2011 Particle Accelerator Conference - List of Authors (Doolittle, L.R.)

Paper

Title

Page

Synchronize Lasers to LCLS e^- Beam

636

G. Huang
TUB, Beijing, People's Republic of China
J.M. Byrd, L.R. Doolittle, R.B. Wilcox
LBNL, Berkeley, California, USA

Fiber based synchronization system is used in LCLS to synchronize the laser for pump probe experiment to average electron beam arrival time. Electron bunch arrival time measured by phase cavity is one of the best measurement for FEL X pulse until now. The average bunch arrival time is transmitted through electronic length stabilized fiber link to AMO and other experiment hall. The laser oscillator is phase locked to this reference signal to maintain low jitter and drift between pump and probe. The in loop error shows the jitter is less then 100 fs and meets the experiment requirement.

TUOCS5

A Next Generation Light Source Facility at LBNL

775

J.N. Corlett, B. Austin, K.M. Baptiste, J.M. Byrd, P. Denes, R.J. Donahue, L.R. Doolittle, R.W. Falcone, D. Filippetto, D.S. Fournier, J. Kirz, D. Li, H.A. Padmore, C. F. Papadopoulos, G.C. Pappas, G. Penn, M. Placidi, S. Prestemon, D. Prosnitz, J. Qiang, A. Ratti, M.W. Reinsch, F. Sannibale, D. Schlueter, R.W. Schoenlein, J.W. Staples, T. Vecchione, M. Venturini, R.P. Wells, R.B. Wilcox, J.S. Wurtele
LBNL, Berkeley, California, USA
A.E. Charman, E. Kur
UCB, Berkeley, California, USA
A. Zholents
ANL, Argonne, USA

Funding: Work supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231
The Next Generation Light Source (NGLS) is a design concept, under development at LBNL, for a multi‐beamline soft x‐ray FEL array powered by a 2 GeV superconducting linear accelerator, operating with a 1 MHz bunch repetition rate. The CW superconducting linear accelerator is supplied by 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 EEHG, HGHG, SASE, or oscillator mode of operation, and will 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.

Slides TUOCS5 [4.758 MB]

WEP222

Low Energy Beam Diagnostic for APEX, the LBNL VHF Photo-injector

1903

D. Filippetto, J.M. Byrd, M.J. Chin, C.W. Cork, S. De Santis, L.R. Doolittle, J. Feng, W.E. Norum, C. F. Papadopoulos, G.J. Portmann, D.G. Quintas, F. Sannibale, M.E. Stuart, R.P. Wells, M.S. Zolotorev
LBNL, Berkeley, 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
A high-repetition rate (MHz-class), high-brightness electron beam photo-gun is under construction at Lawrence Berkeley National Laboratory in the framework of the Advanced Photo-injector EXperiment (APEX). The injector gun is based on a normal conducting 187 MHz RF cavity operating in CW mode. In its first operational phase it will deliver short bunches (~ 1 to tens of picoseconds) with energy of 750keV, and bunch charges ranging from 1pC to 1nC. Different high efficiency cathode materials will be tested, and the beam quality will be studied as a function of parameters as charge, initial bunch length and transverse size, focusing strength. Both the laser and electron beam diagnostics have been designed to assure the needed flexibility. In particular a high-resolution electron diagnostic section after the photo-gun provides the necessary dynamical range for scanned beam parameters: energy and energy spread, charge and current, transverse and longitudinal phase spaces, slice properties. The photo-gun electron beam diagnostic layout is presented, and the hardware choices, resolution and achievable dynamical ranges are also discussed.

THP180

Studies of a Linac Driver for a High Repetition Rate X-ray FEL

2450

M. Venturini, J.N. Corlett, L.R. Doolittle, D. Filippetto, C. F. Papadopoulos, G. Penn, D. Prosnitz, J. Qiang, M.W. Reinsch, R.D. Ryne, F. Sannibale, J.W. Staples, R.P. Wells, J.S. Wurtele, M.S. Zolotorev
LBNL, Berkeley, California, USA
A. Zholents
ANL, Argonne, USA

Funding: Work carried out under Department of Energy contract No. DE-AC02-0SCK11231
We report on on-going studies of a superconducting CW linac driver intended to support a high repetition rate FEL operating in the soft x-rays spectrum. We present a point-design for a 1.8 GeV machine tuned for 300~pC bunches and delivering low-emittance, low-energy spread beams as needed for the SASE and seeded beamlines.

