Anders Rosborg The MAX IV personnel safety system
Overview ● PSS areas ● Control of radiation sources ● Design principles ● Searching beamline hutches ● Searching accelerator areas ● Top-up The MAX IV personnel safety system / Overview
PSS areas
PSS areas The MAX IV personnel safety system / PSS areas / PSS areas
Klystron gallery The MAX IV personnel safety system / PSS areas / Klystron gallery
Gun test The MAX IV personnel safety system / PSS areas / Gun test
Linear accelerator (linac) The MAX IV personnel safety system / PSS areas / Linear accelerator (linac)
Short pulse facility (SPF) The MAX IV personnel safety system / PSS areas / Short pulse facility (SPF)
1.5 GeV ring (R1) The MAX IV personnel safety system / PSS areas / 1.5 GeV ring
3 GeV ring (R3) The MAX IV personnel safety system / PSS areas / 3 GeV ring
Cavity test The MAX IV personnel safety system / PSS areas / Cavity test
SPF beamlines The MAX IV personnel safety system / PSS areas / SPF beamlines
1.5 GeV ring beamlines The MAX IV personnel safety system / PSS areas / 1.5 GeV ring beamlines
3 GeV ring soft x-ray beamlines The MAX IV personnel safety system / PSS areas / 3 GeV ring soft x-ray beamlines
3 GeV ring hard x-ray beamlines The MAX IV personnel safety system / PSS areas / 3 GeV ring hard x-ray beamlines
Control of radiation sources
Contactors Contactors are used by the PSS to control the three-phase power to the equipment that accelerate the electrons. ● Modulator contactors Controls the three-phase power to the modulators powering the electron guns and the linac structures. ● RF transmitter contactors Controls the three-phase power to the RF transmitters powering the RF cavities in the storage rings. The MAX IV personnel safety system / Control of radiation sources / Contactors
Electron beam dumps Electron beam dumps are used by the PSS to control which areas of the facility the electron beams can reach. ● Transfer line to SPF BC2 beam dump and BC2 magnets determine if the electron beam can reach the SPF. ● Transfer line to 1.5 GeV ring TR1 beam dumps determine if the electron beam can reach the 1.5 GeV ring. ● Transfer line to 3 GeV ring TR3 beam dumps determine if the electron beam can reach the 3 GeV ring. The MAX IV personnel safety system / Control of radiation sources / Electron beam dumps
Photon beam shutters Photon beam shutters are used by the PSS to control which areas of the facility the photon beams can reach. ● Front-end beam shutters Two shutters per beamline determine if the photon beam can reach the optics hutch. Heat absorber monitored but not controlled by PSS. ● Monochromatic beam shutters At the hard x-ray beamlines, two shutters per beamline determine if the photon beam can reach the experimental hutch. Additional pairs of shutters at beamlines with additional experimental hutches. The MAX IV personnel safety system / Control of radiation sources / Photon beam shutters
Gun test modulator The MAX IV personnel safety system / Control of radiation sources / Gun test modulator
Linac modulators (transfer lines closed) The MAX IV personnel safety system / Control of radiation sources / Linac modulators (transfer lines closed)
Linac modulators (transfer lines closed) To accommodate access for maintenance etc. the transfer line shafts from the linac to the 1.5 GeV ring and from the linac to the 3 GeV ring are large. A metal gate in each transfer line divide the linac PSS area and the PSS areas of the rings. Radiation from electron losses in the linac can reach the transfer line and the nearby sections in the ring tunnel. There is no access to the top subarea of each ring unless all linac modulator contactors are open. The MAX IV personnel safety system / Control of radiation sources / Linac modulators (transfer lines closed)
Linac modulators (transfer line to SPF open) The MAX IV personnel safety system / Control of radiation sources / Linac modulators (transfer line to SPF open)
Linac modulators (transfer line to R1 open) The MAX IV personnel safety system / Control of radiation sources / Linac modulators (transfer line to R1 open)
Linac modulators (transfer line to R3 open) The MAX IV personnel safety system / Control of radiation sources / Linac modulators (transfer line to R3 open)
1.5 GeV ring RF transmitters The MAX IV personnel safety system / Control of radiation sources / 1.5 GeV ring RF transmitters
3 GeV ring RF transmitters The MAX IV personnel safety system / Control of radiation sources / 3 GeV ring RF transmitters
