IPAC2018 - List of Authors (Jing, C.-J.)

Paper	Title	Page
TUPML064	Staged Two Beam Acceleration Beam Line Design for the AWA Facility	1688
SUSPF040	use link to see paper's listing under its alternate paper code
	N.R. Neveu IIT, Chicago, Illinois, USA W. Gai, C.-J. Jing, J.G. Power ANL, Argonne, Illinois, USA C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA L.K. Spentzouris Illinois Institute of Technology, Chicago, Illinois, USA
	Funding: This work is funded by the DOE Office of Science, grant no. DE-SC0015479, and contract No. DE-AC02- 06CH11357. Two beam acceleration is a candidate for future high energy physics machines and FEL user facilities. This scheme consists of two independent electron beam lines operating synchronously. High-charge, 70 MeV drive bunch trains are injected from the RF photo-injector into decelerating structures to generate a few hundred of MW of RF power. This RF power is transferred through an RF waveguide to accelerating structures that are used to accelerate the witness beam. Staging refers to the sequential acceleration (energy gain) in two or more structures on the witness beam line. A kicker was incorporated on the drive beam line to accomplish a modular design so that each accelerating structure can be independently powered by a separate drive beam. Simulations were performed in OPAL-T to model the two beam lines. Beam sizes at the center of the structures was minimized to ensure good charge transmission. The resulting design will be the basis for proof of principle experiments that will take place at the Argonne Wakefield Accelerator (AWA) facility.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML064
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THPML014	A Metamaterial Wagon Wheel Structure for Wakefield Acceleration by Reversed Cherenkov Radiation	4681
SUSPF036	use link to see paper's listing under its alternate paper code
	X.Y. Lu, I. Mastovsky, M.A. Shapiro, R.J. Temkin MIT/PSFC, Cambridge, Massachusetts, USA M.E. Conde, C.-J. Jing, J.G. Power, J.H. Shao, E.E. Wisniewski ANL, Argonne, Illinois, USA
	Funding: U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award Number DE-SC0015566 and the U.S. Department of Energy Office of Science under Contract No. DE-AC02-06CH11357 We present the design and experimental operation on an X-band metamaterial (MTM) wagon wheel structure for wakefield acceleration. The structure was designed and fabricated at MIT, and tested at the Argonne Wakefield Accelerator (AWA) laboratory at Argonne National Lab. The MTM wagon wheel structure is an all-metal periodic structure at 11.4 GHz. The fundamental TM mode has a negative group velocity, so when an electron beam travels through, energy is extracted from the beam by reversed Cherenkov radiation, which was verified in the experiment. Single bunches up to 45 nC were sent through the structure with a beam aperture of 6 mm and generated microwave power up to 25 MW in a 2 ns pulse, in agreement with both the analytical wakefield theory and the numerical CST simulations. Two bunches with a total charge of 85 nC generated 80 MW of microwave power. The structure is scalable to a power extractor of over 1 GW by increasing the structure length from 8 cm to 22 cm.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML014
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MOPML029	A Portable X-ray Source Based on Dielectric Accelerators	464
	C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA S.P. Antipov, A. Kanareykin, R.A. Kostin Euclid Beamlabs LLC, Bolingbrook, USA
	Funding: The work has been supported by the U.S. Department of Homeland Security (DHS), Domestic Nuclear Detection Office (DNDO), under a competitively awarded contract No. HSHQDC-17-C-00007. The portable low energy accelerator based X-ray sources have attractive applications in the non-destructive examination as a replacement of radiological gamma isotope sources. We are developing an inexpensive ultra-compact dielectric accelerator technology for low energy electron beams. The portability in the realm of this proposal is unprecedented ~ 1 ft3 volume with ~ 50 lbs of weight. The use of ceramics makes the transverse size of the accelerating waveguide comparable to that of a pencil. Because of this size reduction, additional weight reduction of shielding becomes possible. The article will report on the progress of this project.
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MOPML030	Demonstration of a Tunable Electron Beam Chopper for Application in 200 kV stroboscopic TEM	467
	C.-J. Jing, S.V. Baryshev, A. Kanareykin, A. Liu, Y. Zhao Euclid TechLabs, LLC, Solon, Ohio, USA J.W. Lau NIST, Gaithersburg, Maryland, USA D. Masiel, B. Reed Integrated Dynamic Electron Solutions, Pleasanton, California, USA Y. Zhu BNL, Upton, Long Island, New York, USA
