NAPAC2022 - List of Authors (Doran, D.S.)

Paper	Title	Page
MOZE3	Emittance Measurements and Simulations from an X-Band Short-Pulse Ultra-High Gradient Photoinjector	45
	G. Chen, D.S. Doran, C.-J. Jing, S.Y. Kim, W. Liu, W. Liu, P. Piot, J.G. Power, C. Whiteford, E.E. Wisniewski ANL, Lemont, Illinois, USA C.-J. Jing, E.W. Knight, S.V. Kuzikov Euclid TechLabs, Solon, Ohio, USA C.-J. Jing Euclid Beamlabs, Bolingbrook, USA X. Lu, P. Piot, W.H. Tan Northern Illinois University, DeKalb, Illinois, USA
	Funding: This work is supported by the U.S. DOE, under award No. DE-SC0018656 to NIU, DOE SBIR grant No. DE-SC0018709 to Euclid Techlabs LLC, and contract No. DE-AC02-06CH11357 with ANL. A program is under way at the Argonne Wakefield Accelerator facility, in collaboration with the Euclid Techlabs and Northern Illinois University (NIU), to develop a GeV/m scale photocathode gun, with the ultimate goal of demonstrating a high-brightness photoinjector beamline. The novel X-band photoemission gun (Xgun) is powered by high-power, short RF pulses, 9-ns (FWHM), which, in turn, are generated by the AWA drive beam. In a previous proof-of-principle experiment, an unprecedented 400~MV/m gradient on the photocathode surface* was demonstrated. In the current version of the experiment, we added a linac to the beamline to increase the total energy and gain experience tuning the beamline. In this paper, we report on the very first result of emittance measurement as well as several other beam parameters. This preliminary investigation has identified several factors to be improved on in order to achieve one of the ultimate goals; low emittance. * W. H. Tan et al., "Demonstration of sub-GV/m Accelerating Field in a Photoemission Electron Gun Powered by Nanosecond X-Band Radiofrequency Pulses", 2022. arXiv:2203.11598v1
	Slides MOZE3 [5.565 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOZE3
About •	Received ※ 03 August 2022 — Revised ※ 05 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 14 August 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOZE5	Simulation and Experimental Results of Dielectric Disk Accelerating Structures	52
	S. Weatherly, E.E. Wisniewski Illinois Institute of Technology, Chicago, Illinois, USA D.S. Doran, C.-J. Jing, J.F. Power, E.E. Wisniewski ANL, Lemont, Illinois, USA B.T. Freemire, C.-J. Jing Euclid Beamlabs, Bolingbrook, USA
	Funding: Contract DE-SC0019864 to Euclid Beamlabs LLC. AWA work from U.S. DOE Office of Science under Contract DE-AC02-06CH11357. Chicagoland Accelerator Science Traineeship U.S. DOE award number DE-SC-0020379 A method of decreasing the required footprint of linear accelerators and improving their energy efficiency is to employ Dielectric Disk Accelerators (DDAs) with short RF pulses ( ∼ 9 ns). A DDA is an accelerating structure that utilizes dielectric disks to improve the shunt impedance. Two DDA structures have been designed and tested at the Argonne Wakefield Accelerator. A single cell clamped DDA structure recently achieved an accelerating gradient of 1{02} MV/m. A multi-cell clamped DDA structure has been designed and is being fabricated. Simulation results for this new structure show a 1{08} MV/m accelerating gradient with 400 MW of input power with a high shunt impedance and group velocity. The engineering design has been improved from the single cell structure to ensure consistent clamping over the entire structure.
	Slides MOZE5 [9.338 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOZE5
About •	Received ※ 02 August 2022 — Revised ※ 08 August 2022 — Accepted ※ 21 August 2022 — Issue date ※ 06 October 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPA72	Preliminary Tests and Beam Dynamics Simulations of a Straight-Merger Beamline	206
	A.A. Al Marzouk, P. Piot, T. Xu Northern Illinois University, DeKalb, Illinois, USA S.V. Benson, K.E. Deitrick, J. Guo, A. Hutton, G.-T. Park, S. Wang JLab, Newport News, Virginia, USA D.S. Doran, G. Ha, P. Piot, J.G. Power, C. Whiteford, E.E. Wisniewski ANL, Lemont, Illinois, USA C.E. Mitchell, J. Qiang, R.D. Ryne LBNL, Berkeley, California, USA
	Funding: NSF award PHY-1549132 to Cornell University and NIU, U.S. DOE contract DE-AC02-06CH11357 with ANL and DE-AC05-06OR23177 with JLAB. Beamlines capable of merging beams with different energies are critical to many applications related to advanced accelerator concepts and energy-recovery linacs (ERLs). In an ERL, a low-energy "fresh" bright bunch is generally injected into a superconducting linac for acceleration using the fields established by a decelerated "spent" beam traveling on the same axis. A straight-merger system composed of a selecting cavity with a superimposed dipole magnet was proposed and recently test at AWA. This paper reports on the experimental results obtained so far along with detailed beam dynamics investigations of the merger concept and its ability to conserve the beam brightness associated with the fresh bunch.
	Poster MOPA72 [1.659 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA72
