CNGS ISSUES - THAT COULD DISTURB A SMOOTH OPERATION IN 2009 Thanks to colleagues who contributed to the slides: E. Gschwendtner, A. Pardons, H. Vincke, S. Girod, D. Autiero, R. Losito ATOP Days CERN March 6, 2009 Outline CNGS run in 2008 – overview 2008 shutdown – major works Horn/reflector cooling system Waste water handling Prospects for the 2009 run I. Efthymiopoulos, EN/MEF

CNGS Run in 2008  Smooth running, excellent performance of the facility  No radiation problems/effects in the electronics  No problems with the major elements of the secondary beam: target, horn/reflector  OPERA Experiment  10’100 on-time events  1’700 candidate interactions in the bricks I.Efthymiopoulos, EN/MEF 2 ATOP Days, March 2009 Performance Average rate Reference sample: Long tracks (>5 TT planes × 20) CNGS on time events

CNGS Run in 2008 I.Efthymiopoulos, EN/MEF 3 Primary beam 48s supercycle : FT + 3 CNGS + LHC + MD  37.5% CNGS duty cycle 50.4s supercycle : 7 CNGS + LHC  83% CNGS duty cycle Integrated efficiency: 60.94% ATOP Days, March 2009

Physics run in 2008 I.Efthymiopoulos, EN/MEF Beam statistics 4 18kV cable repair MD PS magnet exchange, septum bakeout MD SPS timing fault: vacuum leak & magnet exchange CNGS maintenance: Horn water filter exchange, Hadron stop sump emptying SPS extraction line: Magnet ground fault 1.78E19 pot on November 3 rd Integrated protons on CNGS target 1.4E19 4.0E18 8.0E18 6.0E18 1.0E18 2.0E18 18-JuneJuly 2008August 2008September 2008October 2008 MD CNGS maintenance: Horn water filter exchange 1.0E19 1.2E19 1.6E19 November2008 ATOP Days, March 2009

Protons on Target per Day Beam to CNGS, North Area, LHCBeam to CNGS only CNGS duty cycle: 37.5%, 54%37.5%, 43% 37.5%, 45%, 54% 56%-83% 3.5E17 CNGS Facility – Performance 2008 E. Gschwendtner – AB Seminar Nov’08

Target Beam Position Excellent position stability; ~50microns over entire run. No active position feedback is necessary –1-2 small steerings/week only CNGS Facility – Performance 2008 Horizontal beam position on the last BPM in front of the target E. Gschwendtner – AB Seminar Nov’08

Beam Stability seen on Muon Monitors Position stability of muon beam in pit 2 is ~3cm rms Beam position correlated to beam position on target. –Parallel displacement of primary beam on T40 Horizontal centroid pit 2 Vertical centroid pit 2 CNGS Facility – Performance 2008 E. Gschwendtner – AB Seminar Nov’08

8 Muon Monitors Very sensitive to any beam changes ! –Offset of beam vs target at 0.05mm level CNGS Facility – Performance 2008 Muon Profiles Pit 1 Muon Profiles Pit 2  5cm shift of muon profile centroid  ~80  m parallel beam shift  Centroid of horizontal profile pit2 –Offset of target vs horn at 0.1mm level Target table motorized Horn and reflector tables not E. Gschwendtner – AB Seminar Nov’08

CNGS Run in 2008 I.Efthymiopoulos, EN/MEFATOP Days, March  Very interesting experience to stress the facility  duty cycle : up to 83% (1-2 days only), with ~75-80% of designed pulse intensity  Note: CNGS design of equipment and RP considerations for 2×2.4×10 13 protons/6s, 100% duty cycle Target design with ×2 safety for “ultimate” intensity of 2×3.5×10 13 protons/6s, 100% duty cycle Observations: No unexpected temperature rise in horn/reflector and electrical circuit  Several temperature probes (mainly around the target station) died  Expected, due to integrated intensity  Action : nothing to do!  Increased temperature at the first He-tank window Action : not an issue, should be kept in mind for future (upgrades?)  Lifetime of horn/reflector cooling circuit filters Understood, due to integrated intensity but shorter than expected No degradation of horn/reflector itself Action : work during 2008/09 shutdown High-duty cycle operation

10 CNGS duty cycle: 37.5%, 54%37.5%, 43% 37.5%, 45%, 54% 56%-83% Helium Tube Entrance Window Temperature CNGS Facility – Experience of Operating a 500kW Facility E. Gschwendtner – AB Seminar Nov’08

Helium Tube Entrance Window Temperature Measurements –0.3mm thick –0.8m inner diameter –Clamped with seal between flanges shielding horn ionization chamber target TBID collimator BPM beam Helium tube Ti-window Temperature Measurement Clamping bolt Entrance window Seal Titanium Grade (Ti-6Al-4V) –Ultimate stress: >900MPa >870MPa >850MPa From calculations: - When ventilation vs. beam is such that temp. at flange = 66°C:  Window: Temp. <100°C & Stress <250MPa  Safety factor 3 ensured. From temperature measurements during operation (extrapolate): - If temp. measured < 85°C  Window: Temp. <150°C & Stress <300MPa  Safety factor 2.5 ensured. CNGS Facility – Experience of Operating a 500kW Facility Courtesy of A. Pardons

