1. SPS North Area Operation Shutdown Lectures - 2006 Morning session  Introduction and test beams Ilias Efthymiopoulos Afternoon session  M2 muon beam – COMPASSLau Gatignon  Neutrino beam – CNGSEdda Gschwendtner And…  PS East Area operationM. Delrieux (17 March – PM)  nTOF/FTN line operationnot operational in 2006

2. The SPS North Area Beams Outline  Introduction (6)  The EHN1 Beams (18)  Design highlights (12)  Operational aspects (4)  Safety Issues (8)  Access System Ilias Efthymiopoulos AB/ATB-EA SPS Training Lecture Program March 2006

3. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 3 Introduction (1/6)  The proton beam (400 GeV/c) from SPS is slowly extracted to the North Area at LSS2  The extracted beam is transported in the TT20 tunnel 11% slope to arrive into TCC2 – then horizontal ; ~10m underground  The primary proton beam is split in three parts directed towards to the North Area primary targets: T2, T4 and T6 11% slope

4. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 4 Introduction (2/6) The splitters – how they work!  Optimized beam optics to minimize losses Small  H (~9m) and large  v (~23Km)  The beam splitters are among the “hottest” objects in TCC2 Field-free region Horizontally deflected by the B-field Continues straight - no B-field Losses T2T4T6

5. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 5 Introduction (3/6) The SPS North Area Beams  The three proton beams are directed onto the primary targets: T2  H2 and H4 beam lines T4  H6, H8, and P0 beam lines T6  M2 beam line and Experimental Areas:  ECN3: underground experimental hall, can receive the primary proton beam with high intensity in ECN3  EHN1: surface experimental hall, can receive secondary beams and/or attenuated primary proton beams  EHN2: surface experimental hall, receives the secondary beams or intense muon beam

6. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 6 Introduction (4/6) CCC EHN1 BA81 (ps building) BA80 (ps building) TCC2 access TCC2 targets (underground) EHN2 (COMPASS) ECN3 (NA48) CRN (obsolete)

7. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 7 Introduction (5/6) CMS CERF/SC-RP LHCb ATLAS TOTEM CALICE/ILC GLAST, DREAM, AMS,… ALICE CRYSTALS/LHC Coll. NA49  6.5 Km of beam lines  About 1000 equipment installed

8. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 8 Introduction (6/6)  2006 will be a very interesting year for operations…

9. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 9 The EHN1 beams (1/18)  The SPS North Area was originally designed to house long-lasting experiments demands for high quality of beams: high intensity, high energy, high resolution  In the recent years most of the users are “tests” in particular of LHC detectors with permanent or “semi-permanent” BIG installations several users from astroparticle experiments  The test users have very different requirements from the big experiments: scan the full energy range ; typically [10, 300] GeV/c  with sometimes increased precision (linearity) requirements use beams of all particle types {electrons, pions, protons, muons}  with as good as possible separation and identification and, sometimes request high (or very high) rates and all that during the few (or even one!) week(s) of their allocated time! Rapidly changing environment, quite demanding on beam conditions and tunes

10. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 10 The EHN1 beams (2/18) TargetBeamCharacteristics T2H2High-energy, high-resolution secondary beam. Alternatively can be used to transport: attenuated primary beam of protons, electrons from  -conversion, polarized protons for   decay, enriched low-intensity beam of anti-protons, or K + Main parameters: P max = 400 (450) GeV/c, Acc.=1.5  Sr,  p/p max = ±2.0 % H4High-energy, high-resolution secondary beam. Alternatively can be used to transport: primary protons, electrons from  - conversion, polarized protons for   decay, enriched low-intensity beam of anti-protons, or K + Main parameters: P max = 330 (450) GeV/c, Acc.=1.5  Sr,  p/p max = ±1.4 % T4H6High-energy secondary beam. Main parameters: P max = 203 GeV/c, Acc.= 2.0  Sr,  p/p max = ±1.5 % H8High-energy, high-resolution secondary beam. Alternatively can be used to transport an attenuated primary proton beam Main parameters: P max = 400(450) GeV/c, Acc.= 2.5  Sr,  p/p max = ±1.5 %

11. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 11 The EHN1 beams (3/18) Particle production downstream the primary target  Protons : remnant of the incoming primary beams the target actually serves as attenuator ~40% of the initial incoming intensity of the beam  Pions(hadrons) : produced in hadronic interactions Typical scale: interaction length ( int )  Electrons : produced in electromagnetic processes Typical length scale : radiation length (X 0 )  Muons : produced in the decay of pions At the target and also along the beam line Target Development of hadronic shower Primary p beam (400 GeV/c) Secondary particles (  400 GeV/c) Attenuated proton beam

12. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 12 The EHN1 beams (4/18) Target material and length  The proton intensity on each target can go up to 10 13 protons/pulse limited by target and TAX absorber construction (i.e. cooling, etc.)  The material with largest ratio: X o / int is preferred  Beryllium  Increasing the target length: more production but also more re-absorption lower the energy of the outgoing particles Optimal choice ~ 1 interaction length Material X o (cm) int (cm) X o / int Beryllium Copper Lead 35.3 1.50 0.56 40.7 15.0 17.1 0.87 0.10 0.03

13. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 13 The EHN1 beams (5/18) The target head Beam position monitors  TBIU (upstream), TBID (downstream)  mounted on same girder as the target head for better alignment  beam steering onto the target using BSM located ~30m upstream of the target T4 target PositionH (mm)V (mm)L (mm)Material 012345012345 EMPTY 160 3 160 120 2 10 300 200 100 40 Be Pb T2 target PositionH (mm)V (mm)L (mm)Material 012345012345 EMPTY 160 120 2222222222 300 500 180 100 40 Be = -0.2 mm = -0.4 mm

14. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 14 The EHN1 beams (6/18) T6 target (M2, COMPASS) T4 target (H6, H8, P0) T2 target (H2, H4) Wobbling magnets

15. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 15 The EHN1 beams (7/18) Special cases – tertiary beams from neutrals  Neutral particles ( , K 0,  0 ) are also produced at the target And … 1.Convert the photons using a lead sheet to produce e +, e - pairs That way we can produce the purest electron/positron beams !!! 2.Let short lived neutrals (K 0,  0 ) to decay in air to produce p or  beams Using the energy and decay kinematics can enhance the p,  content of the beam  Use a strong magnet to sweep away all charged particles  Let the neutrals fly through towards the beam line direction  Use the first magnet of the beam to select the sign of particles to transport

16. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 16 The EHN1 beams (8/18) Special cases – Muon beam characteristics  Muon beams are formed by the decay of pions (    or   ) Decay kinematics:  At the pion center of mass system:  At the laboratory frame – boost  Limiting cases: Conclusion:  the muon beam energy is in the interval [0.57,1.0] of the initial pion beam energy   (p *, E * ) 

17. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 17 The EHN1 beams (9/18) – Production rates Hadron beams Electron beams Particle production by 400 GeV/c protons on Be targets, H.W.Atherton et. al.

18. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 18 The EHN1 beams (10/18) – target station wobbling AIM  Additional degrees of freedom  increase the flexibility in using a target station  Produce “several” secondary beams from the same target when the primary beam hits the target basically “all” the particles are produced in a large variety of angles and energies the most energetic particles are in the forward direction should not forget:  The very intense primary proton beam has to be dumped in a controlled way  The secondary beams of the chosen momentum have to go into the directions foreseen by the beam geometry (i.e. inside the vacuum tube of each beam line) Solution:  “wobbling” : hit the target under variable angle

19. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 19 The EHN1 beams (11/18) – target station wobbling Target SPS protons TAX B1 0-order approximation: Target SPS protons TAX B1 1st -order approximation: B1 Target SPS protons TAX B1 2nd -order approximation: B1 single secondary or primary beam fixed production angle two secondary beams one could be the primary beam fixed production angles two secondary beams one could be the primary beam variable production angles

20. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 20 The EHN1 beams (12/18) – T4 target station

21. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 21 The EHN1 beams (13/18) – TAX absorber attenuator

22. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 22 The EHN1 beams (14/18) –– TAX absorber attenuator Preparation and installation of new TAX blocks for T4.

23. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 23 The EHN1 beams (15/18) – T4 Wobbling Example 1:  primary proton beam in P0  H8, H6 secondary beams

24. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 24 The EHN1 beams (16/18) – T4 Wobbling Example 1:  primary proton beam in P0  H8, H6 secondary beams Presently the most frequent case “standard wobbling” settings:

25. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 25 The EHN1 beams (17/18) – T4 Wobbling Example 2:  P0 beam OFF  primary protons in H8 – “micro-beam”  H6 secondary beam

26. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 26 The EHN1 beams (18/18) – T4 Wobbling Safety - Survey  survey (monitor) the current in the “wobbling” magnets and the position of the TBIU, TBID monitors should be automatically done A program called WOBSU should be running continuously  for planned changes to the target station magnets (wobbling changes) a manual INHIBIT signal for the extraction has to be set at the CCC Wobbling changes:  initiated by the EA physicist upon the user requests  presented and discussed in the EATC meeting, documented in the minutes  settings file prepared and communicated by the EA physicist  performed by the operators on the agreed time re-tuning of the the beam lines after the wobbling changes is often required

27. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 27 Design highlights (1/12)  The momentum selection is done in the vertical plane “upstream” V-BENDs (B1, B2) between the primary target and the momentum acceptance collimator “downstream” V-BENDs (B3, B4) the main spectrometer of the beam momentum definition

28. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 28 Design highlights (2/12) View of the H8 and H6 beam lines in TT81 tunnel.

29. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 29 Design highlights (3/12) Beam optics modes:  High Resolution: used in the past to increase the momentum resolution of the beam line Required additional hardware (spectrometer chambers), not available anymore.  High Transmission: allows having the maximum particle flux at a given momentum  Filter Mode : has a focus on both planes at ~130m of the beam line, which allows using an intermediate (tertiary) target Heavily used now days to produce tertiary beams !  Tertiary beams provide more flexibility to the users and relaxes the coupling between the beam lines due to wobble choice. keep longer periods with the same wobble setting

30. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 30 Design highlights (4/12) Tertiary beams  Produced in two distinct ways: H6, H8: use a second target (filter)  beam line tuned for two energies: E1 (high energy) : from the primary target until the filter  momentum selection by the “down” vertical BENDs E2 (< E1) : from the filter until the experiment  momentum selection by BEND-3 and BEND-4 (up vertical bends) H2, H4: from the conversion or decay of secondary neutral particles  tertiary muon beams of well defined momenta are produced by stopping pions in a closed collimator before the last bending magnets of the beam line

31. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 31 Design highlights (5/12) Operational aspects

32. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 32 Design highlights (6/12) Operational aspects

33. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 33 Design highlights (7/12)  introduce a target (filter) after the “upstream” bends  tertiary beams have typically lower rates  choice of target material can enhance/select different particles Cu, Poly, Pb XCON fine positioning filter/converter

34. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 34 Design highlights (8/12) Tertiary beams H2, H4  use the B3 magnet of the wobbling as sweeping magnet charged particles are absorbed in the TAX neutral particles go through and hit the converter note: neutral particles can have zero or non zero production angle  use the converter  on Pb (CONVERTER=LEAD): to produce electrons (e +, e - ) COPNVERTER=AIR (no converter) to let K 0,  0, to decay  K 0   + +  -   0  p +  -  use B1 of the beam line to select the charge and particle for the tertiary beam to the experiment

35. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 35 Design highlights (9/12) Electron beams Secondary beams  electrons produced at the primary target rate goes down with energy increase  longer targets help electron production rate ~proportional to target length  at high energies (  120 GeV/c) can be separated from hadrons by synchrotron radiation  mixed beams pion (hadron) contamination for lower energies user CEDAR or treshold Cherenkov counters for tagging Tertiary beams  H6, H8: use Pb as secondary target few mm, or ~1-2 radiation lengths (X0) radiation length: distance in matter where  electrons loose ~1/e of their energy  hadrons loose ~nothing  H2, H4: electrons from photon conversion high purity beams!

36. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 36 Design highlights (10/12)  Electron beam separation by synchrotron radiation at high energies Electron beam – E0-DE @150 GeV/c  149.197 GeV/c Electron beam- E 0 41mrad angle – DE@180 GeV/c = 200 MeV Hadron beam – no energy loss

37. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 37 Design highlights (11/12) Hadron beams Secondary beams  hadrons are produced at the primary target  for positive sign beam a good fraction of the total hadron rate is protons  using an absorber (~1-2 X 0 of Pb) in the beam we can eliminate any electron contamination Tertiary beams  H6, H8: use secondary target of Cu, (CH) n ~1 interaction length I interaction length: characterizes the average longitudinal distribution of hadronic showers  a high energy hadron has 1- 1/e probability to interact within one lI  I >> X 0 for most of materials  H2, H4: hadrons produced in the decay of neutral mesons  0  p +  -, K 0   + +  -

38. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 38 Design highlights (12/12) Muon beams Secondary beams  muons produced directly at the target area or by the decay of pions muon momentum: 57-100% of the parent pion momentum  to produce a pure muon beam for the experiment, is enough to close out of beam axis the last collimators of the beam line  closing the collimator upstream of the last bend of the line we can obtain momentum selected muons  rule of thump: muons in a 1010cm 2 trigger represent ~1% of the hadron/pion flux there is another ~1% in a cone about 1  1m 2 around the beam axis 10 6 muons / 10  10 cm 2 trigger  1.3 uSv/h Tertiary beams  muons present only for tertiary beams in the energy range 57- 100% of the secondary beam momentum

39. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 39 Operational aspects (1/4) Beam tuning  Goal: deliver good quality of beam to the experiment! sufficient rate, spot size, particle purity,…  Tuning the beam is required each time we change something: energy, wobbling, user Very important:  start from an already prepared beam file by the EA physicists  be sure it corresponds to the present wobbling settings  be sure it can fulfil the user requirements typically the users know “their” files, but good to check it yourself as well!!!

40. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 40 Operational aspects (2/4) The first steps  consult the logbook of the beam line most of the files have been used already in the past new files represent minor variations of existing files  treat each plane independently start with the vertical plane which is the most important to get the beam to the experimental hall  select your observation point a scintillator counter close to the end of the beam line  provided the beam can reache it!!

41. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 41 Operational aspects (3/4) Watch out !!  electrons do not like material! remove triggers or other detectors from the beam line, otherwise you may simply kill the whole beam be careful when you try to measure/monitor things, since you may disturb the users  referring to logbook is fine but be sure you are comparing apples with apples  follow the particles, consistent particle rates use as much as possible normalized rates: rate/pot monitor beam losses, be sure you are looking at the beam not at its halo  similar rates at different places along the beam line scintillator counters are typically  = 100mm but NOT ALL; Exp. Scalers can vary a lot!  switching beam files: secondary beams have high rates  acceptance collimators close tertiary beams have low rates  acceptance collimators wide open therefore: switching from tertiary to secondary beam, load FIRST the collimators and then the magnets Operational aspects

42. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 42 Operational aspects (4/4) Important  Think before acting  To first order, all beam lines are quite similar however there are some differences which need time to become familiar with  Time is important for you and the users there is always a limit to how good a beam can be; let the users decide  Some users are quite experienced with their beam, and can do many things alone  Good documentation is vital beam line snapshot:  status of magnets/files/wobbling settings  status of collimators, target, absorber  rates in few counters (start, middle, end of beam line)  Don’t be afraid to ask for help Operational aspects

43. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 43 Safety Issues (1/8) Radiation Safety Issues Direct in-beam exposure should be avoided at all cases!  Hadron or electron beams containing >10 8 particles/burst are dangerous should be always dumped in special (thick) dumps (controlled losses)  serious irradiation to persons standing close to unshielded loss points  unshielded loss points will cause excessively high radiation levels in the experimental hall and cause dose rate limits at the CERN boundaries any in-beam exposure for even one pulse will cause observable biological damage beam line & areas should be completely shielded  Hadron or electron beams containing >10 6 particles/burst should be treated with respect unshielded loss points will cause limiting radiation levels in the experimental halls and at the CERN boundaries all loss points must be completely shielded (dumps) any in-beam exposure is still serious and will cause significant administrative actions

44. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 44 Safety Issues (2/8) Radiation Safety Issues  Hadron or electron beams containing <10 4 particles/burst could be allowed to travel in open areas still in-beam exposure should be avoided  Heavy ion beams of any intensity cannot be allowed to travel through open areas accidental in-beam exposure is dangerous and must be completely avoided

45. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 45 Safety Issues (3/8) SC/RP Central DAQ  All installed radiation alarm monitors can be read remotely  Data are stored in a database for further retreival  The parameters for each monitor are accessible can only be set/modified by authorized persons (TIS/RP)

46. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 46 Safety Issues (4/8)

47. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 47 Safety Issues (5/8) Additional radiation sources in the areas Radioactive sources  Used by the experiments for their detector calibration  Transport/installation under the TIS/RP responsibility  Normally a garage position should be available sometimes the source is in interlock with the area access system  Warning panels at the door of the experimental area Lasers  Used by the experiments for their detector calibration  Normally setup certified by TIS/RP Radioactive detectors  Uranium calorimeters (not anymore “a la mode”!)  “hot” detectors after irradiation tests transport/installation under TIS/RP supervision Note  Setups are modified quite often by the users it can happen that information on the changes arrives very late

48. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 48 Safety Issues (6/8) Dumps  Used to orderly stop the hadron/electron beams muons go through but undergo multiple scattering ==> larger cone  Typically formed by 2-3 m of iron with at least 80cm in each direction from the beam impact point one or two concrete blocks (80cm each) in each direction  Several dumps can exist in a beam line provide separation between different experimental areas  motorized or build in fixed dump at the end of each line  For high intensity beams the dump is made re-entrant, the particles are dumped into a hole, in order to reduce the particle backsplash  For very high intensities or for special beams (neutrino or muon beams) the dumps consist of many meters of iron, concrete and/or earth shielding examples: M2, P0/NA48, WANF, CNGS

49. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 49 Safety Issues (7/8) Motorized dumps XTDX – horizontal  2-3m of cast iron  several blocks one next to the other variable configuration  replace by concrete the last block for better neutron absorbtion  No concrete shielding around it reinforced shielding in the area XTDV – vertical  3.2m of cast iron  Is embedded in concrete shielding > 80cm in each direction

50. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 50 Safety Issues (8/8) Fences  Used to mark the limits of the controlled areas at least 2m height should not be possible to climb over no ladders allowed at any point against the fences  At least 1-2 m away from the nominal beam axis exact size/shape depends on the size of the experiment Modification to dumps or fences  Can ONLY be initiated by the responsible physicist  Have to be approved by TIS/RP and RSO presented in AB Safety Committee for approval  During SPS operation if for whatever reason the dumps or fences of the areas have to be modified, the MANUAL VETO of the beam line should be set

51. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 51 The access system (1/8) Beamline and Experimental Area classification  Secondary beam areas EHN1 (H2, H4, H6, H8) EHN2 (P61/M2) access granted locally interlock system per beam line/area  Primary beam areas TCC2 (north area targets) ECN3 (P0) same access rules as SPS machine and target zones

52. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 52 The access system (2/8)  The access system is used to prevent in-beam exposure for the personnel  For EA can be separated in two categories: Beam lines and Experimental areas Experimental Area  Perimeter defined by concrete blocks and/or fences typically at least 1m from the beam axis, exact shape depends on detector/installation size high intensity (>10 6 /ppp) proton or heavy-ion beams and exp. areas are completely shielded with concrete visibility to the area should not be blocked  Doors to access each area the main one (PPE) and at least one emergency escape door (PPX, PPG)  Several can exist in a single beam line connected to the same or different interlock chains  Access to downstream areas depend on beam conditions provided there is a dump (XTDV, XTDX, “manual”) in between Beam Line  The beam line: from the target  tunnel  exp.area(hall)  dump  A beam line can contain a single or several interlock chains of experimental areas

53. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 53 The access system (3/8) PPE146 – H6A  Big but “empty” PPE146 PPX146 XTDV PAX monitor

54. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 54 The access system (4/8) PPE168 – H8B  Large area with four doors and a search point  Big and complicated detector installations  Radioactive sources, gas distribution (including flammable) PPX168 PPE168 PPG168 PPX168Search point PAX monitor Beam dumpMagnet interlock XTDV dump

55. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 55 The access system (5/8) Safety elements  Physical elements that provide information for the access system  Doors: allow access to the experimental areas and underground tunnels  Dumps: motorized dumps to separate experimental areas in the same beam line  TAX: motorized blocks “dumps with holes” to attenuate or dump the beam  Magnets: stop the transport of a beam; (“champ null” detector, current limit, interlock)  Equipment: has to be present and in a given configuration  Special case: radiation monitors can stop the beam if above threshold, but not included in the access system  Status information available on the control room

56. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 56 The access system (6/8) Interlock chains  Hardware system to define a status of a beam line receives/treats information form various safety elements specialized electronics and network  Hierarchical organization per beam line (several chains in each beam line) tunnel (several beam lines) building/tunnels/area (TTC2=North)  SPS veto  Interlock signal based on information from at least two safety elements

57. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 57 The access system (7/8) Software Interlock chains - Matrices  Implemented into NODAL (CESAR) system  Should correspond to the actual hardware configuration matrices describing the configuration of each interlock chain  Used to facilitate the users/operators avoid mistakes that can cause access alarms fast help and monitor of the access system however  Mainly intended for high-level commands/programs direct calls to the hardware (ie. move a TAX or XTDV) may still be possible  Software interlocks are not considered as SAFE Note:  Hardware for the interlock system maintained by M.Grill (ST/MA)  Annual inspection before SPS startup

58. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 58 The access system (8/8) Safety Elements Doors  Control the access to experimental areas and beam lines  Users have to take a key to open the door must use the key to enter AND exit the area  At least one PPE and one PPX in each area marked at PPE xxx, PPX xxx (PPG xxx)  Door status defines the status of the area BUT NOT of the beam line free: people can enter without key key access: to enter you have to take a key beam ON/OFF: no access, beam can be present in the area  Timeout (~1min) if a door is left open more than 1min switches automatically to free state  In complicated areas the PPExxx door is combined with a search point acts like a door forces the area patrol to pass by that point Access Rules to Experimental Areas  One person one key no more than 8 people at a time in the area if so, the door/area must go in free mode  Change of door/area states: free  key access  search of the area by SPS operators and the GLIMOS of the experiment key access  beam (beam  key access)  press the end of access system verify that the above rule was not violated  via computer system key access  free  via computer system  door open timeout Emergency button (“force the door”)  stops the beam  drops the interlock chain of the door  AND the next higher level interlock chain

59. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 59 The access system (9/8) PPExxx Door door handle door and area status and control panel keys

60. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 60 The access system (10/8) Dumps – Motorized XTDV, XTDX  Used to separate experimental areas in the same beam line attached to the interlock chain of the downstream area  Motorized XTDV, XTDX dumps, 2-3m of Fe  Two positions defined: IN/OUT  Before moving a dump the beam must be stopped this to avoid spraying particles as the edge of the dump crosses the beamMagnets  Power converter level interlock on polarity current limitation  Direct measurement of the magnetic field zero magnetic field detection (“champ null”) can be very tricky if we have to transport low energy beams

61. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 61 The access system (11/8) TAXs – Target Attenuator  Massive blocks of material (Al-Cu-Fe) different configurations depending on the beam line 3.2m long located downstream the primary targets  Combined function: dump: stop proton/hadron beam  can be quite “hot”; ~5 Sv/hr at the end of shutdown attenuator: let the full (big hole) or attenuated beam (small holes with some material insert) to go through  Fully motorized with remote control two motors (XTAXxxxyyy) per beam  Movement split in ranges SMALL range:  move around the small holes empty or with material insert  used for the primary proton beams MEDIUM range: LARGE range:  can move the full range including the big empty holes  used for secondary or ion beams Access system

62. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 62 The access system (12/8)

63. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 63 The access system (13/8) Equipment MicroCollimator in H8 Beam Line  Combined setup: set of two collimators: XCRH and XCRV their support table: XCRT an IN/OUT collimator: XCIO  Used for the “micro-beam” option in H8 attenuated primary proton beam in H8

64. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 64 The access system (14/8) Interlock Chain – North Area

65. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 65 The access system (15/8) Interlock chain status The chains can be: SAFE  If all the elements in the chain are in the SAFE state it means we can have access to the area or UNSAFE  If any of the elements in the chain is in UNSAFE state we can’t have access the beam is present

66. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 66 The access system (16/8) Door Status and Control Display  Displays the status of the PPE doors  Allows monitoring and control of their state The doors can be in one of the following states FREE (green) No access control KEY ACCESS (yellow) Access with key Limited number of people CLOSED (red) Beam present

67. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 67 The access system (17/8) Search and secure procedure  Is needed in order to switch from Free to Key access an Exp. Area  The search is conducted by the search leader  normally the GLIMOS of the experiment and other authorized persons(s)  The defined procedure should be rigorously followed Procedure:  Ask all the persons present in the area to exit and close all the doors (PPE, PPX, PPG)  Verify that all fences and blocks defining the perimeter of the area are in place  Remove all ladders or any other equipment can be used by people to climb over the fences  Go to the PPE door and call the PCR to switch it from “Free Access” to “Key Access”  Leave one person at the PPE door and start the search. All persons entering the area must take a key. Audible devices can be used during the search to warn people. Take your time and look carefully everywhere  If there is a “Search Box” you must re-arm it although there is a time-out to do so, don’t rush! it is more to force you to look into that area not just to turn the key!  Return all the keys to the PPE door and press the “End of Access” button

68. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 68 The access system (18/8) North Area Beam Interlock Proton extraction to the North is allowed only if the North Area is in SAFE mode  North Area SAFE when ALL the corresponding Beam Lines are in safe mode  Beam Line SAFE if - either the nominal beam energy is limited below the energy of primary protons  ie. cannot transport primary protons - or the beam intensity is limited by beam attenuators (TAX's or combination of TAX's and other beam elements) Ion beam extraction can always be done  Particle type identification from CPS “Oxygen Interlock” signal  Manual operation – “ion key”

69. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 69 The access system (19/8) Example H8 Beam Line: x in a position means that 1 or 0 is allowed Element Actual Status Normal status Micro Beam (primary protons) Protons (secondary) Ions Beam LineSAFE UNSAFE 0101 1010 1010 xxxx TAXTAXMOT(6)NO RGE ALARM 1111 MagnetsBENDLIMITED NON LIMITED 0101 0101 1010 0101 Micro collimator tableTABLE201SAFE UNSAFE 0101 1010 0101 0101 Micro collimatorXCRH201SAFE UNSAFE 1111 1010 xxxx xxxx XCRV201SAFE UNSAFE 1111 1010 xxxx xxxx Protection collimatorXCIO200SAFE UNSAFE 0101 1010 0101 0101

70. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 70 The access system (20/8) TAX Ranges  SMALL/MEDIUM Range only small holes or holes with insert  attenuated beam  LARGE Range big and/or empty holes possible  no attenuation

71. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 71 The access system (21/8) TAX Ranges  status and setting in NODAL CESAR  READactual position (readout)  TAXDTset position (default, BIM-0). The position to reach at the end of an access  SELECT.RGEselected range (set)  ENABLE.RGEallowed (enabled) range based on the beam type in the machine/beamline  CONTROL.RGEcontrol unit status (values: COMPUTER, LOCAL, LOCKED)  ACTUAL.RGEactual range (readout)

72. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 72 The access system (22/8) BEND Limits Interlock condition on the maximum allowed current for the main BENDs of a beam line  LIMITED: I limit < I SPS the primary SPS beam cannot be transported  UNLIMITED: I limit  I SPS the primary SPS beam can be transported North Area

73. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 73 The access system (23/8) Manual Veto  “Key” to veto an interlock chain of a beam line blocks the presence of the beam in an exp. area, regardless the status of the existing safety elements of the chain  Normal status of all exp. area chains during shutdown  Has to be set each time there is work foreseen that can modify the status of an exp. area  Can ONLY be lifted with the agreement (signature) of the EA physicist.  The EA physicist must patrol the exp. area before signing to lift the Manual Veto verify that its perimeter is correctly closed the safety elements (dumps, doors, magnets) are present and functional i.e. must verify that the access system can function correctly

74. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 74 The access system (24/8) Changes to the access system  Changes to the access system (new conditions from the users, modification in the beam line or exp. area) are initiated and are under the responsibility of the EA physicist  The EA physicist takes care that all the parties involved are consulted and agree on the proposed changes EA and BI beam line experts access system experts, ST/MA (M. Grill) TIS/RP and AB/RSO  All modifications are discussed in the EATC meetings and documented in the minutes 1 st meeting of the year: summary of all modifications during the shutdown during operation, in the meeting before the SPS period concerned

75. 21/03/2003ie-spstrainingShutdown Lectures 2006 - 75 Items not discussed  SPS Page-1 – what it means every number there?  Timing –events and their distribution  Beam Instrumentation Collimators, FISCs, WireChambers, Cherenkovs, CEDARs,…  You can find all that and answer all your questions in two week’s time: Dry-Run-2 – week 13 (27-31 March) Full commissioning exercise of the North Area beams Prepare and test the maximum possible before the beam starts. New in 2006: BI hardware renovation, CESAR software, FESA-2, advanced software applications, and all kinds of goodies!!!!