CYCLOTRONS2022 - List of Authors (Fong, K.)

Paper	Title	Page
MOPO015	TRIUMF LLRF Control System Upgrade	91
	X.L. Fu, T. Au, K. Fong, Q. Zheng TRIUMF, Vancouver, Canada
	The LLRF system for Transfer line from Drift Tube LINAC(DTL) to Superconducting Linac (SCB) (DSB) was an analog-digital hybrid system running at 35.36MHz. The system controls the amplitude/phase and tuning for a buncher cavity on the beamline. During the 2022 October shutdown, the system is upgraded to a new fully-digital LLRF system. The new digital LLRF system is based on TRIUMF’s universal LLRF hardware with a new firmware. Instead of using a VXI crate, the new system adopts a NIM bin and uses USB communication with the local control PC. The amplitude/phase regulation is implemented in the FPGA firmware, and the tuning loop is implemented in the PC software, but driven by the FPGA. The Debian 11 linux OS is running on ARM CPU, and the new digital LLRF system works as a standard window HID device. The linux OS allows the firmware be updated in-situ using Ethernet communication. The detailed design is described in this paper.
	Poster MOPO015 [6.084 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOPO015
About •	Received ※ 02 December 2022 — Revised ※ 11 January 2023 — Accepted ※ 01 February 2023 — Issue date ※ 19 February 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPO017	RF Cavity Resonant Control Using Mimimal Seeking Sliding Mode Controller	99
	K. Fong, T. Au, X.L. Fu, R. Leewe, Q. Zheng TRIUMF, Vancouver, Canada
	Accelerating RF normal conducting cavities having Quality Factors of over 10³. These cavities must be constantly tuned to maintain resonance for maximum power efficiency. Traditional tuning method uses ’phase comparison method’ by monitoring the phase shift across the input and output of the cavity. This method suffers from phase drift due to diurnal temperature variations. Since 2017, TRIUMF ISAC-1 cavities are tuned using minimal seeking sliding mode controllers, which eliminate effects drift due to temperature changes. As with all extremum seeking algorithm, chattering is invariable present in the system, especially near the end-stage. This paper also includes a new chattering suppression method known as ’skipping surface’, which is slated to be installed in ISAC-1 LLRF upgrade in 2023.
	Poster MOPO017 [0.969 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOPO017
About •	Received ※ 26 December 2022 — Revised ※ 12 January 2023 — Accepted ※ 01 February 2023 — Issue date ※ 25 May 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

TRIUMF LLRF Control System Upgrade

91

X.L. Fu, T. Au, K. Fong, Q. Zheng
TRIUMF, Vancouver, Canada

The LLRF system for Transfer line from Drift Tube LINAC(DTL) to Superconducting Linac (SCB) (DSB) was an analog-digital hybrid system running at 35.36MHz. The system controls the amplitude/phase and tuning for a buncher cavity on the beamline. During the 2022 October shutdown, the system is upgraded to a new fully-digital LLRF system. The new digital LLRF system is based on TRIUMF’s universal LLRF hardware with a new firmware. Instead of using a VXI crate, the new system adopts a NIM bin and uses USB communication with the local control PC. The amplitude/phase regulation is implemented in the FPGA firmware, and the tuning loop is implemented in the PC software, but driven by the FPGA. The Debian 11 linux OS is running on ARM CPU, and the new digital LLRF system works as a standard window HID device. The linux OS allows the firmware be updated in-situ using Ethernet communication. The detailed design is described in this paper.

Poster MOPO015 [6.084 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOPO015

About •

Received ※ 02 December 2022 — Revised ※ 11 January 2023 — Accepted ※ 01 February 2023 — Issue date ※ 19 February 2023

Cite •

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

MOPO017

RF Cavity Resonant Control Using Mimimal Seeking Sliding Mode Controller

99

K. Fong, T. Au, X.L. Fu, R. Leewe, Q. Zheng
TRIUMF, Vancouver, Canada

Accelerating RF normal conducting cavities having Quality Factors of over 10³. These cavities must be constantly tuned to maintain resonance for maximum power efficiency. Traditional tuning method uses ’phase comparison method’ by monitoring the phase shift across the input and output of the cavity. This method suffers from phase drift due to diurnal temperature variations. Since 2017, TRIUMF ISAC-1 cavities are tuned using minimal seeking sliding mode controllers, which eliminate effects drift due to temperature changes. As with all extremum seeking algorithm, chattering is invariable present in the system, especially near the end-stage. This paper also includes a new chattering suppression method known as ’skipping surface’, which is slated to be installed in ISAC-1 LLRF upgrade in 2023.

Poster MOPO017 [0.969 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOPO017

About •

Received ※ 26 December 2022 — Revised ※ 12 January 2023 — Accepted ※ 01 February 2023 — Issue date ※ 25 May 2023

Cite •

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