argonne Wakefield Accelerator is shown. An analytical model is developed and it agrees with the CST wakefield solver. A scaling study has been performed, and ways to increase the gradient will be discussed. The deep corrugation structure can generate a higher gradient than a dielectric tube with the same beam aperture when excited by the same bunch. The second idea is an elliptical structure for two-beam acceleration (TBA). The unit cell is an elliptical cavity, and the drive beam hole and the witness beam hole are located around the two focal points. The TBA process has been calculated and will be presented. The third idea is a metamaterial ‘wagon wheel' structure for a power extractor design. The fundamental mode is a TM mode with a negative group velocity. A power extractor at 11.7 GHz based on the structure can reach a GW power level when a train of 40 nC bunches with 1.3 GHz rep rate are sent in.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA33

Export •

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

WEPOA34

Progress on Beam-Plasma Effect Simulations in Muon Ionization Cooling Lattices

765

J.S. Ellison
IIT, Chicago, Illinois, USA
P. Snopok
Fermilab, Batavia, Illinois, USA
P. Snopok
Illinois Institute of Technology, Chicago, Illlinois, USA

Funding: Work supported by the U.S. Department of Energy.
New computational tools are essential for accurate modeling and simulation of the next generation of muon-based accelerators. One of the crucial physics processes specific to muon accelerators that has not yet been simulated in detail is beam-induced plasma effect in liquid, solid, and gaseous absorbers. We report here on the progress of developing the required simulation tools and applying them to study the properties of plasma and its effects on the beam in muon ionization cooling channels.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA34

Export •

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

WEPOA36

Simulated Measurements of Beam Cooling in Muon Ionization Cooling Experiment

771

SUPO30

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

T.A. Mohayai
IIT, Chicago, Illinois, USA
D.V. Neuffer, D.V. Neuffer, P. Snopok
Fermilab, Batavia, Illinois, USA
C.T. Rogers
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
P. Snopok
Illinois Institute of Technology, Chicago, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Science Graduate Student Research (SCGSR) under contract No. DE-AC05-06OR23100.
Cooled muon beams are essential to enable future Neutrino Factory and Muon Collider facilities. The international Muon Ionization Cooling Experiment (MICE) aims to demonstrate muon beam cooling through ionization energy loss in material. A figure of merit for muon beam cooling in MICE is the transverse root-mean-square (RMS) emittance reduction and to measure this, the individual muon positions and momenta are reconstructed using two scintillating-fiber tracking detectors housed in spectrometer solenoid modules. The reconstructed positions and momenta before and after a low-Z absorbing material are then used for constructing the covariance matrix and measuring normalized transverse RMS emittance of MICE muon beam. However, RMS emittance is sensitive to nonlinear effects in beam optics. In this study, the direct measurement of phase-space density as an alternative approach to measuring the muon beam cooling using the novel Kernel Density Estimation (KDE) method, is described.

Poster WEPOA36 [1.855 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA36

Export •

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

WEPOA37

Hybrid Methods for Simulation of Muon Ionization Cooling Channels

775

J.D. Kunz, P. Snopok
IIT, Chicago, Illinois, USA
M. Berz
MSU, East Lansing, Michigan, USA
J.D. Kunz
Anderson University, Anderson, USA
P. Snopok
Fermilab, Batavia, Illinois, USA

Funding: Work supported by the U.S. Department of Energy
COSY Infinity is an arbitrary-order beam dynamics simulation and analysis code. It uses high-order transfer maps of combinations of particle optical elements of arbitrary field configurations. New features have been developed and implemented in COSY to follow charged particles through matter. To study in detail the properties of muons passing through a material, the transfer map approach alone is not sufficient. The interplay of beam optics and atomic processes must be studied by a hybrid transfer map–Monte Carlo approach in which transfer map methods describe the average behavior of the particles including energy loss, and Monte Carlo methods are used to provide small corrections to the predictions of the transfer map, accounting for the stochastic nature of scattering and straggling of particles. This way the vast majority of the dynamics is represented by fast application of the high-order transfer map of an entire element and accumulated stochastic effects. The gains in speed simplify the optimization of muon cooling channels which are usually very computationally demanding. Progress on the development of the required algorithms is reported.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA37

