IPAC2021 - List of Authors (Kuzikov, S.V.)

Paper	Title	Page
MOPAB152	High Power Tests of Brazeless Accelerating Structures	532
	S.P. Antipov, P.V. Avrakhov, C.-J. Jing, S.V. Kuzikov Euclid TechLabs, Solon, Ohio, USA V.A. Dolgashev SLAC, Menlo Park, California, USA D.S. Doran, W. Liu, J.G. Power, J.H. Shao, E.E. Wisniewski ANL, Lemont, Illinois, USA
	Funding: DOE SBIR Grant #DE-SC0017749 A typical accelerating structure is a set of copper resonators brazed together. This multi step process is expensive and time consuming. In an effort to optimize production process for rapid prototyping and overall reduction of accelerator cost we developed a split block brazeless accelerating structure. In such structure the vacuum is sealed by the use of knife edges, similar to an industry standard conflat technology. In this paper we present high power tests of several different brazeless structures. First, an inexpensive 1 MeV accelerator powered by radar magnetron. Second, a high gradient power extractor tested at Argonne Wakefield Accelerator Facility. In this experiment a high charge electron beam generated a 180 MW peak power pulse. Finally, we report on high power testing of a brazeless x-band accelerating structure at SLAC.
	Poster MOPAB152 [0.783 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB152
About •	paper received ※ 20 May 2021 paper accepted ※ 24 June 2021 issue date ※ 31 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPAB153	Laser Microfabrication for Accelerator Applications	535
	S.P. Antipov, S.V. Kuzikov Euclid TechLabs, Solon, Ohio, USA A.A. Vikharev IAP/RAS, Nizhny Novgorod, Russia
	Laser microfabrication allows high precision ablation of materials at sub-mm scale. When laser pulse length is shorter than about 10 picoseconds the heat affected zone is minimized and ablation occurs without melting. Work-pieces processed in this fashion exhibit less structural damage and are expected to have a higher damage thresholds. In this paper we will review several case studies of laser-microfabricated components for accelerator and x-ray applications. Ablated materials include diamond, quartz, tungsten, copper, YAG:Ce and silicon.
	Poster MOPAB153 [2.781 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB153
About •	paper received ※ 20 May 2021 paper accepted ※ 01 July 2021 issue date ※ 29 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPAB154	Multi-Cell Accelerating Structure Driven by a Lens-Focused Picosecond THz Pulse	537
	S.P. Antipov, S.V. Kuzikov Euclid TechLabs, Solon, Ohio, USA A.A. Vikharev IAP/RAS, Nizhny Novgorod, Russia
	Recently, gradients on the order of 1 GV/m level have been obtained in a form of a single cycle (~1 ps) THz pulses produced by conversion of a high peak power laser radiation in nonlinear crystals (~1 mJ, 1 ps, up to 3% conversion efficiency). Such high-intensity radiation can be utilized for charged particle acceleration. However, these pulses are short in time (~1ps) and broadband, therefore a new accelerating structure type is required. In this paper, we propose a novel structure based on focusing of THz radiation in accelerating cell and stacking such cells to achieve a long-range interaction required for an efficient acceleration process. We present an example in which a 100 microJoule THz pulse produces a 600 keV energy gain in 5 mm long 10 cell accelerating structure for an ultra-relativistic electron. This design can be readily extended to non-relativistic particles. Such structure had been laser microfabricated and appropriate dimensions were achieved.
	Poster MOPAB154 [1.283 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB154
About •	paper received ※ 27 May 2021 paper accepted ※ 05 July 2021 issue date ※ 14 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPAB155	Magnetic Breakdowns in Side-Coupled X-Band Accelerating Structures	540
	S.P. Antipov, P.V. Avrakhov, S.V. Kuzikov Euclid TechLabs, Solon, Ohio, USA V.A. Dolgashev SLAC, Menlo Park, California, USA C. Jing Euclid Beamlabs, Bolingbrook, USA
