IPAC2016 - List of Authors (De Santis, S.)

Paper	Title	Page
WEPOW049	Physics Design Progress towards a Diffraction Limited Upgrade of the ALS	2956
	C. Steier, J.M. Byrd, S. De Santis, H. Nishimura, D. Robin, F. Sannibale, C. Sun, M. Venturini, W. Wan LBNL, Berkeley, California, USA
	Funding: This work was supported by the Laboratory Directed Research and Development Program of Lawrence Berkeley National Laboratory under U.S. Department of Energy Contract No. DE-AC02-05CH11231. Improvements in brightness and coherent flux of more than two orders of magnitude are possible using multi bend achromat lattice designs. These improvements can be implemented as upgrades of existing facilities, like the proposed upgrade of the Advanced Light Source. We will describe the progress in the physics design of this upgrade, including lattice evolution, error tolerance studies, simulations of collective effects, and intra beam scattering.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW049
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WEPOW051	R+D Progress Towards a Diffraction Limited Upgrade of the ALS	2962
	C. Steier, A. Anders, J.M. Byrd, K. Chow, S. De Santis, R.M. Duarte, J.-Y. Jung, T.H. Luo, H. Nishimura, T. Oliver, J.R. Osborn, H.A. Padmore, G.C. Pappas, D. Robin, F. Sannibale, D. Schlueter, C. Sun, C.A. Swenson, M. Venturini, W.L. Waldron, E.J. Wallén, W. Wan, Y. Yang LBNL, Berkeley, California, USA
	Funding: This work was supported by the Laboratory Directed Research and Development Program of Lawrence Berkeley National Laboratory under U.S. Department of Energy Contract No. DE-AC02-05CH11231. Improvements in brightness and coherent flux of about two orders of magnitude over operational storage ring based light sources are possible using multi bend achromat lattice designs. These improvements can be implemented as upgrades of existing facilities, like the proposed upgrade of the Advanced Light Source, making use of the existing infrastructure, thereby reducing cost and time needed to reach full scientific productivity on a large number of beamlines. An R&D program was started at LBNL to further develop the technologies necessary for diffraction-limited storage rings. It involves many areas, and focuses on the specific needs of soft x-ray facilities: NEG coating of small chambers, swap-out injection, bunch lengthening, magnets/radiation production, x-ray optics, and beam physics design optimization. Hardware prototypes have been built and concepts and equipment was tested in beam tests on the existing ALS.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW051
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WEPOW052	Multimodal Interaction in the ALS Longitudinal Feedback Kicker RF Cavity	2965
	S. De Santis, K.M. Baptiste, J.M. Byrd, S. Kwiatkowski, T.H. Luo, E.R. Sanmateo, C. Steier, C.A. Swenson LBNL, Berkeley, California, USA F. Marcellini PSI, Villigen PSI, Switzerland
	Funding: The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. RF cavities are essential components in particle accelerators not only for beam acceleration, but also for control purposes (bunch lengthening/shortening, deflecting and crabbing, transverse and longitudinal kickers) and for beam diagnostics (BPM). Normally, only a single resonating mode is actively used, although other modes can be excited by the circulating beam. Cavities used as feedback longitudinal kickers are designed with an axial mode which, appropriately excited, provides a kick to the circulating bunches for maintaining beam stability. To provide the necessary bandwidth this mode has to be strongly damped resulting in quality factors of just a few units. In the longitudinal feedback kicker cavity just installed on the ALS we have detected a second axial mode which, although a few hundreds of MHz below the 1.4 GHz design mode, is also strongly damped and has a shunt impedance high enough to be appreciably excited by the feedback amplifier coupling to the first mode. In this paper we show bench measurements on the cavity and with beam during its commissioning and discuss the interaction of the two modes resulting in a modulation of shunt impedance and phase response.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW052
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THPMW038	Prototyping of the ALS-U Fast Kickers	3637
	G.C. Pappas, S. De Santis, J.-Y. Jung, T.H. Luo, C. Steier, C.A. Swenson, W.L. Waldron LBNL, Berkeley, California, USA
	Prototyping of major components for the ALS-U kickers is in progress. A tapered stripline kicker has been built for installation and testing in the ALS, and multiple modulator options to meet the fast rise time required for swap out injection have been considered. High voltage feedthroughs that are matched into the multi GHz range are also being studied. * Pappas et al., "Fast Kicker Systems for ALS-U", Proc. of IPAC'14, Dresden, Germany, MOPME083.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW038
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Paper