Export •

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

WEPOA38

Optically Based Diagnostics for Optical Stochastic Cooling

779

SUPO59

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

M.B. Andorf
Northern Illinois University, DeKalb, Illinois, USA
V.A. Lebedev, P. Piot, J. Ruan
Fermilab, Batavia, Illinois, USA

An Optical Stochastic Cooling (OSC) experiment with electrons is planned in the Integrable Optics Test Accelerator (IOTA) ring currently in construction at Fermilab. OSC requires timing the arrival of an electron and its radiation generated from the upstream pickup undulator into the downstream kicker undulator to a precision on the order of less than a fs. The interference of the pickup and kicker radiation suggests a way to diagnose the arrival time to the required precision.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA38

Export •

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

WEPOA42

RF Design of a 1.3-GHz High Average Beam Power SRF Electron Source

789

SUPO42

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

N. Sipahi, S. Biedron, S.V. Milton
CSU, Fort Collins, Colorado, USA
I.V. Gonin, R.D. Kephart, T.N. Khabiboulline, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, Illinois, USA

There is a significant interest in developing high-average power electron sources, particularly those integrated with Superconducting Radio Frequency (SRF) accelerator systems. Even though there are examples of high-average-power electron sources, they are not compact, highly efficient, or available at a reasonable cost. Adapting the recent advances in SRF cavities, RF power sources, and innovative solutions for an SRF gun and cathode system, we have developed a design concept for a compact SRF high-average power electron linac. This design will produce electron beams with energies up to 10 MeV. In this paper, we present the design results of our cathode structure integrated with modified 9-cell accelerating structure.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA42

Export •

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

WEPOA44

Accleration System of Beam Brightness Booster

796

V.G. Dudnikov
Muons, Inc, Illinois, USA
A.V. Dudnikov
BINP SB RAS, Novosibirsk, Russia

The brightness and intensity of a circulating proton beam now can be increased up to space charge limit by means of charge exchange injection or by an electron cooling but cannot be increased above this limit. Significantly higher brightness can be produced by means of the charge exchange injection with the space charge compensation [1]. The brightness of the space charge compensated beam is limited at low level by development of the electron-proton (e-p) instability [2]. Fortunately, e-p instability can be self-stabilized at a high beam density. A beam brightness booster (BBB) for significant increase of accumulated beam brightness is discussed. Accelerating system with a space charge compensation is proposed and described. The superintense beam production can be simplified by developing of nonlinear nearly integrable focusing system with broad spread of betatron tune and the broadband feedback system for e-p instability suppression .
[1] V. Dudnikov, in Proceedings of the Particle Accelerator Conference, Chicago, 2001..
[2] G. Budker, et al., Sov. Atomic Energy 22, 384 (1967);

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA44

Export •

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

WEPOA62

The Center for Bright Beams

830

J.R. Patterson, G.H. Hoffstaetter
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
Y.K. Kim
University of Chicago, Chicago, Illinois, USA

Funding: National Science Foundation award PHY-1549132.
The Center for Bright Beams (CBB) is a new National Science Foundation-supported Science and Technology Center. CBB's research goal is to increase the brightness of electron beams while reducing the cost and size of key technologies. To achieve this, it will augment the capabilities of accelerator physicists with those of physical chemists, materials scientists, condensed matter physicists, plasma physicists, and mathematicians. This approach has the potential to increase the brightness of electron sources through better photocathodes, the efficiency and gradient of SRF cavities through deeper understanding of superconducting compounds and their surfaces, and better understanding of beam storage and transport and the associated optics by using new mathematical techniques.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA62

Export •

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