	Funding: DOE SBIR Side coupled accelerating structures are popular in the industrial realizations of linacs due to their high shunt impedance and ease of tuning. We designed and fabricated a side-coupled X-band accelerating structure that achieved 133 MOhm/m shut impedance. This structure was fabricated out of two halves using a novel brazeless approach. The two copper halves are joined together using a stainless steel joining piece with knife edges that bite into copper. This structure had been tested at high power at SLAC National Accelerator Laboratory. The performance of the structure had been limited by magnetic breakdowns on the side-coupling cells. In this paper we will present results of the high gradient tests and after-test analysis. Scanning electron microscopy images show a typical magnetic-field induced breakdown.
	Poster MOPAB155 [1.069 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB155
About •	paper received ※ 20 May 2021 paper accepted ※ 23 June 2021 issue date ※ 01 September 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAB163	An X-Band Ultra-High Gradient Photoinjector	2986
	S.V. Kuzikov, S.P. Antipov, P.V. Avrakhov, E. Dosov, C.-J. Jing, E.W. Knight Euclid TechLabs, Solon, Ohio, USA G. Ha, C.-J. Jing, W. Liu, P. Piot, J.G. Power, D.S. Scott, J.H. Shao, E.E. Wisniewski ANL, Lemont, Illinois, USA C.-J. Jing Euclid Beamlabs, Bolingbrook, USA X. Lu MIT/PSFC, Cambridge, Massachusetts, USA X. Lu SLAC, Menlo Park, California, USA P. Piot Fermilab, Batavia, Illinois, USA P. Piot, W.H. Tan Northern Illinois University, DeKalb, Illinois, USA E.E. Wisniewski IIT, Chicago, Illinois, USA
	Funding: This work was supported by DoE SBIR grant # DE-SC0018709. High brightness beams appealing for XFELs and UEM essentially imply a high current and a low emittance. To obtain such beams we propose to raise the accelerating voltage in the gun mitigating repealing Coulomb forces. An ultra-high gradient is achieved utilizing a short-pulse technology. We have designed a room temperature X-band 1,5 cell gun that is able to inject 4 MeV, 100 pC bunches with as low as 0.15 mcm normalized transverse emittance. The gun is operated with as high gradients as 400 MV/m and fed by 200 MW, 10 ns RF pulses generated with Argonne Wakefield Accelerator (AWA) power extractor. We report results of low RF power tests, laser alignment test results, and successful gun conditioning results carried out at nominal RF power.
	Poster WEPAB163 [5.427 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB163
About •	paper received ※ 18 May 2021 paper accepted ※ 02 June 2021 issue date ※ 19 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAB164	Electrodeless Diamond Beam Halo Monitor	2990
	S.V. Kuzikov, S.P. Antipov, P.V. Avrakhov, E. Dosov, E.W. Knight, Y. Zhao Euclid TechLabs, Solon, Ohio, USA J.G. Power, J. Shao ANL, Lemont, Illinois, USA
	Funding: This work was supported by DoE SBIR grant # DE-SC0019642. Beam halo measurement is important for novel x-ray free-electron lasers which have remarkably high repetition rate and average power. We propose diamond as a radiation hard material that can be used to measure the flux of passing particles based on a particle-induced conductivity effect. Our diamond electrodeless monitor is based on a microwave measurement of the change in the resonator coupling and eigenfrequency. For measurements, we put a sensitive diamond sample in a resonator that intercepts the halo. By measuring the change in RF properties of the resonator, one can infer the beam halo parameters scanning across the beam to map its transverse distribution. In recent experiments we used a Vertical Beam Test Stand (VBS), delivered DC electron beam of the 20-200 keV energy with the current up to 50 µA, to characterize several diamond samples. We have designed and fabricated a scanning diamond monitor, based on an X-band resonator, which was tested at Argonne Wakefield Accelerator (AWA) with a multi-MeV electron beam.
