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

Paper	Title	Page
MOP250	NSLS-II High Level Application Infrastructure and Client API Design	582
	G. Shen, K. Shroff, L. Yang BNL, Upton, Long Island, New York, USA
	Funding: Work performed under auspices of the U.S. Department of Energy under Contract No. DE-AC02-98CH10886 with Brookhaven Science Associates, LLC. The beam commissioning software framework of NSLS-II project adopts a client/server based architecture to replace the more traditional monolithic high level application approach. It is an open structure platform, and we try to provide a narrow API set for client application. With this narrow API, existing applications developed in different language under different architecture could be ported to our platform with small modification. This paper describes a detailed client API design, and latest progress.

WEP065	Multiobjective Dynamic Aperture Optimization at NSLS-II	1597
	L. Yang, W. Guo, S. Krinsky, Y. Li BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. In this paper we present a multiobjective approach to the dynamic aperture (DA) optimization. Taking the NSLS- II lattice as an example, we have used both sextupoles and quadrupoles as tuning variables to optimize both on-momentum and off-momentum DA. The geometric and chromatic sextupoles are used for nonlinear properties while the tunes are independently varied by quadrupoles. The dispersion and emittance are fixed during tunes variation. The algorithms, procedures, performances and results of our optimization of DA will be discussed and they are found to be robust, general and easy to apply to similar problems.

WEP066	Tracking Code Developement for Beam Dynamics Optimization	1600
	L. Yang BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Dynamic aperture (DA) optimization with direct particle tracking is a straight forward approach when the computing power is permitted. It can have various realistic errors included and is more close than theoretical estimations. In this approach, a fast and parallel tracking code could be very helpful. In this presentation, we describe an implementation of storage ring particle tracking code TESLA for beam dynamics optimization. It supports MPI based parallel computing and is robust as DA calculation engine. This code has been used in the NSLS-II dynamics optimizations and obtained promising performance.

THP136	Short Pulse Generation by Laser Slicing at NSLSII	2381
	L.-H. Yu, A. Blednykh, O.V. Chubar, W. Guo, S. Krinsky, Y. Li, T.V. Shaftan, G.M. Wang, F.J. Willeke, L. Yang BNL, Upton, Long Island, New York, USA
	Funding: Work supported by DOE contract DE-AC02-98CH10886. We propose an upgrade R&D project for NSLSII to generate sub-pico-second short x-ray pulses using laser slicing. In this paper we discuss the basic parameters for this system and present a specific example for a viable design and its performance. Since the installation of the laser slicing system into the storage ring will break the symmetry of the lattice, we demonstrate it is possible to recover the dynamical aperture to the original design goal of the ring.

THP189	Low Horizontal Beta Function in Long Straights of the NSLS-II Lattice	2471
	F. Lin, J. Bengtsson, W. Guo, S. Krinsky, Y. Li, L. Yang BNL, Upton, Long Island, New York, USA
	Funding: Work supported by U.S. DOE, Contract No. DE-AC02-98CH10886 The NSLS-II storage ring lattice is comprised of 30 DBA cells arranged in 15 superperiods. There are 15 long straight sections (9.3m) for injection, RF and insertion devices and 15 shorter straights (6.6m) for insertion devices. In the baseline lattice, the short straights have small horizontal and vertical beta functions but the long straights have large horizontal beta function optimized for injection. In this note, we explore the possibility of maintaining three long straights with large horizontal beta function while providing the other 12 long straights with smaller horizontal beta function to optimize the brightness of insertion devices. Our study considers the possible linear lattice solutions as well as characterizing the nonlinear dynamics. Results are reported on optimizations of dynamic aperture required for good injection efficiency and adequate Touschek lifetime.