About •	Received ※ 11 August 2022 — Accepted ※ 13 August 2022 — Issue date ※ 02 October 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPA74	Design of a W-Band Corrugated Waveguide for Structure Wakefield Acceleration	210
	B. Leung, X. Lu, C.L. Phillips, P. Piot Northern Illinois University, DeKalb, Illinois, USA D.S. Doran, X. Lu, P. Piot, J.G. Power ANL, Lemont, Illinois, USA
	Current research on structure wakefield acceleration aims to develop radio-frequency structures that can produce high gradients, with work in the sub-terahertz regime being particularly interesting because of the potential to create more compact and economical accelerators. Metallic corrugated waveguides at sub-terahertz frequencies are one such structure. We have designed a W-band corrugated waveguide for a collinear wakefield acceleration experiment at the Argonne Wakefield Accelerator (AWA). Using the CST Studio Suite, we have optimized the structure for the maximum achievable gradient in the wakefield from a nominal AWA electron bunch at 65 MeV. Simulation results from different solvers of CST were benchmarked with each other, with analytical models, and with another simulation code, ECHO. We are investigating the mechanical design, suitable fabrication technologies, and the possibility to apply advanced bunch shaping techniques to improve the structure performance.
	Poster MOPA74 [1.518 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA74
About •	Received ※ 30 July 2022 — Revised ※ 03 August 2022 — Accepted ※ 07 August 2022 — Issue date ※ 26 August 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPA28	Update on the Development of a Low-Cost Button BPM Signal Detector at AWA	409
	W. Liu, G. Chen, D.S. Doran, S.Y. Kim, X. Lu, P. Piot, J.G. Power, C. Whiteford, E.E. Wisniewski ANL, Lemont, Illinois, USA E.E. Wisniewski IIT, Chicago, Illinois, USA
	Funding: Work supported by the US Department of Energy, Office of Science. A single-pulse, high dynamic range, cost-effective BPM signal detector has been on the most wanted list of the Argonne Wakefield Accelerator (AWA) Test Facility for many years. The unique capabilities of the AWA beamline require BPM instrumentation with an unprecedented dynamic range, thus a cost-effective solution could be challenging to design and prototype. With the help of a better circuit model for a button BPM signal source, we are able to do the circuit simulations with more realistic input signals and make predictions much closer to realities. Our most recent design and prototype results are shared in this paper.
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA28
About •	Received ※ 01 August 2022 — Revised ※ 08 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 09 October 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPA82	Transverse Stability in an Alternating Symmetry Planar Dielectric Wakefield Structure	519
	W.J. Lynn, G. Andonian, N. Majernik, S.M. OTool, J.B. Rosenzweig UCLA, Los Angeles, California, USA D.S. Doran, S.Y. Kim, J.F. Power, E.E. Wisniewski ANL, Lemont, Illinois, USA P. Piot Northern Illinois University, DeKalb, Illinois, USA
	Funding: DE-SC0017648 - AWA. Dielectric Wakefield Acceleration (DWA) is a promising technique for realizing the next generation of linear colliders. It provides access to significantly higher accelerating gradients than traditional radio-frequency cavities. One impediment to realizing a DWA-powered accelerator is the issue of the transverse stability of the beams within the dielectric structure due to short-range wakefields. These short-range wakefields have a tendency to induce a phenomenon known as single-bunch beam breakup, which acts as its name implies and destroys the relevant beam. We attempt to solve this issue by leveraging the quadrupole mode excited in a planar dielectric structure and then alternating the orientation of said structure to turn an unstable system into a stable one. We examine this issue computationally to determine the limits of stability and based on those simulations describe a future experimental realization of this strategy.
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA82
About •	Received ※ 02 August 2022 — Revised ※ 11 August 2022 — Accepted ※ 12 August 2022 — Issue date ※ 30 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPA85	First Results from a Multileaf Collimator and Emittance Exchange Beamline	531
	N. Majernik, G. Andonian, C.D. Lorch, W.J. Lynn, J.B. Rosenzweig UCLA, Los Angeles, California, USA D.S. Doran, S.Y. Kim, P. Piot, J.G. Power, C. Whiteford, E.E. Wisniewski ANL, Lemont, Illinois, USA
	Funding: Department of Energy DE-SC0017648 and National Science Foundation PHY-1549132. By shaping the transverse profile of a particle beam prior to an emittance exchange (EEX) beamline, drive and witness beams with variable current profiles and bunch spacing can be produced. Presently at AWA, this transverse shaping is accomplished with individually laser-cut tungsten masks, making the refinement of beam profiles a slow process. In contrast, a multileaf collimator (MLC) is a device that can selectively mask the profile of a beam using many independently actuated leaves. Since an MLC permits real-time adjustment of the beam shape, its use as a beam mask would permit much faster optimization in a manner highly synergistic with machine learning. Beam dynamics simulations have shown that such an approach is functionally equivalent to that offered by the laser cut masks. In this work, the construction and first results from a 40-leaf, UHV compatible MLC are discussed.