	Poster WEPAB164 [5.138 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB164
About •	paper received ※ 14 May 2021 paper accepted ※ 07 June 2021 issue date ※ 31 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAB165	Metamaterial Waveguide HOM Loads for SRF Accelerating Cavities	2994
	S.V. Kuzikov Euclid TechLabs, Solon, Ohio, USA
	Suppression of beam induced HOMs is necessary for most SRF accelerating cavities driven with high currents. One of the problems in design of a HOM load is that vacuum compatible materials with high enough imaginary part of the dielectric permittivity, which provides absorption, have also a high real part of the permittivity. This does not allow absorbing RF radiation at short distance and in broad frequency band. We propose considering artificial metamaterials where besides lossy dielectric pieces, an absorber with high magnetic permeability is included. In our proposal, we suggest composing a waveguide HOM load of a metamaterial consisted of well-known ceramic and ferrite plates placed periodically in a stack. Such a design provides low return losses, compactness and broad frequency range of the operation.
	Poster WEPAB165 [1.844 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB165
About •	paper received ※ 19 May 2021 paper accepted ※ 02 June 2021 issue date ※ 24 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPAB129	Beam Dynamics Simulations in a High-Gradient X-Band Photoinjector	4013
	W.H. Tan, P. Piot Northern Illinois University, DeKalb, Illinois, USA G. Chen, S.V. Kuzikov Euclid TechLabs, Solon, Ohio, USA G. Chen IIT, Chicago, Illinois, USA G. Ha, C.-J. Jing ANL, Lemont, Illinois, USA C.-J. Jing Euclid Beamlabs, Bolingbrook, USA
	A high-gradient X-band (11.7-GHz) photoinjector was recently developed by Euclid Techlabs and is in its commissioning phase at the Argonne Wakefield Accelerator (AWA). This contribution discuss the beam-dynamics modeling of the photoinjector system comprising an RF gun and linac section. We especially discuss beam-dynamics optimization of setup for an integrated proof-of-principle experiments. We also discuss the use of such a photoinjector as a witness-bunch source for a future high-gradient collinear-wakefield accelerator experiments at the AWA. * S. V. Kuzikov, et al. these proceedings.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB129
About •	paper received ※ 20 May 2021 paper accepted ※ 14 July 2021 issue date ※ 31 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPAB331	High-Power Test of a Highly Over-Coupled X-Band RF Gun Driven by Short RF Pulses	4432
	J.H. Shao, D.S. Doran, W. Liu, J.G. Power, C. Whiteford, E.E. Wisniewski ANL, Lemont, Illinois, USA C.-J. Jing, S.V. Kuzikov Euclid TechLabs, Solon, Ohio, USA X. Lu, P. Piot, W.H. Tan Northern Illinois University, DeKalb, Illinois, USA
	Beam brightness, a key figure of merit of RF photocathode guns, can be improved by increasing the cathode surface field which suppresses emittance growth from space charge. The surface field in normal-conducting structures is mainly limited by RF breakdown and it has been experimentally discovered that RF breakdown rate exponentially depends on RF pulse length. A highly over-coupled 1.5-cell X-band photocathode gun has been developed to be powered by 9 ns RF pulses with 3 ns rising time, 3 ns flat-top, and 3 ns falling time generated by an X-band metallic power extractor. In the recent experiment at Argonne Wakefield Accelerator facility, cathode surface field up to ~350 MV/m with a low breakdown rate has been obtained under ~250 MW input power. Strong beam loading from dark current was observed during RF conditioning and quickly recovered to a negligible level after the gun reached the maximum gradient. Detailed high-power test results and data analysis will be reported in this manuscript.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB331
About •	paper received ※ 25 May 2021 paper accepted ※ 14 July 2021 issue date ※ 23 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