	Funding: The project is supported by the Office of Basic Energy Science of DOE through a Small Business Innovative Research grant #DE-SC0013121. For the last several decades, time-resolved transmission electron microscopes (TEM) exploring the sub-microsecond timescale have relied on the photoemission technology to generate the single or train of electron bunches. However, the complexity of additional laser system and the availability of high repitition rate laser limit applications of the laser-driven approach. Lately we have made substantial progress towards pioneering a new kind of time-resolved TEM, complementary to the existing laser-based techniques. Using a tunable RF beam-chopper, we are able to retrofit an exsiting TEM providing a pulsed electron beam at a continuously tunable reptition rate up to 12GHz and a tunable bunch length. In the article we will briefly discuss the working principle and experimental progress to date.
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TUYGBE3	Recent progress of short pulse dielectric two-beam acceleration	640
	J.H. Shao, M.E. Conde, D.S. Doran, W. Gai, W. Liu, N.R. Neveu, J.F. Power, C. Whiteford, E.E. Wisniewski, L.M. Zheng ANL, Argonne, Illinois, USA C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA
	Two-Beam Acceleration (TBA) is a structure-based wakefield acceleration method with the potential to meet the luminosity and cost requirements of a TeV class linear collider. The Argonne Wakefield Accelerator (AWA) facility is developing a dielectric-based short pulse TBA scheme with the potential to withstand high acceleration gradients and to achieve low fabrication cost. Recently, the dielectric short pulse TBA technology was successfully demonstrated using K-band 26 GHz structures, achieving 55 MW output power from the power extractor and 28 MeV/m gradient in the accelerator. To improve the generated rf power, an X-band 11.7 GHz power extractor has been developed, which obtained 10⁵ MW in the high power test. In addition, a novel dielectric disk accelerator (DDA) is currently under investigation to significantly increase the efficiency of linear colliders based on short pulse TBA. Details of these research will be presented in this paper.
	Slides TUYGBE3 [2.219 MB]
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TUPML003	Design of an L-band Accelerating Structure for the Argonne Wakefield Accelerator Facility Witness Beam Line Energy Upgrade	1533
	J.H. Shao, M.E. Conde, D.S. Doran, J.F. Power ANL, Argonne, Illinois, USA C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA
	The Argonne Wakefield Accelerator (AWA) facility has been devoting much effort to the fundamental R&D of two-beam acceleration (TBA) technology with two parallel L-band beam lines. Beginning from the 70 MeV drive beam line, the high frequency (C-band and above) rf power is extracted from the beam by a decelerating structure (a.k.a. power extractor), transferred to an accelerating structure in the witness beam line, and used to accelerate the 15 MeV main beam. These high frequency accelerating structures usually have a small aperture to obtain high gradient and high efficiency, making it difficult for the low energy main beam to pass. To address this issue, one proposal is to increase the main beam energy to above 30 MeV by replacing the current witness linac. A 9-cell 𝜋-mode L-band standing-wave accelerating structure has therefore been designed to meet the high shunt impedance and low cost requirements. In addition, the single-feed coupling cell has been optimized with additional symmetrical ports to eliminate field distortion. The detailed design of the new accelerating structure will be presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML003
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TUPML005	Study of a Dielectric Disk Structure for Short Pulse Two-Beam Acceleration	1539
	J.H. Shao, M.E. Conde, D.S. Doran, J.F. Power ANL, Argonne, Illinois, USA C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA
	Argonne Flexible Linear Collider (AFLC), a proposed 3 TeV electron-positron linear collider based on two-beam acceleration (TBA) scheme, applies a short pulse length (∼20 ns) to obtain a high accelerating gradient (267 MV/m) and a compact footprint (∼18 km). The baseline design of the main accelerator section adopts 26 GHz K-band traveling-wave dielectric-loaded accelerators (DLA) with an rf to beam efficiency 𝜂𝑟𝑓 −𝑏𝑒𝑎𝑚 of 27%. Recently, an alternative structure which is similar to a metallic disk-loaded one but with dielectric disks, noted as dielectric disk accelerator (DDA), has been investigated and optimized, leading to ∼45% improvement in 𝜂𝑟𝑓 −𝑏𝑒𝑎𝑚. To demonstrate the key technologies, an X-band prototype structure has been designed and will be tested at Argonne Wakefield Accelerator (AWA) facility with a 300 MW metallic power extractor. Detailed comparison between K-band DLA and DDA for AFLC main accelerator as well as the preliminary design of the X-band DDA prototype will be presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML005