Title

Page

Physics Design Progress towards a Diffraction Limited Upgrade of the ALS

2956

C. Steier, J.M. Byrd, S. De Santis, H. Nishimura, D. Robin, F. Sannibale, C. Sun, M. Venturini, W. Wan
LBNL, Berkeley, California, USA

Funding: This work was supported by the Laboratory Directed Research and Development Program of Lawrence Berkeley National Laboratory under U.S. Department of Energy Contract No. DE-AC02-05CH11231.
Improvements in brightness and coherent flux of more than two orders of magnitude are possible using multi bend achromat lattice designs. These improvements can be implemented as upgrades of existing facilities, like the proposed upgrade of the Advanced Light Source. We will describe the progress in the physics design of this upgrade, including lattice evolution, error tolerance studies, simulations of collective effects, and intra beam scattering.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW049

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

WEPOW051

R+D Progress Towards a Diffraction Limited Upgrade of the ALS

2962

C. Steier, A. Anders, J.M. Byrd, K. Chow, S. De Santis, R.M. Duarte, J.-Y. Jung, T.H. Luo, H. Nishimura, T. Oliver, J.R. Osborn, H.A. Padmore, G.C. Pappas, D. Robin, F. Sannibale, D. Schlueter, C. Sun, C.A. Swenson, M. Venturini, W.L. Waldron, E.J. Wallén, W. Wan, Y. Yang
LBNL, Berkeley, California, USA

Funding: This work was supported by the Laboratory Directed Research and Development Program of Lawrence Berkeley National Laboratory under U.S. Department of Energy Contract No. DE-AC02-05CH11231.
Improvements in brightness and coherent flux of about two orders of magnitude over operational storage ring based light sources are possible using multi bend achromat lattice designs. These improvements can be implemented as upgrades of existing facilities, like the proposed upgrade of the Advanced Light Source, making use of the existing infrastructure, thereby reducing cost and time needed to reach full scientific productivity on a large number of beamlines. An R&D program was started at LBNL to further develop the technologies necessary for diffraction-limited storage rings. It involves many areas, and focuses on the specific needs of soft x-ray facilities: NEG coating of small chambers, swap-out injection, bunch lengthening, magnets/radiation production, x-ray optics, and beam physics design optimization. Hardware prototypes have been built and concepts and equipment was tested in beam tests on the existing ALS.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW051

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WEPOW052

Multimodal Interaction in the ALS Longitudinal Feedback Kicker RF Cavity

2965

S. De Santis, K.M. Baptiste, J.M. Byrd, S. Kwiatkowski, T.H. Luo, E.R. Sanmateo, C. Steier, C.A. Swenson
LBNL, Berkeley, California, USA
F. Marcellini
PSI, Villigen PSI, Switzerland

Funding: The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
RF cavities are essential components in particle accelerators not only for beam acceleration, but also for control purposes (bunch lengthening/shortening, deflecting and crabbing, transverse and longitudinal kickers) and for beam diagnostics (BPM). Normally, only a single resonating mode is actively used, although other modes can be excited by the circulating beam. Cavities used as feedback longitudinal kickers are designed with an axial mode which, appropriately excited, provides a kick to the circulating bunches for maintaining beam stability. To provide the necessary bandwidth this mode has to be strongly damped resulting in quality factors of just a few units. In the longitudinal feedback kicker cavity just installed on the ALS we have detected a second axial mode which, although a few hundreds of MHz below the 1.4 GHz design mode, is also strongly damped and has a shunt impedance high enough to be appreciably excited by the feedback amplifier coupling to the first mode. In this paper we show bench measurements on the cavity and with beam during its commissioning and discuss the interaction of the two modes resulting in a modulation of shunt impedance and phase response.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW052

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THPMW038

Prototyping of the ALS-U Fast Kickers

3637

G.C. Pappas, S. De Santis, J.-Y. Jung, T.H. Luo, C. Steier, C.A. Swenson, W.L. Waldron
LBNL, Berkeley, California, USA

Prototyping of major components for the ALS-U kickers is in progress. A tapered stripline kicker has been built for installation and testing in the ALS, and multiple modulator options to meet the fast rise time required for swap out injection have been considered. High voltage feedthroughs that are matched into the multi GHz range are also being studied.
* Pappas et al., "Fast Kicker Systems for ALS-U", Proc. of IPAC'14, Dresden, Germany, MOPME083.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW038

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