1. E.Sbrissa EP/TA3 - IC ATLAS EDR_MAG Magnet Project Fault analysis, QA & Failure rate

2. E.Sbrissa EP/TA3 - IC ATLAS EDR_MAG Magnet Project Fault analysis

3. E.Sbrissa EP/TA3 - IC ATLAS EDR_MAG Magnet Project Electrical Network Fault  Normal network off Magnet in slow discharge Diesel switched ON  Return Magnet kept in slow discharge  Diesel out of service Magnet not affected  Return Magnet not affected  Normal network off & Diesel out of service or AUG/AUL Magnet in slow discharge  Return Magnet kept in slow discharge

4. E.Sbrissa EP/TA3 - IC ATLAS EDR_MAG Magnet Project Power circuit fault  PC or cooling water fault Magnet in slow discharge  Return Magnet kept in slow discharge  CP balancing current Alarm Operator  DCCT fault Magnet in slow discharge  Return Magnet kept in slow discharge

5. E.Sbrissa EP/TA3 - IC ATLAS EDR_MAG Magnet Project MCS fault  UPS fault Magnet in slow discharge  Return Magnet kept in slow discharge  PLC I/O fault Magnet in slow discharge  Return Magnet kept in slow discharge  PLC “Watch dog”  PLC “Watch dog” Magnet in slow discharge  Return Magnet kept in slow discharge

6. E.Sbrissa EP/TA3 - IC ATLAS EDR_MAG Magnet Project MSS fault  One Battery system fault Magnet in slow discharge  Return Magnet kept in SD  Two Battery systems fault Magnet in slow discharge  Return Magnet kept in SD  Monitoring fault Magnet in slow discharge  Return Magnet kept in SD  Component fault or lack of 48Vdc Magnet in Fast discharge  Return Magnet kept in FD

7. E.Sbrissa EP/TA3 - IC ATLAS EDR_MAG Magnet Project Quench heater fault  Power supply fault Magnet in slow discharge  Return Magnet kept in SD  Distribution fault Magnet in slow discharge  Return Magnet kept in SD  Cable fault Magnet in slow discharge  Return Magnet kept in SD

8. E.Sbrissa EP/TA3 - IC ATLAS EDR_MAG Magnet Project Reliability of MSS  System fully redundant  Safety or availability?  The main parts of the safety system are fail-safe

9. E.Sbrissa EP/TA3 - IC ATLAS EDR_MAG Magnet Project Fault rate of components  Rules and norms  Environment description  Conditions of estimation  Results

10. E.Sbrissa EP/TA3 - IC ATLAS EDR_MAG Magnet Project Environment & conditions  Estimation with constant fault rate  Life time of components >20 years  Worst case systematically considered  Profile of mission in one phase  Usual environment for communication equipment

11. E.Sbrissa EP/TA3 - IC ATLAS EDR_MAG Magnet Project Failure rate results  ComponentMTBF*MTBF  Voltage measure DVM714000513000  Temperature measure DTM714000513000  Supercond. quench detector DSQD700000476000  Bridge quench detector DBQD714000513000  Analog output module AOM830000  Digital input DIM975000660000  1) Hardwired logic HLM925000  Power supply (Melcher) CVRT 300000  Power supply (RO Ass) CVRT 290000  1) Application interface controller APC626000

12. E.Sbrissa EP/TA3 - IC ATLAS EDR_MAG Magnet Project Siemens S7 series  ComponentMTBF  Digital input SM 421 DI3210 6  Analog input SM431 Gen.purpose290000  Digital output SM421 DO32185000  CPU 414-2201000

13. E.Sbrissa EP/TA3 - IC ATLAS EDR_MAG Magnet Project Quality Assurance  Test of prototypes Check behavior at long term EMC tests foreseen in summer  Production of components Standard settings Test benches provided by Cern  Application to ATLAS Individualization of settings Check the thresholds Tests the complete system  Modifications Procedures to be applied  Periodical tests Shutdown maintenance & checking  Systematical tests Startup checking

14. E.Sbrissa EP/TA3 - IC ATLAS EDR_MAG Magnet Project Procedures We consider three phases during the life of MSS: · The first phase is when we install and start for the first time the electronic of MSS. During this period, the magnet should never be in a critical situation. That means to limit the current at a non-dangerous value and to avoid critical situation with cryogenic. · The second phase is when MSS is ready to work and the first test with high current in the magnet could start. This phase concerns mainly the test on underground/surface period. · The last one is when the magnet is ready to run. Usually the modification should be done during the shutdown period. Along of these phases, parameters on many components of MSS should be adapted, modified or adjusted following tests and commissioning of the magnet. To guaranty the system works well, we need to define and apply some safety procedures to validate these modifications. The procedures below must be applied during the phases two and three.

15. E.Sbrissa EP/TA3 - IC ATLAS EDR_MAG Magnet Project Modification of threshold. o Determine component for new threshold. o Modification of hardware module. o Simulation on test bench. o Installation and test on site. Modification of Hardwired Logic, Mask & Un-mask digital input. o Compilation and simulation on MaxIIPlus tool of the new equations. o Transfer the new logic into Altera. o Simulation on the test bench. o Installation and test on site.