High Power Tests of Brazeless Accelerating Structures

532

S.P. Antipov, P.V. Avrakhov, C.-J. Jing, S.V. Kuzikov
Euclid TechLabs, Solon, Ohio, USA
V.A. Dolgashev
SLAC, Menlo Park, California, USA
D.S. Doran, W. Liu, J.G. Power, J.H. Shao, E.E. Wisniewski
ANL, Lemont, Illinois, USA

Funding: DOE SBIR Grant #DE-SC0017749
A typical accelerating structure is a set of copper resonators brazed together. This multi step process is expensive and time consuming. In an effort to optimize production process for rapid prototyping and overall reduction of accelerator cost we developed a split block brazeless accelerating structure. In such structure the vacuum is sealed by the use of knife edges, similar to an industry standard conflat technology. In this paper we present high power tests of several different brazeless structures. First, an inexpensive 1 MeV accelerator powered by radar magnetron. Second, a high gradient power extractor tested at Argonne Wakefield Accelerator Facility. In this experiment a high charge electron beam generated a 180 MW peak power pulse. Finally, we report on high power testing of a brazeless x-band accelerating structure at SLAC.

Poster MOPAB152 [0.783 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB152

About •

paper received ※ 20 May 2021 paper accepted ※ 24 June 2021 issue date ※ 31 August 2021

Export •

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

MOPAB153

Laser Microfabrication for Accelerator Applications

535

S.P. Antipov, S.V. Kuzikov
Euclid TechLabs, Solon, Ohio, USA
A.A. Vikharev
IAP/RAS, Nizhny Novgorod, Russia

Laser microfabrication allows high precision ablation of materials at sub-mm scale. When laser pulse length is shorter than about 10 picoseconds the heat affected zone is minimized and ablation occurs without melting. Work-pieces processed in this fashion exhibit less structural damage and are expected to have a higher damage thresholds. In this paper we will review several case studies of laser-microfabricated components for accelerator and x-ray applications. Ablated materials include diamond, quartz, tungsten, copper, YAG:Ce and silicon.

Poster MOPAB153 [2.781 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB153

About •

paper received ※ 20 May 2021 paper accepted ※ 01 July 2021 issue date ※ 29 August 2021

Export •

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

MOPAB154

Multi-Cell Accelerating Structure Driven by a Lens-Focused Picosecond THz Pulse

537

S.P. Antipov, S.V. Kuzikov
Euclid TechLabs, Solon, Ohio, USA
A.A. Vikharev
IAP/RAS, Nizhny Novgorod, Russia

Recently, gradients on the order of 1 GV/m level have been obtained in a form of a single cycle (~1 ps) THz pulses produced by conversion of a high peak power laser radiation in nonlinear crystals (~1 mJ, 1 ps, up to 3% conversion efficiency). Such high-intensity radiation can be utilized for charged particle acceleration. However, these pulses are short in time (~1ps) and broadband, therefore a new accelerating structure type is required. In this paper, we propose a novel structure based on focusing of THz radiation in accelerating cell and stacking such cells to achieve a long-range interaction required for an efficient acceleration process. We present an example in which a 100 microJoule THz pulse produces a 600 keV energy gain in 5 mm long 10 cell accelerating structure for an ultra-relativistic electron. This design can be readily extended to non-relativistic particles. Such structure had been laser microfabricated and appropriate dimensions were achieved.

Poster MOPAB154 [1.283 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB154

About •

paper received ※ 27 May 2021 paper accepted ※ 05 July 2021 issue date ※ 14 August 2021

Export •

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

MOPAB155

Magnetic Breakdowns in Side-Coupled X-Band Accelerating Structures

540

S.P. Antipov, P.V. Avrakhov, S.V. Kuzikov
Euclid TechLabs, Solon, Ohio, USA
V.A. Dolgashev
SLAC, Menlo Park, California, USA
C. Jing
Euclid Beamlabs, Bolingbrook, USA

