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

Paper

Title

Page

BPM Inputs to Physics Applications at NSLS-II

465

Y. Hu, L.R. Dalesio, J.H. DeLong, K. Ha, J. Mead, I. Pinayev, G. Shen, O. Singh, Y. Tian, K. Vetter, L.-H. Yu
BNL, Upton, Long Island, New York, USA

A new BPM (Beam Position Monitor) electronics is under development and in good progress at NSLS-II. This in-house BPM receiver with many new features is comparable to commercial solution. BPM data for fast orbit feedback (FOFB) is one of the most important physics applications. The procedure to use BPM for FOFB is introduced firstly. Then, different BPM data flows associated with different physics requirements and applications are discussed. And control implementation of BPM system for physics applications is presented.

WEODN4

NSLS-II Fast Orbit Feedback with Individual Eigenmode Compensation

1488

Y. Tian, L.-H. Yu
BNL, Upton, Long Island, New York, USA

This paper presents the NSLS-II fast orbit feedback system with individual eigenmode compensation. The fast orbit feedback system is a typical multiple-input and multiple-output (MIMO) system. Traditional singular value decomposition (SVD) based fast orbit feedback systems treat each eigenmode the same and the same compensation algorithm is applied to all the eigenmodes. In reality, a MIMO system will have different frequency responses for different eigenmodes and thus it is desirable to design different compensation for each eigenmode. The difficulty with this approach comes from the large amount of computation that needs to be done within the time budget of the orbit feedback system. We designed and implemented the NSLS-II fast orbit feedback (FOFB) system with individual eigenmode compensation by taking advantage of the parallel computation capability of field programmable gate array (FPGA) chips.

Slides WEODN4 [1.064 MB]

THP135

Implementation of a DC Bump at the Storage Ring Injection Straight Section

2378

G.M. Wang, R.P. Fliller, W. Guo, R. Heese, S.L. Kramer, B. Parker, T.V. Shaftan, C.J. Spataro, F.J. Willeke, L.-H. Yu
BNL, Upton, Long Island, New York, USA

Funding: Work supported by U.S. DOE, Contract No.DE-AC02-98CH10886
The NSLS II beam injection works with two septa and four fast kicker magnets. The kicker power supplies each produce a two revolution periods pulsed field, 5.2μs half sine waveform, using ~5kV drive voltage. The corresponding close orbit bump amplitude is ~15mm. It is desired that the bump they produce is transparent to the users for top-off injection. However, high voltage and short pulse power supplies have challenges to maintain pulse-to-pulse stability and magnet-to-magnet reproducibility. To minimize these issues, we propose to implement a DC local bump on top of the fast bump to reduce the fast kicker strength by a factor of 2/3. This bump uses two ring corrector magnets plus one additional magnet at the septum to create a bump. Additionally, these magnets could provide a DC bump, which would simulate the effects of a movable septum on the store beam lifetime. This paper presents the detail design of this DC injection bump and related beam dynamics.

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.

Paper	Title	Page
MOP198	BPM Inputs to Physics Applications at NSLS-II	465
	Y. Hu, L.R. Dalesio, J.H. DeLong, K. Ha, J. Mead, I. Pinayev, G. Shen, O. Singh, Y. Tian, K. Vetter, L.-H. Yu BNL, Upton, Long Island, New York, USA
	A new BPM (Beam Position Monitor) electronics is under development and in good progress at NSLS-II. This in-house BPM receiver with many new features is comparable to commercial solution. BPM data for fast orbit feedback (FOFB) is one of the most important physics applications. The procedure to use BPM for FOFB is introduced firstly. Then, different BPM data flows associated with different physics requirements and applications are discussed. And control implementation of BPM system for physics applications is presented.

WEODN4	NSLS-II Fast Orbit Feedback with Individual Eigenmode Compensation	1488
	Y. Tian, L.-H. Yu BNL, Upton, Long Island, New York, USA
	This paper presents the NSLS-II fast orbit feedback system with individual eigenmode compensation. The fast orbit feedback system is a typical multiple-input and multiple-output (MIMO) system. Traditional singular value decomposition (SVD) based fast orbit feedback systems treat each eigenmode the same and the same compensation algorithm is applied to all the eigenmodes. In reality, a MIMO system will have different frequency responses for different eigenmodes and thus it is desirable to design different compensation for each eigenmode. The difficulty with this approach comes from the large amount of computation that needs to be done within the time budget of the orbit feedback system. We designed and implemented the NSLS-II fast orbit feedback (FOFB) system with individual eigenmode compensation by taking advantage of the parallel computation capability of field programmable gate array (FPGA) chips.
	Slides WEODN4 [1.064 MB]

THP135	Implementation of a DC Bump at the Storage Ring Injection Straight Section	2378
	G.M. Wang, R.P. Fliller, W. Guo, R. Heese, S.L. Kramer, B. Parker, T.V. Shaftan, C.J. Spataro, F.J. Willeke, L.-H. Yu BNL, Upton, Long Island, New York, USA
	Funding: Work supported by U.S. DOE, Contract No.DE-AC02-98CH10886 The NSLS II beam injection works with two septa and four fast kicker magnets. The kicker power supplies each produce a two revolution periods pulsed field, 5.2μs half sine waveform, using ~5kV drive voltage. The corresponding close orbit bump amplitude is ~15mm. It is desired that the bump they produce is transparent to the users for top-off injection. However, high voltage and short pulse power supplies have challenges to maintain pulse-to-pulse stability and magnet-to-magnet reproducibility. To minimize these issues, we propose to implement a DC local bump on top of the fast bump to reduce the fast kicker strength by a factor of 2/3. This bump uses two ring corrector magnets plus one additional magnet at the septum to create a bump. Additionally, these magnets could provide a DC bump, which would simulate the effects of a movable septum on the store beam lifetime. This paper presents the detail design of this DC injection bump and related beam dynamics.

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.