NAPAC2019 - Table of Session: MOZBB (Monday Parallel Session 4)

Paper	Title	Page
MOZBB1	Beam Dynamics in Structure-Based Beam-Driven Accelerators
	S. Baturin Enrico Fermi Institute, University of Chicago, Chicago, Illinois, USA
	Funding: U.S. National Science Foundation under Grant No. PHY- 1549132, the Center for Bright Beams and under Grant No. PHY-1535639 Structure-based beam-driven acceleration scheme still lacks an understanding of many aspects, such as beam stability, energy transfer efficiency. This talk will be focused on analytical methods and simple mathematical models to address these remaining challenges and gain detailed insight into important effects in beam-driven acceleration schemes. S. Baturin, et al., Phys. Rev. Accel. Beams 21(3), 031301 (2018) S. Baturin, et al., arXiv:1807.10708 [physics.acc-ph] S. Baturin, et al., Phys. Rev. Lett. 113, 214801 (2014).
	Slides MOZBB1 [4.399 MB]
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MOZBB2	Experiments with Metamaterial-Based Metallic Accelerating Structures	78
MOPLH20	use link to see paper's listing under its alternate paper code
	X. Lu SLAC, Menlo Park, California, USA M.E. Conde, D.S. Doran, G. Ha, J.G. Power, J.H. Shao, E.E. Wisniewski ANL, Lemont, Illinois, USA C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA X. Lu, I. Mastovsky, J.F. Picard, M.A. Shapiro, R.J. Temkin MIT/PSFC, Cambridge, Massachusetts, USA M.M. Peng AAI/ANL, Lemont, Illinois, USA J. Seok UNIST, Ulsan, Republic of Korea
	Funding: U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award No. DE-SC0015566 at MIT and No. DE-AC02-06CH11357 at ANL We present experimental studies of metamaterial (MTM) structures for wakefield acceleration. The MTM structure is an all-metal periodic structure with its period much smaller than the wavelength at X-band. The fundamental TM mode has a negative group velocity, so an electron beam traveling through the structure radiates by reversed Cherenkov radiation. Two experiments have been completed at the Argonne Wakefield Accelerator (AWA), namely the Stage-I and Stage-II experiments. Differences between the two experiments include: (1) Structure length (Stage-I 8 cm, Stage-II 20 cm); (2) Bunch number used to excite the structure (Stage-I up to 2 bunches, Stage-II up to 8 bunches). In the Stage-I experiment, two bunches with a total charge of 85 nC generated 80 MW of RF power in a 2 ns long pulse. In the Stage-II experiment, the highest peak power reached 380 MW in a 10 ns long pulse from a train of 8 bunches with a total charge of 224 nC. Acceleration of a witness bunch has not been demonstrated yet, but the extracted power can be transferred to a separate accelerator for two-beam acceleration or directly applied to a trailing witness bunch in the same structure for collinear acceleration.
	Slides MOZBB2 [8.172 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOZBB2
About •	paper received ※ 27 August 2019 paper accepted ※ 04 September 2019 issue date ※ 08 October 2019
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MOZBB3	Conceptual Design of a Compact 500 MeV Short-Pulse Two-Beam Acceleration Demonstrator at Argonne Wakefield Accelerator
MOPLH27	use link to see paper's listing under its alternate paper code
	J.H. Shao, M.E. Conde, D.S. Doran, G. Ha, J.G. Power ANL, Lemont, Illinois, USA C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA
	Short-pulse two-beam acceleration (SP-TBA) is an advanced acceleration concept that can potentially meet the luminosity and cost requirements in future linear colliders and XFELs. In this concept, a high charge drive beam travelling through a structure excites short wakefield field (<20 ns) which is used to accelerate a low charge main beam in a parallel structure. A SP-TBA program is under development at the Argonne Wakefield Accelerator (AWA) facility where 300 MW generated power, 150 MeV/m acceleration gradient, and simplified staging have been successfully achieved. Based on the ongoing effort of novel dielectric disk structure, fast kicker/septum, and improved beam quality, a fully-functional demonstrator that can fit into AWA’s current bunker is proposed to demonstrate key technologies required by SP-TBA based machines: GW power generation, >250 MV/m acceleration, drive beam distribution/transportation, successive main beam acceleration, etc. The 70 MeV drive beam will be decelerated by four power extractors in two stages so as to boost the main beam energy from 15 MeV to 500 MeV by the four corresponding accelerators. The conceptual design will be presented in detail.
	Slides MOZBB3 [6.853 MB]
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MOZBB4	High Brightness CW Electron Beams From Superconducting RF Photoinjector