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TUPML006	Updates of the Argonne Cathode Test-stand	1542
	J.H. Shao, M.E. Conde, D.S. Doran, W. Gai, W. Liu, J.F. Power, C. Whiteford, E.E. Wisniewski, L.M. Zheng ANL, Argonne, Illinois, USA S.P. Antipov, G. Chen, E. Gomez, C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA S.V. Baryshev Michigan State University, East Lansing, Michigan, USA
	The Argonne Cathode Test-stand (ACT) is a unique testbed to develop cathodes and to conduct fundamental surface study under ultra-high rf field (up to 700 MV/m with pin-shaped cathodes). The test-stand consists of an L-band 1.3 GHz single-cell photocathode rf gun and a field emission (FE) imaging system to locate emitters with a resolution of ∼20 𝜇m. In the recent upgrade, UV laser has been introduced to improve the imaging system and to significantly expand the ACT towards photoemission and laser-assisted field emission research. In addition, a load-lock system has been added to the beam line to expedite the cathode switching period. The paper will present details of the upgrade as well as experiments planned in the near future.
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TUPML007	Short Pulse High Power RF Generation with an X-Band Dielectric Power Extractor	1546
	J.H. Shao, M.E. Conde, D.S. Doran, W. Gai, W. Liu, N.R. Neveu, J.F. Power, C. Whiteford, E.E. Wisniewski, L.M. Zheng ANL, Argonne, Illinois, USA C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA
	Short pulse high power rf generation is one of the key technologies for the Argonne Flexible Linear Collider (AFLC), a proposed 3 TeV electron-positron linear collider based on two-beam acceleration (TBA) scheme. Compared with metallic power extractors, dielectric structures have the potential to achieve lower fabrication cost and to withstand higher gradient. Recently, an X-band dielectric power extractor (a.k.a, DPETS) has been developed at the Argonne Wakefield Accelerator (AWA) facility and achieved 10⁵ MW output power when driven by a high charge 8-bunch train separated by 770 ps. The design, the cold test measurement, the preliminary high power test results, and the structure inspection will be presented in this paper.
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TUPML061	Study of Mean Transverse Energy of (N)UNCD with Tunable Laser Source	1677
SUSPF050	use link to see paper's listing under its alternate paper code
	G. Chen IIT, Chicago, Illinois, USA G. Adhikari, W.A. Schroeder UIC, Chicago, Illinois, USA S.P. Antipov, C.-J. Jing, K. Kovi Euclid TechLabs, LLC, Solon, Ohio, USA S.V. Baryshev ANL, Argonne, Illinois, USA L.K. Spentzouris Illinois Institute of Technology, Chicago, Illinois, USA
	Funding: NSF grant No. NSF-1739150, DOE SBIR program grant No. DE-SC0013145, NSF grant No. PHYS-1535279, DOE Contract No. DE-AC02-06CH11357. There is a strong motivation to develop and understand novel materials with the potential to be utilized as photocathodes, as these could have desirable photoemission properties for research and industrial applications. Nitrogen-incorporated ultrananocrystalline diamond ((N)UNCD) photocathodes have potential to become a material of choice for photocathode applications. (N)UNCD has high quantum efficiency when processed in hydrogen plasma, low surface roughness, and high electron conductivity through the bulk*. The mean transverse energy (MTE) was calculated for (N)UNCD thin films using the double-solenoid scan method. (N)UNCD thin film with thickness of 160nm was deposited on highly-doped silicon substrate. Studies of the MTE of a (N)UNCD sample were done using a tunable laser source with photon energies of 3.56 eV to 5.26 eV. These results are presented. K.J. Pérez Quintero et al., Appl. Phys. Lett. 105, 123103 (2014). ** S. Bhattacharyya et al., Appl. Phys. Lett. 79, 1441 (2001)
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WEPAF059	A Low Cost Beam Position Monitor System	1961
	C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA J.G. Power, J.H. Shao ANL, Argonne, Illinois, USA C. Yin University of Chicago, Chicago, Illinois, USA
	A Beam Position Monitor (BPM) system is essential to beam diagnostics for almost all particle accelerators. However, a typical BPM system contains customized hardware and complicated processing electronics which considerably drive the cost for large facilities where hundreds of them may be used. It also limits its use in the small scale accelerator facilities. In the paper, we present a low cost BPM system which consists of a commercial available CF flange based signal pickup device, a low cost integrated circuit adjacent to the pickup to filter, sample, digitize, and broadcast the signals out of the pickup electrodes. The digital signal is transmitted out for post processing through noise-protected Wi-Fi router. We will briefly discuss the working principle and experimental progress to date.
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Paper

