PAC2013 - List of Authors (Qiang, J.)

Paper

Title

Page

TOWARDS A GLOBAL OPTIMIZATION OF THE MUON ACCELERATOR FRONT END

547

H. K. Sayed, J.S. Berg, H.G. Kirk, R.B. Palmer, D. Stratakis
BNL, Upton, Long Island, New York, USA
K.T. McDonald
PU, Princeton, New Jersey, USA
D.V. Neuffer
Fermilab, Batavia, USA
J. Qiang, R.D. Ryne
LBNL, Berkeley, California, USA

The baseline design for the neutrino factory and muon collider front end consists of a five major components, namely the muon production target, decay channel, buncher, phase rotator, and the ionization cooling channel. Although each of the mentioned systems has a complex design which is optimized for the best performance with its own set of local objectives, the integration of all of them into one system requires a global optimization to insure the effectiveness of the local objectives and overall performance. This global optimization represents a highly constrained multi-objective optimization problem. The objectives aimed for are the number of muons captured into a stable bunches and their transverse and longitudinal emittances. These objectives are constrained by the momentum and dynamic acceptance of the subsequent acceleration systems in addition to the overall cost. A multi-objective global evolutionary algorithm is employed to address such a challenge. In this study a statement of optimization strategy is discussed along with preliminary results of the optimization.

TUPBA23

Coherent Instability Due to Beam-Beam Interaction in Hadron Colliders

571

S. Paret, J. Qiang
LBNL, Berkeley, California, USA

Funding: This work was partially supported by the U. S. LARP and NERSC of the U. S. Department of Energy under contract No. DE-AC02-05CH11231.
Beam-beam effects can excite coherent modes in circular colliding beams and can thereby cause coherent instabilities. Nevertheless the beams in LHC have been well behaved and no fundamental limitation for the beam-beam parameter has been found in head-on collisions. In this paper we consider beams with much higher intensities than ever collided in any hadron collider. By virtue of 3D strong-strong computer simulations, we investigate the coherent stability and emittance growth of proton beams in head-on collision. The impact of a crossing angle between the beams and of a transverse damper is examined.

WEOAA1

NGLS - A Next Generation Light Source

J.N. Corlett, A.P. Allezy, D. Arbelaez, J.M. Byrd, C.S. Daniels, S. De Santis, W.W. Delp, P. Denes, R.J. Donahue, L.R. Doolittle, P. Emma, D. Filippetto, J.G. Floyd, J.P. Harkins, G. Huang, J.-Y. Jung, D. Li, T.P. Lou, T.H. Luo, G. Marcus, M.T. Monroy, H. Nishimura, H.A. Padmore, C. F. Papadopoulos, G.C. Pappas, S. Paret, G. Penn, M. Placidi, S. Prestemon, D. Prosnitz, H.J. Qian, J. Qiang, A. Ratti, M.W. Reinsch, D. Robin, F. Sannibale, R.W. Schoenlein, C. Serrano, J.W. Staples, C. Steier, C. Sun, M. Venturini, W.L. Waldron, W. Wan, T. Warwick, R.P. Wells, R.B. Wilcox, S. Zimmermann, M.S. Zolotorev
LBNL, Berkeley, California, USA
C. Adolphsen, K.L.F. Bane, Y. Ding, Z. Huang, C.D. Nantista, C.-K. Ng, H.-D. Nuhn, C.H. Rivetta, G.V. Stupakov
SLAC, Menlo Park, California, USA
D. Arenius, G. Neil, T. Powers, J.P. Preble
JLAB, Newport News, Virginia, USA
C.M. Ginsburg, R.D. Kephart, A.L. Klebaner, T.J. Peterson, A.I. Sukhanov
Fermilab, Batavia, USA

Funding: Work supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231
We present an overview of design studies and R&D toward NGLS a Next Generation Light Source initiative at LBNL. The design concept is based on a multi-beamline soft x-ray FEL array powered by a CW superconducting linear accelerator, and operating with a high bunch repetition rate of approximately 1 MHz. The linac design uses TESLA and ILC technology, supplied by an injector based on a CW normal-conducting VHF photocathode electron gun. Electron bunches from the linac are distributed by RF deflecting cavities to the array of independently configurable FEL beamlines with nominal bunch rates of ~100 kHz in each FEL, with uniform pulse spacing, and some FELs capable of operating at the full linac bunch rate. Individual FELs may be configured for different modes of operation, including self-seeded and external-laser-seeded, and each may produce high peak and average brightness x-rays with a flexible pulse format.

Slides WEOAA1 [6.908 MB]

WEPSM18

Investigation of Upstream Transient Wakefields due to Coherent Synchrotron Radiation in Bunch Compression Chicanes

1085

C.E. Mitchell, J. Qiang
LBNL, Berkeley, California, USA

The longitudinal wakefield due to coherent synchrotron radiation (CSR) in the bending magnets of bunch compression chicanes can significantly impact the beam quality in high-brightness FEL light-sources. In addition to single-bend CSR effects, transient radiation that is generated within a bend can follow the electron bunch downstream through one or more lattice elements before interacting with the bunch. An analytical 1-D model is used to estimate the size of these upstream wakefields in the absence of vacuum chamber shielding. An FFT-based, integrated Green function method for computing these wakefields is used in the code IMPACT to investigate their dynamical effects in the bunch compressor of a Next Generation Light Source.