THP190	Additional Quadrupoles at Center of Long Straights in the NSLS-II Lattice	2474
	F. Lin, J. Bengtsson, W. Guo, S. Krinsky, Y. Li, L. Yang BNL, Upton, Long Island, New York, USA
	Funding: Work supported by U.S. DOE, Contract No. DE-AC02-98CH10886 The NSLS-II storage ring lattice is comprised of 30 DBA cells arranged in 15 superperiods. There are 15 long straight sections (9.3m) for injection, RF and insertion devices and 15 shorter straights (6.6m) for insertion devices. In the baseline lattice, the short straights have small horizontal and vertical beta functions but the long straights have large horizontal beta function optimized for injection. In this note, we explore the possibility of installing additional quadrupoles at the center of selected long straight sections in order to provide two low-beta source locations for undulators. The required modification to the linear lattice is discussed as well as the preservation of adequate dynamic aperture required for good injection efficiency and adequate Touschek lifetime.

MOP276	Applying Cascaded Parameter Scan to Study Top-off Safety in NSLS-II Storage Ring	627
	Y. Li, S.V. Badea, W.R. Casey, G. Ganetis, R. Heese, H.-C. Hseuh, P.K. Job, S. Krinsky, B. Parker, T.V. Shaftan, S.K. Sharma, L. Yang BNL, Upton, Long Island, New York, USA
	Funding: Work supported by U.S. DOE, Contract No. DE-AC02-98CH10886 In this paper we introduce a new algorithm, the cascaded parameter scan method, to efficiently carry out the scan over magnet parameters in the safety analysis for the NSLS-II top-off injection. In top-off safety analysis, one must track particles populating phase space through a beamline containing magnets and apertures and clearly demonstrate that for all possible magnet settings and errors, all particles are lost on scrapers within the properly shielded region. In the usual approach, the number of tracking runs increases exponentially with the number of magnet settings. In the cascaded parameter scan method, the number of tracking runs only increases linearly. This reduction of exponential to linear dependence on the number of setpoints, greatly reduces the required computation time and allows one to more densely populate phase space and to increase the number of setpoints scanned for each magnet. An example of applying this approach to analyze an NSLS-II beamline, the damping wiggler beamline, is also given.

Paper

Title

Page

NSLS-II High Level Application Infrastructure and Client API Design

582

G. Shen, K. Shroff, L. Yang
BNL, Upton, Long Island, New York, USA

Funding: Work performed under auspices of the U.S. Department of Energy under Contract No. DE-AC02-98CH10886 with Brookhaven Science Associates, LLC.
The beam commissioning software framework of NSLS-II project adopts a client/server based architecture to replace the more traditional monolithic high level application approach. It is an open structure platform, and we try to provide a narrow API set for client application. With this narrow API, existing applications developed in different language under different architecture could be ported to our platform with small modification. This paper describes a detailed client API design, and latest progress.

WEP065

Multiobjective Dynamic Aperture Optimization at NSLS-II

1597

L. Yang, W. Guo, S. Krinsky, Y. Li
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
In this paper we present a multiobjective approach to the dynamic aperture (DA) optimization. Taking the NSLS- II lattice as an example, we have used both sextupoles and quadrupoles as tuning variables to optimize both on-momentum and off-momentum DA. The geometric and chromatic sextupoles are used for nonlinear properties while the tunes are independently varied by quadrupoles. The dispersion and emittance are fixed during tunes variation. The algorithms, procedures, performances and results of our optimization of DA will be discussed and they are found to be robust, general and easy to apply to similar problems.

WEP066

Tracking Code Developement for Beam Dynamics Optimization

1600

L. Yang
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Dynamic aperture (DA) optimization with direct particle tracking is a straight forward approach when the computing power is permitted. It can have various realistic errors included and is more close than theoretical estimations. In this approach, a fast and parallel tracking code could be very helpful. In this presentation, we describe an implementation of storage ring particle tracking code TESLA for beam dynamics optimization. It supports MPI based parallel computing and is robust as DA calculation engine. This code has been used in the NSLS-II dynamics optimizations and obtained promising performance.

