IPAC2012 - List of Authors (Church, M.D.)

Paper

Title

Page

Status and Plans for a Superconducting RF Accelerator Test Facility at Fermilab

58

J.R. Leibfritz, R. Andrews, C.M. Baffes, K. Carlson, B. Chase, M.D. Church, E.R. Harms, A.L. Klebaner, M.J. Kucera, A. Martinez, S. Nagaitsev, L.E. Nobrega, J. Reid, M. Wendt, S.J. Wesseln
Fermilab, Batavia, USA
P. Piot
Northern Illinois University, DeKalb, Illinois, USA

Funding: Operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy.
The Advanced Superconducting Test Acccelerator (ASTA) is being constructed at Fermilab. The existing New Muon Lab (NML) building is being converted for this facility. The accelerator will consist of an electron gun, injector, beam acceleration section consisting of 3 TTF-type or ILC-type cryomodules, multiple downstream beamlines for testing diagnostics and conducting various beam tests, and a high power beam dump. When completed, it is envisioned that this facility will initially be capable of generating a 750 MeV electron beam with ILC beam intensity. An expansion of this facility was recently completed that will provide the capability to upgrade the accelerator to a total beam energy of 1.5 GeV. Two new buildings were also constructed adjacent to the ASTA facility to house a new cryogenic plant and multiple superconducting RF (SRF) cryomodule test stands. In addition to testing accelerator components, this facility will be used to test RF power systems, instrumentation, and control systems for future SRF accelerators such as the ILC and Project-X. This paper describes the current status and overall plans for this facility.

Slides MOOAC02 [13.423 MB]

TUPPC045

Modeling Investigation on a Deflecting-Accelerating Composite RF-cavity System for Phase Space Beam Control

1266

Y.-M. Shin, M.D. Church, P. Piot
Fermilab, Batavia, USA

Phase space manipulations between the longitudinal and transverse degree of freedoms hold great promise toward the precise control of electron beams. Such transverse-to-longitudinal phase space exchange have been shown to be capable of exchanging the transverse and horizontal emittance or controlling the charge distribution of an electron bunch, for beam-driven advanced accelerator methods. The main limitation impinging on the performance of this exchange mechanism stems from the external coupling nature of a realistic deflecting cavity, compared to a thin-lens model. As an extended idea from *, this paper presents the design of a composite 3.9-GHz RF-system consisting of a deflecting- and accelerating-mode cavities. The system design analysis is discussed with particle-in-cell (PIC) simulations of the device performance.
* A. Zholents, PAC'11.

WEPPD034

Mechanical Design of a High Energy Beam Absorber for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab

2582

C.M. Baffes, M.D. Church, J.R. Leibfritz, S.A. Oplt, I.L. Rakhno
Fermilab, Batavia, USA

Funding: Operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02-07CH11359 with the United States Department of Energy
A high energy beam absorber has been built for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab. In the facility’s initial configuration, an electron beam will be accelerated through 3 TTF-type or ILC-type RF cryomodules to an energy of 750MeV. The electron beam will be directed to one of multiple downstream experimental and diagnostic beam lines and then deposited in one of two beam absorbers. The facility is designed to accommodate up to 6 cryomodules, which would produce a 75kW beam at 1.5GeV; this is the driving design condition for the beam absorbers. The beam absorbers consist of water-cooled graphite, aluminum and copper layers contained in a Helium-filled enclosure. This paper describes the mechanical implementation of the beam absorbers, with a focus on thermal design and analysis. In addition, the potential for radiation-induced degradation of the graphite is discussed.

WEPPR033

Performance of Low-Energy Magnetic Bunch Compression for the ASTA Photoinjector at Fermilab

3006

C.R. Prokop, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
B.E. Carlsten
LANL, Los Alamos, New Mexico, USA
M.D. Church
Fermilab, Batavia, USA

Funding: LANL LDRD program, project 20110067DR -U.S. DOE Contract No. DE-FG02-08ER41532 and DE-AC02-07CH11359.
The Advanced Superconducting Test Accelerator (ASTA) at Fermilab incorporates a magnetic bunch compressor chicane to compress the 40-MeV electron bunches generated in the photoinjector. In this paper, we present a numerical analysis and parametric study of the bunch compressor's performance for various operating scenarios. The beam dynamics simulations, carried out with Astra, Impact-Z and CSRTrack, are compared against each other. Finally, an operating regime with low phase space dilutions is suggested based on the simulation results.

WEPPR034

Longitudinal Phase Space Measurement for the Advanced Superconducting Test Accelerator Photoinjector

3009

C.R. Prokop, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
M.D. Church, Y.-E. Sun
Fermilab, Batavia, USA

Funding: LANL LDRD program, project 20110067DR -U.S. DOE Contract No. DE-FG02-08ER41532 and DE-AC02-07CH11359.
The Advanced Superconducting Test Accelerator (ASTA) at Fermilab uses a high-brightness photoinjector capable of producing electron bunches with charges up to 3.2 nC, to be used in support of a variety of advanced accelerator R&D experiments. The photoinjector incorporates an extensive diagnostics suites including a single-shot longitudinal-phase-space diagnostics composed of a horizontally deflecting cavity followed by a vertical spectrometer. In this paper, we present the design, optimization, and performance analysis (including detrimental collective effects) of the longitudinal phase space diagnostics and especially compare two possible choices of deflecting cavity frequencies.