3 GeV ring RF transmitters One of the RF cavities in the 3 GeV ring is situated on top of the transfer line from the linac to the 3 GeV ring. Additional lead shielding is mounted below the RF cavity to provide shielding towards the linac PSS area. Access to the linac is allowed even when the RF cavities in the 3 GeV ring are running and when there is a stored electron beam. The MAX IV personnel safety system / Control of radiation sources / 3 GeV ring RF transmitters
Cavity test RF transmitters The MAX IV personnel safety system / Control of radiation sources / Cavity test RF transmitters
Front-end beam shutters The MAX IV personnel safety system / Control of radiation sources / Front-end beam shutters
Monochromatic beam shutters (1 st pair) The MAX IV personnel safety system / Control of radiation sources / Monochromatic beam shutters (1 st pair)
Monochromatic beam shutters (2 nd pair) The MAX IV personnel safety system / Control of radiation sources / Monochromatic beam shutters (2 nd pair)
Control room keys Keys in the control room are used to enable the running of different parts of the facility (contactors, electron beam dumps, photon beam shutters). The keys also enable different modes of operation (linac frequency, top-up, I/O tests etc.). During operation of the MAX IV facility, at least one person with the skills to identify and the mandate to address deficiencies in the radiation safety must be physically present at the facility. If no one is present, all keys must be removed. Emergency stops located in the control room shut down the sources of ionizing radiation at different parts of the facility. The MAX IV personnel safety system / Control of radiation sources / Control room keys
Control room keys The MAX IV personnel safety system / Control of radiation sources / Control room keys
Design principles
Design principles The critical safety functions are designed High contribution PFH D based on the general design principles of to risk reduction [1/h] ISO 13849-1 to reach a structure 10 -8 according to category 4 (Cat. 4) and PLe SIL3 performance level e (PLe). 10 -7 Requires use of well-tried safety principles, components with high mean PLd SIL2 time to dangerous failure, adequate 10 -6 measures against common cause failures PLc SIL1 and high diagnostic coverage. PLb 10 -5 PFH D [1/h] = Average probability of dangerous failure per hour PLa 10 -4 Low contribution to risk reduction The MAX IV personnel safety system / Design principles / Design principles
Safety PLCs with distributed I/O nodes The personnel safety system for the accelerators and beamlines is based on Safety PLCs working in a two processor- architecture with one primary and one partner processor. The safety PLCs communicate over Ethernet/IP with distributed I/O nodes equipped with safe and standard I/O cards to which the PSS components are connected. In total, the radiation safety related PSS consists of 5675 I/O signals, out of which 3077 are safe signals, distributed over 76 I/O nodes and 15 safety PLCs. The MAX IV personnel safety system / Design principles / Safety PLCs with distributed I/O nodes
PSS division The MAX IV personnel safety system / Design principles / PSS division
I/O signals The MAX IV personnel safety system / Design principles / I/O signals
Example of safety function Opening a linear accelerator main access door during operation causes a section of the linear accelerator to shut down. ● Each door is monitored using a two- channel interlock switch. ● The input and output signals are handled in instructions in the safe part of the PLC code of the safety PLC. ● Three-phase power to each modulator is controlled by a pair of large contac- tors. Each large contactor is controlled by a small contactor. Mechanically linked positively guided feedback contact on each contactor monitored. The MAX IV personnel safety system / Design principles / Example of safety function
Example of safety function Opening a linear accelerator main access High contribution PFH D door during operation causes a section to risk reduction [1/h] of the linear accelerator to shut down. 10 -8 ● Interlock switch: SensaGuard PLe PFH D [1/h] = 1.12·10 -9 10 -7 ● POINT Guard I/O: 1734-IB8S PLd PFH D [1/h] = 5.10·10 -10 Safety PLC: 1756-L7xS & L7SP 10 -6 PLc PFH D [1/h] = 1.2·10 -9 POINT Guard I/O: 1734-OB8S PLb 10 -5 PFH D [1/h] = 5.14·10 -10 PLa ● Output contactors (365 cycles/year): 10 -4 PFH D [1/h] = 9.05·10 -10 Low contribution PFH D [1/h] = 4.25·10 -9 to risk reduction The MAX IV personnel safety system / Design principles / Example of safety function
Searching beamline hutches
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