	I. Petrushina SUNY SB, Stony Brook, New York, USA T. Hayes, Y.C. Jing, V. Litvinenko, J. Ma, G. Narayan, I. Pinayev, F. Severino, K.S. Smith, G. Wang BNL, Upton, New York, USA V. Litvinenko Stony Brook University, Stony Brook, USA K. Shih SBU, Stony Brook, New York, USA
	The next generation electron beam facilities, such as high-power free electron lasers (FELs), energy-recovery linacs, or coolers for hadron beams, raise the strict requirements on the quality of the electron beam. Fortunately, the superconducting RF (SRF) technology is well suited for generating CW electron beams in high accelerating gradient environments. Recent achievements in the SRF photoinjector realm demonstrated the ability of the modern SRF guns to provide stable operation with high-brightness beams. In this paper, we report the excellent performance of our SRF gun with CsK2Sb photocathode that was built for the Coherent electron Cooling (CeC) Proof of Principle (PoP) experiment at RHIC. The gun is generating high charge electron bunches (up to 10 nC per bunch) and low transverse emittances with the cathodes operating for months without significant loss of quantum efficiency. We will provide a brief overview of the main stages of the commissioning of our gun along with a detailed discussion of the main challenges during the operation. This is followed by the description of the emittance studies, including our experimental results and numerical simulations.
	Slides MOZBB4 [10.537 MB]
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MOZBB5	Magnetized Electron Source for JLEIC Cooler	83
WEPLO22	use link to see paper's listing under its alternate paper code
	R. Suleiman, P.A. Adderley, J.F. Benesch, D.B. Bullard, J.M. Grames, J. Guo, F.E. Hannon, J. Hansknecht, C. Hernandez-Garcia, R. Kazimi, G.A. Krafft, M.A. Mamun, M. Poelker, M.G. Tiefenback, Y.W. Wang, S. Zhang JLab, Newport News, Virginia, USA J.R. Delayen, G.A. Krafft, S.A.K. Wijethunga, J.T. Yoskowitz ODU, Norfolk, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 and supported by Laboratory Directed Research and Development funding. Magnetized bunched-beam electron cooling is a critical part of the Jefferson Lab Electron Ion Collider (JLEIC). Strong cooling of ion beams will be accomplished inside a cooling solenoid where the ions co-propagate with an electron beam generated from a source immersed in magnetic field. This contribution describes the production and characterization of magnetized electron beam using a compact 300 kV DC high voltage photogun and bialkali-antimonide photocathodes. Beam magnetization was studied using a diagnostic beamline that includes viewer screens for measuring the shearing angle of the electron beamlet passing through a narrow upstream slit. Correlated beam emittance with magnetic field at the photocathode was measured for various laser spot sizes. Measurements of photocathode lifetime were carried out at different magnetized electron beam currents up to 28 mA and high bunch charge up to 0.7 nano-Coulomb was demonstrated.
	Slides MOZBB5 [9.236 MB]
	Poster MOZBB5 [1.564 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOZBB5
About •	paper received ※ 27 August 2019 paper accepted ※ 01 September 2019 issue date ※ 08 October 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOZBB6	Measuring the Mean Transverse Energy of Pump-Probe Photoemitted Electrons	87
MOPLH21	use link to see paper's listing under its alternate paper code
SUPLE11	use link to see paper's listing under its alternate paper code
	C.M. Pierce, I.V. Bazarov, L. Cultrera, J.M. Maxson Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: This work was supported by the U.S. National Science Foundation under Award PHY-1549132, the Center for Bright Beams. Low effective mass semiconductor photocathodes have historically failed to exhibit the sub-thermal mean transverse energies (MTEs) expected of them based on their band structure. However, conservation of transverse momentum across the vacuum interface, and therefore a low MTE in these materials, has been observed in time resolved ARPES. To help bridge this gap, we measured the MTE of the pump probe photoemitted electrons seen in the ARPES experiment using methods typical of accelerator physics. We compare the results of these measurements with those of both communities and discuss them in the context of photoemission physics. Kanasaki, J., Tanimura, H., & Tanimura, K. (2014). Imaging Energy-, Momentum-, and Time-Resolved Distributions of Photoinjected Hot Electrons in GaAs. Physical Review Letters, 113(23), 237401.
	Slides MOZBB6 [7.348 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOZBB6
About •	paper received ※ 28 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

