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BI Group Commitments and Major Issues for Distributed Systems. E.B. Holzer , J.J. Gras, O.R. Jones CERN AB/BI Third LHC Project Workshop - Chamonix XV January 24, 2006 Divonne-les-Bains. Outline. BI Responsibilities (J.J. Gras) Beam Synchronous Timing (J.J. Gras)
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BI Group Commitments and Major Issues for Distributed Systems E.B. Holzer, J.J. Gras, O.R. Jones CERN AB/BI Third LHC Project Workshop - Chamonix XV January 24, 2006 Divonne-les-Bains
Outline • BI Responsibilities (J.J. Gras) • Beam Synchronous Timing (J.J. Gras) • Beam Position Monitor System (R. Jones) • Beam Loss Monitor System • Summary
Responsibility Limits • AB/BI will provide • the monitors • the electronics • the front end software • the corresponding expert applications • to develop, test, deploy, diagnose and maintain the instruments produced by the group • AB/BI is NOT responsible for any software above the BI front end servers necessary to operate the machine, i.e. • BPM, BLM Concentrators • RT Feed Back Loops and Fixed Displays • Middle Tier Black Boxes • Operational Applications • Post-mortem and Logging Applications • Video and Analog Signal Transmission
People in Charge • All components of the BI mandate covered
Commitments • The BST (BOB) system based on TTC technology will provide to the LHC beam instrumentation • 40 MHz bunch synchronous clock • 11 kHz LHC revolution frequency • In addition, it will allow the encoding of beam synchronous messages • for LHC instrumentation triggering and • for broadcasting of machine status (mode, intensity, energy, turn number…) • can be updated on every LHC turn • BST system expected to be available at start-up (as soon as the RF signal is received)
Clients • The BPM rely on BST for orbit, trajectories, multi-turn acquisitions and post-mortem triggering • BLM will rely on BST only for the post-mortem and logging trigger • BST will be used by other instruments to synchronise themselves (BTVM, BWS, BSRT…) or with each others • The machine status has proven to be of interest to the LHC experiments, which will receive this information using their standard TTC receivers and decoders [see EDMS 638899]
Testing Plans • BST system is a collaboration between AB/CO (Master HW and Firmware) and AB/BI (Master Server/RT and Receiver HW/FM/SW) • Three systems are foreseen (SPS, LHC B1 and B2) • The recent v2 functionality covers the need (currently being tested) • BOB system will be commissioned on SPS in 2006 and assessed during the LHC sector test (with the SPS BOB Master)
Beam Position Monitors - BPM Status Performance Commissioning Cuts proposed for Stage I
Status of BPM Electronic Components • Wide Band Time Normaliser (analogue front-end) • Successfully tested in TI8 and SPS • Series Production (4500 units) launched by the end of January 2006 • Digital Acquisition Board (DAB64x - TRIUMF) • Series production (1800 units) started.BI standard for BPM, BLM, Fast BCT and Q measurement acquisition • Network Infrastructure in place • Fibre-optic, coaxial cable and WorldFIP control links • The BPM acquisition hardware is expected to be fully functional for LHC start-up
BPM Performance Linearity versus Intensity BPM operating threshold ~1·109 charges/bunch corresponds to 17% nominal ion bunch intensity Nominal resolution (5 μm) for • single bunch: intensity > 2-3·1010 charges per bunch • global orbit: 43 pilot bunches
Commissioning with the BPM System I • Before Beam • Test of the system in the SPS and TI8 • Gives confidence in performance • Allows software development and debugging • Full calibration of the LHC acquisition chain • part of BPM hardware commissioning • First Turn • Asynchronous Mode • Auto-triggered - no dependence on external timing • Intensity Measurement – aim to have this operational BUT • currently concentrating on the position system • implies considerable amount of additional software as intensity measurement uses acquisition system of other ring • lack of intensity card DOES NOT affect position measurement
Commissioning with the BPM System II • First few to 1000 Turns • Timing-in of BST system • Allows bunch/turn tagging • Can be done in parallel to asynchronous acquisition • Circulating Beam at 450 GeV • Global Orbit Mode • Available once BST is timed-in • Allows post-mortem to be used • Real-time orbit data available • Capture Mode • Triggered on request • Allows bunch to bunch and turn-by-turn data • Can generate a large amount of data • will require concentrators and powerful analysis software to be in place
Commissioning with the BPM System • Snapback, Ramp and Squeeze • Real-time global orbit data available for feedback • Requires concentrator, feedback algorithms and real-time correction to be available to implement the feedback.