Title

Page

TUPML064

Staged Two Beam Acceleration Beam Line Design for the AWA Facility

1688

SUSPF040

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

N.R. Neveu
IIT, Chicago, Illinois, USA
W. Gai, C.-J. Jing, J.G. Power
ANL, Argonne, Illinois, USA
C.-J. Jing
Euclid TechLabs, LLC, Solon, Ohio, USA
L.K. Spentzouris
Illinois Institute of Technology, Chicago, Illinois, USA

Funding: This work is funded by the DOE Office of Science, grant no. DE-SC0015479, and contract No. DE-AC02- 06CH11357.
Two beam acceleration is a candidate for future high energy physics machines and FEL user facilities. This scheme consists of two independent electron beam lines operating synchronously. High-charge, 70 MeV drive bunch trains are injected from the RF photo-injector into decelerating structures to generate a few hundred of MW of RF power. This RF power is transferred through an RF waveguide to accelerating structures that are used to accelerate the witness beam. Staging refers to the sequential acceleration (energy gain) in two or more structures on the witness beam line. A kicker was incorporated on the drive beam line to accomplish a modular design so that each accelerating structure can be independently powered by a separate drive beam. Simulations were performed in OPAL-T to model the two beam lines. Beam sizes at the center of the structures was minimized to ensure good charge transmission. The resulting design will be the basis for proof of principle experiments that will take place at the Argonne Wakefield Accelerator (AWA) facility.

