1. 1 Radiation worries in the cavern L.Jirdén 17.6.02

2. 2Access ~55m PLUG ALICE DETECTOR CR1 CR3 CR2 CR4 ACR BEAM ~50m ~15m Cavern only accessible during shutdowns !

3. 3 Magnetic field ~55m PLUG ACR BEAM ~50m ~15m 0.5 T No impact Stray fields, impact ? Shielding DC/DC’s, etc Two main magnets L3 and MUON dipole

4. 4 Radiation levels in ALICE u Simulation made by B.Pastircak u 3 main sources: u Particle production at interaction point: 90% u Beam-gas interactions: 10% u Beam loss at injection: 1% u Conditions u Global running scenario PbPb, CaCa, pp u Geometry as known early 2002 u Results u Normalized to 10 years normal operational scenario Total dose [krad] Fluency [n*cm -2 ] u Rack on the floor ~ 1 ~10 9 u Rack 12m above floor ~ 0.006 ~10 7

5. 5 Radiation levels ~55m PLUG ALICE DETECTOR ACR BEAM ~50m ~15m 200 175 rad hard el. required 2 4.3 COTS ok, SEU strateg 1 0.9 SEU strategy ? 0.006 0.0006 minor effects? racks in c-rooms gas distribution racks in cavern dose n.fl. Krad E10 n/cm2

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7. 7 Radiation tests

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9. 9 Consequences u Test by experiments u Extensive tests of “on-detector components” u Very few tests of ALICE “cavern components” u ATLAS ELMB test since 3 years u Wiener Power supplies, CAEN DC/DC u Test of equipment by LHC machine u Ongoing effort since 5 years u Wide range of equipment tested u power supplies, PLC’s, sensors, gagues, vacum equipment, etc u Mainly using TCC2 facility u Levels in LHC tunnel and ALICE cavern similar? To be checked!

10. 10 SPS - North Experimental Hall TCC2 Hall and Beam Lines TAX collimator M2 beam line T6 Target Radiation Damage Test Area LHC tests

11. 11 Modular Power Supplies Denis Hundzinger - SL/PO u Test of 3 Different Technologies: u Serial Regulation u Switching with Bipolar, Transformer Coupling u Switching with MOS-FET, Transformer Coupling u 28 Units Tested – 11 Types – 6 Manufacturers u Remarks: u Some Units Do Not Restart after Switch-Off u Output Voltage Drifts With or Without Input Power LHC tests

12. 12 Switching Power Supplies Type: - VERO PK55 (2 Modules) - Triple Switching + 5V/5A and 2x 5-15V/1A Notes: - Measurement on 5 Volt Output Only - Load = ~ 4 Amp - Output Voltages increase with the Radiation Dose - Both 5 Volt Output Voltages Start to Deteriorate at ~ 5 Grays ~ 5 Gray ~ 540 Gray LHC tests

13. 13 Preliminary Results u PLC - First Error (Isolated Effect) at < 1 Gy - After Reload, Systematic Memory Error 4-8sec. 5 Gy - No Reply 20 Gy u Edwards Gauges (With Integrated Electronics) - Gauge AIMX-X 50 Gy - WRG-S 1000 Gy u Balzers Gauges - 2 Gauges PKR 251 290 Gy and 430 Gy - 1 Gauge PKR 265 450 Gy LHC tests

14. 14 Lessons Learned u Electronic Equipment that Will not Work Reliably in the LHC Tunnel: u Intelligent Sensors and Actuators (Few Exceptions) (Remote Electronics and Cables Required) u Complete Industrial PLCs (COTS) u Intelligent I/O Modules (COTS) with Micro and Memory u Conventional Switching Power Supplies (NMOS) u Processors Without Error Correction Memory LHC tests

15. 15 Lessons Learned u LHC Electronic Equipment That Needs to be Tested before Installation: u Passive Components (Optical Fibers, Resistors, Capacitors) u Active Components (Signal Conditioners, MUXs, Op.-Amp., ADCs, DACs, FPGAs, EPROMs SRAMs with EDAC) u Sensors, Actuators, Gauges, Positioners,Valves, Flowmeters u Modular Power Supplies (Serial Regulation, Bipolar Transistors, Transformer Coupling Feedback, No OptoCouplers) LHC tests

16. 16 Lessons Learned u RadHard Developments are Required for: u Simple Input/Output Modules with Fieldbus Interfaces to WorldFIP or Profibus (Command/Response Operation) u Dedicated Power Supplies (Quench Protection) u Orbit Corrector Power Converters u Control Processors with EDAC Memory and Remote Reset Capability. LHC tests

17. 17 Conclusions Present Results Suggest that ALL Electronic Systems, Intended for Installation in the Tunnel, Should be Radiation Qualified The Radiation Test Facility is Qualified to Provide a Radiation Environment Similar to That of the LHC Tunnel (Arcs) The On-Line Test Facility can be Used for the Final Qualification of Complete Working Systems LHC tests

18. 18 What equipment is planned for ALICE cavern? u Power distribution (Hazemeyer) + control u Network equipment u LV supplies u CAEN 1527, Wiener PL500, AREM Pro, Eutron, ? u HV supplies u CAEN 1527, ISEG, ? u Gas u Distribution for some detectors u Cooling u Cooling plants & its control u Detector cooling I/O u VME u Crates and modules u Others?

19. 19 Conclusion u More detailed simulations needed u Effects (at middle and low levels) to be better understood u Strategy to be defined u Possibility to move equipment from UX to PX? u Systematic qualification of “cavern equipment”? u Who does what?