Bericht vom Accelerator Reliability Workshop ARW 2011

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1 Bericht vom Accelerator Reliability Workshop ARW 2011
A. Denker Reliability gemäß LEO: Ausfallsicherheit Betriebssicherheit Funktionsfähigkeit Verlässlichkeit Zuverlässigkeit

2 Statistik: Übersicht 1. 2002 ESRF 2. 2009 Triumf 3. 2011 Kapstadt
41 Beiträge von Beschleunigern 78 Teilnehmer, ohne “Locals”: 1/3 Amerika, 1/5 Asien, knapp ½ Europa 3 Beiträge aus anderen Einrichtungen Kernkraftwerk Koeberg, SALT (South African Large Telescope): jwd, Temp.gradienten South African Square Kilometer Array Project: jwd, möglichst ferngesteuert, da bereits ein Handy stört Zwei Diskussionsrunden Magnete Webseite/Forum

3 Statistik: wer war da Lichtquellen: SLAC, BNL, Diamond, ESRF, PSI, Australian synchroton, Spring8, SSRF Spallationsquellen: PSI, SNS Zyklotrons: allg.: NSCL, iThemba, Uppsala, RIKEN, IBA med.: MGH, Orsay, HZB, Sonstige: GSI, HIMAC, INFN, DaLinac, Siemens, CERN, Fermilab

4 Historischer Überblick: Hardy (ESRF)

5 Ausblick: Hardy (ESRF)

6 Ansprüche Spallation: PSI

7 Theorie und Programme: SNS

8 Theorie <-> echtes Leben

9 Trend formale Organisation: GSI

10 Trend formale Organisation: SLAC

11 Trend formale Organisation: CERN

12 Trend formale Organisation: BNL

13 Trend formale Organisation: NSCL

14 Automatisierung: Australien
Lichtquellen: SLAC, BNL, Diamond, ESRF, PSI, Australian synchroton, Spring8, SSRF Spallationsquellen: PSI, SNS Zyklotrons: allg.: NSCL, iThemba, Uppsala, RIKEN, IBA med.: MGH, Orsay, HZB, Sonstige: GSI, HIMAC, INFN, DaLinac, Siemens, CERN, Fermilab

15 Kontrollsystem: ESRF

16 e_log: INFN

17 e_log: http://midas.psi.ch/elog

18 RF verbessert: RIKEN Ringzyklotron
Erreicht durch Vakuum verbessert CW – konditionieren…

19 RF verbessert: DALINAC
Temp.sensor auf RF Regelkarte

20 Diagnose: Diamond Remotely Controlled, Mobile, Thermal Imaging Platform

21 fehlende Diagnose: CERN

22 Wartung auch für Ersatzteile: Spring 8

23 Probleme durch Kleinigkeiten: SINAP

24 Probleme durch Kleinigkeiten: CERN

25 Umfrage: Magnetfehler

26 Stromausfälle: iThemba

27 Stromausfälle: Australien

28 med. Beschleuniger: MGH: >95%

29 med. Beschleuniger: Orsay

30 med. Beschleuniger: Siemens, prev. maintenance

31 med. Beschleuniger: IBA, Field Replaceable Unit

32 Reliability unter besonderen Umständen

33 Reliability unter besonderen Umständen
uptime: 94%

34 Zusammenfassung Erfahrungsberichte aus der Praxis – nicht geschönt
große Unterschiede zwischen den Beschleunigeranwendungen: die Probleme sind jedoch bei allen ähnlich intensiver Austausch, sowohl in Podiumsdiskussionen Lüdeke - zentrale Datenbank für Reliability, Spencer - als auch mit den Teilnehmern viele Ideen für zu Hause mitgebracht Lichtquellen Kernphysik/Spallation Med. Beschleuniger Betriebszeit ~ 4500 h ~ 6000 h stark variierend Uptime > 98 % > 90 % > 95 %

35 History 1977: start of cyclotron operation for nuclear physics (VICKSI) 1995 – 2006: Ionenstrahllabor ISL – laboratory for ion beam applications internal and external (~ 70%) users ion energy: eV < Eion< 800 MeV research areas: materials modification and ion-solid-interaction materials analysis medical applications since 2007: accelerator operation for therapy purposes only

36 Accelerator Layout 5.5 MV Van-de-Graaff
2 x 14.5 GHz ECR sources on 150 kV platforms RFQ 16 dedicated target stations k = 132

