IPAC2015 - List of Authors (Bachimanchi, R.)

Paper	Title	Page
MOPWI021	The LCLS-II LLRF System	1195
	C. Hovater, R. Bachimanchi JLab, Newport News, Virginia, USA S. Babel, B. Hong, D. Van Winkle SLAC, Menlo Park, California, USA B.E. Chase, E. Cullerton, P. Varghese Fermilab, Batavia, Illinois, USA L.R. Doolittle, G. Huang, A. Ratti, C. Serrano LBNL, Berkeley, California, USA
	Funding: This work was supported by the LCLS-II Project and the U.S. Department of Energy, Contract DE-AC02-76SF00515. The SLAC National Accelerator Laboratory is planning an upgrade (LCLS-II) to the Linear Coherent Light Source with a 4 GeV CW superconducting (SCRF) linac. The SCRF linac consists of 35 ILC style cryomodules (eight cavities each) for a total of 280 cavities. Expected cavity gradients are 16 MV/m with a loaded QL of ~ 4x10⁷. The RF system will have 3.8 kW solid state amplifiers driving single cavities. To ensure optimum field stability a single source single cavity control system has been chosen. It consists of a precision four channel cavity receiver and RF stations (Forward, Reflected and Drive signals). In order to regulate the resonant frequency variations of the cavities due to He pressure, the tuning of each cavity is controlled by a Piezo actuator and a slow stepper motor. In addition the system (LLRF-amplifier-cavity) is being modeled and cavity microphonic testing has started. This paper describes the LLRF system under consideration, including recent modeling and cavity tests.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWI021
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THXB1	CEBAF SRF Performance during Initial 12 GeV Commissioning	3638
	R. Bachimanchi, T.L. Allison, E. Daly, M.A. Drury, C. Hovater, G.E. Lahti, C.I. Mounts, R.M. Nelson, T. E. Plawski JLab, Newport News, Virginia, USA
	The Continuous Electron Beam Accelerator Facility (CEBAF) energy upgrade from 6 GeV to 12 GeV includes the installation of eleven new 100 MV cryomodules (88 cavities). The superconducting RF cavities are designed to operate CW at an accelerating gradient of 19.3 MV/m with a QL of 3×107. Not all the cavities were operated at the minimum gradient of 19.3 MV/m with the beam. Though the initial 12 GeV milestones were achieved during the initial commissioning of CEBAF, there are still some issues to be addressed for long term reliable operation of these modules. This paper reports the operational experiences during the initial commissioning and the path forward to improve the performance of C100 (100 MV) modules.
	Slides THXB1 [5.595 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THXB1
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

The LCLS-II LLRF System

1195

C. Hovater, R. Bachimanchi
JLab, Newport News, Virginia, USA
S. Babel, B. Hong, D. Van Winkle
SLAC, Menlo Park, California, USA
B.E. Chase, E. Cullerton, P. Varghese
Fermilab, Batavia, Illinois, USA
L.R. Doolittle, G. Huang, A. Ratti, C. Serrano
LBNL, Berkeley, California, USA

Funding: This work was supported by the LCLS-II Project and the U.S. Department of Energy, Contract DE-AC02-76SF00515.
The SLAC National Accelerator Laboratory is planning an upgrade (LCLS-II) to the Linear Coherent Light Source with a 4 GeV CW superconducting (SCRF) linac. The SCRF linac consists of 35 ILC style cryomodules (eight cavities each) for a total of 280 cavities. Expected cavity gradients are 16 MV/m with a loaded QL of ~ 4x10⁷. The RF system will have 3.8 kW solid state amplifiers driving single cavities. To ensure optimum field stability a single source single cavity control system has been chosen. It consists of a precision four channel cavity receiver and RF stations (Forward, Reflected and Drive signals). In order to regulate the resonant frequency variations of the cavities due to He pressure, the tuning of each cavity is controlled by a Piezo actuator and a slow stepper motor. In addition the system (LLRF-amplifier-cavity) is being modeled and cavity microphonic testing has started. This paper describes the LLRF system under consideration, including recent modeling and cavity tests.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWI021

Export •

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

THXB1

CEBAF SRF Performance during Initial 12 GeV Commissioning

3638

R. Bachimanchi, T.L. Allison, E. Daly, M.A. Drury, C. Hovater, G.E. Lahti, C.I. Mounts, R.M. Nelson, T. E. Plawski
JLab, Newport News, Virginia, USA

The Continuous Electron Beam Accelerator Facility (CEBAF) energy upgrade from 6 GeV to 12 GeV includes the installation of eleven new 100 MV cryomodules (88 cavities). The superconducting RF cavities are designed to operate CW at an accelerating gradient of 19.3 MV/m with a QL of 3×107. Not all the cavities were operated at the minimum gradient of 19.3 MV/m with the beam. Though the initial 12 GeV milestones were achieved during the initial commissioning of CEBAF, there are still some issues to be addressed for long term reliable operation of these modules. This paper reports the operational experiences during the initial commissioning and the path forward to improve the performance of C100 (100 MV) modules.

Slides THXB1 [5.595 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THXB1

Export •

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