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA85
About •	Received ※ 16 July 2022 — Revised ※ 02 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 12 August 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEXD5	Benchmarking Simulation for AWA Drive Linac and Emittance Exchange Beamline Using OPAL, GPT, and Impact-T	552
	S.Y. Kim, G. Chen, D.S. Doran, G. Ha, W. Liu, J.G. Power, E.E. Wisniewski ANL, Lemont, Illinois, USA E.A. Frame, P. Piot Northern Illinois University, DeKalb, Illinois, USA
	At the Argonne Wakefield Accelerator (AWA) facility, particle-tracking simulations have been critical to guiding beam-dynamic experiments, e.g., for various beam manipulations using an available emittance-exchange beamline (EEX). The unique beamline available at AWA provide a test case to perform in-depth comparison between different particle-tracking programs including collective effects such as space-charge force and coherent synchrotron radiation. In this study, using AWA electron injector and emittance exchange beamline, we compare the simulations results obtained by GPT, OPAL, and Impact-T beam-dynamics programs. We will specifically report on convergence test as a function of parameters that controls the underlying algorithms.
	Slides WEXD5 [1.847 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEXD5
About •	Received ※ 03 August 2022 — Revised ※ 06 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 22 August 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEYD4	Design and Fabrication of a Metamaterial Wakefield Accelerating Structure	564
	D.C. Merenich, X. Lu Northern Illinois University, DeKalb, Illinois, USA D.S. Doran, X. Lu, J.G. Power ANL, Lemont, Illinois, USA
	Metamaterials (MTMs) are engineered materials that can show exotic electromagnetic properties such as simultaneously negative permittivity and permeability. MTMs are promising candidates for structure-based wakefield acceleration structures, which can mitigate the impact of radio frequency (RF) breakdown, thus achieving a high gradient. Previous experiments carried out at the Argonne Wakefield Accelerator (AWA) successfully demonstrated MTM structures as efficient power extraction and transfer structures (PETS) from a high-charge drive beam. Here we present the design, fabrication, and cold test of an X-band MTM accelerator structure for acceleration of the witness beam in the two-beam acceleration scheme. The MTM structure design was performed using the CST Studio Suite, with the unit cell and the complete multi-cell periodic structure both optimized for high gradient. Cold test of the fabricated structure shows good agreement with simulation results. Future work includes a beam test at AWA to study the short-pulse RF breakdown physics in the MTM structure, as an important component towards a future compact linear collider based on two-beam acceleration.
	Slides WEYD4 [2.322 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEYD4
About •	Received ※ 03 August 2022 — Revised ※ 09 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 31 August 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THZE3	An Electrodeless Diamond Beam Monitor	904
	S.V. Kuzikov, P.V. Avrakhov, C.-J. Jing, E.W. Knight Euclid TechLabs, Solon, Ohio, USA D.S. Doran, C.-J. Jing, J.G. Power, E.E. Wisniewski ANL, Lemont, Illinois, USA C.-J. Jing Euclid Beamlabs, Bolingbrook, USA
	Funding: The work was supported by DoE SBIR grant #DE-SC0019642. Being a wide-band semiconductor, diamond can be used to measure the flux of passing particles based on a particle-induced conductivity effect. We recently demonstrated a diamond electrodeless electron beam halo monitor. That monitor was based on a thin piece of diamond (blade) placed in an open high-quality microwave resonator. The blade partially intercepted the beam. By measuring the change in RF properties of the resonator, one could infer the beam parameters. At Argonne Wakefield Accelerator we have tested 1D and 2D monitors. To enhance the sensitivity of our diamond sensor, we proposed applying a bias voltage to the diamond which can sustain the avalanche of free carriers. In experiment carried out with 120 kV, ~1 µA beam we showed that the response signal for the avalanche monitor biased with up to 5 kV voltage can be up to 100 times larger in comparison with the signal of the same non-biased device.
	Slides THZE3 [4.257 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-THZE3
About •	Received ※ 20 July 2022 — Revised ※ 28 July 2022 — Accepted ※ 06 August 2022 — Issue date ※ 08 August 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Emittance Measurements and Simulations from an X-Band Short-Pulse Ultra-High Gradient Photoinjector

