1. Collimator Controls Readiness of collimators control – from bottom to top State of automated collimator positioning Extended LTC Session 6 - Readiness of Controls Friday 07 March 2008 14h30 2008/03/07 MJJ

2. Collimator Controls Primary Actors (from bottom – to top) – Alessandro Masi, Mathieu Donze, Arnaud Brielmann, Jerome Lendaro, Roberto Losito – Jacky Brahy, Enrique Blanco Vinuela – Guy Surback, Roland Chery, Nicolas Zaganidis – Stefano Redaelli, Eric Veyrunes, Delphine Jacquet Support from LSA team, AB/CO-DM, M.Lamont

3. Outline Installation status Architecture evolution Functional Status Environmental Survey Positioning & Survey Application Layer Automatic Collimator Positioning (Beam Based Optimisation)

4. LHC tunnel Underground, low radiation area Surface support building Control room Baseline Architecture (as decided in 2005 ) Collimator Supervisory System (one or two per LHC point) Collimator Supervisory System (one or two per LHC point) BLM system Beam Permit Central Collimation Application Ethernet Controls Network Data Base Actual Machine Parameters Data Base Critical Settings... Machine Timing Machine Timing Distribution Synchronisation Fan out Control room software: Management of settings (LSA) Preparation for ramp Assistance in collimator tuning – Based on standard LSA components – Dedicated graphical interface for collimator control and tuning – OP responsibility Collimator Supervisor System (CSS): – Environmental Supervision through standard PVSS class – Support building, VME / FESA Fesa Gateway to Control Room Software Synchronization of movements Beam Based Alignment primitives Takes action on position errors (FB) – Receives timing, send sync signals over fiber to low level (Ramp & Beam Based Alignment) – Synchronization and communication (udp) with BLM – CO responsibility Low level control systems – 3 distinct systems Motor drive PXI Position readout and survey PXI Environment Survey PLC – ATB responsibility & CO for Environment Local Ethernet Segment Motor Drive Control PXI Position Readout and Survey PXI Environment Survey PLC OP CO ATB

5. HW Installation status Today some 75 Collimators are installed. == 92 by April ! Details in talk of O.Aberle

6. HW Installation status Temperature readout – All PLC’s in place – All installed collimators connected – All temperature gauges tested except in IP7 Very few surprises IP7: waiting for 220V power connections

7. HW Installation status PXI installation – All PXI systems installed – Test in progress: stages Pre-Commissioning – Test signal connectivity – No motor movement – All done (IP7 finished yesterday) Commissioning 1 – Requires tunnel access for visual confirmation of mechanical movements, swichtches etc. – IP5, IP6 in progress, followed by IP2, IP8, IP1 (constrained by tunnel access), then IP3, IP7. – First LVDT-Calibration Commissioning 2 – Remote tests – Including PC-gateway & synch-signal – LVDT-reCalibration, autoretraction, mechanical play – Finished by last week of May

8. HW Installation status CSS related hardware – PC Gateways installed in all points except BA7 – Fibers connectivity for synchronisation signals: Ready in IP1, IP2, IP3, IP6, IP7 IP8, IP5 before end of March

9. Temperature monitoring Based on standard UNICOS / PVSS control environment PVSS Server PLC Logging DB PVSS Client Alarm System PVSS Client Japc Clients PLC programs automatically generated from excel files (excel files are extracted from Collimation Configuration tables in the DB with additional dump and alarm limits per temperature sensor Collimation Configuration PLC supervised by standard PVSS server Internal store (Months of data) Feeds various clients (LoggingDb, Alarm, JapC, Configurable PVSS clients,)

10. Configurable PVSS clients Temperature monitoring

11. Collimator Supervisory System (one or two per LHC point) Collimator Supervisory System (one or two per LHC point) Beam Permit Central Collimation Application Ethernet Controls Network Data Base Actual Machine Parameters Data Base Critical Settings Machine Timing Machine Timing Distribution Synchronisation Fan out Local Ethernet Segment Motor Drive Control PXI Position Readout and Survey PXI Collimator Supervisory System (one or two per LHC point) Collimator Supervisory System (one or two per LHC point) Beam Permit Central Collimation Application Ethernet Controls Network Data Base Actual Machine Parameters Data Base Critical Settings Machine Timing Machine Timing Distribution Synchronisation Fan out Local Ethernet Segment Motor Drive Control PXI Position Readout and Survey PXI Low Level Fesa (one or two per LHC point) Low Level Fesa (one or two per LHC point) Architecture Evolution Only considering Position control: 3 Layers For various reasons (responsibility delimitation) the architecture grew more complex with 4 layers. A low level Fesa Server was introduced Longer Execution Path More resources, more maintenance Duplicated functionality For not much benefit And a complication for MCS Low Level Fesa Server taking more and more responsibility (calibration, expert access, …) What is the solution ? Make Low Level Fesa Server to implement the same property interface as CSS Suggest to include also synchronisation control in the Low Level Fesa Server. Low Level Fesa CSS

