ICALEPCS2019 - List of Authors (Tao, F.)

Paper	Title	Page
MOPHA066	Electronics for LCLS-II Beam Containment System Shut-off	366
MOPHA065	use link to see paper's listing under its alternate paper code
	R.A. Kadyrov, D.G. Brown, E.P. Chin, C.I. Clarke, M. Petree, E. Rodriguez, F. Tao SLAC, Menlo Park, California, USA
	LCLS-II is a new FEL which is under construction at SLAC National Accelerator Laboratory. Its superconducting electron linac is able to produce up to 1.2 MW of beam power. Beam Containment System (BCS) is employed to limit the beam power and prevent excessive radiation in case of electron beam loss or FEL breach. Fast and slow shut-off paths are designed for devices with different response requirements. The system is required to shut-off the beam within 200 µs for some of the fast sensors. Fast path is based on custom electronic designs, and slow path leverages industrial safety-rated PLC hardware. The system spans for 4 km of LCLS-II and combines inputs from about 150 sensors of different complexity. Architecture is based on multiple levels starting with summing sensor inputs locally and to converting them into permits for the shut-off devices. Each level is implemented redundantly. Automated test and manual tests at all levels are implemented in the system. System architecture, electronics design and cable plant challenges are presented below.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2019-MOPHA066
About •	paper received ※ 27 September 2019 paper accepted ※ 10 October 2019 issue date ※ 30 August 2020
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPHA141	Dynamic System Reliability Modelling of SLAC’s Radiation Safety Systems	558
	F. Tao, K.W. Belt SLAC, Menlo Park, California, USA
	When the LCLS-II project is complete, there will be three major Department of Energy (DOE) beam programs occupying the same 2-mile long accelerator tunnel, e.g. LCLS, LCLS-II and FACET-II. In addition to the geographical overlap, the number of beam loss monitors of all types has been also significantly expanded to detect power beam loss from all sources. All these factors contribute to highly complex Radiation Safety Systems (RSS) at SLAC. As RSS are subject to rigorous configuration control, and their outputs are permits directly related to beam production, even small faults can cause a long down time. As all beam programs at SLAC have the 95% beam availability target, the complex RSS’s contribution to overall beam availability and maintainability is an important subject worth detailed analysis. In this paper, we apply the dynamic system reliability engineering techniques to create the RSS reliability model for all three beam programs. Both qualitative and semi-quantitative approaches are used to identify the most critical common causes, the most vulnerable subsystem as well as the areas that require future design improvement for better maintainability.
	Poster MOPHA141 [0.863 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2019-MOPHA141
About •	paper received ※ 01 October 2019 paper accepted ※ 10 October 2019 issue date ※ 30 August 2020
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPHA142	FACET-II Radiation Safety Systems Development	562
	F. Tao, B.M. Bennett, N. Lipkowitz SLAC, Menlo Park, California, USA
	Facility for Advanced Accelerator Experimental Tests (FACET)-II is an upgrade of the FACET. It uses the middle third of SLAC’s 2-mile long linear accelerator to accelerate the electron beam to 10 GeV, with positron beam to be added in the Stage 2 of the project. Once the project completes in late 2019, it will be operated as a Department of Energy (DOE) user facilities for advanced accelerator science studies. In this paper, we will describe the Radiation Safety Systems (RSS) design and implementation for FACET-II project. RSS include Personnel Protection System (PPS) and Beam Containment System (BCS). Though both systems are safety critical, different technologies are used to implement safety functions. PPS uses Siemens PLC as the backbone for control but legacy CAMAC for data acquisition, while BCS develops customized electronics for faster response to protect safety devices from radiation induced damage.
	Poster MOPHA142 [1.284 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2019-MOPHA142
About •	paper received ※ 01 October 2019 paper accepted ※ 10 October 2019 issue date ※ 30 August 2020
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THCPR03	A Safety Rated FPGA Framework for Fast Safety Systems	1626
	F. Tao, B.M. Bennett, D.G. Brown, J. Jones, M.W. Stettler SLAC, Menlo Park, California, USA
	In this paper, we will introduce a generic safety-rated FPGA design template. FMEDA analysis, hardware reliability modeling, firmware development, verification and validation will be described in details to demonstrate the IEC 61508 compliant development process. In this dual redundant design, each chain consists a FPGA chip from different manufacturers to minimize the potential common cause failures. Cross checks between FPGAs and end-to-end self-checks are performed to increase the diagnostic coverage and improve the reliability. Based on this safety FPGA template, an Average Current Monitor (ACM) system is developed at SLAC with the addition of a safety PLC for diagnostics and a HMI for user interface. The overall system is deployed as part of Beam Containment System (BCS) to limit the beam current with the target Safety Integrity Level (SIL) 2.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2019-THCPR03
About •	paper received ※ 01 October 2019 paper accepted ※ 08 October 2019 issue date ※ 30 August 2020
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