MOZBB1

Beam Dynamics in Structure-Based Beam-Driven Accelerators

S. Baturin
Enrico Fermi Institute, University of Chicago, Chicago, Illinois, USA

Funding: U.S. National Science Foundation under Grant No. PHY- 1549132, the Center for Bright Beams and under Grant No. PHY-1535639
Structure-based beam-driven acceleration scheme still lacks an understanding of many aspects, such as beam stability, energy transfer efficiency. This talk will be focused on analytical methods and simple mathematical models to address these remaining challenges and gain detailed insight into important effects in beam-driven acceleration schemes.
S. Baturin, et al., Phys. Rev. Accel. Beams 21(3), 031301 (2018)
S. Baturin, et al., arXiv:1807.10708 [physics.acc-ph]
S. Baturin, et al., Phys. Rev. Lett. 113, 214801 (2014).

Slides MOZBB1 [4.399 MB]

Export •

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

MOZBB2

Experiments with Metamaterial-Based Metallic Accelerating Structures

78

MOPLH20

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

X. Lu
SLAC, Menlo Park, California, USA
M.E. Conde, D.S. Doran, G. Ha, J.G. Power, J.H. Shao, E.E. Wisniewski
ANL, Lemont, Illinois, USA
C.-J. Jing
Euclid TechLabs, LLC, Solon, Ohio, USA
X. Lu, I. Mastovsky, J.F. Picard, M.A. Shapiro, R.J. Temkin
MIT/PSFC, Cambridge, Massachusetts, USA
M.M. Peng
AAI/ANL, Lemont, Illinois, USA
J. Seok
UNIST, Ulsan, Republic of Korea

Funding: U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award No. DE-SC0015566 at MIT and No. DE-AC02-06CH11357 at ANL
We present experimental studies of metamaterial (MTM) structures for wakefield acceleration. The MTM structure is an all-metal periodic structure with its period much smaller than the wavelength at X-band. The fundamental TM mode has a negative group velocity, so an electron beam traveling through the structure radiates by reversed Cherenkov radiation. Two experiments have been completed at the Argonne Wakefield Accelerator (AWA), namely the Stage-I and Stage-II experiments. Differences between the two experiments include: (1) Structure length (Stage-I 8 cm, Stage-II 20 cm); (2) Bunch number used to excite the structure (Stage-I up to 2 bunches, Stage-II up to 8 bunches). In the Stage-I experiment, two bunches with a total charge of 85 nC generated 80 MW of RF power in a 2 ns long pulse. In the Stage-II experiment, the highest peak power reached 380 MW in a 10 ns long pulse from a train of 8 bunches with a total charge of 224 nC. Acceleration of a witness bunch has not been demonstrated yet, but the extracted power can be transferred to a separate accelerator for two-beam acceleration or directly applied to a trailing witness bunch in the same structure for collinear acceleration.

Slides MOZBB2 [8.172 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOZBB2

About •

paper received ※ 27 August 2019 paper accepted ※ 04 September 2019 issue date ※ 08 October 2019

Export •

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

MOZBB3

Conceptual Design of a Compact 500 MeV Short-Pulse Two-Beam Acceleration Demonstrator at Argonne Wakefield Accelerator

MOPLH27

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

J.H. Shao, M.E. Conde, D.S. Doran, G. Ha, J.G. Power
ANL, Lemont, Illinois, USA
C.-J. Jing
Euclid TechLabs, LLC, Solon, Ohio, USA

Short-pulse two-beam acceleration (SP-TBA) is an advanced acceleration concept that can potentially meet the luminosity and cost requirements in future linear colliders and XFELs. In this concept, a high charge drive beam travelling through a structure excites short wakefield field (<20 ns) which is used to accelerate a low charge main beam in a parallel structure. A SP-TBA program is under development at the Argonne Wakefield Accelerator (AWA) facility where 300 MW generated power, 150 MeV/m acceleration gradient, and simplified staging have been successfully achieved. Based on the ongoing effort of novel dielectric disk structure, fast kicker/septum, and improved beam quality, a fully-functional demonstrator that can fit into AWA’s current bunker is proposed to demonstrate key technologies required by SP-TBA based machines: GW power generation, >250 MV/m acceleration, drive beam distribution/transportation, successive main beam acceleration, etc. The 70 MeV drive beam will be decelerated by four power extractors in two stages so as to boost the main beam energy from 15 MeV to 500 MeV by the four corresponding accelerators. The conceptual design will be presented in detail.