45

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

Funding: This work is supported by the U.S. DOE, under award No. DE-SC0018656 to NIU, DOE SBIR grant No. DE-SC0018709 to Euclid Techlabs LLC, and contract No. DE-AC02-06CH11357 with ANL.
A program is under way at the Argonne Wakefield Accelerator facility, in collaboration with the Euclid Techlabs and Northern Illinois University (NIU), to develop a GeV/m scale photocathode gun, with the ultimate goal of demonstrating a high-brightness photoinjector beamline. The novel X-band photoemission gun (Xgun) is powered by high-power, short RF pulses, 9-ns (FWHM), which, in turn, are generated by the AWA drive beam. In a previous proof-of-principle experiment, an unprecedented 400~MV/m gradient on the photocathode surface* was demonstrated. In the current version of the experiment, we added a linac to the beamline to increase the total energy and gain experience tuning the beamline. In this paper, we report on the very first result of emittance measurement as well as several other beam parameters. This preliminary investigation has identified several factors to be improved on in order to achieve one of the ultimate goals; low emittance.
* W. H. Tan et al., "Demonstration of sub-GV/m Accelerating Field in a Photoemission Electron Gun Powered by Nanosecond X-Band Radiofrequency Pulses", 2022. arXiv:2203.11598v1

Slides MOZE3 [5.565 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOZE3

About •

Received ※ 03 August 2022 — Revised ※ 05 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 14 August 2022

Cite •

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

MOZE5

Simulation and Experimental Results of Dielectric Disk Accelerating Structures

52

S. Weatherly, E.E. Wisniewski
Illinois Institute of Technology, Chicago, Illinois, USA
D.S. Doran, C.-J. Jing, J.F. Power, E.E. Wisniewski
ANL, Lemont, Illinois, USA
B.T. Freemire, C.-J. Jing
Euclid Beamlabs, Bolingbrook, USA

