IPAC2012 - List of Authors (Pappas, G.C.)

Paper	Title	Page
TUPPP037	Status of the ALS Brightness Upgrade	1692
	C. Steier, B.J. Bailey, A. Biocca, A.T. Black, D. Colomb, N. Li, A. Madur, S. Marks, H. Nishimura, G.C. Pappas, S. Prestemon, D. Robin, S.L. Rossi, T. Scarvie, D. Schlueter, C. Sun, W. Wan LBNL, Berkeley, California, USA
	Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. The Advanced Light Source (ALS) at Berkeley Lab while one of the earliest 3rd generation light sources remains one of the brightest sources for sof x-rays. Another multiyear upgrade of the ALS is currently under way, which includes new and replacement x-ray beamlines, a replacement of many of the original insertion devices and many upgrades to the accelerator. The accelerator upgrade that affects the ALS performance most directly is the ALS brightness upgrade, which will reduce the horizontal emittance from 6.3 to 2.2 nm (2.6 nm effective). This will result in a brightness increase by a factor of three for bendmagnet beamlines and at least a factor of two for insertion device beamlines. Magnets for this upgrade are currently under production and will be installed later this year.

TUPPP071	Design Concepts of a Beam Spreader for a Next Generation Free Electron Laser	1765
	M. Placidi, P. Emma, J.-Y. Jung, G.C. Pappas, D. Robin, C. Sun, W. Wan LBNL, Berkeley, California, USA
	LBNL is developing design concepts for a multi-beamline soft x-ray FEL array powered by a superconducting linear accelerator, operating with a high bunch repetition rate of approximately one MHz. Electron bunches are distributed from the linac to the array (up to 10) independently configurable FEL beamlines with nominal bunch rates up to 100 kHz in each FEL, and with even pulse spacing. This distribution to the different FELs is made by the beam spreader for which the design has to relative compact while not significantly perturbing the quality of the electron beam and subsequent performance of the FELs. We report on our conceptual design for the spreader. The spreader lattice has two distinct parts, namely the beam take-off section and the FEL fan-out distributions section. Each section is achromatic and isochronous. The effect of coherent synchrotron radiation and micro-bunching has been studied when passing through the spreader and simulations show no significant deterioration in the beam quality.

TUPPR095	Update on Kicker Development for the NGLS	2053
	G.C. Pappas, S. De Santis, J.E. Galvin, M.V. Orocz, M. Placidi LBNL, Berkeley, California, USA
	The latest requirements for the Next Generation Light Source (NGLS) beam spreader call for a kicker to deflect a 2.4 GeV electron beam by an angle of 3 mrad over a length of 2 meters. The rise and fall time requirements for the integrated B field are <50 ns, the pulse frequency is up to 100 kHz, and both the inter-pulse and pulse to pulse ripple requirements are <0.01% of full scale. These requirements, along with the basic design of the beam spreader are still evolving, and several magnet types and modulator topologies have been considered. This paper will discuss this evolution as it pertains to the kickers, what the current status is of the R&D effort, and the plan to build a full power prototype system.

TUPPP070	Next Generation Light Source R&D and Design Studies at LBNL	1762
	J.N. Corlett, B. Austin, K.M. Baptiste, D.L. Bowring, J.M. Byrd, S. De Santis, P. Denes, R.J. Donahue, L.R. Doolittle, P. Emma, D. Filippetto, G. Huang, T. Koettig, S. Kwiatkowski, D. Li, T.P. Lou, H. Nishimura, H.A. Padmore, C. F. Papadopoulos, G.C. Pappas, G. Penn, M. Placidi, S. Prestemon, D. Prosnitz, J. Qiang, A. Ratti, M.W. Reinsch, D. Robin, F. Sannibale, D. Schlueter, R.W. Schoenlein, J.W. Staples, C. Steier, C. Sun, T. Vecchione, M. Venturini, W. Wan, R.P. Wells, R.B. Wilcox, J.S. Wurtele LBNL, Berkeley, California, USA
	Funding: Work supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. LBNL is developing design concepts for a multi-beamline soft x-ray FEL array powered by a superconducting linear accelerator, operating with a high bunch repetition rate of approximately one MHz. The cw superconducting linear accelerator is supplied by an injector based on a high-brightness, high-repetition-rate photocathode electron gun. Electron bunches are distributed from the linac to the array of independently configurable FEL beamlines with nominal bunch rates up to 100 kHz in each FEL, and with even pulse spacing. Individual FELs may be configured for different modes of operation, and each may produce high peak and average brightness x-rays with a flexible pulse format, and with pulse durations ranging from sub-femtoseconds to hundreds of femtoseconds. In this paper we describe conceptual design studies and optimizations. We describe recent developments in the design and performance parameters, and progress in R&D activities.

