Peter-Raymond Kettle MEG Review February 2007 1 BeamBeam LineLine StatusStatus

Peter-Raymond KettlePeter-Raymond Kettle MEG Review February 2007MEG Review February 2007 11

BeamBeamBeamBeam

LineLineLineLine

StatusStatusStatusStatus


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


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


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


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


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!!!!


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


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


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


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


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

Documents

Peter-Raymond Kettle MEG Review February 2007 1 BeamBeam LineLine StatusStatus