Cuts proposed for Stage I on Multi Turn Acqu. System • Multi turn acquisition up to 100’000 turns on • one user selected bunch or • the beam average • Always on consecutive turns • Always on all BPMs at the same time
Beam Loss Monitors - BLM Status System Tests Updating the Threshold Tables Synchronization BLM for Ions
Status I • Network infrastructure: done • Detectors: almost all components received • Ionization chambers (3800): Production at CERN started (40), Production in Prodvino will start in February. • Production rate 20/day, total production time: 1 year • Secondary emission monitors, SEM (320): Prototyping phase, working design. Production foreseen to start Q1 2007, and take 2 months • Expected to be ready for LHC commissioning (not for sector test)
Status II • Electronics • Crates (456 in the tunnel and 105 on the surface) and power supplies: installation started • Acquisition in the tunnel: pre-series production started (50 out of 750 cards) • Acquisition on the surface: series production started for DAB card, pre-series production started for mezzanine card (30 out of 400 cards) • Interlock and testing (“combiner card”, 25 cards): under design • To be done – all expected to be ready for LHC commissioning • Addition to DAB card program • Post-mortem • Final communication tests with threshold tables • Combiner card • CFC program: implementation of additional high voltage tests
System ready for LHC and fulfill the Specifications? • Hardware expected to be ready for LHC start-up • Plan B: possible to install smaller number of detectors - unlikely • Threshold tables (calibration of BLM) based on simulations. • Plan B: ask for beam tests in the LHC to calibrate the BLM system • Analysis effort of BLM logging and post-mortem data (sector test and LHC beam data, “parasitic” and dedicated tests) to be started in 2006! • Calibration of threshold tables • Interpretation of BLM signal patterns • Large amount of data to be analyzed • Extensive software tools for data analysis essential to fulfill the specifications! Start now to specify and implement! • Logging and post-mortem need to work for Sector Test!
BLMS Testing Procedures PhD thesis G. Guaglio Detector Tunnel electronics Surface electronics Combiner Functional tests Barcode check Current source test (last installation step) Radioactive source test (before start-up) HV modulation test (implemented) Beam inhibit lines tests (under discussion) Threshold table beam inhibit test (under discussion) 10 pA test (implemented) Double optical line comparison (implemented) Thresholds and channel assignment SW checks (implemented) Inspection frequency: ReceptionInstallation and yearly maintenanceBefore (each) fillParallel with beam
Updating the Threshold Tables • How to change threshold tables technically • Possibility to write them via VME interface: will be used in the lab and disabled by a hardware switch when installed in the tunnel • During commissioning and during operation the threshold tables can only be changed locally via a dedicated interface • How to change them conceptually • Empirically define procedure • After analysis of loss data possibility to change the energy and loss duration dependence • Define needs and production of software tools • Generation of threshold tables • “Management of Critical Settings” (MCS) • Managing and Archiving of threshold tables • Group monitors according to magnet types for faster changing of threshold tables
BLM DAB 1 BLM DAB 1 BLM DAB 2 BLM DAB 2 5.5 s max. 82 ms time jitter 1 s Logging Readout Frequency 1 Hz Synchronization • For reliability reasons the BLM system does not use external timing (other than for post-mortem and logging triggering) • Synchronization of timing windows between different BLM DAB cards? • e.g.: update interval of 5.5 s time window is 82 ms: time
BLM for Ions I • Considerably less simulations available than for protons at the moment much higher uncertainty for the BLM system • Simulations of ion loss maps done (H. Braun) additional monitors; Error studies still to be done (AB/ABP) H. Braun
BLM for Ions II • BFPP simulations for ALICE: loss positions (J. Jowett) and showers through dipole magnet (R. Bruce) additional monitors • Main dipoles: ratio of energy deposited in magnet versus energy deposited in the BLM detector is roughly the same as for protons • Ratio of quench (damage) level to BLM signal about the same as for protons Similar threshold tables for protons and ions • standard BLMs (local aperture limitations) at right position • Future simulations (other EM processes) might lead to more requests for BLMs Energy position in the hottest part of the coil and at the BLM location (FLUKA, LHC Project Note 379, R. Bruce et al.)
Summary • The BST, BPM (possibly excluding intensity measurement) and BLM hardware systems are expected to be fully operational for LHC start-up. • BPM various modes of acquisition should allow the necessary data to be available when required. • BLM calibration requires logging and post-mortem plus MCS - starting from the Sector Test.
Functional Tests • Radiation tests of tunnel electronics (PSI) • Temperature test (tunnel electronics) • Detector test in booster, T2, H6, PSI: uncertainty (up to a factor of 2) to be corrected for with the results of M. Stockner’s thesis. • Long term test of whole acquisition system: booster and DESY • Test of quench levels (threshold calibration): Laboratory, HERA, sector test, simulations
Required Accuracy for Damage Protection Arc Dipole Magnet Quench protection system (damage protection) BLM system damage protection, no redundancy Fast current transformer (DIDT) will protect against fast (1 turn) losses only from phase 2 of the LHC (absolute calibration by software during phase 1 too slow – phase two: hardware implemented) Accurately known quench levels will increase operational efficiency
Beam Shower development in the Cryostat L. Ponce • Impact position varied along the MQ • Highest signal from loss at the beginning of the MQ • Position of detectors optimized • to catch losses: • Transition between MB – MQ • Middle of MQ • Transition between MQ – MB • to minimize uncertainty of ratio of energy deposition in coil and detector • Beam I – II discrimination