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Peter-Raymond KettlePeter-Raymond Kettle MEG Review February 2007MEG Review February 2007 11
BeamBeamBeamBeam
LineLineLineLine
StatusStatusStatusStatus
Peter-Raymond KettlePeter-Raymond Kettle MEG Review February 2007MEG Review February 2007 22
SituationSituation @ last Review @ last ReviewSituationSituation @ last Review @ 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 line @ centre COBRA tested full beam line @ centre COBRA tested onlyonly with 6cm Tg.E so far with 6cm Tg.E so far • full beam line @ centre COBRA 4cm Tg.E full beam line @ centre COBRA 4cm Tg.E withoutwithout DegraderDegrader
• 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 line @ centre COBRA tested full beam line @ centre COBRA tested onlyonly with 6cm Tg.E so far with 6cm Tg.E so far • full beam line @ centre COBRA 4cm Tg.E full beam line @ centre COBRA 4cm Tg.E withoutwithout DegraderDegrader
COBRA US Radial Btot Distribution
3120.0
3140.0
3160.0
3180.0
3200.0
3220.01
2 34
56
7
8
9
10
11
12
1314
1516
171819
202122
2324
25
26
27
28
29
30
3132
3334
35 36
COBRA RadialAsymmetry
BERGAare
Top
Outstanding Problems to be solved:Outstanding Problems to be solved:
1.1. Beam Misalignment due to Solenoidal Bfield Asymmetry caused Beam Misalignment due to Solenoidal Bfield Asymmetry caused by magnet material under hall floorby magnet material under hall floor
2. Muons prematurely ranging-out due to air/gas contamination +2. Muons prematurely ranging-out due to air/gas contamination + inadequate mixing in/of COBRA He-atmosphereinadequate mixing in/of COBRA He-atmosphere
3. APD-Array System needed for future phase space measurements3. APD-Array System needed for future phase space measurements
Outstanding Problems to be solved:Outstanding Problems to be solved:
1.1. Beam Misalignment due to Solenoidal Bfield Asymmetry caused Beam Misalignment due to Solenoidal Bfield Asymmetry caused by magnet material under hall floorby magnet material under hall floor
2. Muons prematurely ranging-out due to air/gas contamination +2. Muons prematurely ranging-out due to air/gas contamination + inadequate mixing in/of COBRA He-atmosphereinadequate mixing in/of COBRA He-atmosphere
3. APD-Array System needed for future phase space measurements3. APD-Array System needed for future phase space measurements
Remaining Components:Remaining Components:
• US End-CapUS End-Cap• DS End-CapDS End-Cap• Insertion System Insertion System + Drive System+ Drive System
Remaining Components:Remaining Components:
• US End-CapUS End-Cap• DS End-CapDS End-Cap• Insertion System Insertion System + Drive System+ Drive System
Peter-Raymond KettlePeter-Raymond Kettle MEG Review February 2007MEG Review February 2007 33
Full MEG Beam LineFull MEG Beam Line11 Main Components11 Main Components
All now All now Implemented Implemented
Full MEG Beam LineFull MEG Beam Line11 Main Components11 Main Components
All now All now Implemented Implemented
DSDSEnd-CapEnd-Cap+ Insertion System+ Insertion System
DSDSEnd-CapEnd-Cap+ Insertion System+ Insertion System
US End-CapUS End-CapUS End-CapUS End-Cap
BTSBTSBTSBTSDegraderDegraderDegraderDegrader
Triplet I + II + SeperatorTriplet I + II + Seperator Triplet I + II + SeperatorTriplet I + II + Seperator
Steering MagnetSteering MagnetSteering MagnetSteering Magnet
CollimatorCollimatorCollimatorCollimator
CompensationCompensationCoils 4xCoils 4xCompensationCompensationCoils 4xCoils 4x
Peter-Raymond KettlePeter-Raymond Kettle MEG Review February 2007MEG Review February 2007 44
Problem Solving: 1) Beam MisalignmentProblem Solving: 1) Beam MisalignmentProblem Solving: 1) Beam MisalignmentProblem Solving: 1) Beam Misalignment
CompensationCompensationCoils 4xCoils 4xCompensationCompensationCoils 4xCoils 4x
Horizontal (SM41H) + Vertical (SM41V) Horizontal (SM41H) + Vertical (SM41V) Steering Magnets made, placed on DS-side BTS –Steering Magnets made, placed on DS-side BTS –Between focii (water-cooled)Between focii (water-cooled)Power Supplies installed on galleryPower Supplies installed on gallery
Horizontal (SM41H) + Vertical (SM41V) Horizontal (SM41H) + Vertical (SM41V) Steering Magnets made, placed on DS-side BTS –Steering Magnets made, placed on DS-side BTS –Between focii (water-cooled)Between focii (water-cooled)Power Supplies installed on galleryPower Supplies installed on gallery
SMH41SMH41SMH41SMH41
SMV41SMV41SMV41SMV41
