Peter-Raymond Kettle MEG Review February BeamBeam LineLine StatusStatus

Peter-Raymond KettleMEG Review February last Review Beam Study at Centre of COBRA with – Beam Study at Centre of COBRA with – 4cm Tg.E + Degrader System Needed !!! 4cm Tg.E + Degrader System Needed !!! full beam centre COBRA tested only with 6cm Tg.E so far full beam centre COBRA tested only with 6cm Tg.E so far full beam centre COBRA 4cm Tg.E without Degrader full beam centre COBRA 4cm Tg.E without Degrader Beam Study at Centre of COBRA with – Beam Study at Centre of COBRA with – 4cm Tg.E + Degrader System Needed !!! 4cm Tg.E + Degrader System Needed !!! full beam centre COBRA tested only with 6cm Tg.E so far full beam centre COBRA tested only with 6cm Tg.E so far full beam centre COBRA 4cm Tg.E without Degrader full beam centre COBRA 4cm Tg.E without Degrader TopTop Outstanding Problems to be solved: 1. Beam Misalignment due to Solenoidal Bfield Asymmetry caused by magnet material under hall floor by magnet material under hall floor 2. Muons prematurely ranging-out due to air/gas contamination + inadequate mixing in/of COBRA He-atmosphere inadequate mixing in/of COBRA He-atmosphere 3. APD-Array System needed for future phase space measurements Outstanding Problems to be solved: 1. Beam Misalignment due to Solenoidal Bfield Asymmetry caused by magnet material under hall floor by magnet material under hall floor 2. Muons prematurely ranging-out due to air/gas contamination + inadequate mixing in/of COBRA He-atmosphere inadequate mixing in/of COBRA He-atmosphere 3. APD-Array System needed for future phase space measurements Remaining Components: US End-CapUS End-Cap DS End-CapDS End-Cap Insertion SystemInsertion System + Drive System + Drive System Remaining Components: US End-CapUS End-Cap DS End-CapDS End-Cap Insertion SystemInsertion System + Drive System + Drive System

Peter-Raymond KettleMEG Review February Full MEG Beam Line 11 Main Components All now Implemented DSEnd-Cap + Insertion System DSEnd-Cap US End-Cap BTSBTS DegraderDegrader Triplet I + II + Seperator Steering Magnet CollimatorCollimator Compensation Coils 4x Compensation

Peter-Raymond KettleMEG Review February Problem Solving: 1) Beam Misalignment Compensation Coils 4x Compensation Horizontal (SM41H) + Vertical (SM41V) Steering Magnets made, placed on DS-side BTS – Between focii (water-cooled) Power Supplies installed on gallery Horizontal (SM41H) + Vertical (SM41V) Steering Magnets made, placed on DS-side BTS – Between focii (water-cooled) Power Supplies installed on gallery SMH41SMH41 SMV41SMV41 Power Supplies: 2x 250A(limited 200A) 55V unipolar Ramp-rate 0.5A/s (BTS/COBRA) Bdl = 24 G  m at 200A Power Supplies: 2x 250A(limited 200A) 55V unipolar Ramp-rate 0.5A/s (BTS/COBRA) Bdl = 24 G  m at 200A *** No simple solution for Compensation *** *** No simple solution for Compensation *** Since phase space rotation in BTS & COBRA Horizontal field:  Vertical & Horizontal displacement Vertical field:  Horizontal & Vertical displacement Hence for given correction at given z Hence for given correction at given z  Solve simultaneous equations  Solve simultaneous equations *** No simple solution for Compensation *** *** No simple solution for Compensation *** Since phase space rotation in BTS & COBRA Horizontal field:  Vertical & Horizontal displacement Vertical field:  Horizontal & Vertical displacement Hence for given correction at given z Hence for given correction at given z  Solve simultaneous equations  Solve simultaneous equations

Peter-Raymond KettleMEG Review February Problem Solving: 2) Gas Quality + Mixing Last Run: Air Contamination responsible for Muons Ranging-out gradient 3-9% air along z 7-11% (air + C 2 H 6 ) with DCs 7-11% (air + C 2 H 6 ) with DCs New Run: Improved COBRA He-System With End-Caps 3 Volumes treated separately 3 Volumes treated separately (i)Central Volume (i)Central Volume (ii+iii) US+DS End-Cap (ii+iii) US+DS End-Cap distributed equalized-flow distributed equalized-flow inlets inlets equalized flow outlets equalized flow outlets Pressure Regulation Pressure Regulation He-Monitoring He-Monitoring Last Run: Air Contamination responsible for Muons Ranging-out gradient 3-9% air along z 7-11% (air + C 2 H 6 ) with DCs 7-11% (air + C 2 H 6 ) with DCs New Run: Improved COBRA He-System With End-Caps 3 Volumes treated separately 3 Volumes treated separately (i)Central Volume (i)Central Volume (ii+iii) US+DS End-Cap (ii+iii) US+DS End-Cap distributed equalized-flow distributed equalized-flow inlets inlets equalized flow outlets equalized flow outlets Pressure Regulation Pressure Regulation He-Monitoring He-Monitoring

