ICALEPCS2023 - List of Keywords (emittance)

Paper	Title	Other Keywords	Page
TUPDP086	Operational Tool for Automatic Setup of Controlled Longitudinal Emittance Blow-Up in the CERN SPS	controls, operation, target, software	723
	N. Bruchon, I. Karpov, N. Madysa, G. Papotti, D. Quartullo CERN, Meyrin, Switzerland
	The controlled longitudinal emittance blow-up is necessary to ensure the stability of high-intensity LHC-type beams in the CERN SPS. It consists of diffusing the particles in the bunch core by injecting a bandwidth-limited noise into the beam phase loop of the main 200 MHz RF system. Obtaining the correct amplitude and bandwidth of this noise signal is non-trivial, and it may be tedious and time-demanding if done manually. An automatic approach was developed to speed up the determination of optimal settings. The problem complexity is reduced by splitting the blow-up into multiple sub-intervals for which the noise parameters are optimized by observing the longitudinal profiles at the end of each sub-interval. The derived bunch lengths are used to determine the objective function which measures the error with respect to the requirements. The sub-intervals are tackled sequentially. The optimization moves to the next one only when the previous sub-interval is completed. The proposed tool is integrated into the CERN generic optimization framework that features pre-implemented optimization algorithms. Both single- and multi-bunch high-intensity beams are quickly and efficiently stabilized by the optimizer, used so far in high-intensity studies. A possible extension to Bayesian optimization is being investigated.
DOI •	reference for this paper ※ doi:10.18429/JACoW-ICALEPCS2023-TUPDP086
About •	Received ※ 05 October 2023 — Accepted ※ 11 December 2023 — Issued ※ 19 December 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPDP034	The Application of Pyapas in Linac Beam Commissioning at HEPS	linac, MMI, controls, framework	1391
	X.H. Lu IHEP CSNS, Guangdong Province, People’s Republic of China H.F. Ji, Y. Jiao, J.Y. Li, N. Li, C. Meng, Y.M. Peng, G. Xu, Y.L. Zhao, P. Zhu IHEP, Beijing, People’s Republic of China
	The beam commissioning of the Linac at High Energy Photon Source (HEPS) started on March 9th this year. High-level applications (HLAs) based on Pyapas were successfully applied to the beam commissioning. To meet the beam commissioning requirements of the Linac, a series of HLAs were developed, including physics-based control application, PR target data analysis application, emittance measurement application, energy and energy spread measurement application, acceleration phase scanning application, BBA and feedback orbit correction application. Before applying these applications to real beam commissioning, they were tested thoroughly on a virtual accelerator to ensure the correctness of the algorithms and the stability of the application operation. Thanks to the repeated testing on the virtual accelerator, the HLAs of the Linac performed well after being put online, helping the beam commissioning operators to quickly achieve the full-line transmission of the beam and optimize the parameters to the expected values in a short time. This paper will provide a detailed introduction to the application of the relevant HLAs in the Linac beam commissioning at HEPS.
DOI •	reference for this paper ※ doi:10.18429/JACoW-ICALEPCS2023-THPDP034
About •	Received ※ 11 October 2023 — Revised ※ 12 October 2023 — Accepted ※ 10 December 2023 — Issued ※ 14 December 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

TUPDP086

Operational Tool for Automatic Setup of Controlled Longitudinal Emittance Blow-Up in the CERN SPS

controls, operation, target, software

723

N. Bruchon, I. Karpov, N. Madysa, G. Papotti, D. Quartullo
CERN, Meyrin, Switzerland

The controlled longitudinal emittance blow-up is necessary to ensure the stability of high-intensity LHC-type beams in the CERN SPS. It consists of diffusing the particles in the bunch core by injecting a bandwidth-limited noise into the beam phase loop of the main 200 MHz RF system. Obtaining the correct amplitude and bandwidth of this noise signal is non-trivial, and it may be tedious and time-demanding if done manually. An automatic approach was developed to speed up the determination of optimal settings. The problem complexity is reduced by splitting the blow-up into multiple sub-intervals for which the noise parameters are optimized by observing the longitudinal profiles at the end of each sub-interval. The derived bunch lengths are used to determine the objective function which measures the error with respect to the requirements. The sub-intervals are tackled sequentially. The optimization moves to the next one only when the previous sub-interval is completed. The proposed tool is integrated into the CERN generic optimization framework that features pre-implemented optimization algorithms. Both single- and multi-bunch high-intensity beams are quickly and efficiently stabilized by the optimizer, used so far in high-intensity studies. A possible extension to Bayesian optimization is being investigated.

DOI •

reference for this paper ※ doi:10.18429/JACoW-ICALEPCS2023-TUPDP086

About •

Received ※ 05 October 2023 — Accepted ※ 11 December 2023 — Issued ※ 19 December 2023

Cite •

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

THPDP034

The Application of Pyapas in Linac Beam Commissioning at HEPS

linac, MMI, controls, framework

1391

X.H. Lu
IHEP CSNS, Guangdong Province, People’s Republic of China
H.F. Ji, Y. Jiao, J.Y. Li, N. Li, C. Meng, Y.M. Peng, G. Xu, Y.L. Zhao, P. Zhu
IHEP, Beijing, People’s Republic of China

The beam commissioning of the Linac at High Energy Photon Source (HEPS) started on March 9th this year. High-level applications (HLAs) based on Pyapas were successfully applied to the beam commissioning. To meet the beam commissioning requirements of the Linac, a series of HLAs were developed, including physics-based control application, PR target data analysis application, emittance measurement application, energy and energy spread measurement application, acceleration phase scanning application, BBA and feedback orbit correction application. Before applying these applications to real beam commissioning, they were tested thoroughly on a virtual accelerator to ensure the correctness of the algorithms and the stability of the application operation. Thanks to the repeated testing on the virtual accelerator, the HLAs of the Linac performed well after being put online, helping the beam commissioning operators to quickly achieve the full-line transmission of the beam and optimize the parameters to the expected values in a short time. This paper will provide a detailed introduction to the application of the relevant HLAs in the Linac beam commissioning at HEPS.

DOI •

reference for this paper ※ doi:10.18429/JACoW-ICALEPCS2023-THPDP034

About •

Received ※ 11 October 2023 — Revised ※ 12 October 2023 — Accepted ※ 10 December 2023 — Issued ※ 14 December 2023

Cite •

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