CNGS Run in 2008 I.Efthymiopoulos, EN/MEFATOP Days, March Helium Tube Entrance Window Horn Beam He window

CNGS Run in 2008  TBID detector broke down on July 19, only after 1.2×10 18 pot)  the ionization chambers can be used for setting up  reduced handle to verify target integrity and beam steering I.Efthymiopoulos, EN/MEF 13 TBID Detector TBID signal Ionization Chamber ATOP Days, March 2009 Origin of the problem  Short circuit in the isolation bias of the screens  Could be either in the cable, the connectors, or in the device itself

CNGS Run in 2008 I.Efthymiopoulos, EN/MEFATOP Days, March TBID Detector TBID Target Horn Beam Possibility to repair?  Radiation levels are rather high  ~27mSv/h at floor level  Difficult to remove it due to cables  No spare available  Review again with BE/BI & RP before startup if something can be done, also in view of other operations…

Major shutdown activities  Repair of the ventilation unit in TCV4  Modifications to the horn/reflector cooling system to improve the filter lifetime  Evacuation and handling of the CNGS sumps water  Inspection of target unit CNGS Preparation for 2009 I.Efthymiopoulos, EN/MEF 15 ATOP Days, March 2009

TCV4 Ventilation repair  Leak of chilled water in one of the TCV4 units(1 st floor)  small leak, triggered no alarm, but still ~2.5m3 of water in the floor and on top of equipment  no damages except in one of the cameras  the water became radioactive as it washed the nearby filters of the ventilation unit  Repair ongoing along with standard maintenance of all ventilation units  work next to the filters, had to wait for cool- down I.Efthymiopoulos, EN/MEF 16 Solutions  Difficult to install detection system for such small leaks; small fraction of total water flow in the CNGS area  Install additional cameras to monitor the TCV4 cavern !! ATOP Days, March 2009

Cooling system for the horns  Resin filters are used to maintain a low conductivity level in the circuit  Two reasons: avoid short-circuit inside the horn limit long-term corrosion effects  About 1/3 of the flow goes through the filters  Required level: [0.1,10.0]  S/cm  Two filters in place (active + spare) equipped with quick connectors  Filters get activated – temporarily stored in TSG4 for initial cool-down Main issues:  Filter lifetime before saturation  wished to be one year, but really unknown  2008 run showed they saturate much sooner !!  long access (>20h stop) each time to replace them (10min)  The filters used have plastic pieces (tubes) inside; not a real issue but better to avoid  The filters are radioactive waste, their use must be optimized I.Efthymiopoulos, EN/MEF 17 Filters ATOP Days, March 2009

Cooling system for the horns I.Efthymiopoulos, EN/MEF 18 Filter lifetime - horn Filter exchange Limit for safe operation : 10  S/cm 7.5E18 pot 45 days  This would imply ~6 filter exchanges for a nominal CNGS year (4.5×10 19 pot) ! Water conductivity Integrated pot ATOP Days, March 2009

Cooling system for the horns I.Efthymiopoulos, EN/MEF 19 Filter lifetime - reflector Filter exchange  Filter exchange at 1.15E19 pot  4 filter (4.5×10 19 pot) ! ATOP Days, March 2009

Cooling system for the horns I.Efthymiopoulos, EN/MEF 20  Increase the filter capacity of the system  use 2 × 50(100) lt filters instead of single 40lt today  × 2.5 gain, survive a full nominal year with only one exchange  New optimized filter container design  allow easier manipulation (installation/removal) of the filters  maintain the quick connectors  possibility to empty the resin and re-use the container  less radioactive waste design to be validated by safety and RP Modifications for 2009 ATOP Days, March 2009

Cooling system for the horns I.Efthymiopoulos, EN/MEF 21 Horn/reflector cooling system – modifications shutdown 2009 ATOP Days, March 2009  New chassis to add to existing one  Enough space for 2(3) cartridges of 50(100) lt  Additional metallic filter to capture resin debris in case of an accident

CNGS sumps I.Efthymiopoulos, EN/MEF 22 Layout ATOP Days, March 2009

CNGS water handling 1.Sumps TNM41 – TNM42  infiltrations along the decay tube (1-1.5lt/h) – nothing can be easily done to reduce it  Requires access to TI8 line – foreseen during the injector MD periods 2.Sumps in TSG4  water inflow from condensation in the ventilation system : 1 evacuation during operation, ~4 during shutdown 3. Horn/reflector cooling water  2× 600 lt ; highly radioactive (up to 80 MBq/lt)  Yearly exchange 4. Hadron stop cooling water  ~2000 lt, highly radioactive I.Efthymiopoulos, EN/MEF 23 ATOP Days, March 2009 Summary

