1 Commissioning and Early Operation – View from Machine Protection Jan Uythoven (AB/BT) Thanks to the members of the MPWG

Jan Uythoven, AB/BT 2006, Comm.– view from MP Page 2 Commissioning of the Machine Protection System  The LHC cannot be operated without a Machine Protection System (MPS) which is guaranteed to work properly  Significant damage and long downtimes can be the result of a not properly working MPS  The path of commissioning of the MPS needs to be well defined in advance  This will be a recurring task during the commissioning of the LHC but also after shutdowns, access, etc.

Beam Energy Tracking Beam Dumping System 4 x DCCT Dipole Current (4/5, 5/6, 6/7, 7/8) RF turn clock Powering Interlock System Quench Protection Power Converters Discharge Switches AUG UPS Cryogenics essential circuits auxiliary circuits Safe LHC Parameters Beam Current Monitors Current Energy SafeBeam Flag Required also for safe beam SPS Extraction Interlocks TL collimators Timing PM Trigger BLMs aperture BPMs for Beam Dump LHC Experiments Collimators / Absorbers NC Magnet Interlocks Vacuum System RF + Damper dI/dt beam current BLMs arc BPMs for dx/dt + dy/dt dI/dt magnet current Operators Software Interlocks Screens Machine Protection System and connected equipment Injection Kickers LHC Beam Interlock System Access Safety System Beam Dump Trigger Required for unsafe beam

Jan Uythoven, AB/BT 2006, Comm.– view from MP Page 4 Systems to Commission  The core of the system  The Beam Interlock System (BIS)  The LHC Beam Dumping System (LBDS)  All the systems connected to it  BLM  QPS – PIC – WIC  Collimator System  ….  Related systems  Hardware  Safe Beam Parameters  Beam Presence Flag  Software  Post Mortem system  Management of critical settings  Software Interlock System  Sequencer

Jan Uythoven, AB/BT 2006, Comm.– view from MP Page 5 Stages in Commissioning I. Without Beam  Commissioning of MPS and connected equipment  First test in the laboratory  Followed by equipment test in the machine  Followed by hardware Commissioning  Equipment tests under ‘normal operating conditions’  Interface between systems  A maximum of functions should be tested without beam  Individual equipment, interface between systems, Post Mortem analysis, Sequencer, Safe Beam Parameters, etc.  Also if they can only be tested partially without beam, the partial tests should be done as soon as possible

Jan Uythoven, AB/BT 2006, Comm.– view from MP Page 6 II. With beam  Many systems, like the BLM, Collimators and the LBDS, will also need to be commissioned WITH beam  Test individual systems with beam  Test interface between systems with beam  The tests might need to be repeated at different stages in the commissioning  Different beam intensities  Different beam energies  Different operational states:  Optics (squeeze )  Polarities of the magnets of the experiments  Ion operation

Jan Uythoven, AB/BT 2006, Comm.– view from MP Page 7 Different Stages of Commissioning  Different stages of operation  Increasing risk  Different operational states, not checked before  After commissioning of a stage, operation should be declared safe for given conditions (intensity, energy, state)  The ‘jump’ to the next stage should be small enough so that the commissioning process itself is safe  Several systems might move into the next stage together, but only one should be commissioned at a time  Step small enough to detect ‘misbehaviour’ but still functioning safely  Commissioning of stage for a system  Can be ‘binary’: system not used before, to be used as of that stage  Can already be commissioned at an earlier stage than required  Can be ‘continuous’: systems need to be retested to check the effect of larger beam intensities or energy or state on that specific equipment  Need to be re-commissioned at each defined stage

Jan Uythoven, AB/BT 2006, Comm.– view from MP Page 8 Definition of Stages  Different stages  Can be different, and will be probably be more, than the stages as defined by Roger (1 bunch, 43 bunches, energies…)  Will be different for the different systems  Injection system will not have different states depending on beam energy: always at 450 GeV  LBDS will have many stages depending on energy and fewer depending on intensity  Different Stages not ‘linear’: not always increasing in intensity and energy  First energy ramp with safe beam intensity, although injection might already be commissioned for higher intensities  Reduce intensity again when change of optics etc.  Complex description of the stages at which the different machine protection elements will need to be commissioned

Jan Uythoven, AB/BT 2006, Comm.– view from MP Page 9 Simplification of the Different Stages  Some ‘main stages’ which can be identified for the different systems  Based on possible damage levels  Will need additional sub stages and not always ‘linear’ ( see previous slide)  Used in next talk  Jörg Wenninger: ‘What systems request a beam dump?’ Comm. before first beam First pilotN = 10^12 p+43 bunches156 bunches936 bunches 0.45 and 7 TeV

Jan Uythoven, AB/BT 2006, Comm.– view from MP Page 10 Different Systems  In this session, details of the commissioning of the following systems will be presented  Injection System (Verena Kain)  Beam Dumping System (Brennan Goddard)  Collimation System (Ralph Assmann, Guillaume Robert- Demolaize)  Beam Loss Monitoring System (Bernd Dehning)

Jan Uythoven, AB/BT 2006, Comm.– view from MP Page 11 Sequence of Commissioning  For a new stage different systems might need to be commissioned ‘simultaneously’  Can only do one at a time. Proposed logical order of commissioning: 1. Injection System 2. Beam Dumping System 3. Other Systems – expected or unexpected beam dependence (BPMs, noise pick-up) 4. BLM System 5. Collimation System

Jan Uythoven, AB/BT 2006, Comm.– view from MP Page 12 Formal Tests  Tests should be formalised  Checklist to be established and agreed BEFORE the tests  If conditions are not met - tests not successful  not allowed to enter into the next stage  To be done without and with beam  Similar as already done for the hardware commissioning  Should be applied to tests foreseen this year  CNGS nominal intensity operation (JW)  TI 8 (higher intensity?)  TT40 high intensity tests with LHC beam (collimator tests)  Sector test (low intensity, but important to check functionality)

Jan Uythoven, AB/BT 2006, Comm.– view from MP Page 13 Proposal of Machine Protection Coordination Team  Defines the different stages of commissioning of the Machine Protection System  In collaboration with operation team and equipment experts  Dynamic specification, will need to change ‘on the way’  But still agreed and no changes ‘over night’  Defines the tests to be performed to go from one stage to the next  Dynamic specification  But still agreed and no changes ‘over night’  Declares when a protection system is fully commissioned  Participates in the commissioning of the Machine Protection System  Consulted in case of non-standard situations  Certain pre-defined conditions are not met: can operation continue?  Still avoid decisions ‘over night’ (during the night)

Jan Uythoven, AB/BT 2006, Comm.– view from MP Page 14 Machine Protection Coordination Team  Small team of Machine Protection Experts  4 – 6 people, always some of them available on short notice  If required one contact person can be assigned  on duty for about a week  Can be contacted by Machine Coordinator, EiC, etc.  Advise on operation outside predefined conditions  Will contact Machine Coordinator, EiC, etc.  Bring to attention possible dangers, not foreseen, by following up closely the operation of the machine  They will contact other MPS specialists if required

Jan Uythoven, AB/BT 2006, Comm.– view from MP Page 15 Conclusions  Commissioning of the machine protection system will take place in stages  Starting without beam during equipment tests and the hardware commissioning period  Followed by many different stages with beam  Different for the different types of equipment  The different stages and the formal acceptance will need to be defined and agreed upon before the tests  See talks this session: overview, filling, dumping, collimation, BLMs  Creation of a Machine Protection Coordination Team  Formalise the above procedures and validate tests  Small team of experts, available for consultation +