12. Architecture (as evolved after 2007 runs ) Beam Permit Central Collimation Application Ethernet Controls Network Data Base Actual Machine Parameters Data Base Critical Settings Machine Timing Machine Timing Distribution Synchronisation Fan out ATB kindly agreed to include the synchronisation control in the Low Level Fesa Low Level Fesa Server became de facto the CSS Central Collimator Application can (almost) talk directly to ATB CSS implementation as if it was the CO CSS implementation Many thanks to A.Masi for this 2007 Christmas present. Local Ethernet Segment Motor Drive Control PXI Position Readout and Survey PXI Collimator Supervisory System (one or two per LHC point) Collimator Supervisory System (one or two per LHC point) ATB

13. Architecture (to be completed in 2008 ) Beam Permit Central Collimation Application Ethernet Controls Network Data Base Actual Machine Parameters Data Base Critical Settings Machine Timing Machine Timing Distribution Synchronisation Fan out ATB kindly agreed to include the synchronisation control in the Low Level Fesa Low Level Fesa Server became de facto the CSS Central Collimator Application can (almost) talk directly to ATB CSS implementation as if it was the CO CSS implementation Missing functionality CSS is now reporting asynchronously to requests. (i.e. more work for Stefano). Beam Based optimisation primitives not provided Need an independent process that runs on the PC gateway Local Ethernet Segment Motor Drive Control PXI Position Readout and Survey PXI BLM system Beam Based Optimisation (one or two per LHC point) Beam Based Optimisation (one or two per LHC point) Collimator Supervisory System (one or two per LHC point) Collimator Supervisory System (one or two per LHC point) Optimisation Application

14. PXI and CSS All functionality defined and ~implemented on PXI (except multi movement option for fast optimisation) Merge of Fesa Servers Expert application for LVDT- Calibration Interacts with Fesa Server to calibrate Calibration stored in MCS Updates under control of RBAC Fesa device delivery tool Takes information from Collimation Configuration DB PXI configuration DB Feed Fesa Configuration DB

15. RWA, LHC MAC 12/0715 PXI: Tracking Jaw Positions Setting Reading 50  m 20 s 50  m Setting Reading 10  m 20 s Generally excellent resolution and performance. In the tunnel at some locations pickup noise. Being analyzed. S. Redaelli

16. PXI and CSS To be finalized and tested Function driven execution Machine protection functionality Warning and Dump limits Machine Protection limits (MCS) depending on Energy Synchronisation Reception of Energy and other Machine Parameters Interaction with applications layer (trim and Sequencer) New functionality to be commisioned in April. Actual priority is HW commissioning in the tunnel.

17. Stefano has provided a lot of work in collaboration with Eric and Delphine Database Table definitions to store collimator configuration WEB interface Collimator configuration database population Collimator Control Application Definition of parameter space to control collimators settings and limits. Adaptation of trim editor (with CO/AP) to visualize more conveniently the collimators following the Beam-IP-family hierarchy Application Layer

18. 18 Collimation Configuration

19. Collimator Control Application

20. Collimator Parameter Space High level Trim parameter is expressed in N  Absolute values are obtained by folding in the beam based  beam X beam  beam  is obtained from Momentum,  beam and  coll.  beam is the nominal emmittance for which the machine is protected. It is a collimator specific parameter. Measured   must be <  beam  coll can be trimmed based on beam based alignment, to correct for local  beating Same hierachy for warning and dump limits.

