1. LHC sector test - summary 1 14/03/2008 Possible injection into part of the machine Options etc.Mike Lamont Stopping the beamStefano Redaelli Proposed Tests with beamMassimo Gianvanozzi Quenches with beamRalph Assmann Radiation implicationsHelmut Vincke Secretary: Verena Kain

2. LHC sector test - summary 2 14/03/2008 Motivation Beam tests form a integral part of full beam commissioning  everything planned has to be done Beam:  Polarities, Aperture, Magnet field quality  Beam Instrumentation Full test of a majority of subsystems Allows staged approach to the full problem space Time to fully resolve problems before the real thing  Analysis, improvements, problem resolution The lessons learnt will reduce the time needed for full commissioning

3. LHC sector test - summary 3 14/03/2008 Integration & commission with beam Full-blown system wide integration test

4. LHC sector test - summary 4 14/03/2008 Options

5. LHC sector test - summary 5 14/03/2008 Option 1: Beam 2 to IR7 Use collimators to stop beam in IR7  3 primary, 5 secondary collimators for the single beam No temporary installation of beam instrumentation at IR7. Need  Small part of 8-1, all 7-8 hardware commissioned to 450 GeV+.  Circuit list presented. Minimal Impact Solution

6. LHC sector test - summary 6 14/03/2008 Stopping the beam in IR7 Stefano Redaelli

7. LHC sector test - summary 7 14/03/2008 Option 1: Pros and Cons Easier. Minimal requirements on Cryogenics & HWC  2 sectors Less area classified by RP Less impact on other systems  BI, LBDS  Only one sector - less systems tested  BI, LBDS, collimators missed  BI configuration not perfect  Rely on in situ instrumentation  Not ideal – no BCT – some implications for measurements  Activation of machine components (mainly primary collimators)

8. LHC sector test - summary 8 14/03/2008 Option 2: Beam to IR6 Use TCDQ and TCS to block down stream aperture – safeguard only - no installation of temporary dump. Beam onto beam dump absorber block (TDE) Can use correctors to steer into dump channel  should be able to guarantee very little beam goes onto TCDQ etc. Rely on in situ instrumentation (BCT in dump line etc.). No temporary installation required. Need small part of 8-1, all 7-8, all 6-7 hardware commissioned to 450 GeV+.

9. LHC sector test - summary 9 14/03/2008 Beam to beam dump Stefano Raedelli

10. LHC sector test - summary 10 14/03/2008 Option 2: Pros & Cons Commission beam dump and related systems with beam Don't irradiate ring - beam onto TDE (beam dump block) Check IR7 optics, performance of warm magnets, beam through 3 IRs, 2 full sectors Full suite of Beam Instrumentation in place  FBCT, Screens, BLMs  Support required for 3 cold sectors cold while work in progress elsewhere in ring - clearly test has more of an impact. Favoured Solution

11. LHC sector test - summary 11 14/03/2008 Option 3: Beam 1 to IR3 Outside possibility – would imply problems elsewhere Need partial 1-2, complete 2-3 Dump on collimators in IR3 ☺ Only realistic solution for beam 1! ☺/  Same pro’s and con’s as IP7  Less collimator absorption (only 1 TCP): irradiated area bigger

12. LHC sector test - summary 12 14/03/2008 Tests with beam 1 week with beam Pilot Beam for the most part:  single bunch of 5 - 10 x 10 9 protons  Some tests with 1-3 x 10 10 or up to 1 x 10 11 p+ in one bunch Beam emittance: 1 µm < ε n < 3.5 µm Momentum spread: nominal Nominal tunes, nominal magnetic machine Total intensity injected:  2 - 3 x 10 13 protons Massimo Giovannozzi

13. LHC sector test - summary 13 14/03/2008 Main Objectives Injection Threading Optics measurements BLM system response Aperture checks Effect of magnetic cycle Field quality checks Quench limits and BLM response Pre-requisites and procedures detailed

14. LHC sector test - summary 14 14/03/2008 Tests with beam

15. LHC sector test - summary 15 14/03/2008 Quenches with beam Dangers elucidated  limited number of quenches per magnet  no spares for some types of magnets  message: number of beam-induced quenches should be minimized LHC magnets will have to suffer beam-induced quenches, whether we like it or not. Minimize total number of quenches by controlled tests on beam loss and optimal BLM threshold: Do not wait for uncontrolled beam-induced quenches before starting these tests.  take opportunity to understand quenches in controlled way Ralph Assmann

16. LHC sector test - summary 16 14/03/2008 How to Optimize the BLM Thresholds? Carefully select magnets to minimize impact.  Select a magnet unlikely to quench during operation: MB in middle of arc, Spares available A limited test program was presented. Risks essentially excluded. If unexpected damage: Important to find early with low intensity! Much more serious risks later must be handled at high intensity! Ralph Assmann