37 Accelerator Performance
cyclotron in operation since 1977 averaged downtime before 1995: 10 % start of therapy start of RFQ operation for users

38 Reduction of Downtime step by step process
addressing all subsystems: sources, injectors, beam lines, cyclotron, control system preventive maintenance increased redundancy modernisation improved diagnosis reduction of elements

39 Preventive Maintenance
regular belt change of Van-de-Graaff service of rotating parts cyclic change of spare power supplies used on HV terminal drying of SF6 gas cleaning of isolators service on vacuum pumps: oil, bearings replacement of water tubes

40 Modernisation new computers for control system
replacement of old dipole power supplies exchange of shunt against transducer regulation in quadrupole power supplies (gain in stability: factor 10) discrete rectifiers replaced by complete 3-phase modules replacement of main coil power supply of cyclotron side effect: less energy consumption

41 Redundancy / Reduction of elements
smaller variety of pumps, vacuum gauges, power supplies…. whenever possible: spare parts for quick exchange low intensity proton beams: no pre-bunching no water cooling of deflector plates in beam line dipoles

42 Improved Diagnostics display of accelerator status

43 Improved Diagnostics display of accelerator status 24 h charts
start of main magnet overshoot procedure

44 Improved Diagnostics display of accelerator status 24 h charts
beam stability programme

45 ISL  Protons for Therapy (PT)
11/04: decision to close ISL at the end of 2006 Post-Docs and technical staff on temporary positions left people were transferred to other departments stop of investments 9/06: start of planning operation solely for PT reduced man-power (less beam-time) reduction of beam lines, cables… this step: almost completed nevertheless: maintain reliability

46 Accelerator Performance
small number of beam time hours: major events have huge impact on statistics ~ 4500 hours/year ~ 1750 hours/year

47 ISL  PT: Operation Comparison
changing ion species and energies ~ 15 target stations varying requirements on focusing 34 weeks/year 3 shifts a day (24/24) H, 68 MeV cyclotron fixed frequency one NMR-probe/dipole 2 target stations, identical focusing 1/4 of existing beam line system 12 therapy weeks/year 2 shift operation (6:00 -22:00) Thursday: start up and tuning Friday: quality control of accelerator weekend: standby* Monday-Friday: Therapy exceptions on weekends: - experiments - infants, requiring more than 4 sessions

48 PT: Reliability availability 95 % in /3 of downtime due to one major event: electrostatic injection preventive maintenance replacement of Ta shields by Ti (good experience in ECR source) after one week: failure fault of new ceramics ? Ti shields (now Ta again) delay of 2 days uptime 2008: 98 % worst case: failure in electricity supply at 6:00 am delay of 2 hours

49 Accelerator Operation: Reliability
uptime 2009: 95 % 1/3 of downtime again due to one major event: water leak in RF interruption of therapy week for the first time since (110 therapy weeks) availability 2010: 95 % frequent drops in RF error difficult to find: isolator problems on tube socket of anode power supply

50 Lessons Learned turbo pumps on 60 % of rotational speed (standby mode) increases service intervals about factor 5 analysis of residual gas for water logging of electricity for failure analysis cryo pumps on cryo pumps off

51 Wish List Uninteruptable Power supplies:
overall solution: too expensive in investment and man power thus only for computers of control system counter on frequently moved Faraday cups

52 ISL  PT: Installation of a Tandetron
further shortening of beam lines less rooms reduction of radiation safety easy and reliable operation: no moving parts source on “ground potential” installation: Apr. 07: purchased from BAM, start of dismantling Oct. 07: transfer to HMI, installation starts Sep. 08: first beam from source Oct. 08: first beam through tandetron Mar. 09: first beam through cyclotron Aug. 10: acceptance test finished, applied for licence Dec. 10: licence granted Jan. 11: first therapy with tandetron as injector

53 ISL  PT: Installation of a Tandetron
start of tandetron beam tests: perfect short term stability measured on FC behind cyclotron

54 ISL  PT: Installation of a Tandetron
start of tandetron beam tests: perfect short term stability but long term stability unsatisfactory

55 ISL  PT: Installation of a Tandetron
start of tandetron beam tests: long term stability unsatisfactory now: short and long term stability better than 5 %

56 Conclusion 12 therapy weeks per year past years: uptime at least 95 %

57 Thank you for your attention!
Conclusion 12 therapy weeks per year past years: uptime at least 95 % but: the finest hardware is useless without dedicated personnel → sincere thanks to all the people involved Thank you for your attention!