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THPML014

A Metamaterial Wagon Wheel Structure for Wakefield Acceleration by Reversed Cherenkov Radiation

4681

SUSPF036

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

X.Y. Lu, I. Mastovsky, M.A. Shapiro, R.J. Temkin
MIT/PSFC, Cambridge, Massachusetts, USA
M.E. Conde, C.-J. Jing, J.G. Power, J.H. Shao, E.E. Wisniewski
ANL, Argonne, Illinois, USA

Funding: U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award Number DE-SC0015566 and the U.S. Department of Energy Office of Science under Contract No. DE-AC02-06CH11357
We present the design and experimental operation on an X-band metamaterial (MTM) wagon wheel structure for wakefield acceleration. The structure was designed and fabricated at MIT, and tested at the Argonne Wakefield Accelerator (AWA) laboratory at Argonne National Lab. The MTM wagon wheel structure is an all-metal periodic structure at 11.4 GHz. The fundamental TM mode has a negative group velocity, so when an electron beam travels through, energy is extracted from the beam by reversed Cherenkov radiation, which was verified in the experiment. Single bunches up to 45 nC were sent through the structure with a beam aperture of 6 mm and generated microwave power up to 25 MW in a 2 ns pulse, in agreement with both the analytical wakefield theory and the numerical CST simulations. Two bunches with a total charge of 85 nC generated 80 MW of microwave power. The structure is scalable to a power extractor of over 1 GW by increasing the structure length from 8 cm to 22 cm.

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MOPML029

A Portable X-ray Source Based on Dielectric Accelerators

464

C.-J. Jing
Euclid TechLabs, LLC, Solon, Ohio, USA
S.P. Antipov, A. Kanareykin, R.A. Kostin
Euclid Beamlabs LLC, Bolingbrook, USA

Funding: The work has been supported by the U.S. Department of Homeland Security (DHS), Domestic Nuclear Detection Office (DNDO), under a competitively awarded contract No. HSHQDC-17-C-00007.
The portable low energy accelerator based X-ray sources have attractive applications in the non-destructive examination as a replacement of radiological gamma isotope sources. We are developing an inexpensive ultra-compact dielectric accelerator technology for low energy electron beams. The portability in the realm of this proposal is unprecedented ~ 1 ft3 volume with ~ 50 lbs of weight. The use of ceramics makes the transverse size of the accelerating waveguide comparable to that of a pencil. Because of this size reduction, additional weight reduction of shielding becomes possible. The article will report on the progress of this project.

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MOPML030

Demonstration of a Tunable Electron Beam Chopper for Application in 200 kV stroboscopic TEM

467

C.-J. Jing, S.V. Baryshev, A. Kanareykin, A. Liu, Y. Zhao
Euclid TechLabs, LLC, Solon, Ohio, USA
J.W. Lau
NIST, Gaithersburg, Maryland, USA
D. Masiel, B. Reed
Integrated Dynamic Electron Solutions, Pleasanton, California, USA
Y. Zhu
BNL, Upton, Long Island, New York, USA

Funding: The project is supported by the Office of Basic Energy Science of DOE through a Small Business Innovative Research grant #DE-SC0013121.
For the last several decades, time-resolved transmission electron microscopes (TEM) exploring the sub-microsecond timescale have relied on the photoemission technology to generate the single or train of electron bunches. However, the complexity of additional laser system and the availability of high repitition rate laser limit applications of the laser-driven approach. Lately we have made substantial progress towards pioneering a new kind of time-resolved TEM, complementary to the existing laser-based techniques. Using a tunable RF beam-chopper, we are able to retrofit an exsiting TEM providing a pulsed electron beam at a continuously tunable reptition rate up to 12GHz and a tunable bunch length. In the article we will briefly discuss the working principle and experimental progress to date.

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TUYGBE3

Recent progress of short pulse dielectric two-beam acceleration

640

J.H. Shao, M.E. Conde, D.S. Doran, W. Gai, W. Liu, N.R. Neveu, J.F. Power, C. Whiteford, E.E. Wisniewski, L.M. Zheng
ANL, Argonne, Illinois, USA
C.-J. Jing
Euclid TechLabs, LLC, Solon, Ohio, USA

Two-Beam Acceleration (TBA) is a structure-based wakefield acceleration method with the potential to meet the luminosity and cost requirements of a TeV class linear collider. The Argonne Wakefield Accelerator (AWA) facility is developing a dielectric-based short pulse TBA scheme with the potential to withstand high acceleration gradients and to achieve low fabrication cost. Recently, the dielectric short pulse TBA technology was successfully demonstrated using K-band 26 GHz structures, achieving 55 MW output power from the power extractor and 28 MeV/m gradient in the accelerator. To improve the generated rf power, an X-band 11.7 GHz power extractor has been developed, which obtained 10⁵ MW in the high power test. In addition, a novel dielectric disk accelerator (DDA) is currently under investigation to significantly increase the efficiency of linear colliders based on short pulse TBA. Details of these research will be presented in this paper.

