IPAC2013 - List of Authors (Hutton, A.)

Paper	Title	Page
MOPWO078	A Harmonic Kicker Scheme for the Circulator Cooler Ring in the Medium Energy Electron-ion Collider	1061
	E.W. Nissen, A. Hutton, A.J. Kimber JLAB, Newport News, Virginia, USA
	Funding: Supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357. The current electron cooler design for the proposed Medium Energy Electron-Ion collider (MEIC) at Jefferson Lab utilizes a circulator ring for reuse of the cooling electron bunch up to 100 times to cool the ion beams. This cooler requires a fast kicker system for injecting and extracting individual bunches in the circulator ring. Such a kicker must work at a high repetition rate, up to 7.5 to 75 MHz depending on the number of turns in the recirculator ring. It also must have a very short rise and fall time (of order of 1 ns) such that it will kick an individual bunch without disturbing the others in the ring. Both requirements are orders of magnitude beyond the present state-of-the-art as well as the goals of other on-going kicker R&D programs such as that for the ILC damping rings. In this paper we report a scheme of creating this fast, high repetition rate kicker by combining RF waveforms at multiple frequencies to create a kicker waveform that will, for example, kick every eleventh bunch while leaving the other ten unperturbed. We also present a possible implementation of this scheme as well as discuss its limitations.

MOPWO081	The Scheme of Beam Synchronization in MEIC	1067
	Y. Zhang, Y.S. Derbenev, A. Hutton JLAB, Newport News, Virginia, USA
	Funding: Supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357. Synchronizing colliding beams at single or multiple collision points is a critical R&D issue in the design of a medium energy electron-ion collider (MEIC) at Jefferson Lab. The path-length variation due to changes in the ion energy, which varies over 20 to 100 GeV, could be more than several times the bunch spacing. The scheme adopted in the present MEIC baseline is centered on varying the number of bunches (i.e., harmonic number) stored in the collider ring. This could provide a set of discrete energies for proton or ions such that the beam synchronization condition is satisfied. To cover the ion energy between these synchronized values, we further propose to vary simultaneously the electron ring circumference and the frequency of the RF systems in both collider rings. We also present in this paper the requirement of frequency tunability of SRF cavities to support the scheme.

MOPWO083	LEIC - A Polarized Low Energy Electron-ion Collider at Jefferson Lab	1070
	Y. Zhang, Y.S. Derbenev, A. Hutton, G.A. Krafft, R. Li, F. Lin, V.S. Morozov, E.W. Nissen, R.A. Rimmer, H. Wang, S. Wang, B.C. Yunn, H. Zhang JLAB, Newport News, Virginia, USA M.K. Sullivan SLAC, Menlo Park, California, USA
	Funding: Supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357. A polarized electron-ion collider is envisioned as the future nuclear science program at JLab beyond the 12 GeV CEBAF. Presently, a medium energy collider (MEIC) is set as an immediate goal with options for a future energy upgrade. A comprehensive design report for MEIC has been released recently. The MEIC facility could also accommodate electron and proton/ion collisions in a low CM energy range, covering proton energies from 10 to 25 GeV and ion energies with a similar magnetic rigidity, for additional science reach. In this paper, we present a conceptual design of this low energy collider, LEIC, showing its luminosity can reach above 10³³ cm^-2s⁻¹. The design specifies that the large booster of the MEIC is converted to a low energy ion collider ring with an interaction region and an electron cooler integrated into it. The design provides options for either sharing the detector with the MEIC or a dedicated low energy detector in a third collision point, with advantages of either a minimum cost or extra detection parallel to the MEIC operation, respectively. The LEIC could be positioned as the first and low cost phase of a multi-stage approach to realize the full MEIC.

WEPWA068	Design Concepts for the NGLS Linac	2271
	A. Ratti, J.M. Byrd, J.N. Corlett, L.R. Doolittle, P. Emma, J. Qiang, M. Venturini, R.P. Wells LBNL, Berkeley, California, USA C. Adolphsen, C.D. Nantista SLAC, Menlo Park, California, USA D. Arenius, S.V. Benson, D. Douglas, A. Hutton, G. Neil, W. Oren, G.P. Williams JLAB, Newport News, Virginia, USA C.M. Ginsburg, R.D. Kephart, T.J. Peterson, A.I. Sukhanov Fermilab, Batavia, USA
	The Next Generation Light Source (NGLS) is a design concept for a multibeamline soft x-ray FEL array powered by a ~2.4 GeV CW superconducting linear accelerator, operating with a 1 MHz bunch repetition rate. This paper describes the concepts under development for a linac operating at 1.3 GHZ and based on minimal modifications to the design of ILC cryomodules in order to leverage the extensive R&D that resulted in the ILC design. Due to the different nature of the two applications, particular attention is given here to high loaded Q operation andμphonics control, as well as high reliability and expected up time.

