1. MPSCWG 12/12/2007 1 Operational scenario of the BLM system 4/?

2. MPSCWG 12/12/2007 2 Addressed questions 1.Strategy for operation of the BLM system 2.Operation with < 4000 channels available? 3.Mobile BLM? 4.Tests with beam?

3. MPSCWG 12/12/2007 3 Summary of previous discussions For settings generation, BLM are grouped in families Via an expert application, a thresholds table is generated by family and stored in ORACLE database (family_info table). This table and the monitor_info table are used to derived the MASTER table, within the Database (SQL request) The MASTER tables (one per crate) is protected and set to a so- called ”max safe value” of the different equipment (energy and integration dependant ). Inside the database, an APLLIED table is derived from the same family_info and monitor_info tables AND multiplying by a factor F, 0<F≤1. Internal check within ORACLE: APPLIED table ≤ MASTER table Present implementation, there is one F per family

4. MPSCWG 12/12/2007 4 Proposed values for the different tables ElementProposed “Max safe level” Master Table Applied table Maskable/ unmaskab le Number of monitors MQ, MBSafe beam flag Max safe value Quench level Maskable2160 LSS quadSafe beam flag Max safe value Quench level Unmaskable360 DS quadSafe beam flag Max safe value Quench level Unmaskable480 TCP,TCS%, TDI, TCH, TCLP,TCLI,T CDQ,… ??Max safe value Damage level Maskable~330 MQW, MBWSafe beam flag Max safe value Damage level Maskable60 MSI, MSDSafe beam flag Max safe value Damage level Unmaskable24+60 MBR%Safe beam flag Max safe value Quench level Unmaskable

5. MPSCWG 12/12/2007 5 ElementDamage level Master Table Applied table Maskable/ unmaskab le Number of monitors MKD, MKBSafe beam flag Damage level Unmaskable24 MBXSafe beam flag Damage level Quench level Unmaskable4 TAN,TAS?Damage level Maskable8 XRP?Damage level Unmaskable9 BCM?Damage level Unmaskable BPMSW?Damage level Maskable8

6. MPSCWG 12/12/2007 6 Naming convention Official name (i.e the layout one) : refer to the location in the cell, no indication of the beam, need to be change if one monitor in added, and BLMQI.A7L8 is attached to Q6!! The expert name to identify the location: BLMQI.6R7.B1E3_MQTLH BLM location: Q for on a quad E for other location D for the dump line BLM type: I for IC S for SEM Cell and sector position Beam 1 or beam 2 observed Transverse position: E for external I for internal T/B for top bottom Position on the element: 1 for entrance 2 or 2x for inside 3 for exit Observed element: TCT, … MSI ….

7. MPSCWG 12/12/2007 7 NrDescriptionMTF query (WHERE EXPERT NAME LIKE...)cell locationNo ofMagnet BLMsType 1Arc monitor 1 on B1BLMQI.(12-34)%B1.%1_MQQ12-34 IR 1/2/3/4/5/6/7/8360MQ Problem:eg. BLMQI.11L6.B1E1_MQ 2Arc monitor 2 on B1BLMQI.%.B1.%2_MQ 360MQ...22 rows foreach cell? 3Arc monitor 3 on B1BLMQI.%.B1.%3_MQ 360MQ 4Arc monitor 1 on B2BLMQI.%.B2.%1_MQ 360MQ 5Arc monitor 2 on B2BLMQI.%.B2.%2_MQ 360MQ 6Arc monitor 3 on B2BLMQI.%.B2.%3_MQ 360MQ 7Cell 11BLMQI.11%.B1.%1_MQQ11 IR 1,2,3,4,5,6,7,816MQ 8 BLMQI.11%.B1.%2_MQ 16MQ 9 BLMQI.11%.B1.%3_MQ 16MQ 10 BLMQI.11%.B2.%1_MQ 16MQ 11 BLMQI.11%.B2.%2_MQ 16MQ 12 BLMQI.11%.B2.%3_MQ 16MQ 13Dispersion suppressor(BLMQI.8%(1,2,4,5,6,8)B1.%1_MQML) orQ8 Q9 Q10 IR 1/2/4/5/6/836MQML (BLMQI.9%(1,2,4,5,6,8)B1%1_MQM) or MQM (BLMQI.10%(1,2,4,5,6,8)B1.%1_MQML) MQML Probably:(BLMQI.8%B1.%1_MQML) or Cell 9 is different... can be easier?(BLMQI.9%B1.%1_MQM) or (BLMQI.10%B1.%1_MQML) 14Dispersion suppressorBLMQI.8%(1,2,4,5,6,8)B1.%2_MQML orQ8 Q9 Q10 IR 1/2/4/5/6/836MQML BLMQI.9%(1,2,4,5,6,8)B1.%2_MQM or MQML BLMQI.10%(1,2,4,5,6,8)B1.%2_MQML MQML 15Dispersion suppressorBLMQI.(8,10)%(1,2,4,5,6,8)B1.%3_MQML orQ8 Q9 Q10 IR 1/2/4/5/6/836MQML BLMQI.9%(1,2,4,5,6,8)B1.%3_MQM 16Dispersion suppressorBLMQI.(8,10)%(1,2,4,5,6,8)B2.%1_MQML orQ8 Q9 Q10 IR 1/2/4/5/6/836MQML BLMQI.9%(1,2,4,5,6,8)B2.%1_MQM 17Dispersion suppressorBLMQI.(8,10)%(1,2,4,5,6,8)B2.%2_MQML orQ8 Q9 Q10 IR 1/2/4/5/6/836MQML BLMQI.9%(1,2,4,5,6,8)B2.%2_MQM 18Dispersion suppressorBLMQI.(8,10)%(1,2,4,5,6,8)B2.%3_MQML orQ8 Q9 Q10 IR 1/2/4/5/6/836MQML IP3,7 cell 8,10:BLMQI.9%(1,2,4,5,6,8)B2.%3_MQM 19 BLMQI.8%3.B1.%1_MQ orQ8 Q10 IR 3/78MQ BLMQI.8%7.B1.%1_MQ or BLMQI.10%3.B1.%1_MQ or