Slides TUYGBE3 [2.219 MB]

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TUPML003

Design of an L-band Accelerating Structure for the Argonne Wakefield Accelerator Facility Witness Beam Line Energy Upgrade

1533

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

The Argonne Wakefield Accelerator (AWA) facility has been devoting much effort to the fundamental R&D of two-beam acceleration (TBA) technology with two parallel L-band beam lines. Beginning from the 70 MeV drive beam line, the high frequency (C-band and above) rf power is extracted from the beam by a decelerating structure (a.k.a. power extractor), transferred to an accelerating structure in the witness beam line, and used to accelerate the 15 MeV main beam. These high frequency accelerating structures usually have a small aperture to obtain high gradient and high efficiency, making it difficult for the low energy main beam to pass. To address this issue, one proposal is to increase the main beam energy to above 30 MeV by replacing the current witness linac. A 9-cell 𝜋-mode L-band standing-wave accelerating structure has therefore been designed to meet the high shunt impedance and low cost requirements. In addition, the single-feed coupling cell has been optimized with additional symmetrical ports to eliminate field distortion. The detailed design of the new accelerating structure will be presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML003

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TUPML005

Study of a Dielectric Disk Structure for Short Pulse Two-Beam Acceleration

1539

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

Argonne Flexible Linear Collider (AFLC), a proposed 3 TeV electron-positron linear collider based on two-beam acceleration (TBA) scheme, applies a short pulse length (∼20 ns) to obtain a high accelerating gradient (267 MV/m) and a compact footprint (∼18 km). The baseline design of the main accelerator section adopts 26 GHz K-band traveling-wave dielectric-loaded accelerators (DLA) with an rf to beam efficiency 𝜂𝑟𝑓 −𝑏𝑒𝑎𝑚 of 27%. Recently, an alternative structure which is similar to a metallic disk-loaded one but with dielectric disks, noted as dielectric disk accelerator (DDA), has been investigated and optimized, leading to ∼45% improvement in 𝜂𝑟𝑓 −𝑏𝑒𝑎𝑚. To demonstrate the key technologies, an X-band prototype structure has been designed and will be tested at Argonne Wakefield Accelerator (AWA) facility with a 300 MW metallic power extractor. Detailed comparison between K-band DLA and DDA for AFLC main accelerator as well as the preliminary design of the X-band DDA prototype will be presented in this paper.

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TUPML006

Updates of the Argonne Cathode Test-stand

1542

J.H. Shao, M.E. Conde, D.S. Doran, W. Gai, W. Liu, J.F. Power, C. Whiteford, E.E. Wisniewski, L.M. Zheng
ANL, Argonne, Illinois, USA
S.P. Antipov, G. Chen, E. Gomez, C.-J. Jing
Euclid TechLabs, LLC, Solon, Ohio, USA
S.V. Baryshev
Michigan State University, East Lansing, Michigan, USA

The Argonne Cathode Test-stand (ACT) is a unique testbed to develop cathodes and to conduct fundamental surface study under ultra-high rf field (up to 700 MV/m with pin-shaped cathodes). The test-stand consists of an L-band 1.3 GHz single-cell photocathode rf gun and a field emission (FE) imaging system to locate emitters with a resolution of ∼20 𝜇m. In the recent upgrade, UV laser has been introduced to improve the imaging system and to significantly expand the ACT towards photoemission and laser-assisted field emission research. In addition, a load-lock system has been added to the beam line to expedite the cathode switching period. The paper will present details of the upgrade as well as experiments planned in the near future.