Power Supplies:Power Supplies:2x 250A(limited 200A) 55V unipolar2x 250A(limited 200A) 55V unipolarRamp-rate 0.5A/s (BTS/COBRA)Ramp-rate 0.5A/s (BTS/COBRA)Bdl = 24 GBdl = 24 Gm at 200Am at 200A
Power Supplies:Power Supplies:2x 250A(limited 200A) 55V unipolar2x 250A(limited 200A) 55V unipolarRamp-rate 0.5A/s (BTS/COBRA)Ramp-rate 0.5A/s (BTS/COBRA)Bdl = 24 GBdl = 24 Gm at 200Am at 200A
*** No simple solution for Compensation ****** No simple solution for Compensation ***Since phase space rotation in BTS & COBRASince phase space rotation in BTS & COBRAHorizontal field: Horizontal field: Vertical & Horizontal displacement Vertical & Horizontal displacementVertical field: Vertical field: Horizontal & Vertical displacement Horizontal & Vertical displacement
Hence for given correction at given zHence for given correction at given z Solve simultaneous equationsSolve simultaneous equations
*** No simple solution for Compensation ****** No simple solution for Compensation ***Since phase space rotation in BTS & COBRASince phase space rotation in BTS & COBRAHorizontal field: Horizontal field: Vertical & Horizontal displacement Vertical & Horizontal displacementVertical field: Vertical field: Horizontal & Vertical displacement Horizontal & Vertical displacement
Hence for given correction at given zHence for given correction at given z Solve simultaneous equationsSolve simultaneous equations
Peter-Raymond KettlePeter-Raymond Kettle MEG Review February 2007MEG Review February 2007 55
Problem Solving: 2) Gas Quality + MixingProblem Solving: 2) Gas Quality + MixingProblem Solving: 2) Gas Quality + MixingProblem Solving: 2) Gas Quality + MixingLast Run: Last Run: Air Contamination responsible Air Contamination responsible for Muons Ranging-outfor Muons Ranging-outgradient 3-9% air along zgradient 3-9% air along z 7-11% (air + C7-11% (air + C22HH66) with DCs) with DCs
New Run:New Run:Improved COBRA He-SystemImproved COBRA He-SystemWith End-CapsWith End-Caps• 3 Volumes treated separately3 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 inletsinlets• equalized flow outletsequalized flow outlets• Pressure RegulationPressure Regulation• He-MonitoringHe-Monitoring
Last Run: Last Run: Air Contamination responsible Air Contamination responsible for Muons Ranging-outfor Muons Ranging-outgradient 3-9% air along zgradient 3-9% air along z 7-11% (air + C7-11% (air + C22HH66) with DCs) with DCs
New Run:New Run:Improved COBRA He-SystemImproved COBRA He-SystemWith End-CapsWith End-Caps• 3 Volumes treated separately3 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 inletsinlets• equalized flow outletsequalized flow outlets• Pressure RegulationPressure Regulation• He-MonitoringHe-Monitoring
Peter-Raymond KettlePeter-Raymond Kettle MEG Review February 2007MEG Review February 2007 66
Problem Solving: 3) APD-Array System Problem Solving: 3) APD-Array System Problem Solving: 3) APD-Array System Problem Solving: 3) APD-Array System
Geiger-mode APDGeiger-mode APD
APD-ArrayAPD-Array10 mm pitch10 mm pitchAPD-ArrayAPD-Array10 mm pitch10 mm pitch Fast Photoniques Fast Photoniques
PreampPreamp
Fast Photoniques Fast Photoniques
PreampPreampGeiger-mode APDGeiger-mode APDGeiger-mode APDGeiger-mode APD
Single mounted Test Single mounted Test Single mounted Test Single mounted Test
yyyyxxxx
x- y-distributionsx- y-distributions
Beam Test: Photonique Geiger-mode APDBeam Test: Photonique Geiger-mode APD + BCF20 Scintillator (2x2)mm+ BCF20 Scintillator (2x2)mm22
• large gain/rate dependence large gain/rate dependence modify Rmodify R11 R R2 2 on Preampon Preamp• optimized preamp. Bias voltage vs. gainoptimized preamp. Bias voltage vs. gain• radiation damage studied radiation damage studied
Beam Test: Photonique Geiger-mode APDBeam Test: Photonique Geiger-mode APD + BCF20 Scintillator (2x2)mm+ BCF20 Scintillator (2x2)mm22
• large gain/rate dependence large gain/rate dependence modify Rmodify R11 R R2 2 on Preampon Preamp• optimized preamp. Bias voltage vs. gainoptimized preamp. Bias voltage vs. gain• radiation damage studied radiation damage studied
17481748pixelspixels17481748pixelspixels
BackBackfacefaceBackBackfaceface
Discovered high radiation damage sensitivityDiscovered high radiation damage sensitivityto eto e++ & & s -pixels don’t recovers -pixels don’t recover > dark current < gain with > fluence> dark current < gain with > fluenceLIFE EXPECTANCY ~ 8 hrs in full beamLIFE EXPECTANCY ~ 8 hrs in full beam CANNOT USE for ARRAY !!!!CANNOT USE for ARRAY !!!!