Funding: Contract DE-SC0019864 to Euclid Beamlabs LLC. AWA work from U.S. DOE Office of Science under Contract DE-AC02-06CH11357. Chicagoland Accelerator Science Traineeship U.S. DOE award number DE-SC-0020379
A method of decreasing the required footprint of linear accelerators and improving their energy efficiency is to employ Dielectric Disk Accelerators (DDAs) with short RF pulses ( ∼ 9 ns). A DDA is an accelerating structure that utilizes dielectric disks to improve the shunt impedance. Two DDA structures have been designed and tested at the Argonne Wakefield Accelerator. A single cell clamped DDA structure recently achieved an accelerating gradient of 1{02} MV/m. A multi-cell clamped DDA structure has been designed and is being fabricated. Simulation results for this new structure show a 1{08} MV/m accelerating gradient with 400 MW of input power with a high shunt impedance and group velocity. The engineering design has been improved from the single cell structure to ensure consistent clamping over the entire structure.

Slides MOZE5 [9.338 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOZE5

About •

Received ※ 02 August 2022 — Revised ※ 08 August 2022 — Accepted ※ 21 August 2022 — Issue date ※ 06 October 2022

Cite •

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

MOPA72

Preliminary Tests and Beam Dynamics Simulations of a Straight-Merger Beamline

206

A.A. Al Marzouk, P. Piot, T. Xu
Northern Illinois University, DeKalb, Illinois, USA
S.V. Benson, K.E. Deitrick, J. Guo, A. Hutton, G.-T. Park, S. Wang
JLab, Newport News, Virginia, USA
D.S. Doran, G. Ha, P. Piot, J.G. Power, C. Whiteford, E.E. Wisniewski
ANL, Lemont, Illinois, USA
C.E. Mitchell, J. Qiang, R.D. Ryne
LBNL, Berkeley, California, USA

Funding: NSF award PHY-1549132 to Cornell University and NIU, U.S. DOE contract DE-AC02-06CH11357 with ANL and DE-AC05-06OR23177 with JLAB.
Beamlines capable of merging beams with different energies are critical to many applications related to advanced accelerator concepts and energy-recovery linacs (ERLs). In an ERL, a low-energy "fresh" bright bunch is generally injected into a superconducting linac for acceleration using the fields established by a decelerated "spent" beam traveling on the same axis. A straight-merger system composed of a selecting cavity with a superimposed dipole magnet was proposed and recently test at AWA. This paper reports on the experimental results obtained so far along with detailed beam dynamics investigations of the merger concept and its ability to conserve the beam brightness associated with the fresh bunch.

Poster MOPA72 [1.659 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA72

About •

Received ※ 11 August 2022 — Accepted ※ 13 August 2022 — Issue date ※ 02 October 2022

Cite •

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

MOPA74

Design of a W-Band Corrugated Waveguide for Structure Wakefield Acceleration

210

B. Leung, X. Lu, C.L. Phillips, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
D.S. Doran, X. Lu, P. Piot, J.G. Power
ANL, Lemont, Illinois, USA

Current research on structure wakefield acceleration aims to develop radio-frequency structures that can produce high gradients, with work in the sub-terahertz regime being particularly interesting because of the potential to create more compact and economical accelerators. Metallic corrugated waveguides at sub-terahertz frequencies are one such structure. We have designed a W-band corrugated waveguide for a collinear wakefield acceleration experiment at the Argonne Wakefield Accelerator (AWA). Using the CST Studio Suite, we have optimized the structure for the maximum achievable gradient in the wakefield from a nominal AWA electron bunch at 65 MeV. Simulation results from different solvers of CST were benchmarked with each other, with analytical models, and with another simulation code, ECHO. We are investigating the mechanical design, suitable fabrication technologies, and the possibility to apply advanced bunch shaping techniques to improve the structure performance.