WEEPPB004	Status of the APEX Project at LBNL	2173
	F. Sannibale, B.J. Bailey, K.M. Baptiste, J.M. Byrd, C.W. Cork, J.N. Corlett, S. De Santis, L.R. Doolittle, J.A. Doyle, P. Emma, J. Feng, D. Filippetto, G. Huang, H. Huang, T.D. Kramasz, S. Kwiatkowski, W.E. Norum, H.A. Padmore, C. F. Papadopoulos, G.C. Pappas, G.J. Portmann, J. Qiang, D.G. Quintas, J.W. Staples, T. Vecchione, M. Venturini, M. Vinco, W. Wan, R.P. Wells, M.S. Zolotorev, F.A. Zucca LBNL, Berkeley, California, USA M. J. Messerly, M.A. Prantil LLNL, Livermore, California, USA C.M. Pogue NPS, Monterey, California, USA
	Funding: This work was supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231. The Advanced Photo-injector Experiment (APEX) at the Lawrence Berkeley National Laboratory is focused on the development of a high-brightness high-repetition rate (MHz-class) electron injector for X-ray FEL applications. The injector is based on a new concept gun, utilizing a normal conducting 186 MHz RF cavity operating in cw mode in conjunction with high quantum efficiency photocathodes capable of delivering the required repetition rates with available laser technology. The APEX activities are staged in 3 main phases. In Phases 0 and I, the gun will be tested at its nominal energy of 750 keV and several different photocathodes are tested at full repetition rate. In Phase II, a pulsed linac will be added for accelerating the beam at several tens of MeV to reduce space charge effects and measure the high-brightness performance of the gun when integrated in an injector scheme. At Phase II energies, the radiation shielding configuration of APEX limits the repetition rate to a maximum of several Hz. Phase 0 is under commissioning, Phase I under installation, and initial activities for Phase II are underway. This paper presents an update on the status of these activities.

Paper

Title

Page

Status of the ALS Brightness Upgrade

1692

C. Steier, B.J. Bailey, A. Biocca, A.T. Black, D. Colomb, N. Li, A. Madur, S. Marks, H. Nishimura, G.C. Pappas, S. Prestemon, D. Robin, S.L. Rossi, T. Scarvie, D. Schlueter, C. Sun, W. Wan
LBNL, Berkeley, California, USA

Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
The Advanced Light Source (ALS) at Berkeley Lab while one of the earliest 3rd generation light sources remains one of the brightest sources for sof x-rays. Another multiyear upgrade of the ALS is currently under way, which includes new and replacement x-ray beamlines, a replacement of many of the original insertion devices and many upgrades to the accelerator. The accelerator upgrade that affects the ALS performance most directly is the ALS brightness upgrade, which will reduce the horizontal emittance from 6.3 to 2.2 nm (2.6 nm effective). This will result in a brightness increase by a factor of three for bendmagnet beamlines and at least a factor of two for insertion device beamlines. Magnets for this upgrade are currently under production and will be installed later this year.

TUPPP071

Design Concepts of a Beam Spreader for a Next Generation Free Electron Laser

1765

M. Placidi, P. Emma, J.-Y. Jung, G.C. Pappas, D. Robin, C. Sun, W. Wan
LBNL, Berkeley, California, USA

LBNL is developing design concepts for a multi-beamline soft x-ray FEL array powered by a superconducting linear accelerator, operating with a high bunch repetition rate of approximately one MHz. Electron bunches are distributed from the linac to the array (up to 10) independently configurable FEL beamlines with nominal bunch rates up to 100 kHz in each FEL, and with even pulse spacing. This distribution to the different FELs is made by the beam spreader for which the design has to relative compact while not significantly perturbing the quality of the electron beam and subsequent performance of the FELs. We report on our conceptual design for the spreader. The spreader lattice has two distinct parts, namely the beam take-off section and the FEL fan-out distributions section. Each section is achromatic and isochronous. The effect of coherent synchrotron radiation and micro-bunching has been studied when passing through the spreader and simulations show no significant deterioration in the beam quality.

