IPAC2012 - List of Authors (Sun, C.)

Paper	Title	Page
MOPPC086	Accelerator Simulation - Beyond High Performance Computing	340
	S. James, G.M. Jung, B.C. Li, K. Muriki, H. Nishimura, Y. Qin, K. Song, C. Sun LBNL, Berkeley, California, USA
	Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. Accelerator modeling and simulation studies heavily rely on High Performance Computing (HPC). Public Cloud computing has opened a new service horizon for HPC by offering an on-demand, Virtual Private Cloud (VPC). Previously, we investigated using Amazon HPC public Cloud for lattice optimization applications and evaluated performance. In this research, we use the Amazon VPC technology to extend local HPC resources to provide a seamless, hybrid, and secure environment when the demand for computing capacity spikes. C. Sun et al., "HPC Cloud Applied to Lattice Optimization," Proc. PAC2011, New York, WEP151, p. 1767 (2011).

TUPPP039	Vertical Dispersion Bump Design for Femto-second Slicing Beamline at the ALS	1698
	C. Sun, C. Steier, W. Wan LBNL, Berkeley, California, USA
	Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. Femto-second (fs) slicing beamline has been brought to the operation at the Advanced Light Source (ALS) since 2002. It employs the resonant interaction of an electron bunch with a fs laser beam in a wiggler to energy-modulate a short section of the bunch. The induced energy modulation is then converted to a transverse displacement using a vertical dispersion bump downstream of the wiggler. Thus, the radiation from the fs pulse can be separated from the main bunch radiation. The current dispersion bump design has proved to be an effective and reliable one. However, the ALS storage ring lattice is under an upgrade to improve its brightness. After the completion of the upgrade, a new low emittance will be implemented, and the current dispersion bump design needs to be modified to provide the adequate vertical displacement, while minimizing the vertical emittance and spurious dispersion. In this paper, we present the new design of a vertical dispersion bump using Multi-Objective Genetic Algorithm (MOGA) for the ALS upgrade lattice.

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.

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.

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.

THPPR054	Progress in the Design of a Curved Superconducting Dipole for a Therapy Gantry	4097
	S. Caspi, D. Arbelaez, L.N. Brouwer, D.R. Dietderich, R.R. Hafalia, D. Robin, A. Sessler, C. Sun, W. Wan LBNL, Berkeley, California, USA
	A curved superconducting magnet for a carbon therapy gantry requires a large bore and a field around 5T. The design reduces the gantry’s size and weight and makes it more comparable with gantries used for proton therapy. In this paper we report on a combined function superconducting dipole magnet that is half the size needed for carbon gantry and is about the size of a proton gantry. The half scale, with a 130 mm bore diameter that is curved 90 degrees at a radius of 634 mm, superimposes two layers of oppositely wound and skewed solenoids that are energized in a way that nulls the solenoid field and doubles the dipole field. Furthermore, the combined architecture of the windings can create a selection of field terms that are off the near-pure dipole field. In this paper we report on the design of a two layers curved coil and the production of the winding mandrel. Some details on the magnet assembly are included.

THPPR055	Compact Gantry with Large Momentum Acceptance	4100
	W. Wan, D. Robin, A. Sessler, C. Sun LBNL, Berkeley, California, USA
	Rotatable Ion Beam Cancer Therapy (IBCT) delivery systems or gantries are the largest features in an ion beam therapy facility. They weight 100+ tons and require large (~3 story) heavily shielded rooms to house them. Reducing the size of ion beam gantries using high field One disadvantage of superconducting magnets is the difficulty of changing the fields quickly in order to adjust the beam momentum to scan the depth of penetration. In this paper we present a design of a gantry consisting of many combined function superconducting magnets that have a large enough momentum acceptance (> pm 10%) such that the magnets do not need to be changed while changing the beam energy.

Paper

Title

Page

Accelerator Simulation - Beyond High Performance Computing

340

S. James, G.M. Jung, B.C. Li, K. Muriki, H. Nishimura, Y. Qin, K. Song, C. Sun
LBNL, Berkeley, California, USA

Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
Accelerator modeling and simulation studies heavily rely on High Performance Computing (HPC). Public Cloud computing has opened a new service horizon for HPC by offering an on-demand, Virtual Private Cloud (VPC). Previously, we investigated using Amazon HPC public Cloud for lattice optimization applications and evaluated performance*. In this research, we use the Amazon VPC technology to extend local HPC resources to provide a seamless, hybrid, and secure environment when the demand for computing capacity spikes.
* C. Sun et al., "HPC Cloud Applied to Lattice Optimization," Proc. PAC2011, New York, WEP151, p. 1767 (2011).

TUPPP039

Vertical Dispersion Bump Design for Femto-second Slicing Beamline at the ALS

1698

C. Sun, C. Steier, W. Wan
LBNL, Berkeley, California, USA

Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
Femto-second (fs) slicing beamline has been brought to the operation at the Advanced Light Source (ALS) since 2002. It employs the resonant interaction of an electron bunch with a fs laser beam in a wiggler to energy-modulate a short section of the bunch. The induced energy modulation is then converted to a transverse displacement using a vertical dispersion bump downstream of the wiggler. Thus, the radiation from the fs pulse can be separated from the main bunch radiation. The current dispersion bump design has proved to be an effective and reliable one. However, the ALS storage ring lattice is under an upgrade to improve its brightness. After the completion of the upgrade, a new low emittance will be implemented, and the current dispersion bump design needs to be modified to provide the adequate vertical displacement, while minimizing the vertical emittance and spurious dispersion. In this paper, we present the new design of a vertical dispersion bump using Multi-Objective Genetic Algorithm (MOGA) for the ALS upgrade lattice.

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.

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.

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.

THPPR054

Progress in the Design of a Curved Superconducting Dipole for a Therapy Gantry

4097

S. Caspi, D. Arbelaez, L.N. Brouwer, D.R. Dietderich, R.R. Hafalia, D. Robin, A. Sessler, C. Sun, W. Wan
LBNL, Berkeley, California, USA

A curved superconducting magnet for a carbon therapy gantry requires a large bore and a field around 5T. The design reduces the gantry’s size and weight and makes it more comparable with gantries used for proton therapy. In this paper we report on a combined function superconducting dipole magnet that is half the size needed for carbon gantry and is about the size of a proton gantry. The half scale, with a 130 mm bore diameter that is curved 90 degrees at a radius of 634 mm, superimposes two layers of oppositely wound and skewed solenoids that are energized in a way that nulls the solenoid field and doubles the dipole field. Furthermore, the combined architecture of the windings can create a selection of field terms that are off the near-pure dipole field. In this paper we report on the design of a two layers curved coil and the production of the winding mandrel. Some details on the magnet assembly are included.

THPPR055

Compact Gantry with Large Momentum Acceptance

4100

W. Wan, D. Robin, A. Sessler, C. Sun
LBNL, Berkeley, California, USA

Rotatable Ion Beam Cancer Therapy (IBCT) delivery systems or gantries are the largest features in an ion beam therapy facility. They weight 100+ tons and require large (~3 story) heavily shielded rooms to house them. Reducing the size of ion beam gantries using high field One disadvantage of superconducting magnets is the difficulty of changing the fields quickly in order to adjust the beam momentum to scan the depth of penetration. In this paper we present a design of a gantry consisting of many combined function superconducting magnets that have a large enough momentum acceptance (> pm 10%) such that the magnets do not need to be changed while changing the beam energy.