Peter-Raymond KettleMEG Review February Problem Solving: 3) APD-Array System Geiger-mode APD APD-Array 10 mm pitch APD-Array Fast Photoniques Preamp Preamp Fast Photoniques Preamp Preamp Geiger-mode APD Single mounted Test yy xx x- y-distributions Beam Test: Photonique Geiger-mode APD + BCF20 Scintillator (2x2)mm 2 + BCF20 Scintillator (2x2)mm 2 large gain/rate dependence large gain/rate dependence  modify R 1 R 2 on Preamp  modify R 1 R 2 on Preamp optimized preamp. Bias voltage vs. gain optimized preamp. Bias voltage vs. gain radiation damage studied radiation damage studied Beam Test: Photonique Geiger-mode APD + BCF20 Scintillator (2x2)mm 2 + BCF20 Scintillator (2x2)mm 2 large gain/rate dependence large gain/rate dependence  modify R 1 R 2 on Preamp  modify R 1 R 2 on Preamp optimized preamp. Bias voltage vs. gain optimized preamp. Bias voltage vs. gain radiation damage studied radiation damage studied 1748pixels1748pixels BackfaceBackface Discovered high radiation damage sensitivity to e + &  s -pixels don’t recover > dark current fluence > dark current fluence LIFE EXPECTANCY ~ 8 hrs in full beam  CANNOT USE for ARRAY !!!!  CANNOT USE for ARRAY !!!! Discovered high radiation damage sensitivity to e + &  s -pixels don’t recover > dark current fluence > dark current fluence LIFE EXPECTANCY ~ 8 hrs in full beam  CANNOT USE for ARRAY !!!!  CANNOT USE for ARRAY !!!! Intensive investigation started at PSI with Photoniques varies makes geiger-mode APD Investigated  ALL show similar effects!!!! Intensive investigation started at PSI with Photoniques varies makes geiger-mode APD Investigated  ALL show similar effects!!!!

Peter-Raymond KettleMEG Review February Component Status: US End-Cap COBRA US End-Cap Manufactured & assembled & INSTALLED COBRA US End-Cap Manufactured & assembled & INSTALLED US End-Cap Gas Distribution System INSTALLED US End-Cap Gas Distribution System INSTALLED COBRA US End-Cap Manufactured & assembled & INSTALLED COBRA US End-Cap Manufactured & assembled & INSTALLED US End-Cap Gas Distribution System INSTALLED US End-Cap Gas Distribution System INSTALLED VacuumChamberconnectionVacuumChamberconnection N 2 Bag + TC TC N 2 Bag + TC TC Outside View Inside View Installation with N 2 -Bag Not Optimal Not Optimal have learned how to have learned how to improve on several improve on several points !!! points !!! Installation Finished 12/10/2006 InsideCOBRA N 2 -Bag EC sand- wich foil Arrived 13/7/2006

Peter-Raymond KettleMEG Review February DS End-Cap & Insertion System Problem with frictional drive of Insertion System (IS) – Designed Kurath Eng. - Built Bieri Eng. Too weak for frictional Force We managed the impossible with Bieri Eng. !!! Design + Construction of New Drive System + adaptation to IS + delivery  *** 3 WEEKS ***  *** 3 WEEKS *** Problem with frictional drive of Insertion System (IS) – Designed Kurath Eng. - Built Bieri Eng. Too weak for frictional Force We managed the impossible with Bieri Eng. !!! Design + Construction of New Drive System + adaptation to IS + delivery  *** 3 WEEKS ***  *** 3 WEEKS *** Installed 14/12/2006 Delivered 24/10/2006 NBR Bellows System Stroke ~ 1.6m Stroke ~ 1.6m NBR Bellows System Stroke ~ 1.6m Stroke ~ 1.6m New Belt-driven Insertion System under test at Bieri Engineering Winterthur New Belt-driven Insertion System under test at Bieri Engineering Winterthur Belt driven system