Funding: DOE SBIR
Side coupled accelerating structures are popular in the industrial realizations of linacs due to their high shunt impedance and ease of tuning. We designed and fabricated a side-coupled X-band accelerating structure that achieved 133 MOhm/m shut impedance. This structure was fabricated out of two halves using a novel brazeless approach. The two copper halves are joined together using a stainless steel joining piece with knife edges that bite into copper. This structure had been tested at high power at SLAC National Accelerator Laboratory. The performance of the structure had been limited by magnetic breakdowns on the side-coupling cells. In this paper we will present results of the high gradient tests and after-test analysis. Scanning electron microscopy images show a typical magnetic-field induced breakdown.

Poster MOPAB155 [1.069 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB155

About •

paper received ※ 20 May 2021 paper accepted ※ 23 June 2021 issue date ※ 01 September 2021

Export •

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

WEPAB163

An X-Band Ultra-High Gradient Photoinjector

2986

S.V. Kuzikov, S.P. Antipov, P.V. Avrakhov, E. Dosov, C.-J. Jing, E.W. Knight
Euclid TechLabs, Solon, Ohio, USA
G. Ha, C.-J. Jing, W. Liu, P. Piot, J.G. Power, D.S. Scott, J.H. Shao, E.E. Wisniewski
ANL, Lemont, Illinois, USA
C.-J. Jing
Euclid Beamlabs, Bolingbrook, USA
X. Lu
MIT/PSFC, Cambridge, Massachusetts, USA
X. Lu
SLAC, Menlo Park, California, USA
P. Piot
Fermilab, Batavia, Illinois, USA
P. Piot, W.H. Tan
Northern Illinois University, DeKalb, Illinois, USA
E.E. Wisniewski
IIT, Chicago, Illinois, USA

Funding: This work was supported by DoE SBIR grant # DE-SC0018709.
High brightness beams appealing for XFELs and UEM essentially imply a high current and a low emittance. To obtain such beams we propose to raise the accelerating voltage in the gun mitigating repealing Coulomb forces. An ultra-high gradient is achieved utilizing a short-pulse technology. We have designed a room temperature X-band 1,5 cell gun that is able to inject 4 MeV, 100 pC bunches with as low as 0.15 mcm normalized transverse emittance. The gun is operated with as high gradients as 400 MV/m and fed by 200 MW, 10 ns RF pulses generated with Argonne Wakefield Accelerator (AWA) power extractor. We report results of low RF power tests, laser alignment test results, and successful gun conditioning results carried out at nominal RF power.

Poster WEPAB163 [5.427 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB163

About •

paper received ※ 18 May 2021 paper accepted ※ 02 June 2021 issue date ※ 19 August 2021

Export •

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

WEPAB164

Electrodeless Diamond Beam Halo Monitor

2990

S.V. Kuzikov, S.P. Antipov, P.V. Avrakhov, E. Dosov, E.W. Knight, Y. Zhao
Euclid TechLabs, Solon, Ohio, USA
J.G. Power, J. Shao
ANL, Lemont, Illinois, USA

Funding: This work was supported by DoE SBIR grant # DE-SC0019642.
Beam halo measurement is important for novel x-ray free-electron lasers which have remarkably high repetition rate and average power. We propose diamond as a radiation hard material that can be used to measure the flux of passing particles based on a particle-induced conductivity effect. Our diamond electrodeless monitor is based on a microwave measurement of the change in the resonator coupling and eigenfrequency. For measurements, we put a sensitive diamond sample in a resonator that intercepts the halo. By measuring the change in RF properties of the resonator, one can infer the beam halo parameters scanning across the beam to map its transverse distribution. In recent experiments we used a Vertical Beam Test Stand (VBS), delivered DC electron beam of the 20-200 keV energy with the current up to 50 µA, to characterize several diamond samples. We have designed and fabricated a scanning diamond monitor, based on an X-band resonator, which was tested at Argonne Wakefield Accelerator (AWA) with a multi-MeV electron beam.