Poster MOPA74 [1.518 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA74

About •

Received ※ 30 July 2022 — Revised ※ 03 August 2022 — Accepted ※ 07 August 2022 — Issue date ※ 26 August 2022

Cite •

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

TUPA28

Update on the Development of a Low-Cost Button BPM Signal Detector at AWA

409

W. Liu, G. Chen, D.S. Doran, S.Y. Kim, X. Lu, P. Piot, J.G. Power, C. Whiteford, E.E. Wisniewski
ANL, Lemont, Illinois, USA
E.E. Wisniewski
IIT, Chicago, Illinois, USA

Funding: Work supported by the US Department of Energy, Office of Science.
A single-pulse, high dynamic range, cost-effective BPM signal detector has been on the most wanted list of the Argonne Wakefield Accelerator (AWA) Test Facility for many years. The unique capabilities of the AWA beamline require BPM instrumentation with an unprecedented dynamic range, thus a cost-effective solution could be challenging to design and prototype. With the help of a better circuit model for a button BPM signal source, we are able to do the circuit simulations with more realistic input signals and make predictions much closer to realities. Our most recent design and prototype results are shared in this paper.

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA28

About •

Received ※ 01 August 2022 — Revised ※ 08 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 09 October 2022

Cite •

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

TUPA82

Transverse Stability in an Alternating Symmetry Planar Dielectric Wakefield Structure

519

W.J. Lynn, G. Andonian, N. Majernik, S.M. OTool, J.B. Rosenzweig
UCLA, Los Angeles, California, USA
D.S. Doran, S.Y. Kim, J.F. Power, E.E. Wisniewski
ANL, Lemont, Illinois, USA
P. Piot
Northern Illinois University, DeKalb, Illinois, USA

Funding: DE-SC0017648 - AWA.
Dielectric Wakefield Acceleration (DWA) is a promising technique for realizing the next generation of linear colliders. It provides access to significantly higher accelerating gradients than traditional radio-frequency cavities. One impediment to realizing a DWA-powered accelerator is the issue of the transverse stability of the beams within the dielectric structure due to short-range wakefields. These short-range wakefields have a tendency to induce a phenomenon known as single-bunch beam breakup, which acts as its name implies and destroys the relevant beam. We attempt to solve this issue by leveraging the quadrupole mode excited in a planar dielectric structure and then alternating the orientation of said structure to turn an unstable system into a stable one. We examine this issue computationally to determine the limits of stability and based on those simulations describe a future experimental realization of this strategy.

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA82

About •

Received ※ 02 August 2022 — Revised ※ 11 August 2022 — Accepted ※ 12 August 2022 — Issue date ※ 30 September 2022

Cite •

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

TUPA85

First Results from a Multileaf Collimator and Emittance Exchange Beamline

531

N. Majernik, G. Andonian, C.D. Lorch, W.J. Lynn, J.B. Rosenzweig
UCLA, Los Angeles, California, USA
D.S. Doran, S.Y. Kim, P. Piot, J.G. Power, C. Whiteford, E.E. Wisniewski
ANL, Lemont, Illinois, USA

Funding: Department of Energy DE-SC0017648 and National Science Foundation PHY-1549132.
By shaping the transverse profile of a particle beam prior to an emittance exchange (EEX) beamline, drive and witness beams with variable current profiles and bunch spacing can be produced. Presently at AWA, this transverse shaping is accomplished with individually laser-cut tungsten masks, making the refinement of beam profiles a slow process. In contrast, a multileaf collimator (MLC) is a device that can selectively mask the profile of a beam using many independently actuated leaves. Since an MLC permits real-time adjustment of the beam shape, its use as a beam mask would permit much faster optimization in a manner highly synergistic with machine learning. Beam dynamics simulations have shown that such an approach is functionally equivalent to that offered by the laser cut masks. In this work, the construction and first results from a 40-leaf, UHV compatible MLC are discussed.