MOPHA066

Electronics for LCLS-II Beam Containment System Shut-off

366

MOPHA065

use link to see paper's listing under its alternate paper code

R.A. Kadyrov, D.G. Brown, E.P. Chin, C.I. Clarke, M. Petree, E. Rodriguez, F. Tao
SLAC, Menlo Park, California, USA

LCLS-II is a new FEL which is under construction at SLAC National Accelerator Laboratory. Its superconducting electron linac is able to produce up to 1.2 MW of beam power. Beam Containment System (BCS) is employed to limit the beam power and prevent excessive radiation in case of electron beam loss or FEL breach. Fast and slow shut-off paths are designed for devices with different response requirements. The system is required to shut-off the beam within 200 µs for some of the fast sensors. Fast path is based on custom electronic designs, and slow path leverages industrial safety-rated PLC hardware. The system spans for 4 km of LCLS-II and combines inputs from about 150 sensors of different complexity. Architecture is based on multiple levels starting with summing sensor inputs locally and to converting them into permits for the shut-off devices. Each level is implemented redundantly. Automated test and manual tests at all levels are implemented in the system. System architecture, electronics design and cable plant challenges are presented below.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2019-MOPHA066

About •

paper received ※ 27 September 2019 paper accepted ※ 10 October 2019 issue date ※ 30 August 2020

Export •

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

MOPHA141

Dynamic System Reliability Modelling of SLAC’s Radiation Safety Systems

558

F. Tao, K.W. Belt
SLAC, Menlo Park, California, USA

When the LCLS-II project is complete, there will be three major Department of Energy (DOE) beam programs occupying the same 2-mile long accelerator tunnel, e.g. LCLS, LCLS-II and FACET-II. In addition to the geographical overlap, the number of beam loss monitors of all types has been also significantly expanded to detect power beam loss from all sources. All these factors contribute to highly complex Radiation Safety Systems (RSS) at SLAC. As RSS are subject to rigorous configuration control, and their outputs are permits directly related to beam production, even small faults can cause a long down time. As all beam programs at SLAC have the 95% beam availability target, the complex RSS’s contribution to overall beam availability and maintainability is an important subject worth detailed analysis. In this paper, we apply the dynamic system reliability engineering techniques to create the RSS reliability model for all three beam programs. Both qualitative and semi-quantitative approaches are used to identify the most critical common causes, the most vulnerable subsystem as well as the areas that require future design improvement for better maintainability.

Poster MOPHA141 [0.863 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2019-MOPHA141

About •

paper received ※ 01 October 2019 paper accepted ※ 10 October 2019 issue date ※ 30 August 2020

Export •

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

MOPHA142

FACET-II Radiation Safety Systems Development

562

F. Tao, B.M. Bennett, N. Lipkowitz
SLAC, Menlo Park, California, USA

Facility for Advanced Accelerator Experimental Tests (FACET)-II is an upgrade of the FACET. It uses the middle third of SLAC’s 2-mile long linear accelerator to accelerate the electron beam to 10 GeV, with positron beam to be added in the Stage 2 of the project. Once the project completes in late 2019, it will be operated as a Department of Energy (DOE) user facilities for advanced accelerator science studies. In this paper, we will describe the Radiation Safety Systems (RSS) design and implementation for FACET-II project. RSS include Personnel Protection System (PPS) and Beam Containment System (BCS). Though both systems are safety critical, different technologies are used to implement safety functions. PPS uses Siemens PLC as the backbone for control but legacy CAMAC for data acquisition, while BCS develops customized electronics for faster response to protect safety devices from radiation induced damage.

Poster MOPHA142 [1.284 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2019-MOPHA142

About •

paper received ※ 01 October 2019 paper accepted ※ 10 October 2019 issue date ※ 30 August 2020

Export •

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

THCPR03

A Safety Rated FPGA Framework for Fast Safety Systems

1626

F. Tao, B.M. Bennett, D.G. Brown, J. Jones, M.W. Stettler
SLAC, Menlo Park, California, USA

In this paper, we will introduce a generic safety-rated FPGA design template. FMEDA analysis, hardware reliability modeling, firmware development, verification and validation will be described in details to demonstrate the IEC 61508 compliant development process. In this dual redundant design, each chain consists a FPGA chip from different manufacturers to minimize the potential common cause failures. Cross checks between FPGAs and end-to-end self-checks are performed to increase the diagnostic coverage and improve the reliability. Based on this safety FPGA template, an Average Current Monitor (ACM) system is developed at SLAC with the addition of a safety PLC for diagnostics and a HMI for user interface. The overall system is deployed as part of Beam Containment System (BCS) to limit the beam current with the target Safety Integrity Level (SIL) 2.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2019-THCPR03

About •

paper received ※ 01 October 2019 paper accepted ※ 08 October 2019 issue date ※ 30 August 2020

Export •

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