17. LHC sector test - summary 17 14/03/2008 Estimate for residual dose rate in the area of the TDI absorber (no walls considered) after a beam impact of 2.5E12 protons uSv/h Cooling time: 1 day Helmut Vincke

18. LHC sector test - summary 18 14/03/2008 Summary of residual dose rates expected around the various irradiated magnets Beam impact point OPTION 1 total intensity OPTION 2 total intensity 1 day cooling (uSv/h) 1 m / contact 1 week cooling (uSv/h) 1 m / contact ARC 78 - threading ~5E12 10 / 501 / 5 ARC 78 - aperture studies ARC 78 - quench studies IR7 - quench1.00E+12 2 / 100.2 / 1 ARC 67 - threading 2.50E+11 4.5 / 22.50.45 / 2.25 ARC 67 - aperture studies 2.00E+12 Beam impact pointPredictions about area classifications ARC 78 - threading Controlled Radiation Area up to1 week, after this period area will be classified as Supervised ARC 78 - aperture studies ARC 78 - quench studies IR7 - quenchSupervised, but might be different due to TCP operation ARC 67 - threading Controlled Radiation Area up to a few days, after this period this area will be classified as Supervised ARC 67 - aperture studies Dose rate range at accessible areas close to magnet Helmut Vincke

19. LHC sector test - summary 19 14/03/2008 Actions after a Sector Test No access to the LHC until air is renewed (~1 hour) The LHC areas affected by the Sectors Test will remain closed until RP has performed a radiation survey (including contamination checks) in the areas All areas showing dose rates below 15 uSv/h will be classified as Supervised Radiation Areas. If possible, hot spots will be fenced off or shielded. All remaining areas will be classified as Controlled Radiation Areas. Access doors to Controlled Radiation Areas will be closed by the radiation veto. Water samples will be taken from water circuits and analyzed. After sufficient cool down time (some days – 1 week), Controlled Radiation Areas will be re-classified as Supervised Areas, the Radiation veto will be lifted. The radiological data needs to be summarized in a RP documentation. Helmut Vincke

20. LHC sector test - summary 20 14/03/2008 Supervised Area: Personal dosimeter Controlled areas, additional requirements: Area will not be freely accessible (access doors closed by radiation veto) Operational dosimeter Job and dose planning Material leaving classified areas: All material leaving radiation areas needs to be controlled and classified by RP Radioactive material (equipment) has to be treated in radioactive workshops or stored in dedicated radioactive storage areas Consequence of radiation area classification Helmut Vincke

21. LHC sector test - summary 21 14/03/2008 Other systems Injection elements: septa, kickers Collimators Machine Protection Beam Instrumentation:  BPMs, BLMs, BTV, BCT, BST Magnet Model Controls Software/tools Access system Radiation Protection Radiation Monitoring Test preparation largely orthogonal to HWC Leading to Partial Machine Checkout

22. LHC sector test - summary 22 14/03/2008 Impact - Access – closing the whole ring Pre-preparation, DSO tests  2 months Closing the ring: patrols etc  3-4 days Experiments out for a week  “a disturbance but acceptable” HWC  commissioning in other sectors can continue  Scheduled access possible (could imagine access/day if we can guaranteed a reasonable efficient recovery). Supervised areas after test  Given analysis, and measurements during and after the test, it is envisaged that: Certain areas might be declared controlled areas for the first few days after the test; Thereafter these areas would join the rest of the sectors involved as supervised areas

23. LHC sector test - summary 23 14/03/2008 Impact Sector test makes clear demands on:  What is needed to be cold & commissioned and to what level  Fairly limited: Beam 2 Circuits & limited recycling  Fully enumerated for all options Cryogenics, QPS, HWC support required during test  In general, low current levels with occasional cycles  Interesting possibility of quenches LHCb  becomes a supervised area

24. LHC sector test - summary 24 14/03/2008 Conclusions 1/3 Three operational scenarios are on the table:  Beam 2 to IP6 ➝ beam dump operational, TCSG+TCDQ  Beam 2 to IP7 ➝ Close three TCP’s  Beam 1 to IP3 ➝ Close 1 TCP and TCSG’s For all scenarios there are solutions to safely stop the beam Operationally, clear preference for the option of beam 2 to IP6

25. LHC sector test - summary 25 14/03/2008 Conclusions 2/3 Commissioning is going to be hard enough  If there’s any chance to get a start on this we must take it  A sector test undoubtedly speed full commissioning with beam  Most of it has to be done anyway The impact is not negligible, mainly because the whole ring has to be closed  This in itself is a very useful exercise  Machine as is or as will be. Work carries on elsewhere.  All major installation will have finished and access to the zones affected after the test will be limited.

26. LHC sector test - summary 26 14/03/2008 Conclusions 3/3 Clear that sector test is a back up solution  to be invoke only if delays occur Pencil it into schedule and plan to ensure that if required it can be performed with the minimum of disruption Commission and test access system to allow full closure in June Bear requirements in mind during HWC planning and prioritize where appropriate Will required a lead time of ~2 months Thanks!