Beam%20Bunch%20Distribution

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Beam Bunch Distribution

• Mike Lamont

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Communication

• GMT
• BST
• DIP pub/sub
• Oracle
• Advance Queues JMS publication
• JAPC monitoring pub/sub
• CMW get/set pub/sub

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Timing - Basic concepts

• EVENTS
• Events arrive asynchronously and can be
  subscribed to
• Each event is a 32-Bit quantity
• Type of event 4-Bits
• TimingCTIM, UTC-Time, Telegram .
• Accelerator 4-Bits
• LHC, SPS, CPS, PSB, ADE
• Code 8-Bits
• Event-Code, Telegram-Group
• Payload 16-Bits
• User, UTC, Telegram-Group-Value
• TELEGRAMS
• Sent out at fixed frequency, 1 Hz in the LHC
• Snapshot
• SAFE MACHINE PARAMETERS
• as events telegrams

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• Baudrenghiens Convention
• The 400 MHz RF defines 35640 buckets, spaced by
  one RF period, and numbered from 1 to 35640
• Bucket 1 is the first bucket after the 3 ms long
  abort gap (defined from bucket 34442 to 35640)
• Bunches in bucket 1 of the two rings collide in
  IP1

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Injection request

• BTNI Next injection Beam Type
• The LSEQ may request a certain type of beam to be
  injected, but if the requested value does not
  correspond to the actual beam type being provided
  by the injector chain, then the request can not
  be fulfilled and no injection can take place.
• BKNI Next injection RF Bucket
• There are 35640 RF buckets around the LHC ring.
  It is essential that this parameter is
  established before RF re-synchronization starts
  between the CPS and the SPS RF systems, namely
  450ms before CPS extraction towards the SPS
• RNGI Next injection Ring
• This parameter determines the value of the SPS
  beam destination in the DEST group of the
  telegram. Various ways to do this are possible.
  Its an OP decision.
• BCNT Number of CPS batches

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Beam Type

• Incoming and Circulating Beams
• 24 telegrams per beam
• Number of bunches
• bunch spacing units of 25 ns
• bunch intensity units of 109
• particle type 0 protons, 1 ions
• BST
• Number of bunches, average bunch intensity

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Bunch Configuration - proposal

• We have 35640 RF buckets
• Max occupancy 3000
• short occupiedBucketsB13000
• 1,11,21.
• short numberOccupiedBucketsB1
• 72
• We will inject maximum of 300 bunches
• short incomingDestinationBucketsB1300
• 1,11,21
• short numberIncomingBunchesB1
• 288
• or see Andys suggestion encoding based on PS/SPS
  spacings etc.

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Bunch Configuration

• Covers all cases
• four equidistance bunches
• off by one bucket collisions
• 1,43,156
• Set on database
• LHC run configuration
• published to DIP
• publish to JMS any high level applications
• Updated preceding injection incoming
• Updated post injection circulating
• assume time constraints for experiment not
  critical during injection phase
• Set RF FESA property
• Circulating 3564 bit array required at low level
• Incoming 924 bits
• To be discussed/decided after this meeting!

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FBCT

• averageBunchIntensities
• -- double/array(3564) --individual bunch
  intensities averaged over 1 second
• historyBeamIntensity
• double/array(337500) --30-seconds history of
  whole beam intensity turn by turn.
• historyBeamIntensityNextIndex
• long/scalar --index in history of the next data
  point.
• historyBeamIntensityT
• long/array(2) --absolute timestamp of youngest
  history data point, seconds, microseconds
• historyBeamIntensityTS
• double/array(337500) --relative timestamps
  30-seconds history of whole beam intensity turn
  by turn.
• nbAveragesBunchIntensities
• -- long/scalar --the number of measurements
  which are going into the averaging. Each
  measurement covers 227 turns (20ms) in order to
  suppress 50Hz ambient radio noise.
• nbTurnsBunchIntensities
• long/scalar --the number of turns which are going
  into the averaging. Each measurement covers 227
  turns (20ms) in order to suppress 50Hz ambient
  radio noise.

Will push averageBunchIntensites over DIP