Peter-Raymond KettleMEG Review February Target System polyesterpolyester Rohacell DC Support Pneumatic Drive Drive Movement Polyester/Rohacell target Pneumatic (He) drive Target System: 175  m Polyester ellipse 210x70 mm 175  m Polyester ellipse 210x70 mm Rohacell support frame + stems Rohacell support frame + stems strain-relieved target mount strain-relieved target mount He-driven pneumatic insertion He-driven pneumatic insertion electronic position end-markers electronic position end-markers *** System Worked Very Well *** *** System Worked Very Well *** Expected Muon Stop-rate: R s ~ 0.62R 0 R 0 = incoming muon rate Decay + He interaction ~12% R 0 Stop in slanted target ~ 70% R 0 Target System: 175  m Polyester ellipse 210x70 mm 175  m Polyester ellipse 210x70 mm Rohacell support frame + stems Rohacell support frame + stems strain-relieved target mount strain-relieved target mount He-driven pneumatic insertion He-driven pneumatic insertion electronic position end-markers electronic position end-markers *** System Worked Very Well *** *** System Worked Very Well *** Expected Muon Stop-rate: R s ~ 0.62R 0 R 0 = incoming muon rate Decay + He interaction ~12% R 0 Stop in slanted target ~ 70% R 0 DCsDCs Inside COBRA in parking position USTCsUSTCs

Peter-Raymond KettleMEG Review February Commissioning Run Dec US COBRA Commissioning finished 28/11/2006 US COBRA Commissioning finished 28/11/2006 delays to closing DS End-Cap DC/N 2 -Bag conflict delays to closing DS End-Cap DC/N 2 -Bag conflict waiting for IS to be delivered waiting for IS to be delivered Full Beam Line (all components), 4cm Tg.E Ready 14/12/2006 *** 9 DAYS of Beam Left *** 14/12/2006 *** 9 DAYS of Beam Left *** Naturally decide to Maximize Commissioning time for DC, TC, Trigger, DAQ testing BUT priority beam Question to be answered first  Beam Misalignment Compensation at COBRA centre Lost time to finish studies Lost time to finish studies  2007  2007 US COBRA Commissioning finished 28/11/2006 US COBRA Commissioning finished 28/11/2006 delays to closing DS End-Cap DC/N 2 -Bag conflict delays to closing DS End-Cap DC/N 2 -Bag conflict waiting for IS to be delivered waiting for IS to be delivered Full Beam Line (all components), 4cm Tg.E Ready 14/12/2006 *** 9 DAYS of Beam Left *** 14/12/2006 *** 9 DAYS of Beam Left *** Naturally decide to Maximize Commissioning time for DC, TC, Trigger, DAQ testing BUT priority beam Question to be answered first  Beam Misalignment Compensation at COBRA centre Lost time to finish studies Lost time to finish studies  2007  2007 collimatorcollimatorcentredcentred above DegraderDegrader APD Problem solved APD Problem solved (temporarily) (temporarily) Large depletion layer Large depletion layer (non-Geiger mode) + v. fast Preamp sag-compensated 2-D sag-compensated 2-D Scanner with >3.5 m reach APD Problem solved APD Problem solved (temporarily) (temporarily) Large depletion layer Large depletion layer (non-Geiger mode) + v. fast Preamp sag-compensated 2-D sag-compensated 2-D Scanner with >3.5 m reach

Peter-Raymond KettleMEG Review February Commissioning Run Provisional Results Collimator Collimator transmission ε = 95% Collimator Collimator transmission ε = 95% Data still under Analysis PROVISIONAL Rate at Entrance COBRA 1.15  10 8  + s -1 at 1.8mA, 4cm Tg Rate at COBRA centre > 6  10 7  + s -1 at 1.8mA, 4cm Tg (under investigation) Beam Spot σ ~ 10.8 mm (as expected) Data still under Analysis PROVISIONAL Rate at Entrance COBRA 1.15  10 8  + s -1 at 1.8mA, 4cm Tg Rate at COBRA centre > 6  10 7  + s -1 at 1.8mA, 4cm Tg (under investigation) Beam Spot σ ~ 10.8 mm (as expected) Separation Quality Separation Quality High Intensity (slits open) 7.4σ Low Intensity 8.1σ Separation Quality Separation Quality High Intensity (slits open) 7.4σ Low Intensity 8.1σ e+e+e+e+ e+e+e+e+ ++++ ++++ Low Intensity SMH41 SMV41 SMH41 SMV41 Correction Correction at at Centre of COBRA ~ 2 mm Horizontally ~ 2 mm Horizontally ~ 7 mm Vertically ~ 7 mm Vertically CORRECTION CORRECTION WORKS !!! WORKS !!! COBRAcentreCOBRAcentre COBRAcentreCOBRAcentre