1. André Augustinus 16 September 2002 Safety issues

2. André Augustinus 16 September 2002DCS Workshop 2 Safety Systems  What is Safety: Safety of people (prevent injuries or worse) Safety of equipment (protect capital investment)  What systems are involved in Safety for ALICE: Detector Control System (DCS) Experimental area safety system (DSS) CERN Safety System (CSS)

3. André Augustinus 16 September 2002DCS Workshop 3 Safety System overview CSS TCR Fire Brigade to P2 Alice Control Room “Safety console” smoke fire gas flood DSS ambient temperature water temperature humidity water leak Status (interlock) DCS services: electricity gas water signals actions Alice Control Room “DCS console(s)” detector equipment control and monitoring HV, LV, cooling etc. actions (high granularity)

4. André Augustinus 16 September 2002DCS Workshop 4 Detector Control System DCS ensures integrity through: Alarm reporting (for operator intervention) and automation Detailed control on detector level and control of infrastructure and services (with high granularity) Interlocks on detector level but does not necessarily cover: Experiment environment Parameters not covered by a detector nor by CSS: Ambient temperature or humidity, cooling water temperature, small water leaks, … Cross-detector interlocks Detectors could have the need to act on other detectors or services Not their responsibility Do not endanger personnel

5. André Augustinus 16 September 2002DCS Workshop 5 Detector Safety System  Name might be misleading, DSS covers more than only detector safety Think of it as experimental area surveillance system  Will be a (redundant) PLC based system  Will act autonomously and with a lower granularity as DCS  We preliminary identified around 100 inputs, and 100 outputs for ALICE  “Back-end” in the control room should also serve as interface to CSS  Common effort across four LHC experiments “basic” DSS system available in summer 2003

6. André Augustinus 16 September 2002DCS Workshop 6 DCS vs. DSS  DCS Infrastructure (environment, rack control) will monitor temperatures, humidity etc. Relatively high granularity “Friendly” actions can be programmed With “DCS reliability”  DSS will also monitor temperatures etc. With lower granularity Only rather coarse actions can be programmed With “High reliability”

7. André Augustinus 16 September 2002DCS Workshop 7 Detector integrity  Integrity of a detector is primarily that detectors responsibility  Regulation and control via software (DCS)  Ultimate protection via local interlocks  But, can only act on where it has control over DCS Software action interlock Detector

8. André Augustinus 16 September 2002DCS Workshop 8 External to a detector  Higher level DCS can implement cross- detector actions  DSS can implement cross-detector interlocks or interlock to a service Detector Software action across detectors Software action on service Cross-detector interlock Interlock to service

9. André Augustinus 16 September 2002DCS Workshop 9 Experiment environment  DSS can act on problems outside the control of detectors  Can act on several detectors or services  Can only be done with lower granularity Detector

10. André Augustinus 16 September 2002DCS Workshop 10 Again, requirements…  We would like to know what you need Local interlocks Share expertise and experience Try to uniform interlocks What external signals do you need E.g. gas, stop of primary water, magnet, … On what external system do you want to act What in the environment could endanger your detector

11. André Augustinus 16 September 2002DCS Workshop 11 Level 3 Alarms (CSS)  Covers: Fire/Smoke, Flammable gas, O 2 deficiency, evacuation, flood, emergency stops New “Sniffer” project (common for all LHC experiments) Environment inside the experiment (magnet)  Currently using what is left from LEP times  First new installation starts end this year  Basic rule: It is up to Alice to define what is needed when and where (GLIMOS, TC and TIS)

12. André Augustinus 16 September 2002DCS Workshop 12 Cable trays  Monitoring of temperature is not a good indication Electrical insulation tends to be a good thermal isolator as well  Sampling the air with sensitive smoke detectors is a much better method Perforated tube on cable trays

13. André Augustinus 16 September 2002DCS Workshop 13 Planning overview 20022003200420052006 Prototyping DSS 1 st DSS available Flam. Gas/O 2 Def. (surface) ‘Sniffer’ URD ready Upgrade fire det. (surface) Evacuation (underground) DCS activity (TPC) Infrastructure DCS (racks) Flammable Gas (SG) Upgrade fire det. (underground) Flam. Gas/O2 Def. (undergr.)