Discovered high radiation damage sensitivityDiscovered high radiation damage sensitivityto eto e++ & & s -pixels don’t recovers -pixels don’t recover > dark current < gain with > fluence> dark current < gain with > fluenceLIFE EXPECTANCY ~ 8 hrs in full beamLIFE EXPECTANCY ~ 8 hrs in full beam CANNOT USE for ARRAY !!!!CANNOT USE for ARRAY !!!!
Intensive investigation started at PSI with Intensive investigation started at PSI with Photoniques varies makes geiger-mode APDPhotoniques varies makes geiger-mode APDInvestigated Investigated ALL show similar effects!!!! ALL show similar effects!!!!
Intensive investigation started at PSI with Intensive investigation started at PSI with Photoniques varies makes geiger-mode APDPhotoniques varies makes geiger-mode APDInvestigated Investigated ALL show similar effects!!!! ALL show similar effects!!!!
Peter-Raymond KettlePeter-Raymond Kettle MEG Review February 2007MEG Review February 2007 77
Component Status: US End-CapComponent Status: US End-CapComponent Status: US End-CapComponent Status: US End-Cap• COBRA US End-Cap Manufactured & assembled & COBRA US End-Cap Manufactured & assembled & INSTALLEDINSTALLED• US End-Cap Gas Distribution System US End-Cap Gas Distribution System INSTALLEDINSTALLED• COBRA US End-Cap Manufactured & assembled & COBRA US End-Cap Manufactured & assembled & INSTALLEDINSTALLED• US End-Cap Gas Distribution System US End-Cap Gas Distribution System INSTALLEDINSTALLED
Vacuum Vacuum ChamberChamberconnectionconnection
Vacuum Vacuum ChamberChamberconnectionconnection
NN2 2 Bag Bag
++ TC TC
NN2 2 Bag Bag
++ TC TC
Outside ViewOutside ViewOutside ViewOutside View
Inside ViewInside ViewInside ViewInside View
Installation with NInstallation with N22-Bag-Bag
• Not OptimalNot Optimal• have learned how tohave learned how to improve on several improve on several points !!!points !!!