Poster WEPAB164 [5.138 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB164

About •

paper received ※ 14 May 2021 paper accepted ※ 07 June 2021 issue date ※ 31 August 2021

Export •

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

WEPAB165

Metamaterial Waveguide HOM Loads for SRF Accelerating Cavities

2994

S.V. Kuzikov
Euclid TechLabs, Solon, Ohio, USA

Suppression of beam induced HOMs is necessary for most SRF accelerating cavities driven with high currents. One of the problems in design of a HOM load is that vacuum compatible materials with high enough imaginary part of the dielectric permittivity, which provides absorption, have also a high real part of the permittivity. This does not allow absorbing RF radiation at short distance and in broad frequency band. We propose considering artificial metamaterials where besides lossy dielectric pieces, an absorber with high magnetic permeability is included. In our proposal, we suggest composing a waveguide HOM load of a metamaterial consisted of well-known ceramic and ferrite plates placed periodically in a stack. Such a design provides low return losses, compactness and broad frequency range of the operation.

Poster WEPAB165 [1.844 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB165

About •

paper received ※ 19 May 2021 paper accepted ※ 02 June 2021 issue date ※ 24 August 2021

Export •

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

THPAB129

Beam Dynamics Simulations in a High-Gradient X-Band Photoinjector

4013

W.H. Tan, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
G. Chen, S.V. Kuzikov
Euclid TechLabs, Solon, Ohio, USA
G. Chen
IIT, Chicago, Illinois, USA
G. Ha, C.-J. Jing
ANL, Lemont, Illinois, USA
C.-J. Jing
Euclid Beamlabs, Bolingbrook, USA

A high-gradient X-band (11.7-GHz) photoinjector was recently developed by Euclid Techlabs and is in its commissioning phase at the Argonne Wakefield Accelerator (AWA). This contribution discuss the beam-dynamics modeling of the photoinjector system comprising an RF gun and linac section. We especially discuss beam-dynamics optimization of setup for an integrated proof-of-principle experiments. We also discuss the use of such a photoinjector as a witness-bunch source for a future high-gradient collinear-wakefield accelerator experiments at the AWA.
* S. V. Kuzikov, et al. these proceedings.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB129

About •

paper received ※ 20 May 2021 paper accepted ※ 14 July 2021 issue date ※ 31 August 2021

Export •

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

THPAB331

High-Power Test of a Highly Over-Coupled X-Band RF Gun Driven by Short RF Pulses

4432

J.H. Shao, D.S. Doran, W. Liu, J.G. Power, C. Whiteford, E.E. Wisniewski
ANL, Lemont, Illinois, USA
C.-J. Jing, S.V. Kuzikov
Euclid TechLabs, Solon, Ohio, USA
X. Lu, P. Piot, W.H. Tan
Northern Illinois University, DeKalb, Illinois, USA

Beam brightness, a key figure of merit of RF photocathode guns, can be improved by increasing the cathode surface field which suppresses emittance growth from space charge. The surface field in normal-conducting structures is mainly limited by RF breakdown and it has been experimentally discovered that RF breakdown rate exponentially depends on RF pulse length. A highly over-coupled 1.5-cell X-band photocathode gun has been developed to be powered by 9 ns RF pulses with 3 ns rising time, 3 ns flat-top, and 3 ns falling time generated by an X-band metallic power extractor. In the recent experiment at Argonne Wakefield Accelerator facility, cathode surface field up to ~350 MV/m with a low breakdown rate has been obtained under ~250 MW input power. Strong beam loading from dark current was observed during RF conditioning and quickly recovered to a negligible level after the gun reached the maximum gradient. Detailed high-power test results and data analysis will be reported in this manuscript.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB331

About •

paper received ※ 25 May 2021 paper accepted ※ 14 July 2021 issue date ※ 23 August 2021

Export •

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