WEOBS5

Status of the Short-Pulse X-ray Project (SPX) at the Advanced Photon Source (APS)

1427

R. Nassiri, N.D. Arnold, G. Berenc, M. Borland, D.J. Bromberek, Y.-C. Chae, G. Decker, L. Emery, J.D. Fuerst, A.E. Grelick, D. Horan, F. Lenkszus, R.M. Lill, V. Sajaev, T.L. Smith, G.J. Waldschmidt, G. Wu, B.X. Yang, A. Zholents
ANL, Argonne, USA
J.M. Byrd, L.R. Doolittle, G. Huang
LBNL, Berkeley, California, USA
G. Cheng, G. Ciovati, J. Henry, P. Kneisel, J.D. Mammosser, R.A. Rimmer, L. Turlington, H. Wang
JLAB, Newport News, Virginia, USA

Funding: Work at Argonne is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11354.
The Advanced Photon Source Upgrade project (APS-U) at Argonne includes implementation of Zholents’* deflecting cavity scheme for production of short x-ray pulses. This is a joint project between Argonne National Laboratory, Thomas Jefferson National Laboratory, and Lawrence Berkeley National Laboratory. This paper describes performance characteristics of the proposed source and technical issues related to its realization. Ensuring stable APS storage ring operation requires reducing quality factors of these modes by many orders of magnitude. These challenges reduce to those of the design of a single-cell SC cavity that can achieve the desired operating deflecting fields while providing needed damping of all these modes. The project team is currently prototyping and testing several promising designs for single-cell cavities with the goal of deciding on a winning design in the near future.
*A. Zholents et al., NIM A 425, 385 (1999).

Slides WEOBS5 [1.730 MB]

Paper	Title	Page
MOP279	Synchronize Lasers to LCLS e^- Beam	636
	G. Huang TUB, Beijing, People's Republic of China J.M. Byrd, L.R. Doolittle, R.B. Wilcox LBNL, Berkeley, California, USA
	Fiber based synchronization system is used in LCLS to synchronize the laser for pump probe experiment to average electron beam arrival time. Electron bunch arrival time measured by phase cavity is one of the best measurement for FEL X pulse until now. The average bunch arrival time is transmitted through electronic length stabilized fiber link to AMO and other experiment hall. The laser oscillator is phase locked to this reference signal to maintain low jitter and drift between pump and probe. The in loop error shows the jitter is less then 100 fs and meets the experiment requirement.

TUOCS5	A Next Generation Light Source Facility at LBNL	775
	J.N. Corlett, B. Austin, K.M. Baptiste, J.M. Byrd, P. Denes, R.J. Donahue, L.R. Doolittle, R.W. Falcone, D. Filippetto, D.S. Fournier, J. Kirz, D. Li, H.A. Padmore, C. F. Papadopoulos, G.C. Pappas, G. Penn, M. Placidi, S. Prestemon, D. Prosnitz, J. Qiang, A. Ratti, M.W. Reinsch, F. Sannibale, D. Schlueter, R.W. Schoenlein, J.W. Staples, T. Vecchione, M. Venturini, R.P. Wells, R.B. Wilcox, J.S. Wurtele LBNL, Berkeley, California, USA A.E. Charman, E. Kur UCB, Berkeley, California, USA A. Zholents ANL, Argonne, USA
	Funding: Work supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 The Next Generation Light Source (NGLS) is a design concept, under development at LBNL, for a multi‐beamline soft x‐ray FEL array powered by a 2 GeV superconducting linear accelerator, operating with a 1 MHz bunch repetition rate. The CW superconducting linear accelerator is supplied by 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 EEHG, HGHG, SASE, or oscillator mode of operation, and will 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.
	Slides TUOCS5 [4.758 MB]

