IPAC2019 - List of Authors (Doran, D.S.)

Paper	Title	Page
MOPRB069	Generation of High Power Short Rf Pulses using an X-Band Metallic Power Extractor Driven by High Charge Multi-Bunch Train	734
	J.H. Shao, M.E. Conde, D.S. Doran, G. Ha, W. Liu, J.G. Power, C. Whiteford, E.E. Wisniewski ANL, Argonne, Illinois, USA H.B. Chen, M.M. Peng, J. Shi, H. Zha TUB, Beijing, People’s Republic of China C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA J. Seok UNIST, Ulsan, Republic of Korea
	Short pulse two-beam acceleration (TBA) is a structure wakefield acceleration (SWFA) approach aiming to achieve gradient above 250 MV/m using rf pulses less than 20 ns. An X-band 11.7 GHz metallic power extractor has been developed as the power source to test accelerating structures in this extreme regime. The power extractor is designed to be driven by high charge bunches separated by 769.2 ps (9 times the X-band period) on an L-band 1.3 GHz beamline. In the recent experiment, ~280 MW rf pulses with 3 ns flat-top have been measured by a coaxial rf pickup when driven by 8-bunch trains with a total charge of ~500 nC. The power level is ~50% lower than the theoretical prediction and simulation. Experimental investigation suggests that the missing power was mainly caused by the multipacting issue inside the rf pickup, which could be eliminated by a newly-designed directional coupler.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB069
About •	paper received ※ 19 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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TUPTS090	Experimental Results of Dense Array Diamond Field Emitters in RF Gun	2134
	K.E. Nichols, H.L. Andrews, D. Kim, E.I. Simakov LANL, Los Alamos, New Mexico, USA S.P. Antipov Euclid Beamlabs LLC, Bolingbrook, USA G. Chen IIT, Chicago, Illinois, USA M.E. Conde, D.S. Doran, G. Ha, W. Liu, J.F. Power, J.H. Shao, C. Whiteford, E.E. Wisniewski ANL, Argonne, Illinois, USA
	We present experimental emission results from arrays of diamond field emitter tips operating in an RF gun at the Argonne Cathode Test-stand. Results from various arrays will be presented with different spacing between array elements. Very high charge densities were produced at various field gradients. The maximum field gradient for a particular geometry was discovered and break-down effects will be presented. Cathode lifetime was preliminarily studied. Further experiments are being planned and work on the cathode design optimization to produce higher quality beams will be discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS090
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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THPGW073	Status on a Laser Injection in Beam Driven Dielectric Wakefield Accelerator Experiment	3761
	G. Andonian, T.J. Campese, F.H. O’Shea RadiaBeam, Santa Monica, California, USA D.L. Bruhwiler, N.M. Cook RadiaSoft LLC, Boulder, Colorado, USA M.E. Conde, D.S. Doran, G. Ha, J.G. Power, J.H. Shao, E.E. Wisniewski ANL, Argonne, Illinois, USA J.B. Rosenzweig UCLA, Los Angeles, California, USA T. Xu Northern Illinois University, DeKalb, Illinois, USA
	The generation of high-brightness beams with ultra-low emittance using the plasma photocathode technique has gained significant traction in recent years. The practical execution of a combined plasma wakefield acceleration section and a laser injected typically requires a dual gas medium for precision ionization of low and high ionization thresholds. The concept can be partially simplified in experiment by replacing the plasma wakefield acceleration component with a dielectric wakefield acceleration scheme, sacrificing field gradient but maintaining low emittance beam generation. In this paper, we describe the progress on the design of a hybrid scheme, using laser injection in a gas medium within a dielectric wakefield accelerator structure. The proof-of-concept experiment is planned to take place at the Argonne Wakefield Accelerator.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW073
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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THPGW088	Transformer Ratio Measurements from Ramped Beams in the Plasma Blowout Regime using Emittance Exchange	3778
SUSPFO134	use link to see paper's listing under its alternate paper code
	R.J. Roussel, G. Andonian, W.J. Lynn, J.B. Rosenzweig UCLA, Los Angeles, California, USA M.E. Conde, D.S. Doran, G. Ha, J.G. Power, C. Whiteford, E.E. Wisniewski ANL, Argonne, Illinois, USA J. Seok UNIST, Ulsan, Republic of Korea
	Funding: Work is supported by DOE contract DE-SC0017648. We present initial measurements from a UCLA-Argonne Wakefield Accelerator collaborative plasma wakefield acceleration (PWFA) experiment aimed at demonstrating the dependence of transformer ratio on longitudinal beam shape. The transformer ratio or the ratio between the maximum acceleration of the witness and the maximum deceleration of the drive beam, is key to a mature, beam-based, plasma wakefield accelerator design. Utilizing the unique capabilities of the emittance exchange (EEX) beamline, we may obtain transformer ratios in excess of six in PWFA. We present the experimental beamline design, relevant beam diagnostics and explore preservation of the longitudinal beam profile.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW088
About •	paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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THPRB107	A Novel Design of a Laser Phase Monitor for AWA RF Photocathode Electron Gun	4076
	W. Liu, M.E. Conde, D.S. Doran, G. Ha, J.G. Power, J.H. Shao, C. Whiteford, E.E. Wisniewski ANL, Argonne, Illinois, USA
	It is critical to maintain a stable laser phase for RF photocathode electron gun to achieve high beam stability. In order to achieve a higher beam stability for AWA(Argonne Wakefield Accelerator) beamline, a novel laser phase monitor has been designed to allow us to monitor and feedback on. Both the design and its applications at AWA are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB107
About •	paper received ※ 13 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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Paper

