Failure Analysis Tools at DESY. M. Bieler, T. Lensch, M. Werner, DESY ARW 2013, Melbourne,

M. Bieler | Failure Analysis Tools at DESY| April 17, 2013 | Page 2 Content > PETRA III overview > PETRA III Machine Protection System > Failure Analysis through the MPS > Conclusion

M. Bieler | Failure Analysis Tools at DESY| April 17, 2013 | Page 3 PETRA III Overview > 2.3 km circumference > 6 GeV positrons > 20 damping wigglers > 14 undulator beamlines > 1 nm rad x 10 pmrad > 100 mA > TopUp operation, 1% beam current variation

M. Bieler | Failure Analysis Tools at DESY| April 17, 2013 | Page 4 PETRA III Overview > only 1/8 of the circumference used for beamlines > 8 double bend acromat cells > 14 undulator beamlines:  2 m Undulators: 11  5 m Undulators: 3 (2+1)  5 m Apple Undulator: 1

M. Bieler | Failure Analysis Tools at DESY| April 17, 2013 | Page 5 PETRA III Overview Possible faults: > 850 magnets with 550 power supplies > 2 RF transmitters with 4 klystrons > 2.3 km vacuum system > 5 km cooling water installations > …. Risk potential: > enough SR power to melt the beam pipe > enough beam power to damage magnets Fault Sensors: > BPMs > temperature sensors > alarms from many components > ….

M. Bieler | Failure Analysis Tools at DESY| April 17, 2013 | Page 6 PETRA III Machine Protection System Specification: > signal processing within 100 μs > combination of alarms > minimum number of alarms for a beam dump (configurable) > identification of the primary alarm > post mortem trigger for other systems to freeze their buffers  Dump if local beam orbit out of tolerance and undulator magnet gap less than 50 mm and beam current more than 1 mA  Dump if more than two vacuum pumps above the threshold

M. Bieler | Failure Analysis Tools at DESY| April 17, 2013 | Page 7 PETRA III Machine Protection System Alarm sources: beam permit vacuum valves getter pumps undulator gaps undulator fail beamline interlock fast valves BPMs temperature water flow manual dump screen monitor manual valves current limit bunch current limit interlock test Sum Alarm diagnostic: magnets RF kicker magnets Sum > Limited number of signals. > Challenges:  spread all over the site  combination of signals  speed

M. Bieler | Failure Analysis Tools at DESY| April 17, 2013 | Page 8 PETRA III Machine Protection System System overview:

M. Bieler | Failure Analysis Tools at DESY| April 17, 2013 | Page 9 PETRA III Machine Protection System > Distributed system  10 crates in 9 halls > Alarm collection in every crate > Redundant fiber optic link distributes  Beam current  Dump event  Post Mortem trigger  Synchronisation of the modules

M. Bieler | Failure Analysis Tools at DESY| April 17, 2013 | Page 10 PETRA III Machine Protection System Beam Current Monitor Dedicated Beam Current Monitor for the MPS: > Detects beam losses (more than 2 mA within 108 μs)  Relative timing between beam dump and beam loss Beam Loss before Beam Dump Beam Dump before Beam Loss

M. Bieler | Failure Analysis Tools at DESY| April 17, 2013 | Page 11 Failure Analysis through the MPS Matrix of all input signals Colour Code

M. Bieler | Failure Analysis Tools at DESY| April 17, 2013 | Page 12 Failure Analysis through the MPS Active alarm Detailed information about the alarms in the column chosen on the left side. Reason for the last beam dump. Signature of the last beam dump.

M. Bieler | Failure Analysis Tools at DESY| April 17, 2013 | Page 13 Failure Analysis through the MPS Reason for the last beam dump. How do we know?

M. Bieler | Failure Analysis Tools at DESY| April 17, 2013 | Page 14 Failure Analysis through the MPS Beam line interlock Clean dump. Example: Dump due to a beam line interlock

M. Bieler | Failure Analysis Tools at DESY| April 17, 2013 | Page 15 Failure Analysis through the MPS Example for a clean dump:

M. Bieler | Failure Analysis Tools at DESY| April 17, 2013 | Page 16 Failure Analysis through the MPS MPS archive viewer: Information about every beam dump available.

M. Bieler | Failure Analysis Tools at DESY| April 17, 2013 | Page 17 Conclusion > PETRA III needs a Machine Protection System (MPS) > The MPS collects data from all major components > The MPS generates precise timing information for every beam loss > With this information and the help of a rule based system, the MPS identifies the likely course of a beam dump > The MPS is the first source for every failure analysis