Paper	Title	Page
TUPBA11	TOWARDS A GLOBAL OPTIMIZATION OF THE MUON ACCELERATOR FRONT END	547
	H. K. Sayed, J.S. Berg, H.G. Kirk, R.B. Palmer, D. Stratakis BNL, Upton, Long Island, New York, USA K.T. McDonald PU, Princeton, New Jersey, USA D.V. Neuffer Fermilab, Batavia, USA J. Qiang, R.D. Ryne LBNL, Berkeley, California, USA
	The baseline design for the neutrino factory and muon collider front end consists of a five major components, namely the muon production target, decay channel, buncher, phase rotator, and the ionization cooling channel. Although each of the mentioned systems has a complex design which is optimized for the best performance with its own set of local objectives, the integration of all of them into one system requires a global optimization to insure the effectiveness of the local objectives and overall performance. This global optimization represents a highly constrained multi-objective optimization problem. The objectives aimed for are the number of muons captured into a stable bunches and their transverse and longitudinal emittances. These objectives are constrained by the momentum and dynamic acceptance of the subsequent acceleration systems in addition to the overall cost. A multi-objective global evolutionary algorithm is employed to address such a challenge. In this study a statement of optimization strategy is discussed along with preliminary results of the optimization.

TUPBA23	Coherent Instability Due to Beam-Beam Interaction in Hadron Colliders	571
	S. Paret, J. Qiang LBNL, Berkeley, California, USA
	Funding: This work was partially supported by the U. S. LARP and NERSC of the U. S. Department of Energy under contract No. DE-AC02-05CH11231. Beam-beam effects can excite coherent modes in circular colliding beams and can thereby cause coherent instabilities. Nevertheless the beams in LHC have been well behaved and no fundamental limitation for the beam-beam parameter has been found in head-on collisions. In this paper we consider beams with much higher intensities than ever collided in any hadron collider. By virtue of 3D strong-strong computer simulations, we investigate the coherent stability and emittance growth of proton beams in head-on collision. The impact of a crossing angle between the beams and of a transverse damper is examined.

WEOAA1	NGLS - A Next Generation Light Source
	J.N. Corlett, A.P. Allezy, D. Arbelaez, J.M. Byrd, C.S. Daniels, S. De Santis, W.W. Delp, P. Denes, R.J. Donahue, L.R. Doolittle, P. Emma, D. Filippetto, J.G. Floyd, J.P. Harkins, G. Huang, J.-Y. Jung, D. Li, T.P. Lou, T.H. Luo, G. Marcus, M.T. Monroy, H. Nishimura, H.A. Padmore, C. F. Papadopoulos, G.C. Pappas, S. Paret, G. Penn, M. Placidi, S. Prestemon, D. Prosnitz, H.J. Qian, J. Qiang, A. Ratti, M.W. Reinsch, D. Robin, F. Sannibale, R.W. Schoenlein, C. Serrano, J.W. Staples, C. Steier, C. Sun, M. Venturini, W.L. Waldron, W. Wan, T. Warwick, R.P. Wells, R.B. Wilcox, S. Zimmermann, M.S. Zolotorev LBNL, Berkeley, California, USA C. Adolphsen, K.L.F. Bane, Y. Ding, Z. Huang, C.D. Nantista, C.-K. Ng, H.-D. Nuhn, C.H. Rivetta, G.V. Stupakov SLAC, Menlo Park, California, USA D. Arenius, G. Neil, T. Powers, J.P. Preble JLAB, Newport News, Virginia, USA C.M. Ginsburg, R.D. Kephart, A.L. Klebaner, T.J. Peterson, A.I. Sukhanov Fermilab, Batavia, USA
	Funding: Work supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 We present an overview of design studies and R&D toward NGLS a Next Generation Light Source initiative at LBNL. The design concept is based on a multi-beamline soft x-ray FEL array powered by a CW superconducting linear accelerator, and operating with a high bunch repetition rate of approximately 1 MHz. The linac design uses TESLA and ILC technology, supplied by an injector based on a CW normal-conducting VHF photocathode electron gun. Electron bunches from the linac are distributed by RF deflecting cavities to the array of independently configurable FEL beamlines with nominal bunch rates of ~100 kHz in each FEL, with uniform pulse spacing, and some FELs capable of operating at the full linac bunch rate. Individual FELs may be configured for different modes of operation, including self-seeded and external-laser-seeded, and each may produce high peak and average brightness x-rays with a flexible pulse format.
	Slides WEOAA1 [6.908 MB]

WEPSM18	Investigation of Upstream Transient Wakefields due to Coherent Synchrotron Radiation in Bunch Compression Chicanes	1085
	C.E. Mitchell, J. Qiang LBNL, Berkeley, California, USA
	The longitudinal wakefield due to coherent synchrotron radiation (CSR) in the bending magnets of bunch compression chicanes can significantly impact the beam quality in high-brightness FEL light-sources. In addition to single-bend CSR effects, transient radiation that is generated within a bend can follow the electron bunch downstream through one or more lattice elements before interacting with the bunch. An analytical 1-D model is used to estimate the size of these upstream wakefields in the absence of vacuum chamber shielding. An FFT-based, integrated Green function method for computing these wakefields is used in the code IMPACT to investigate their dynamical effects in the bunch compressor of a Next Generation Light Source.