Operational scenario of the BLM system 4/?

1
Operational scenario of the BLM system 4/?
2
Addressed questions

1. Strategy for operation of the BLM system
2. Operation with lt 4000 channels available?
3. Mobile BLM?
4. Tests with beam?

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, 0ltF1.
• Internal check within ORACLE APPLIED table
  MASTER table
• Present implementation, there is one F per family

4
Proposed values for the different tables
Element Proposed Max safe level Master Table Applied table Maskable/ unmaskable Number of monitors
MQ, MB Safe beam flag Max safe value Quench level Maskable 2160
LSS quad Safe beam flag Max safe value Quench level Unmaskable 360
DS quad Safe beam flag Max safe value Quench level Unmaskable 480
TCP,TCS, TDI, TCH, TCLP,TCLI,TCDQ, ?? Max safe value Damage level Maskable 330
MQW, MBW Safe beam flag Max safe value Damage level Maskable 60
MSI, MSD Safe beam flag Max safe value Damage level Unmaskable 2460
MBR Safe beam flag Max safe value Quench level Unmaskable
5
Element Damage level Master Table Applied table Maskable/ unmaskable Number of monitors
MKD, MKB Safe beam flag Damage level Damage level Unmaskable 24
MBX Safe beam flag Damage level Quench level Unmaskable 4
TAN,TAS ? Damage level Damage level Maskable 8
XRP ? Damage level Unmaskable 9
BCM ? Damage level Unmaskable
BPMSW ? Damage level Maskable 8
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

• BLM type
• I for IC
• S for SEM

• Position on the element
• 1 for entrance
• 2 or 2x for inside
• 3 for exit

Beam 1 or beam 2 observed
BLMQI.6R7.B1E3_MQTLH

• BLM location
• Q for on a quad
• E for other location
• D for the dump line

• Observed element
• TCT,
• MSI
• .

• Transverse position
• E for external
• I for internal
• T/B for top bottom

Cell and sector position
7
Nr Description MTF query (WHERE EXPERT NAME LIKE ...) cell location No of Magnet
BLMs Type

1 Arc monitor 1 on B1 BLMQI.(12-34)B1.1_MQ Q12-34 IR 1/2/3/4/5/6/7/8 360 MQ
  Problem eg. BLMQI.11L6.B1E1_MQ      
2 Arc monitor 2 on B1 BLMQI..B1.2_MQ   360 MQ
    ...22 rows foreach cell?      
           
3 Arc monitor 3 on B1 BLMQI..B1.3_MQ   360 MQ
4 Arc monitor 1 on B2 BLMQI..B2.1_MQ   360 MQ
5 Arc monitor 2 on B2 BLMQI..B2.2_MQ   360 MQ
6 Arc monitor 3 on B2 BLMQI..B2.3_MQ   360 MQ
7 Cell 11 BLMQI.11.B1.1_MQ Q11 IR 1,2,3,4,5,6,7,8 16 MQ
8   BLMQI.11.B1.2_MQ   16 MQ
9   BLMQI.11.B1.3_MQ   16 MQ
10   BLMQI.11.B2.1_MQ   16 MQ
11   BLMQI.11.B2.2_MQ   16 MQ
12   BLMQI.11.B2.3_MQ   16 MQ
13 Dispersion suppressor (BLMQI.8(1,2,4,5,6,8)B1.1_MQML) or Q8 Q9 Q10 IR 1/2/4/5/6/8 36 MQML
    (BLMQI.9(1,2,4,5,6,8)B11_MQM) or     MQM
    (BLMQI.10(1,2,4,5,6,8)B1.1_MQML)     MQML
  Probably (BLMQI.8B1.1_MQML) or      
  Cell 9 is different... can be easier? (BLMQI.9B1.1_MQM) or      
    (BLMQI.10B1.1_MQML)      
14 Dispersion suppressor BLMQI.8(1,2,4,5,6,8)B1.2_MQML or Q8 Q9 Q10 IR 1/2/4/5/6/8 36 MQML
    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
15 Dispersion suppressor BLMQI.(8,10)(1,2,4,5,6,8)B1.3_MQML or Q8 Q9 Q10 IR 1/2/4/5/6/8 36 MQML
    BLMQI.9(1,2,4,5,6,8)B1.3_MQM      
16 Dispersion suppressor BLMQI.(8,10)(1,2,4,5,6,8)B2.1_MQML or Q8 Q9 Q10 IR 1/2/4/5/6/8 36 MQML
    BLMQI.9(1,2,4,5,6,8)B2.1_MQM      
17 Dispersion suppressor BLMQI.(8,10)(1,2,4,5,6,8)B2.2_MQML or Q8 Q9 Q10 IR 1/2/4/5/6/8 36 MQML
    BLMQI.9(1,2,4,5,6,8)B2.2_MQM      
18 Dispersion suppressor BLMQI.(8,10)(1,2,4,5,6,8)B2.3_MQML or Q8 Q9 Q10 IR 1/2/4/5/6/8 36 MQML
  IP3,7 cell 8,10 BLMQI.9(1,2,4,5,6,8)B2.3_MQM      
19   BLMQI.83.B1.1_MQ or Q8 Q10 IR 3/7 8 MQ
    BLMQI.87.B1.1_MQ or      
    BLMQI.103.B1.1_MQ or      
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
• -gt There is no general family for region like
  DS, injection
• -gt 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.
• -gt We have to ask for this implementation?
• -gt We can read it back and compare with DB?
• -gt Do we push to get also the internal
  comparison?

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
BLM system signals available

• 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)

11
Strategy remarks/questions

• The masking is done at the CIBU level you mask
  all the channels connected at the same time!
• -gt Is it acceptable from machine protection point
  of view?
• For the pair SEM-IC, interlock on the SEM?
• -gt 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
2. Operation with lt 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
2. Operation with lt 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
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 gt all needed
• MSI,MKD, MSD.. gt ??
• collimators gt all needed

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
Simulation typical result

• Maximum of the shower 1m after impacting point
  in material
• increase of the signal in magnet free locations
• Amplitude/length of the pressure bump?

z (cm)
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
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
• gt Accurately known quench levels will increase
  operational efficiency!

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?