THP136

Short Pulse Generation by Laser Slicing at NSLSII

2381

L.-H. Yu, A. Blednykh, O.V. Chubar, W. Guo, S. Krinsky, Y. Li, T.V. Shaftan, G.M. Wang, F.J. Willeke, L. Yang
BNL, Upton, Long Island, New York, USA

Funding: Work supported by DOE contract DE-AC02-98CH10886.
We propose an upgrade R&D project for NSLSII to generate sub-pico-second short x-ray pulses using laser slicing. In this paper we discuss the basic parameters for this system and present a specific example for a viable design and its performance. Since the installation of the laser slicing system into the storage ring will break the symmetry of the lattice, we demonstrate it is possible to recover the dynamical aperture to the original design goal of the ring.

THP189

Low Horizontal Beta Function in Long Straights of the NSLS-II Lattice

2471

F. Lin, J. Bengtsson, W. Guo, S. Krinsky, Y. Li, L. Yang
BNL, Upton, Long Island, New York, USA

Funding: Work supported by U.S. DOE, Contract No. DE-AC02-98CH10886
The NSLS-II storage ring lattice is comprised of 30 DBA cells arranged in 15 superperiods. There are 15 long straight sections (9.3m) for injection, RF and insertion devices and 15 shorter straights (6.6m) for insertion devices. In the baseline lattice, the short straights have small horizontal and vertical beta functions but the long straights have large horizontal beta function optimized for injection. In this note, we explore the possibility of maintaining three long straights with large horizontal beta function while providing the other 12 long straights with smaller horizontal beta function to optimize the brightness of insertion devices. Our study considers the possible linear lattice solutions as well as characterizing the nonlinear dynamics. Results are reported on optimizations of dynamic aperture required for good injection efficiency and adequate Touschek lifetime.

THP190

Additional Quadrupoles at Center of Long Straights in the NSLS-II Lattice

2474

F. Lin, J. Bengtsson, W. Guo, S. Krinsky, Y. Li, L. Yang
BNL, Upton, Long Island, New York, USA

Funding: Work supported by U.S. DOE, Contract No. DE-AC02-98CH10886
The NSLS-II storage ring lattice is comprised of 30 DBA cells arranged in 15 superperiods. There are 15 long straight sections (9.3m) for injection, RF and insertion devices and 15 shorter straights (6.6m) for insertion devices. In the baseline lattice, the short straights have small horizontal and vertical beta functions but the long straights have large horizontal beta function optimized for injection. In this note, we explore the possibility of installing additional quadrupoles at the center of selected long straight sections in order to provide two low-beta source locations for undulators. The required modification to the linear lattice is discussed as well as the preservation of adequate dynamic aperture required for good injection efficiency and adequate Touschek lifetime.

MOP276

Applying Cascaded Parameter Scan to Study Top-off Safety in NSLS-II Storage Ring

627

Y. Li, S.V. Badea, W.R. Casey, G. Ganetis, R. Heese, H.-C. Hseuh, P.K. Job, S. Krinsky, B. Parker, T.V. Shaftan, S.K. Sharma, L. Yang
BNL, Upton, Long Island, New York, USA

Funding: Work supported by U.S. DOE, Contract No. DE-AC02-98CH10886
In this paper we introduce a new algorithm, the cascaded parameter scan method, to efficiently carry out the scan over magnet parameters in the safety analysis for the NSLS-II top-off injection. In top-off safety analysis, one must track particles populating phase space through a beamline containing magnets and apertures and clearly demonstrate that for all possible magnet settings and errors, all particles are lost on scrapers within the properly shielded region. In the usual approach, the number of tracking runs increases exponentially with the number of magnet settings. In the cascaded parameter scan method, the number of tracking runs only increases linearly. This reduction of exponential to linear dependence on the number of setpoints, greatly reduces the required computation time and allows one to more densely populate phase space and to increase the number of setpoints scanned for each magnet. An example of applying this approach to analyze an NSLS-II beamline, the damping wiggler beamline, is also given.