Slides MOZBB3 [6.853 MB]

Export •

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

MOZBB4

High Brightness CW Electron Beams From Superconducting RF Photoinjector

I. Petrushina
SUNY SB, Stony Brook, New York, USA
T. Hayes, Y.C. Jing, V. Litvinenko, J. Ma, G. Narayan, I. Pinayev, F. Severino, K.S. Smith, G. Wang
BNL, Upton, New York, USA
V. Litvinenko
Stony Brook University, Stony Brook, USA
K. Shih
SBU, Stony Brook, New York, USA

The next generation electron beam facilities, such as high-power free electron lasers (FELs), energy-recovery linacs, or coolers for hadron beams, raise the strict requirements on the quality of the electron beam. Fortunately, the superconducting RF (SRF) technology is well suited for generating CW electron beams in high accelerating gradient environments. Recent achievements in the SRF photoinjector realm demonstrated the ability of the modern SRF guns to provide stable operation with high-brightness beams. In this paper, we report the excellent performance of our SRF gun with CsK2Sb photocathode that was built for the Coherent electron Cooling (CeC) Proof of Principle (PoP) experiment at RHIC. The gun is generating high charge electron bunches (up to 10 nC per bunch) and low transverse emittances with the cathodes operating for months without significant loss of quantum efficiency. We will provide a brief overview of the main stages of the commissioning of our gun along with a detailed discussion of the main challenges during the operation. This is followed by the description of the emittance studies, including our experimental results and numerical simulations.

Slides MOZBB4 [10.537 MB]

Export •

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

MOZBB5

Magnetized Electron Source for JLEIC Cooler

83

WEPLO22

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

R. Suleiman, P.A. Adderley, J.F. Benesch, D.B. Bullard, J.M. Grames, J. Guo, F.E. Hannon, J. Hansknecht, C. Hernandez-Garcia, R. Kazimi, G.A. Krafft, M.A. Mamun, M. Poelker, M.G. Tiefenback, Y.W. Wang, S. Zhang
JLab, Newport News, Virginia, USA
J.R. Delayen, G.A. Krafft, S.A.K. Wijethunga, J.T. Yoskowitz
ODU, Norfolk, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 and supported by Laboratory Directed Research and Development funding.
Magnetized bunched-beam electron cooling is a critical part of the Jefferson Lab Electron Ion Collider (JLEIC). Strong cooling of ion beams will be accomplished inside a cooling solenoid where the ions co-propagate with an electron beam generated from a source immersed in magnetic field. This contribution describes the production and characterization of magnetized electron beam using a compact 300 kV DC high voltage photogun and bialkali-antimonide photocathodes. Beam magnetization was studied using a diagnostic beamline that includes viewer screens for measuring the shearing angle of the electron beamlet passing through a narrow upstream slit. Correlated beam emittance with magnetic field at the photocathode was measured for various laser spot sizes. Measurements of photocathode lifetime were carried out at different magnetized electron beam currents up to 28 mA and high bunch charge up to 0.7 nano-Coulomb was demonstrated.

Slides MOZBB5 [9.236 MB]

Poster MOZBB5 [1.564 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOZBB5

About •

paper received ※ 27 August 2019 paper accepted ※ 01 September 2019 issue date ※ 08 October 2019

Export •

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

MOZBB6

Measuring the Mean Transverse Energy of Pump-Probe Photoemitted Electrons

87

MOPLH21

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

SUPLE11

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

C.M. Pierce, I.V. Bazarov, L. Cultrera, J.M. Maxson
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: This work was supported by the U.S. National Science Foundation under Award PHY-1549132, the Center for Bright Beams.
Low effective mass semiconductor photocathodes have historically failed to exhibit the sub-thermal mean transverse energies (MTEs) expected of them based on their band structure. However, conservation of transverse momentum across the vacuum interface, and therefore a low MTE in these materials, has been observed in time resolved ARPES*. To help bridge this gap, we measured the MTE of the pump probe photoemitted electrons seen in the ARPES experiment using methods typical of accelerator physics. We compare the results of these measurements with those of both communities and discuss them in the context of photoemission physics.
* Kanasaki, J., Tanimura, H., & Tanimura, K. (2014). Imaging Energy-, Momentum-, and Time-Resolved Distributions of Photoinjected Hot Electrons in GaAs. Physical Review Letters, 113(23), 237401.

Slides MOZBB6 [7.348 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOZBB6

About •

paper received ※ 28 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019

Export •

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