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TUPML007

Short Pulse High Power RF Generation with an X-Band Dielectric Power Extractor

1546

J.H. Shao, M.E. Conde, D.S. Doran, W. Gai, W. Liu, N.R. Neveu, J.F. Power, C. Whiteford, E.E. Wisniewski, L.M. Zheng
ANL, Argonne, Illinois, USA
C.-J. Jing
Euclid TechLabs, LLC, Solon, Ohio, USA

Short pulse high power rf generation is one of the key technologies for the Argonne Flexible Linear Collider (AFLC), a proposed 3 TeV electron-positron linear collider based on two-beam acceleration (TBA) scheme. Compared with metallic power extractors, dielectric structures have the potential to achieve lower fabrication cost and to withstand higher gradient. Recently, an X-band dielectric power extractor (a.k.a, DPETS) has been developed at the Argonne Wakefield Accelerator (AWA) facility and achieved 10⁵ MW output power when driven by a high charge 8-bunch train separated by 770 ps. The design, the cold test measurement, the preliminary high power test results, and the structure inspection will be presented in this paper.

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TUPML061

Study of Mean Transverse Energy of (N)UNCD with Tunable Laser Source

1677

SUSPF050

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G. Chen
IIT, Chicago, Illinois, USA
G. Adhikari, W.A. Schroeder
UIC, Chicago, Illinois, USA
S.P. Antipov, C.-J. Jing, K. Kovi
Euclid TechLabs, LLC, Solon, Ohio, USA
S.V. Baryshev
ANL, Argonne, Illinois, USA
L.K. Spentzouris
Illinois Institute of Technology, Chicago, Illinois, USA

Funding: NSF grant No. NSF-1739150, DOE SBIR program grant No. DE-SC0013145, NSF grant No. PHYS-1535279, DOE Contract No. DE-AC02-06CH11357.
There is a strong motivation to develop and understand novel materials with the potential to be utilized as photocathodes, as these could have desirable photoemission properties for research and industrial applications. Nitrogen-incorporated ultrananocrystalline diamond ((N)UNCD) photocathodes have potential to become a material of choice for photocathode applications*. (N)UNCD has high quantum efficiency when processed in hydrogen plasma*, low surface roughness, and high electron conductivity through the bulk**. The mean transverse energy (MTE) was calculated for (N)UNCD thin films using the double-solenoid scan method. (N)UNCD thin film with thickness of 160nm was deposited on highly-doped silicon substrate. Studies of the MTE of a (N)UNCD sample were done using a tunable laser source with photon energies of 3.56 eV to 5.26 eV. These results are presented.
* K.J. Pérez Quintero et al., Appl. Phys. Lett. 105, 123103 (2014).
** S. Bhattacharyya et al., Appl. Phys. Lett. 79, 1441 (2001)

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WEPAF059

A Low Cost Beam Position Monitor System

1961

C.-J. Jing
Euclid TechLabs, LLC, Solon, Ohio, USA
J.G. Power, J.H. Shao
ANL, Argonne, Illinois, USA
C. Yin
University of Chicago, Chicago, Illinois, USA

A Beam Position Monitor (BPM) system is essential to beam diagnostics for almost all particle accelerators. However, a typical BPM system contains customized hardware and complicated processing electronics which considerably drive the cost for large facilities where hundreds of them may be used. It also limits its use in the small scale accelerator facilities. In the paper, we present a low cost BPM system which consists of a commercial available CF flange based signal pickup device, a low cost integrated circuit adjacent to the pickup to filter, sample, digitize, and broadcast the signals out of the pickup electrodes. The digital signal is transmitted out for post processing through noise-protected Wi-Fi router. We will briefly discuss the working principle and experimental progress to date.

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