TUPPR095

Update on Kicker Development for the NGLS

2053

G.C. Pappas, S. De Santis, J.E. Galvin, M.V. Orocz, M. Placidi
LBNL, Berkeley, California, USA

The latest requirements for the Next Generation Light Source (NGLS) beam spreader call for a kicker to deflect a 2.4 GeV electron beam by an angle of 3 mrad over a length of 2 meters. The rise and fall time requirements for the integrated B field are <50 ns, the pulse frequency is up to 100 kHz, and both the inter-pulse and pulse to pulse ripple requirements are <0.01% of full scale. These requirements, along with the basic design of the beam spreader are still evolving, and several magnet types and modulator topologies have been considered. This paper will discuss this evolution as it pertains to the kickers, what the current status is of the R&D effort, and the plan to build a full power prototype system.

TUPPP070

Next Generation Light Source R&D and Design Studies at LBNL

1762

J.N. Corlett, B. Austin, K.M. Baptiste, D.L. Bowring, J.M. Byrd, S. De Santis, P. Denes, R.J. Donahue, L.R. Doolittle, P. Emma, D. Filippetto, G. Huang, T. Koettig, S. Kwiatkowski, D. Li, T.P. Lou, H. Nishimura, H.A. Padmore, C. F. Papadopoulos, G.C. Pappas, G. Penn, M. Placidi, S. Prestemon, D. Prosnitz, J. Qiang, A. Ratti, M.W. Reinsch, D. Robin, F. Sannibale, D. Schlueter, R.W. Schoenlein, J.W. Staples, C. Steier, C. Sun, T. Vecchione, M. Venturini, W. Wan, R.P. Wells, R.B. Wilcox, J.S. Wurtele
LBNL, Berkeley, California, USA

Funding: Work supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
LBNL is developing design concepts for a multi-beamline soft x-ray FEL array powered by a superconducting linear accelerator, operating with a high bunch repetition rate of approximately one MHz. The cw superconducting linear accelerator is supplied by an injector based on a high-brightness, high-repetition-rate photocathode electron gun. Electron bunches are distributed from the linac to the array of independently configurable FEL beamlines with nominal bunch rates up to 100 kHz in each FEL, and with even pulse spacing. Individual FELs may be configured for different modes of operation, and each may produce high peak and average brightness x-rays with a flexible pulse format, and with pulse durations ranging from sub-femtoseconds to hundreds of femtoseconds. In this paper we describe conceptual design studies and optimizations. We describe recent developments in the design and performance parameters, and progress in R&D activities.

WEEPPB004

Status of the APEX Project at LBNL

2173

F. Sannibale, B.J. Bailey, K.M. Baptiste, J.M. Byrd, C.W. Cork, J.N. Corlett, S. De Santis, L.R. Doolittle, J.A. Doyle, P. Emma, J. Feng, D. Filippetto, G. Huang, H. Huang, T.D. Kramasz, S. Kwiatkowski, W.E. Norum, H.A. Padmore, C. F. Papadopoulos, G.C. Pappas, G.J. Portmann, J. Qiang, D.G. Quintas, J.W. Staples, T. Vecchione, M. Venturini, M. Vinco, W. Wan, R.P. Wells, M.S. Zolotorev, F.A. Zucca
LBNL, Berkeley, California, USA
M. J. Messerly, M.A. Prantil
LLNL, Livermore, California, USA
C.M. Pogue
NPS, Monterey, California, USA

Funding: This work was supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231.
The Advanced Photo-injector Experiment (APEX) at the Lawrence Berkeley National Laboratory is focused on the development of a high-brightness high-repetition rate (MHz-class) electron injector for X-ray FEL applications. The injector is based on a new concept gun, utilizing a normal conducting 186 MHz RF cavity operating in cw mode in conjunction with high quantum efficiency photocathodes capable of delivering the required repetition rates with available laser technology. The APEX activities are staged in 3 main phases. In Phases 0 and I, the gun will be tested at its nominal energy of 750 keV and several different photocathodes are tested at full repetition rate. In Phase II, a pulsed linac will be added for accelerating the beam at several tens of MeV to reduce space charge effects and measure the high-brightness performance of the gun when integrated in an injector scheme. At Phase II energies, the radiation shielding configuration of APEX limits the repetition rate to a maximum of several Hz. Phase 0 is under commissioning, Phase I under installation, and initial activities for Phase II are underway. This paper presents an update on the status of these activities.