8. MPSCWG 12/12/2007 8 Pending questions Which value for the “damage level”: “Safe beam flag” for cold element? With this strategy, MASTER table is below the damage level ( factor 320 to 1000 between damage level and quench level according to the beam energy, but the same constant is used ) too much conservative? Thresholds are defined by families: -> There is no “general” family for region like DS, injection… -> Do we need to define OP family? How (already in LSA, in TRIM)? It is possible to copy the MASTER Table and keep it in the flash memory of the BLETC. -> We have to ask for this implementation? -> We can read it back and compare with DB? -> Do we push to get also the internal comparison?

9. MPSCWG 12/12/2007 9 Status of the software Expert application for thresholds generation exists (ROOT scripts) and is used to fill the DB. (expert to LSA?) Database : Work in progress, structure defined, prototype exists with some 10 families, still some discussions about history of changes TRIM for operation : Work in progress External tables comparison (MCS extension): to be done, but no major problem

10. MPSCWG 12/12/2007 10 12 running sums (40 μs to 84 s) to cover the loss duration and 32 energy levels used for filling different buffers: logging: at 1 Hz, max loss rate in each running sums over the last second + corresponding quench levels + error and status from tests Post-Mortem : the last 1.7 s with a 40 μs sample rate (43690 values) + the last 2 min of the logging data + thresholds and masking tables + system status info XPOC : possible to get up to 32000 values per channel for the chosen running sum (need to be specified by LBDS) Collimation: on request, 32 consecutive sums of 2,54 ms Study Data: can be triggered by a timing event (to de detailed) BLM system : signals available

11. MPSCWG 12/12/2007 11 Strategy : remarks/questions The masking is done at the CIBU level: you mask all the channels connected at the same time! -> Is it acceptable from machine protection point of view? For the pair SEM-IC, interlock on the SEM? -> OK for SEM for collimators, but for MSD, MKD…? The maskable/unmaskable status can be defined only at the BLM level, without reconfiguring the BIS? What about reconfiguration of the BIS in case of disconnecting or changing the masking status at the BLM level?

12. MPSCWG 12/12/2007 12 2. Operation with < 4000 channels? (1/2) Reliability of the BLM system: G. Guaglio Ph-D thesis Designed to be SIL 3 level : redundancy in the electronics when necessary, experience with the SPS… acquire statistic with the existing system on SPS and LHC one as soon as available (150 days of running for the moment) The new software part need to be included in this study

13. MPSCWG 12/12/2007 13 2. Operation with < 4000 channels? (2/2) staged approach: how much protection is needed or how much can we relax on it during commissioning with hope to gain operational efficiency? The system need to be fully operational for phase A.5 Minimum system for each phase can/should be defined (MPSCWG) Possibility to change status of channel via the same soft as for the Thresholds masking helps for wrong evaluation of the threshold possibility to change at the BLM level the maskable/unmaskable status (what about reconfiguration of the BIS?)

14. MPSCWG 12/12/2007 14 How many channels we can lose? For commissioning:  Assumption: The loss can be seen by another monitor so we can lose locally up to 2 out of 3 on the quad according to the margin to damage level taken (the famous C factor) for the arcs  Do we have to go through the different loss patterns? (accidental case?) What about :  LSS => all needed  MSI,MKD, MSD.. => ??  collimators => all needed 

15. MPSCWG 12/12/2007 15 Mobile BLMs? Mobile BLM Same Ionisation Chambers use the spare channels per card : 2 in the arcs at each quad, a bit more complicated in the LSS because of more elements. electronics is commissioned as for connected channel All the free channels/cards… will be predefined to allow their display without touching the threshold tables Need access to connect the extra chambers Can cover a half-cell every 3-m if 2 chambers per channel No dump thresholds For which use: He leak detection: is it enough? Need some evaluation of the expected pressure dump to evaluate the signal In the LSS?

16. MPSCWG 12/12/2007 16 Simulation : typical result z (cm) Maximum of the shower ~ 1m after impacting point in material increase of the signal in magnet free locations Amplitude/length of the pressure bump?

17. MPSCWG 12/12/2007 17 4. BLM tests Functional test of full acquisition chain with Radioactive Source The procedure for this test will be described in a dedicated document made in collaboration with TIS. The purpose is to create a signal on the chamber with the RA source and check its presence in the corresponding DAB card channels. Time estimation : 0.5 to 1 hour per front-end station (8 BLMs) Provoked magnet quench possibility to check steady state losses quench limit with circulating beam (part of the MPS commissioning) possibility to check fast losses quench behavior if sector test  What do we lose if we cannot do the tests?

18. MPSCWG 12/12/2007 18 Restricted tests? Testing only a given set of BLMs with the radioactive source? Motivation of the quench test: Verification of the correlation between energy deposition in the coil (= quench level) and BLM signal (= thresholds) Verify or establish „real-life“ quench levels Verify simulated BLM signal and loss patterns => Accurately known quench levels will increase operational efficiency!

19. MPSCWG 12/12/2007 19 Conclusion GO for implementation? Acquire statistics on the reliability of the connections and the applications during the coming dry runs Evaluate the safety of the solution in March and if not satisfactory, close the HW switch! Strategy to run with non-working channels? Action for the MPWG?