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA85

About •

Received ※ 16 July 2022 — Revised ※ 02 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 12 August 2022

Cite •

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

WEXD5

Benchmarking Simulation for AWA Drive Linac and Emittance Exchange Beamline Using OPAL, GPT, and Impact-T

552

S.Y. Kim, G. Chen, D.S. Doran, G. Ha, W. Liu, J.G. Power, E.E. Wisniewski
ANL, Lemont, Illinois, USA
E.A. Frame, P. Piot
Northern Illinois University, DeKalb, Illinois, USA

At the Argonne Wakefield Accelerator (AWA) facility, particle-tracking simulations have been critical to guiding beam-dynamic experiments, e.g., for various beam manipulations using an available emittance-exchange beamline (EEX). The unique beamline available at AWA provide a test case to perform in-depth comparison between different particle-tracking programs including collective effects such as space-charge force and coherent synchrotron radiation. In this study, using AWA electron injector and emittance exchange beamline, we compare the simulations results obtained by GPT, OPAL, and Impact-T beam-dynamics programs. We will specifically report on convergence test as a function of parameters that controls the underlying algorithms.

Slides WEXD5 [1.847 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEXD5

About •

Received ※ 03 August 2022 — Revised ※ 06 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 22 August 2022

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

WEYD4

Design and Fabrication of a Metamaterial Wakefield Accelerating Structure

564

D.C. Merenich, X. Lu
Northern Illinois University, DeKalb, Illinois, USA
D.S. Doran, X. Lu, J.G. Power
ANL, Lemont, Illinois, USA

Metamaterials (MTMs) are engineered materials that can show exotic electromagnetic properties such as simultaneously negative permittivity and permeability. MTMs are promising candidates for structure-based wakefield acceleration structures, which can mitigate the impact of radio frequency (RF) breakdown, thus achieving a high gradient. Previous experiments carried out at the Argonne Wakefield Accelerator (AWA) successfully demonstrated MTM structures as efficient power extraction and transfer structures (PETS) from a high-charge drive beam. Here we present the design, fabrication, and cold test of an X-band MTM accelerator structure for acceleration of the witness beam in the two-beam acceleration scheme. The MTM structure design was performed using the CST Studio Suite, with the unit cell and the complete multi-cell periodic structure both optimized for high gradient. Cold test of the fabricated structure shows good agreement with simulation results. Future work includes a beam test at AWA to study the short-pulse RF breakdown physics in the MTM structure, as an important component towards a future compact linear collider based on two-beam acceleration.

Slides WEYD4 [2.322 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEYD4

About •

Received ※ 03 August 2022 — Revised ※ 09 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 31 August 2022

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THZE3

An Electrodeless Diamond Beam Monitor

904

S.V. Kuzikov, P.V. Avrakhov, C.-J. Jing, E.W. Knight
Euclid TechLabs, Solon, Ohio, USA
D.S. Doran, C.-J. Jing, J.G. Power, E.E. Wisniewski
ANL, Lemont, Illinois, USA
C.-J. Jing
Euclid Beamlabs, Bolingbrook, USA

Funding: The work was supported by DoE SBIR grant #DE-SC0019642.
Being a wide-band semiconductor, diamond can be used to measure the flux of passing particles based on a particle-induced conductivity effect. We recently demonstrated a diamond electrodeless electron beam halo monitor. That monitor was based on a thin piece of diamond (blade) placed in an open high-quality microwave resonator. The blade partially intercepted the beam. By measuring the change in RF properties of the resonator, one could infer the beam parameters. At Argonne Wakefield Accelerator we have tested 1D and 2D monitors. To enhance the sensitivity of our diamond sensor, we proposed applying a bias voltage to the diamond which can sustain the avalanche of free carriers. In experiment carried out with 120 kV, ~1 µA beam we showed that the response signal for the avalanche monitor biased with up to 5 kV voltage can be up to 100 times larger in comparison with the signal of the same non-biased device.

Slides THZE3 [4.257 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-THZE3

About •

Received ※ 20 July 2022 — Revised ※ 28 July 2022 — Accepted ※ 06 August 2022 — Issue date ※ 08 August 2022

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