HB2016 - List of Keywords (feedback)

Paper	Title	Other Keywords	Page
TUPM1X01	Broadband Feedback System for Instability Damping in the SNS Ring	operation, betatron, accumulation, extraction	288
	N.J. Evans ORNL RAD, Oak Ridge, Tennessee, USA
	Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy The transverse feedback system in the Accumulator Ring of the Spallation Neutron Source~(SNS) is intended to damp broadband (≈40-120~MHz), coherent betatron motion due to e-p interaction. The SNS feedback system is based on an analog delay-line model with some signal conditioning and tuning parameters implemented digitally. This system provides a simple setup with two primary knobs, phase and gain, as well as an equalizer. This simplicity comes at the cost of some flexibility normally found in a standard mode-by-mode design, namely mode-by-mode phase, and gain control. In this paper we discuss the design, tuning, evaluation, and operation of the SNS feedback damper, and discuss the tradeoffs implicit in the design of the system.
	Slides TUPM1X01 [2.352 MB]
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPM5X01	Injection Painting Improvements in the J-PARC RCS	injection, power-supply, controls, target	299
	S. Kato, K. Horino, H. Hotchi, M. Kinsho, K. Okabe, P.K. Saha, Y. Shobuda, T. Takayanagi, T. Tobita, T. Ueno JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan H. Harada JAEA, Ibaraki-ken, Japan
	In the J-PARC 3GeV RCS, the injection painting is essential method for the reduction of the space charge force. In this method, the H⁻ beam from Linac is arranged on the large phase space area of the ring orbit during multiple turns. To implement this method, painting magnets form the time variable beam orbit. Therefore, the precise output current control of the magnet power supply is required. Because the power supply controlled by mainly feedforward signal is operated, we developed the iterative tuning method for the optimum feedforward parameter determination. As a result, we could reduce the tracking error of the current compared to before. Furthermore, to improve the accuracy of the painting area size, we applied the output readjustment additionally. Because the current monitor value of the power supply was different from the actual magnetic field due to the delay in the circuit and the leakage field, we corrected the tracking of the current based on the measured painting area size determined by the analysis of the measured COD. As a result, we achieved the precise injection painting. This talk presents these improvement results of the injection painting in the RCS.
	Slides TUPM5X01 [4.122 MB]
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

TUPM1X01

Broadband Feedback System for Instability Damping in the SNS Ring

operation, betatron, accumulation, extraction

288

N.J. Evans
ORNL RAD, Oak Ridge, Tennessee, USA

Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy
The transverse feedback system in the Accumulator Ring of the Spallation Neutron Source~(SNS) is intended to damp broadband (≈40-120~MHz), coherent betatron motion due to e-p interaction. The SNS feedback system is based on an analog delay-line model with some signal conditioning and tuning parameters implemented digitally. This system provides a simple setup with two primary knobs, phase and gain, as well as an equalizer. This simplicity comes at the cost of some flexibility normally found in a standard mode-by-mode design, namely mode-by-mode phase, and gain control. In this paper we discuss the design, tuning, evaluation, and operation of the SNS feedback damper, and discuss the tradeoffs implicit in the design of the system.

Slides TUPM1X01 [2.352 MB]

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPM5X01

Injection Painting Improvements in the J-PARC RCS

injection, power-supply, controls, target

299

S. Kato, K. Horino, H. Hotchi, M. Kinsho, K. Okabe, P.K. Saha, Y. Shobuda, T. Takayanagi, T. Tobita, T. Ueno
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
H. Harada
JAEA, Ibaraki-ken, Japan

In the J-PARC 3GeV RCS, the injection painting is essential method for the reduction of the space charge force. In this method, the H⁻ beam from Linac is arranged on the large phase space area of the ring orbit during multiple turns. To implement this method, painting magnets form the time variable beam orbit. Therefore, the precise output current control of the magnet power supply is required. Because the power supply controlled by mainly feedforward signal is operated, we developed the iterative tuning method for the optimum feedforward parameter determination. As a result, we could reduce the tracking error of the current compared to before. Furthermore, to improve the accuracy of the painting area size, we applied the output readjustment additionally. Because the current monitor value of the power supply was different from the actual magnetic field due to the delay in the circuit and the leakage field, we corrected the tracking of the current based on the measured painting area size determined by the analysis of the measured COD. As a result, we achieved the precise injection painting. This talk presents these improvement results of the injection painting in the RCS.

Slides TUPM5X01 [4.122 MB]

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)