21. Collimator Function Trim

22. Automated Collimator Positioning 94 (up to 160 in final upgrade) collimators, to protect against machine damage and magnet quenches. The collimation process is a multi-staged process that require precise (0.1  beam ) setting of the jaws with respect to the beam envelope. Goal for positioning accuracy is  20  m (0.1  beam at 7 TeV). Actual beam envelope (position and size) may change (from fill to fill ?, by how much?) Adapt to changing beam parameters to guarantee machine protection and to keep good cleaning efficiency There are 376 degrees of freedom (4 motors per collimator) (188 if not considering the angle of the jaws) 30 seconds per degree of freedom (a very efficient operator) still requires about 3 hours.  We need automated tools and procedures by Chiara Bracco 12 minutes for two positions

23. Beam Probing Beam Loss Monitor Traditional method to establish the beam position, angle and size by touching the actual beam. (Required with new optics or after substantial changes of beam parameters) – Starts with producing a well-defined cut-off in the beam distribution. – Each collimator jaw is moved until the beam edge is touched. This step defines an absolute reference position for each jaw. (and angle if two motors are moved independently) Note: Best done from the last element in the cleaning insertion to the first Collimators may stay in place Machine is better protected against quenches Disadvantages: Only possible with low intensity beam (i.e. 5 bunches, extrapolation from 5 to 3000 ??). Slow if done manually (188 positions ) Delicate (e.g. moving a collimator too far changes the cut-off in the beam distribution).

24. Fast beam based setup Beam Loss Monitor Complements the traditional set-up method (possible with nominal beam intensity). Adjust positions to reproduce known beam loss pattern. – Based on experience of other accelerators: Collimation efficiency is more closely related to beam loss patterns than to absolute collimator positions, which are sensitive to orbit deviations, beta beat, etc. Move jaws in hierarchical order into the beam halo up to the point where a specified beam loss level is recorded in the adjacent beam loss monitors. Fast if implemented as an automated procedure: –Start at a fixed offset relative to a previously known position (only have to move short distances, no need to be retracted. –Two beam can be tuned in parallel in the two cleaning insertions IR3 and IR7

25. Fast beam based setup Procedure in practice: The collimators are set at 1.5 σ retracted with respect to the last optimised value. The jaws are optimised one by one in a precise order. Optimization by moving in steps of 0.05 σ until the associated set of Beam Loss Monitors (BLM) detects a predefined value of beam loss. The BLM reference levels are found empirically and may be updated from fill to fill. Timing implications: Starting position –1.5 σ, step size of 0.05 σ (  50 μm @ 450 GeV) ⇒ 30 steps/motor ⇒ 9600 steps in total (only position, no angles, final upgrade). Available time 5 min. two rings in parallel ⇒ 60 ms per step (16 Hz) @ 2mm/s 50 μm ⇒ 25 ms per step needed for motor movement => 35 ms for driving, data collection, reading BLM, deciding

26. Fast Optimisation Primitives Collimator Supervisory System (CSS) –Send a trigger to adjacent BLM system on every motor movement –BLM system sends a short “transient” data to the CSS –Optimization primitive command (on CSS) Move until BLM-level Parameters Motors and step size BLM signals and limits Repetition frequency Maximum steps –Example: Move Jaw-left in steps of 10 um every 30 ms until BL signal reaches 10 3 This optimization primitive can be used by a central application for –Beam Probing –Fast beam based optimization Collimator Supervisory System (one or two per LHC point) Collimator Supervisory System (one or two per LHC point) BLM system Synchronisation Fan out Local Ethernet Segment Motor Drive Control PXI Position Readout and Survey PXI Beam Loss Monitor

27. The real chalenge Motor movement 10ms (20  m) Long tails after collimator movement, Large noise components If these effect are also present in the LHC, optimisation will me more challenging. During the SPS MD, not able to make clean cut in the beam distribution Beam-dynamics: Re-poppulatution of tails over several 100 th of ms. Motor movement 50ms (25  m) (70 Hz) 50, 150, 300, 450 & 600 Hz noise Loss tails with echo 12 sec

28. Fast Optimisation Implementation To be developed this year. Implement Multi-Step movements at Low Level Development of Optimiser Process −Beam Based Optimisation Primitive −Already useful for operator assisted collimator setup. Development of Central Optimisation Control Process −Sequencing the optimisation of the individual jaw positions −Driven by a DB configuration, able to react intelligently if there is unexpected behaviour. −Initially simple, improve by learning. Doctoral student ? The challenges Convince BI/SW that transfer of 600 bytes @ 30Hz is sustainable (when used occasionally for a single BLM crate at the time). Understanding the beam loss response

29. Conclusions Collimation controls is ready to set the collimators for the first beam. Still to be demonstrated Function driven control. Machine protection functionality still to be tested. Collimation position setup will be challenging. Development of tools and applications required