Paper

Title

Page

A Harmonic Kicker Scheme for the Circulator Cooler Ring in the Medium Energy Electron-ion Collider

1061

E.W. Nissen, A. Hutton, A.J. Kimber
JLAB, Newport News, Virginia, USA

Funding: Supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357.
The current electron cooler design for the proposed Medium Energy Electron-Ion collider (MEIC) at Jefferson Lab utilizes a circulator ring for reuse of the cooling electron bunch up to 100 times to cool the ion beams. This cooler requires a fast kicker system for injecting and extracting individual bunches in the circulator ring. Such a kicker must work at a high repetition rate, up to 7.5 to 75 MHz depending on the number of turns in the recirculator ring. It also must have a very short rise and fall time (of order of 1 ns) such that it will kick an individual bunch without disturbing the others in the ring. Both requirements are orders of magnitude beyond the present state-of-the-art as well as the goals of other on-going kicker R&D programs such as that for the ILC damping rings. In this paper we report a scheme of creating this fast, high repetition rate kicker by combining RF waveforms at multiple frequencies to create a kicker waveform that will, for example, kick every eleventh bunch while leaving the other ten unperturbed. We also present a possible implementation of this scheme as well as discuss its limitations.

MOPWO081

The Scheme of Beam Synchronization in MEIC

1067

Y. Zhang, Y.S. Derbenev, A. Hutton
JLAB, Newport News, Virginia, USA

Funding: Supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357.
Synchronizing colliding beams at single or multiple collision points is a critical R&D issue in the design of a medium energy electron-ion collider (MEIC) at Jefferson Lab. The path-length variation due to changes in the ion energy, which varies over 20 to 100 GeV, could be more than several times the bunch spacing. The scheme adopted in the present MEIC baseline is centered on varying the number of bunches (i.e., harmonic number) stored in the collider ring. This could provide a set of discrete energies for proton or ions such that the beam synchronization condition is satisfied. To cover the ion energy between these synchronized values, we further propose to vary simultaneously the electron ring circumference and the frequency of the RF systems in both collider rings. We also present in this paper the requirement of frequency tunability of SRF cavities to support the scheme.

MOPWO083

LEIC - A Polarized Low Energy Electron-ion Collider at Jefferson Lab

1070

Y. Zhang, Y.S. Derbenev, A. Hutton, G.A. Krafft, R. Li, F. Lin, V.S. Morozov, E.W. Nissen, R.A. Rimmer, H. Wang, S. Wang, B.C. Yunn, H. Zhang
JLAB, Newport News, Virginia, USA
M.K. Sullivan
SLAC, Menlo Park, California, USA

Funding: Supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357.
A polarized electron-ion collider is envisioned as the future nuclear science program at JLab beyond the 12 GeV CEBAF. Presently, a medium energy collider (MEIC) is set as an immediate goal with options for a future energy upgrade. A comprehensive design report for MEIC has been released recently. The MEIC facility could also accommodate electron and proton/ion collisions in a low CM energy range, covering proton energies from 10 to 25 GeV and ion energies with a similar magnetic rigidity, for additional science reach. In this paper, we present a conceptual design of this low energy collider, LEIC, showing its luminosity can reach above 10³³ cm^-2s⁻¹. The design specifies that the large booster of the MEIC is converted to a low energy ion collider ring with an interaction region and an electron cooler integrated into it. The design provides options for either sharing the detector with the MEIC or a dedicated low energy detector in a third collision point, with advantages of either a minimum cost or extra detection parallel to the MEIC operation, respectively. The LEIC could be positioned as the first and low cost phase of a multi-stage approach to realize the full MEIC.

WEPWA068

Design Concepts for the NGLS Linac

2271

A. Ratti, J.M. Byrd, J.N. Corlett, L.R. Doolittle, P. Emma, J. Qiang, M. Venturini, R.P. Wells
LBNL, Berkeley, California, USA
C. Adolphsen, C.D. Nantista
SLAC, Menlo Park, California, USA
D. Arenius, S.V. Benson, D. Douglas, A. Hutton, G. Neil, W. Oren, G.P. Williams
JLAB, Newport News, Virginia, USA
C.M. Ginsburg, R.D. Kephart, T.J. Peterson, A.I. Sukhanov
Fermilab, Batavia, USA

The Next Generation Light Source (NGLS) is a design concept for a multibeamline soft x-ray FEL array powered by a ~2.4 GeV CW superconducting linear accelerator, operating with a 1 MHz bunch repetition rate. This paper describes the concepts under development for a linac operating at 1.3 GHZ and based on minimal modifications to the design of ILC cryomodules in order to leverage the extensive R&D that resulted in the ILC design. Due to the different nature of the two applications, particular attention is given here to high loaded Q operation andμphonics control, as well as high reliability and expected up time.