Title

Page

Generation of High Power Short Rf Pulses using an X-Band Metallic Power Extractor Driven by High Charge Multi-Bunch Train

734

J.H. Shao, M.E. Conde, D.S. Doran, G. Ha, W. Liu, J.G. Power, C. Whiteford, E.E. Wisniewski
ANL, Argonne, Illinois, USA
H.B. Chen, M.M. Peng, J. Shi, H. Zha
TUB, Beijing, People’s Republic of China
C.-J. Jing
Euclid TechLabs, LLC, Solon, Ohio, USA
J. Seok
UNIST, Ulsan, Republic of Korea

Short pulse two-beam acceleration (TBA) is a structure wakefield acceleration (SWFA) approach aiming to achieve gradient above 250 MV/m using rf pulses less than 20 ns. An X-band 11.7 GHz metallic power extractor has been developed as the power source to test accelerating structures in this extreme regime. The power extractor is designed to be driven by high charge bunches separated by 769.2 ps (9 times the X-band period) on an L-band 1.3 GHz beamline. In the recent experiment, ~280 MW rf pulses with 3 ns flat-top have been measured by a coaxial rf pickup when driven by 8-bunch trains with a total charge of ~500 nC. The power level is ~50% lower than the theoretical prediction and simulation. Experimental investigation suggests that the missing power was mainly caused by the multipacting issue inside the rf pickup, which could be eliminated by a newly-designed directional coupler.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB069

About •

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

Export •

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

TUPTS090

Experimental Results of Dense Array Diamond Field Emitters in RF Gun

2134

K.E. Nichols, H.L. Andrews, D. Kim, E.I. Simakov
LANL, Los Alamos, New Mexico, USA
S.P. Antipov
Euclid Beamlabs LLC, Bolingbrook, USA
G. Chen
IIT, Chicago, Illinois, USA
M.E. Conde, D.S. Doran, G. Ha, W. Liu, J.F. Power, J.H. Shao, C. Whiteford, E.E. Wisniewski
ANL, Argonne, Illinois, USA

We present experimental emission results from arrays of diamond field emitter tips operating in an RF gun at the Argonne Cathode Test-stand. Results from various arrays will be presented with different spacing between array elements. Very high charge densities were produced at various field gradients. The maximum field gradient for a particular geometry was discovered and break-down effects will be presented. Cathode lifetime was preliminarily studied. Further experiments are being planned and work on the cathode design optimization to produce higher quality beams will be discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS090

About •

paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

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

THPGW073

Status on a Laser Injection in Beam Driven Dielectric Wakefield Accelerator Experiment

3761

G. Andonian, T.J. Campese, F.H. O’Shea
RadiaBeam, Santa Monica, California, USA
D.L. Bruhwiler, N.M. Cook
RadiaSoft LLC, Boulder, Colorado, USA
M.E. Conde, D.S. Doran, G. Ha, J.G. Power, J.H. Shao, E.E. Wisniewski
ANL, Argonne, Illinois, USA
J.B. Rosenzweig
UCLA, Los Angeles, California, USA
T. Xu
Northern Illinois University, DeKalb, Illinois, USA

The generation of high-brightness beams with ultra-low emittance using the plasma photocathode technique has gained significant traction in recent years. The practical execution of a combined plasma wakefield acceleration section and a laser injected typically requires a dual gas medium for precision ionization of low and high ionization thresholds. The concept can be partially simplified in experiment by replacing the plasma wakefield acceleration component with a dielectric wakefield acceleration scheme, sacrificing field gradient but maintaining low emittance beam generation. In this paper, we describe the progress on the design of a hybrid scheme, using laser injection in a gas medium within a dielectric wakefield accelerator structure. The proof-of-concept experiment is planned to take place at the Argonne Wakefield Accelerator.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW073

About •

paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

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

THPGW088

Transformer Ratio Measurements from Ramped Beams in the Plasma Blowout Regime using Emittance Exchange

3778

SUSPFO134

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

R.J. Roussel, G. Andonian, W.J. Lynn, J.B. Rosenzweig
UCLA, Los Angeles, California, USA
M.E. Conde, D.S. Doran, G. Ha, J.G. Power, C. Whiteford, E.E. Wisniewski
ANL, Argonne, Illinois, USA
J. Seok
UNIST, Ulsan, Republic of Korea

Funding: Work is supported by DOE contract DE-SC0017648.
We present initial measurements from a UCLA-Argonne Wakefield Accelerator collaborative plasma wakefield acceleration (PWFA) experiment aimed at demonstrating the dependence of transformer ratio on longitudinal beam shape. The transformer ratio or the ratio between the maximum acceleration of the witness and the maximum deceleration of the drive beam, is key to a mature, beam-based, plasma wakefield accelerator design. Utilizing the unique capabilities of the emittance exchange (EEX) beamline, we may obtain transformer ratios in excess of six in PWFA. We present the experimental beamline design, relevant beam diagnostics and explore preservation of the longitudinal beam profile.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW088

About •

paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

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

THPRB107

A Novel Design of a Laser Phase Monitor for AWA RF Photocathode Electron Gun

4076

W. Liu, M.E. Conde, D.S. Doran, G. Ha, J.G. Power, J.H. Shao, C. Whiteford, E.E. Wisniewski
ANL, Argonne, Illinois, USA

It is critical to maintain a stable laser phase for RF photocathode electron gun to achieve high beam stability. In order to achieve a higher beam stability for AWA(Argonne Wakefield Accelerator) beamline, a novel laser phase monitor has been designed to allow us to monitor and feedback on. Both the design and its applications at AWA are presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB107

About •

paper received ※ 13 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

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