WEP222	Low Energy Beam Diagnostic for APEX, the LBNL VHF Photo-injector	1903
	D. Filippetto, J.M. Byrd, M.J. Chin, C.W. Cork, S. De Santis, L.R. Doolittle, J. Feng, W.E. Norum, C. F. Papadopoulos, G.J. Portmann, D.G. Quintas, F. Sannibale, M.E. Stuart, R.P. Wells, M.S. Zolotorev LBNL, Berkeley, 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 A high-repetition rate (MHz-class), high-brightness electron beam photo-gun is under construction at Lawrence Berkeley National Laboratory in the framework of the Advanced Photo-injector EXperiment (APEX). The injector gun is based on a normal conducting 187 MHz RF cavity operating in CW mode. In its first operational phase it will deliver short bunches (~ 1 to tens of picoseconds) with energy of 750keV, and bunch charges ranging from 1pC to 1nC. Different high efficiency cathode materials will be tested, and the beam quality will be studied as a function of parameters as charge, initial bunch length and transverse size, focusing strength. Both the laser and electron beam diagnostics have been designed to assure the needed flexibility. In particular a high-resolution electron diagnostic section after the photo-gun provides the necessary dynamical range for scanned beam parameters: energy and energy spread, charge and current, transverse and longitudinal phase spaces, slice properties. The photo-gun electron beam diagnostic layout is presented, and the hardware choices, resolution and achievable dynamical ranges are also discussed.

THP180	Studies of a Linac Driver for a High Repetition Rate X-ray FEL	2450
	M. Venturini, J.N. Corlett, L.R. Doolittle, D. Filippetto, C. F. Papadopoulos, G. Penn, D. Prosnitz, J. Qiang, M.W. Reinsch, R.D. Ryne, F. Sannibale, J.W. Staples, R.P. Wells, J.S. Wurtele, M.S. Zolotorev LBNL, Berkeley, California, USA A. Zholents ANL, Argonne, USA
	Funding: Work carried out under Department of Energy contract No. DE-AC02-0SCK11231 We report on on-going studies of a superconducting CW linac driver intended to support a high repetition rate FEL operating in the soft x-rays spectrum. We present a point-design for a 1.8 GeV machine tuned for 300~pC bunches and delivering low-emittance, low-energy spread beams as needed for the SASE and seeded beamlines.

WEOBS5	Status of the Short-Pulse X-ray Project (SPX) at the Advanced Photon Source (APS)	1427
	R. Nassiri, N.D. Arnold, G. Berenc, M. Borland, D.J. Bromberek, Y.-C. Chae, G. Decker, L. Emery, J.D. Fuerst, A.E. Grelick, D. Horan, F. Lenkszus, R.M. Lill, V. Sajaev, T.L. Smith, G.J. Waldschmidt, G. Wu, B.X. Yang, A. Zholents ANL, Argonne, USA J.M. Byrd, L.R. Doolittle, G. Huang LBNL, Berkeley, California, USA G. Cheng, G. Ciovati, J. Henry, P. Kneisel, J.D. Mammosser, R.A. Rimmer, L. Turlington, H. Wang JLAB, Newport News, Virginia, USA
	Funding: Work at Argonne is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11354. The Advanced Photon Source Upgrade project (APS-U) at Argonne includes implementation of Zholents’* deflecting cavity scheme for production of short x-ray pulses. This is a joint project between Argonne National Laboratory, Thomas Jefferson National Laboratory, and Lawrence Berkeley National Laboratory. This paper describes performance characteristics of the proposed source and technical issues related to its realization. Ensuring stable APS storage ring operation requires reducing quality factors of these modes by many orders of magnitude. These challenges reduce to those of the design of a single-cell SC cavity that can achieve the desired operating deflecting fields while providing needed damping of all these modes. The project team is currently prototyping and testing several promising designs for single-cell cavities with the goal of deciding on a winning design in the near future. *A. Zholents et al., NIM A 425, 385 (1999).
	Slides WEOBS5 [1.730 MB]