Installation Finished 12/10/2006Installation Finished 12/10/2006Installation Finished 12/10/2006Installation Finished 12/10/2006InsideInsideCOBRA COBRA
NN22-Bag-Bag
EC sand-EC sand-wich foilwich foil
Arrived 13/7/2006Arrived 13/7/2006Arrived 13/7/2006Arrived 13/7/2006
Peter-Raymond KettlePeter-Raymond Kettle MEG Review February 2007MEG Review February 2007 88
DS End-Cap & Insertion SystemDS End-Cap & Insertion SystemDS End-Cap & Insertion SystemDS End-Cap & Insertion System Problem with frictional driveProblem with frictional driveof Insertion System (IS) of Insertion System (IS) – – Designed Kurath Eng.Designed Kurath Eng.- Built Bieri Eng.- Built Bieri Eng.Too weak for frictionalToo weak for frictionalForceForceWe managed the impossibleWe managed the impossiblewith Bieri Eng. !!!with Bieri Eng. !!!Design + Construction of Design + Construction of New Drive System +New Drive System +adaptation to IS + delivery adaptation to IS + delivery *** 3 WEEKS ****** 3 WEEKS ***
Problem with frictional driveProblem with frictional driveof Insertion System (IS) of Insertion System (IS) – – Designed Kurath Eng.Designed Kurath Eng.- Built Bieri Eng.- Built Bieri Eng.Too weak for frictionalToo weak for frictionalForceForceWe managed the impossibleWe managed the impossiblewith Bieri Eng. !!!with Bieri Eng. !!!Design + Construction of Design + Construction of New Drive System +New Drive System +adaptation to IS + delivery adaptation to IS + delivery *** 3 WEEKS ****** 3 WEEKS ***
Installed 14/12/2006Installed 14/12/2006Installed 14/12/2006Installed 14/12/2006
Delivered 24/10/2006Delivered 24/10/2006Delivered 24/10/2006Delivered 24/10/2006
NBR Bellows SystemNBR Bellows System Stroke ~ 1.6mStroke ~ 1.6mNBR Bellows SystemNBR Bellows System Stroke ~ 1.6mStroke ~ 1.6m
New Belt-drivenNew Belt-drivenInsertion System underInsertion System undertest at Bieri Engineering test at Bieri Engineering WinterthurWinterthur
New Belt-drivenNew Belt-drivenInsertion System underInsertion System undertest at Bieri Engineering test at Bieri Engineering WinterthurWinterthur Belt driven systemBelt driven systemBelt driven systemBelt driven system
Peter-Raymond KettlePeter-Raymond Kettle MEG Review February 2007MEG Review February 2007 99
Target SystemTarget SystemTarget SystemTarget System
polyesterpolyesterpolyesterpolyester
RohacellRohacell
DC SupportDC SupportPneumaticPneumatic DriveDrive
MovementMovement
Polyester/Rohacell targetPolyester/Rohacell targetPolyester/Rohacell targetPolyester/Rohacell target
Pneumatic (He) drivePneumatic (He) drivePneumatic (He) drivePneumatic (He) driveTarget System:Target System:• 175175m Polyester ellipse 210x70 mmm Polyester ellipse 210x70 mm• Rohacell support frame + stemsRohacell support frame + stems• strain-relieved target mountstrain-relieved target mount• He-driven pneumatic insertionHe-driven pneumatic insertion• electronic position end-markerselectronic position end-markers *** System Worked Very Well ****** System Worked Very Well ***
Expected Muon Stop-rate: Expected Muon Stop-rate: RRss~ 0.62R~ 0.62R00
RR00 = incoming muon rate = incoming muon rate
Decay + He interaction ~12% RDecay + He interaction ~12% R00
Stop in Stop in slantedslanted target ~ 70% R target ~ 70% R00
Target System:Target System:• 175175m Polyester ellipse 210x70 mmm Polyester ellipse 210x70 mm• Rohacell support frame + stemsRohacell support frame + stems• strain-relieved target mountstrain-relieved target mount• He-driven pneumatic insertionHe-driven pneumatic insertion• electronic position end-markerselectronic position end-markers *** System Worked Very Well ****** System Worked Very Well ***
Expected Muon Stop-rate: Expected Muon Stop-rate: RRss~ 0.62R~ 0.62R00
RR00 = incoming muon rate = incoming muon rate
Decay + He interaction ~12% RDecay + He interaction ~12% R00
Stop in Stop in slantedslanted target ~ 70% R target ~ 70% R00
DCsDCsDCsDCs
Inside COBRA in parking positionInside COBRA in parking positionInside COBRA in parking positionInside COBRA in parking position
USUSTCsTCsUSUSTCsTCs
Peter-Raymond KettlePeter-Raymond Kettle MEG Review February 2007MEG Review February 2007 1010
