1. The ALICE TRD - HVDistribution System A. Markouizos, P. Mantzaridis, P. Mitseas, A. Petridis, S. Potirakis, M. Tsilis, M. Vassiliou Athens University ALICE DCS Workshop CERN, November 2007

2. Outline 1.HVD system @ CERN 2.HV Control System 3.Magnetic field test  Setup and procedure  Results 4.Test on the TRD – SM II 5.Current status – Future Plans ALICE DCS Workshop CERN, November 2007

3. HVD system @ CERN 1 Anode + 1 Drift Crate @ P2 to power 3 TRD - SMs Each crate contains: 1 DCS Board 1 Backplane supplies the Master HV to each card distributes the isolated LV to the active components enables the CAN bus communication 15 HVD cards 8 Transformer boards for the auxiliary power supplies on each HVD card 4 LV power supplies (5V, ±12V) ALICE DCS Workshop CERN, November 2007

4. HVD Crates and Card images

5. Specifications of the HVDS Anode Voltage - dynamical range900 – 1900 V - ramp-up rateup to 30 V/s - ramp-down rateup to 100 V/s - voltage stability  V < 50 mV - voltage readout10 Hz - max. current6.3  A - response time < 50 ms (e.g. overcurrent) ALICE DCS Workshop CERN, November 2007

6. Specs. (cont) Drift Voltage - dynamical range1450 – 2450 V - ramp-up rateup to 30 V/s - ramp-down rateup to 100 V/s - voltage stability Δ V < 50 mV - voltage readout 10 Hz - max. current260 mA - response time < 50 ms (e.g. overcurrent) ALICE DCS Workshop CERN, November 2007

7. Emergency Ramp Down Procedure: This is a special function that ramps down the channel but the rate may be different from the set one. (We suppose that the voltage measurement system is out of order) Control error on Current measurement Activate the emergency ramp down Ramp down and switch off the channel, or ignore. Due to three (or more) successive comm. errors the channel current Measure is halted. This affects Current Measurement, Over-Current Functions. ISO ADC communication failed 304 Communication error in Current measurement System No action. Channel must be inspected Warning: Communication error detected in current measurement system. The warning appears for the first and second time this error occurs. Error in ISO ADC communication detected 303 Control error on Voltage measurement Activate the emergency ramp down Emergency Ramp- Down Procedure may be activated. Channel has to be switched off. Due to three (or more) successive comm. errors the channel voltage control is halted. This affects Voltage Measurement, Over-Voltage, Ramp Functions. Voltage ADC communication failed 302 Communication error in Voltage measurement System No action. Channel must be inspected Warning: Communication error detected in voltage measurement system. The warning appears for the first and second time this error occurs. Error in Voltage ADC communication detected 301 PVSS Msg User Actions DescriptionTechnical Info Error No Error Messages (Hardware Errors)

8. General Communication Error (error #) Card has to be inspected From this error # the error messages are related with SJA1000 (can controller ) hardware errors. Multiple errors in a short period of time, may be a sign of future loss of the card. SJA1000 (Can Controller) Errors 308 Channel out of order No action. Actions should have been taken during the previous events Due to previous events the control of the channel is halted Hardware Error on channel 307 Voltage can not be increased to the desired value Ramp down channel, and then switch it off Voltage Value has reached the highest hardware possible value. This occurs due to either wrong voltage set or error in voltage control system Min Voltage DAC Value exceeded 306 Voltage can not be reduced to the desired value Ramp down channel, and then switch it off Voltage Value has reached the lowest hardware possible value. This occurs due to either wrong voltage set or error in voltage control system Max Voltage DAC Value exceeded 305 PVSS Msg User Actions DescriptionTechnical Info Error No

9. Error Messages Voltage Errors  Over Voltage  message: max allowed voltage is exceeded  action: voltage is set to the max allowed value  Under Voltage  message: min allowed voltage is out of range  action: voltage is set to the max allowed value  Limits Error  message: set value is out of limits  action: limit is set to the default value Current Errors (Hardware Error)  Over Current  alarm: max allowed current is exceeded or a short-circuit occurred Ramping Errors  Ramping Rate  message: max allowed rate is exceeded  action: rate is set to the max allowed value  Ramping End Value  message: end value is out of limits  Action: value is set to the max allowed  Limits Error  message: set value is out of limits  action: limit is set to the default value

10. HV Control System (I) ALICE DCS Workshop CERN, November 2007

11. HV Control System (II) ALICE DCS Workshop CERN, November 2007

12. HV Control System (III) ALICE DCS Workshop CERN, November 2007

13. HV Control System (IV) ALICE DCS Workshop CERN, November 2007

14. HV Control System (V) ALICE DCS Workshop CERN, November 2007

15. HV Control System (VI) ALICE DCS Workshop CERN, November 2007

16. Magnetic Field Test Tests performed in the MNP22 Facility at CERN The Anode (Drift) crate gets 15 HV inputs each from one ISEG EHSF630p-F HV module (two ISEG EHS8630n-F HV modules),mounted on an ISEG crate Combined HV system (ISEG+HVD) controlled and monitored by the developed PVSS project running on a laptop ALICE DCS Workshop CERN, November 2007

17. Test Procedure Each crate tested separately HV set at -2.4 kV (Drift), 1.8 kV (Anode) B increased from 0 to 220 Gauss Both field polarities Two crate configurations Successful over current test ALICE DCS Workshop CERN, November 2007

18. HVD crate configurations ALICE DCS Workshop CERN, November 2007

19. Results: Drift HVD @ -2.4 kV ALICE DCS Workshop CERN, November 2007 magnet onmagnet off σ < 14 mV

20. Results: Anode HVD @ 1.8 kV ALICE DCS Workshop CERN, November 2007 magnet onmagnet off σ < 14 mV

21. Test on the TRD - SM II HVD system connected with the SM-II Anode voltage @ 1.45 kV Drift voltage @ -1.5 kV, -1.9 kV Successful overcurrent test ALICE DCS Workshop CERN, November 2007

22. Results: Test on the TRD - SM II ALICE DCS Workshop CERN, November 2007 Anode HVD @ 1450 V σ < 15 mV Drift HVD @ 1900 V

23. Current status – Future plans Another 2 HVD crates (1 anode + 1 drift) will be delivered at CERN in November: – 4 crates in total to power 6 TRD – SMs HVD control system: completion of the FSM integration to the TRD/DCS Installation at Point 2 ALICE DCS Workshop CERN, November 2007

24. Thank you! ALICE DCS Workshop CERN, November 2007

25. Backup

26. ALICE DCS Workshop CERN, November 2007