IPAC2012 - List of Authors (Placidi, M.)

Paper

Title

Page

Instrumentation and Diagnostics for High Repetition Rate Linac-driven FELs

23

J.M. Byrd, S. De Santis, L.R. Doolittle, D. Filippetto, G. Huang, M. Placidi, A. Ratti
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.
One of the concepts for the next generation of linac-driven FELs is a cw superconducting linac driving an electron beam with MHz repetition rates. The beam is then switched into an array of independently configurable FELs. The demand for high brightness beams and the high rep-rate presents a number of challenges for the instrumentation and diagnostics. The high rep-rate also presents opportunities for increased beam stability because of the ability for much higher sampling rates for beam-based feedbacks. In this paper, we present our plans for instrumentation and diagnostics for such a machine.

Slides MOOAA02 [1.710 MB]

MOPPR076

Using the BRAN Luminosity Detectors for Beam Emittance Monitoring During LHC Physics Runs

966

A. Ratti, H.S. Matis, M. Placidi, W.C. Turner
LBNL, Berkeley, California, USA
E. Bravin
CERN, Geneva, Switzerland
T.E. Lahey
SLAC, Menlo Park, California, USA
E.S.M. McCrory
Fermilab, Batavia, USA
R. Miyamoto
ESS, Lund, Sweden
S.M. White
BNL, Upton, Long Island, New York, USA

Funding: This work partially supported by the US Department of Energy through the US LHC Accelerator Research Program (LARP).
The BRAN Ionization Chambers installed at the IP1 and IP5 Interaction Points of the LHC provide a relative measurement of the total and bunch-by-bunch luminosities. This information, combined with the logged bunch charges from a fast BCT monitor, offers the possibility of evaluating the Interaction Area in collision for each of the colliding bunch pairs and monitor its time evolution. A Graphic User Interface (GUI) has been implemented to display the interaction area of the proton bunches interacting in IP1 and IP5 during each of the Physics Runs in the attempt of displaying the contribution to the Luminosity time decay originating from possible emittance blow-up when operating the Accelerator close to the beam-beam limit. Early results confirm the ability to characterize the bunch by bunch emittance behavior during the store and study possible differences among bunches in the same fill.

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.

TUPPP074

Beam Dynamics Studies of a High-repetition Rate Linac Driver for a 4th-generation Light Source

1771

M. Venturini, J.N. Corlett, P. Emma, C. F. Papadopoulos, G. Penn, M. Placidi, J. Qiang, M.W. Reinsch, F. Sannibale, C. Steier, R.P. Wells
LBNL, Berkeley, California, USA

We present progress toward the design of a super-conducting linac driver of a high repetition rate FEL-based soft x-ray light source. The machine is intended to accept beams generated by the APEX* photocathode gun, operating in the MHz range, and deliver them to an array of SASE and seeded FEL beamlines. After reviewing the beam-dynamics considerations that are informing specific lattice choices we discuss the expected performance of the proposed machine design and its ability to meet the desired FEL specifications. We consider the merit of possible alternate designs (e.g., a one-stage compressor vs. a two-stage compressor) and the trade-offs between competing demands on the beam attributes (e.g., high peak current vs. acceptable energy spread).
* F. Sannibale et al., this conference.

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.

Paper	Title	Page
MOOAA02	Instrumentation and Diagnostics for High Repetition Rate Linac-driven FELs	23
	J.M. Byrd, S. De Santis, L.R. Doolittle, D. Filippetto, G. Huang, M. Placidi, A. Ratti 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. One of the concepts for the next generation of linac-driven FELs is a cw superconducting linac driving an electron beam with MHz repetition rates. The beam is then switched into an array of independently configurable FELs. The demand for high brightness beams and the high rep-rate presents a number of challenges for the instrumentation and diagnostics. The high rep-rate also presents opportunities for increased beam stability because of the ability for much higher sampling rates for beam-based feedbacks. In this paper, we present our plans for instrumentation and diagnostics for such a machine.
	Slides MOOAA02 [1.710 MB]

MOPPR076	Using the BRAN Luminosity Detectors for Beam Emittance Monitoring During LHC Physics Runs	966
	A. Ratti, H.S. Matis, M. Placidi, W.C. Turner LBNL, Berkeley, California, USA E. Bravin CERN, Geneva, Switzerland T.E. Lahey SLAC, Menlo Park, California, USA E.S.M. McCrory Fermilab, Batavia, USA R. Miyamoto ESS, Lund, Sweden S.M. White BNL, Upton, Long Island, New York, USA
	Funding: This work partially supported by the US Department of Energy through the US LHC Accelerator Research Program (LARP). The BRAN Ionization Chambers installed at the IP1 and IP5 Interaction Points of the LHC provide a relative measurement of the total and bunch-by-bunch luminosities. This information, combined with the logged bunch charges from a fast BCT monitor, offers the possibility of evaluating the Interaction Area in collision for each of the colliding bunch pairs and monitor its time evolution. A Graphic User Interface (GUI) has been implemented to display the interaction area of the proton bunches interacting in IP1 and IP5 during each of the Physics Runs in the attempt of displaying the contribution to the Luminosity time decay originating from possible emittance blow-up when operating the Accelerator close to the beam-beam limit. Early results confirm the ability to characterize the bunch by bunch emittance behavior during the store and study possible differences among bunches in the same fill.

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.

TUPPP074	Beam Dynamics Studies of a High-repetition Rate Linac Driver for a 4th-generation Light Source	1771
	M. Venturini, J.N. Corlett, P. Emma, C. F. Papadopoulos, G. Penn, M. Placidi, J. Qiang, M.W. Reinsch, F. Sannibale, C. Steier, R.P. Wells LBNL, Berkeley, California, USA
	We present progress toward the design of a super-conducting linac driver of a high repetition rate FEL-based soft x-ray light source. The machine is intended to accept beams generated by the APEX* photocathode gun, operating in the MHz range, and deliver them to an array of SASE and seeded FEL beamlines. After reviewing the beam-dynamics considerations that are informing specific lattice choices we discuss the expected performance of the proposed machine design and its ability to meet the desired FEL specifications. We consider the merit of possible alternate designs (e.g., a one-stage compressor vs. a two-stage compressor) and the trade-offs between competing demands on the beam attributes (e.g., high peak current vs. acceptable energy spread). * F. Sannibale et al., this conference.

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.