Commissioning Run Dec. 2006Commissioning Run Dec. 2006Commissioning Run Dec. 2006Commissioning Run Dec. 2006• US COBRA Commissioning finished 28/11/2006US COBRA Commissioning finished 28/11/2006• delays to closing DS End-Cap DC/Ndelays to closing DS End-Cap DC/N22-Bag conflict-Bag conflict• waiting for IS to be deliveredwaiting for IS to be delivered
Full Beam Line (all components), 4cm Tg.E ReadyFull Beam Line (all components), 4cm Tg.E Ready 14/12/2006 14/12/2006 ****** 9 DAYS of Beam Left ***9 DAYS of Beam Left ***Naturally decide to Maximize Commissioning time for Naturally decide to Maximize Commissioning time for DC, TC, Trigger, DAQ testing DC, TC, Trigger, DAQ testing BUT priority beamBUT priority beamQuestion to be answered first Question to be answered first Beam Misalignment Beam MisalignmentCompensation at COBRA centreCompensation at COBRA centre Lost time to finish studies Lost time to finish studies 20072007
• US COBRA Commissioning finished 28/11/2006US COBRA Commissioning finished 28/11/2006• delays to closing DS End-Cap DC/Ndelays to closing DS End-Cap DC/N22-Bag conflict-Bag conflict• waiting for IS to be deliveredwaiting for IS to be delivered
Full Beam Line (all components), 4cm Tg.E ReadyFull Beam Line (all components), 4cm Tg.E Ready 14/12/2006 14/12/2006 ****** 9 DAYS of Beam Left ***9 DAYS of Beam Left ***Naturally decide to Maximize Commissioning time for Naturally decide to Maximize Commissioning time for DC, TC, Trigger, DAQ testing DC, TC, Trigger, DAQ testing BUT priority beamBUT priority beamQuestion to be answered first Question to be answered first Beam Misalignment Beam MisalignmentCompensation at COBRA centreCompensation at COBRA centre Lost time to finish studies Lost time to finish studies 20072007
collimatorcollimatorcollimatorcollimator
centredcentredcentredcentred
aboveabove
DegraderDegraderDegraderDegrader
APD Problem solvedAPD Problem solved (temporarily)(temporarily)• Large depletion layer Large depletion layer (non-Geiger mode) + v. fast(non-Geiger mode) + v. fastPreampPreamp• sag-compensated 2-Dsag-compensated 2-DScanner with >3.5 m reachScanner with >3.5 m reach
APD Problem solvedAPD Problem solved (temporarily)(temporarily)• Large depletion layer Large depletion layer (non-Geiger mode) + v. fast(non-Geiger mode) + v. fastPreampPreamp• sag-compensated 2-Dsag-compensated 2-DScanner with >3.5 m reachScanner with >3.5 m reach
Peter-Raymond KettlePeter-Raymond Kettle MEG Review February 2007MEG Review February 2007 1111
Commissioning Run Provisional ResultsCommissioning Run Provisional ResultsCommissioning Run Provisional ResultsCommissioning Run Provisional Results
Collimator Collimator transmission transmission εε = 95% = 95% Collimator Collimator transmission transmission εε = 95% = 95%
Data still under Analysis Data still under Analysis PROVISIONALPROVISIONALRate at Entrance COBRA 1.15Rate at Entrance COBRA 1.15101088 ++ss-1 -1 at 1.8mA, 4cm Tgat 1.8mA, 4cm TgRate at COBRA centre > 6 Rate at COBRA centre > 6 101077 ++ss-1-1 at 1.8mA, 4cm Tg (under investigation) at 1.8mA, 4cm Tg (under investigation)Beam Spot Beam Spot σσ ~ 10.8 mm (as expected) ~ 10.8 mm (as expected)
Data still under Analysis Data still under Analysis PROVISIONALPROVISIONALRate at Entrance COBRA 1.15Rate at Entrance COBRA 1.15101088 ++ss-1 -1 at 1.8mA, 4cm Tgat 1.8mA, 4cm TgRate at COBRA centre > 6 Rate at COBRA centre > 6 101077 ++ss-1-1 at 1.8mA, 4cm Tg (under investigation) at 1.8mA, 4cm Tg (under investigation)Beam Spot Beam Spot σσ ~ 10.8 mm (as expected) ~ 10.8 mm (as expected)
Separation QualitySeparation QualityHigh Intensity (slits open) 7.4High Intensity (slits open) 7.4σσLow Intensity 8.1Low Intensity 8.1σσ
Separation QualitySeparation QualityHigh Intensity (slits open) 7.4High Intensity (slits open) 7.4σσLow Intensity 8.1Low Intensity 8.1σσ
ee++ee++
++++
Low IntensityLow IntensityLow IntensityLow Intensity
SMH41 SMV41SMH41 SMV41 CorrectionCorrection at at Centre of COBRACentre of COBRA
~ 2 mm Horizontally~ 2 mm Horizontally ~ 7 mm Vertically~ 7 mm Vertically
CORRECTIONCORRECTION WORKS !!!WORKS !!!
COBRACOBRAcentrecentreCOBRACOBRAcentrecentre
COBRACOBRAcentrecentreCOBRACOBRAcentrecentre