Paper	Title	Page
MOOAC02	Status and Plans for a Superconducting RF Accelerator Test Facility at Fermilab	58
	J.R. Leibfritz, R. Andrews, C.M. Baffes, K. Carlson, B. Chase, M.D. Church, E.R. Harms, A.L. Klebaner, M.J. Kucera, A. Martinez, S. Nagaitsev, L.E. Nobrega, J. Reid, M. Wendt, S.J. Wesseln Fermilab, Batavia, USA P. Piot Northern Illinois University, DeKalb, Illinois, USA
	Funding: Operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy. The Advanced Superconducting Test Acccelerator (ASTA) is being constructed at Fermilab. The existing New Muon Lab (NML) building is being converted for this facility. The accelerator will consist of an electron gun, injector, beam acceleration section consisting of 3 TTF-type or ILC-type cryomodules, multiple downstream beamlines for testing diagnostics and conducting various beam tests, and a high power beam dump. When completed, it is envisioned that this facility will initially be capable of generating a 750 MeV electron beam with ILC beam intensity. An expansion of this facility was recently completed that will provide the capability to upgrade the accelerator to a total beam energy of 1.5 GeV. Two new buildings were also constructed adjacent to the ASTA facility to house a new cryogenic plant and multiple superconducting RF (SRF) cryomodule test stands. In addition to testing accelerator components, this facility will be used to test RF power systems, instrumentation, and control systems for future SRF accelerators such as the ILC and Project-X. This paper describes the current status and overall plans for this facility.
	Slides MOOAC02 [13.423 MB]

TUPPC045	Modeling Investigation on a Deflecting-Accelerating Composite RF-cavity System for Phase Space Beam Control	1266
	Y.-M. Shin, M.D. Church, P. Piot Fermilab, Batavia, USA
	Phase space manipulations between the longitudinal and transverse degree of freedoms hold great promise toward the precise control of electron beams. Such transverse-to-longitudinal phase space exchange have been shown to be capable of exchanging the transverse and horizontal emittance or controlling the charge distribution of an electron bunch, for beam-driven advanced accelerator methods. The main limitation impinging on the performance of this exchange mechanism stems from the external coupling nature of a realistic deflecting cavity, compared to a thin-lens model. As an extended idea from , this paper presents the design of a composite 3.9-GHz RF-system consisting of a deflecting- and accelerating-mode cavities. The system design analysis is discussed with particle-in-cell (PIC) simulations of the device performance. A. Zholents, PAC'11.

WEPPD034	Mechanical Design of a High Energy Beam Absorber for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab	2582
	C.M. Baffes, M.D. Church, J.R. Leibfritz, S.A. Oplt, I.L. Rakhno Fermilab, Batavia, USA
	Funding: Operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02-07CH11359 with the United States Department of Energy A high energy beam absorber has been built for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab. In the facility’s initial configuration, an electron beam will be accelerated through 3 TTF-type or ILC-type RF cryomodules to an energy of 750MeV. The electron beam will be directed to one of multiple downstream experimental and diagnostic beam lines and then deposited in one of two beam absorbers. The facility is designed to accommodate up to 6 cryomodules, which would produce a 75kW beam at 1.5GeV; this is the driving design condition for the beam absorbers. The beam absorbers consist of water-cooled graphite, aluminum and copper layers contained in a Helium-filled enclosure. This paper describes the mechanical implementation of the beam absorbers, with a focus on thermal design and analysis. In addition, the potential for radiation-induced degradation of the graphite is discussed.

WEPPR033	Performance of Low-Energy Magnetic Bunch Compression for the ASTA Photoinjector at Fermilab	3006
	C.R. Prokop, P. Piot Northern Illinois University, DeKalb, Illinois, USA B.E. Carlsten LANL, Los Alamos, New Mexico, USA M.D. Church Fermilab, Batavia, USA
	Funding: LANL LDRD program, project 20110067DR -U.S. DOE Contract No. DE-FG02-08ER41532 and DE-AC02-07CH11359. The Advanced Superconducting Test Accelerator (ASTA) at Fermilab incorporates a magnetic bunch compressor chicane to compress the 40-MeV electron bunches generated in the photoinjector. In this paper, we present a numerical analysis and parametric study of the bunch compressor's performance for various operating scenarios. The beam dynamics simulations, carried out with Astra, Impact-Z and CSRTrack, are compared against each other. Finally, an operating regime with low phase space dilutions is suggested based on the simulation results.

WEPPR034	Longitudinal Phase Space Measurement for the Advanced Superconducting Test Accelerator Photoinjector	3009
	C.R. Prokop, P. Piot Northern Illinois University, DeKalb, Illinois, USA M.D. Church, Y.-E. Sun Fermilab, Batavia, USA
	Funding: LANL LDRD program, project 20110067DR -U.S. DOE Contract No. DE-FG02-08ER41532 and DE-AC02-07CH11359. The Advanced Superconducting Test Accelerator (ASTA) at Fermilab uses a high-brightness photoinjector capable of producing electron bunches with charges up to 3.2 nC, to be used in support of a variety of advanced accelerator R&D experiments. The photoinjector incorporates an extensive diagnostics suites including a single-shot longitudinal-phase-space diagnostics composed of a horizontally deflecting cavity followed by a vertical spectrometer. In this paper, we present the design, optimization, and performance analysis (including detrimental collective effects) of the longitudinal phase space diagnostics and especially compare two possible choices of deflecting cavity frequencies.