CNGS water handling I.Efthymiopoulos, EN/MEF 24  Evacuate the water from the different areas  Special equipment for TI8/hadron stop available Can pass under the vacuum pipe in TI8 tunnel  Transfer the water in special containers for storage  Accumulate the water for one operational year  Elimination path(s)  Via CEA Marcoule A complete chemical analysis needs to be done each time before they can accept the water  Evaporator NUMI uses a such a system for their tritiated alkaline water can treat 85gallons(320lt)/day of 90’000pCi/ml (3.4MBq/lt) H3 contained water of PH  Discussions ongoing in a working group with A&T safety and RP colleagues Plan for 2009 ATOP Days, March 2009

CNGS water handling I.Efthymiopoulos, EN/MEF 25 Transient water storage in BA4  Retention bag connected to L3 alarm  Foreseen space for 18 containers (18m 3 )  Isolation against freezing if needed (cost an issue) ATOP Days, March 2009

TARGET inspection I.Efthymiopoulos, EN/MEF 26  During the standard maintenance, a problem appeared in the motorization for the target rotation  From investigations so far it seems the torque needed to turn the target unit exceeds the capacity of the motor and the torque limiter  Proposed plan:  Open the target shielding to view the status of the target unit with the crane camera  Install a test stand upstream in TCC4 and bring the target unit for further observations with cameras and if possible prepare tooling to do rotation tests.  The EN/STI experts are already working on the spare unit to optimize the manipulations in CNGS  More news in the coming weeks… ATOP Days, March 2009

TARGET inspection I.Efthymiopoulos, EN/MEF 27 ATOP Days, March 2009  CNGS target magazine during assembly

TARGET inspection I.Efthymiopoulos, EN/MEF 28 TCC4 inspection – outside the shielding ATOP Days, March 2009  Signs of rust are observed in parts of the motorizations and limit switches  Could be the origin of the torque increase  To be investigated once the target is out from its shielding.

TARGET inspection I.Efthymiopoulos, EN/MEF 29 Target magazine inspection in TCC4  Work in the area to be defined and discussed in collaboration with SC/RP  Lab tests with the spare unit would allow to optimize the time needed in agreement with the ALARA principle Target magazine in its transport chassis Camera locations ATOP Days, March 2009 Pb screens

CNGS Preparation for 2009 I.Efthymiopoulos, EN/MEF 30  Floor rectification for the traveling of the PPP-TSG41 plug  Make new solid flat surface for the big plug to roll  Consolidation/preventive maintenance of horn/reflector power supplies  Small consolidation project for 2009/2010  preventive maintenance to replace thyristor capacitance charges  cross-check all bus-bars connections and screws to avoid similar incident as last year  Improvements in the irradiation test installation – CNRAD test area  Complete installation of all four stations, correct powering problems  Support stands for irradiation samples (not laying everything on the floor)  Complete RADMON installation and define reference positions  Finalize access and material handling procedures … and  Standard maintenance of various systems 2008/2009 Shutdown activities ATOP Days, March 2009

LNGS News I.Efthymiopoulos, EN/MEF 31  OPERA is advancing with the analysis of the 2008 data  They accumulated in 2008 about on time events, mostly interaction in the rock, among which 1700 neutrino interactions in the bricks  They aim in completing the analysis of 2008 data by the start of 2009 run  OPERA looks forward to a smooth run in 2009 with integrated intensity as close as possible to the nominal value of pot   They transmit their thanks to all the accelerator teams for their continuing efforts to support the beam line and the LNGS physics ATOP Days, March 2009

OPERA Event Gallery I.Efthymiopoulos, EN/MEFATOP Days, March  Charm mesons produced in um interactions  2.1 expected charm events during  Seen: 2 charm-like topologies Event analysis - preliminary

CNGS – prospects for Beam to CNGS, LHC, FT, MD Beam to CNGS, LHC, FT Beam to CNGS, MD 2009 : 175 days with beam  2.80×10 19 pot for 2.0×10 13 prot/extr  3.36×10 19 pot for2.4×10 13 prot/extr (MTE)  3.70×10 19 pot with 2.0×10 13 prot/extr  4.44×10 19 pot with 2.4×10 13 prot/extr (MTE)  4.80×10 19 pot with 2.0×10 13 prot/extr  5.76×10 19 pot with 2.0×10 13 prot/extr (MTE) I.Efthymiopoulos, EN/MEFATOP Days, March 2009

 2008 was a very good year for CNGS  Many thanks to those who worked hard during last year’s shutdown,  and the operations teams for providing the beam to the facility and the experiments  2009 shutdown work is advancing well, getting ready for the startup  but still some last minute surprises like with the target  Looking forward for a smooth and efficient run in 2009 Summary I.Efthymiopoulos, EN/MEF 34 ATOP Days, March 2009