MEG 2008 Run Run Coordinator’s view

Peter-Raymond KettlePeter-Raymond Kettle MEG Review February 2009MEG Review February 2009 11

MEG2008 Run

Run Coordinator’sview

MEG2008 Run

Run Coordinator’sview

0.9

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s in

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10 14 m Decay

s in

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EE ee/E/E Max

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/E/E MaxMax


Situation - Review Feb. 2008Situation - Review Feb. 2008Back to “Square One” - TOTAL Detector DISMANTLED post Back to “Square One” - TOTAL Detector DISMANTLED post 2007 Engineering Run2007 Engineering Run - for Maintenance/Repair /Improvement - for Maintenance/Repair /Improvement

TCs: Fibre light-leakTCs: Fibre light-leak+ new N+ new N2 2 Bags + APD Bags + APD

amplifier/electronicsamplifier/electronics

TCs: Fibre light-leakTCs: Fibre light-leak+ new N+ new N2 2 Bags + APD Bags + APD

amplifier/electronicsamplifier/electronics

DCs: Support StructureDCs: Support Structure+ new Target Angle ++ new Target Angle +HV InvestigationHV Investigation

DCs: Support StructureDCs: Support Structure+ new Target Angle ++ new Target Angle +HV InvestigationHV Investigation

Calo: new HVCalo: new HVFeed-thro’s + LNFeed-thro’s + LN22

Cooling-pipe mod.Cooling-pipe mod.(heat-load) + lnvest.(heat-load) + lnvest.LXe Light-Yield mod.LXe Light-Yield mod.Purification systemPurification system

Calo: new HVCalo: new HVFeed-thro’s + LNFeed-thro’s + LN22

Cooling-pipe mod.Cooling-pipe mod.(heat-load) + lnvest.(heat-load) + lnvest.LXe Light-Yield mod.LXe Light-Yield mod.Purification systemPurification system

C-WC-WC-WC-W

BTSBTSBTSBTSCalo.Calo.Calo.Calo.

DS-ECDS-EC+ IS+ IS

DS-ECDS-EC+ IS+ IS

DCsDCsDCsDCsTCsTCsTCsTCs TCsTCsTCsTCs

ECECECEC


2008 Beam Time & Constraints2008 Beam Time & Constraints2008 Run Goals:2008 Run Goals:

final beam operational conditions to be tuned/optimized {(final beam operational conditions to be tuned/optimized {(mm-, -, - & p-beams C-W)}- & p-beams C-W)}

Full set of detector calibrations + optimization/exploitation of various techniquesFull set of detector calibrations + optimization/exploitation of various techniques

optimized detector/trigger settingsoptimized detector/trigger settings

asas fuller set of information as possible, necessary for Data-analysisfuller set of information as possible, necessary for Data-analysis

+ “Long-term” Goal of understanding our Detector+ “Long-term” Goal of understanding our Detector

Max. ExpectationMax. ExpectationMEG-Physics DataMEG-Physics Data

~ 16 weeks~ 16 weeks

Max. ExpectationMax. ExpectationMEG-Physics DataMEG-Physics Data

~ 16 weeks~ 16 weeks

End-of-ShutdownEnd-of-Shutdown


Planning & OrganizationPlanning & Organization

Total of 62 persons for 959 shifts (Full Run Only)Total of 62 persons for 959 shifts (Full Run Only)Total of 62 persons for 959 shifts (Full Run Only)Total of 62 persons for 959 shifts (Full Run Only)

Basic Run LayoutBasic Run LayoutBasic Run LayoutBasic Run Layout

Full Run Part IFull Run Part ICEX Run +CEX Run + Trigger Trigger

Setup + calibrationsSetup + calibrationsDetector monitoringDetector monitoring

Full Run Part IFull Run Part ICEX Run +CEX Run + Trigger Trigger

Setup + calibrationsSetup + calibrationsDetector monitoringDetector monitoring

Parasitic RunParasitic RunBeam optimizationBeam optimization

in parallel within parallel withDebug, Tune &Debug, Tune &

CalibrateCalibrate

Parasitic RunParasitic RunBeam optimizationBeam optimization

in parallel within parallel withDebug, Tune &Debug, Tune &

CalibrateCalibrate

Full Run Part IIFull Run Part IIPre-physics data checkPre-physics data check

Physics DataPhysics Data(MEG + RD)(MEG + RD)

Full Run Part IIFull Run Part IIPre-physics data checkPre-physics data check

Physics DataPhysics Data(MEG + RD)(MEG + RD)

2 Shift2 ShiftCoordinatorsCoordinators 7 weeks tot.7 weeks tot.

2 Shift2 ShiftCoordinatorsCoordinators 7 weeks tot.7 weeks tot.

13 Shift Coordinators13 Shift Coordinators 2 weeks/person2 weeks/person 13 Shift Coordinators13 Shift Coordinators 2 weeks/person2 weeks/person

Run CoordinatorRun Coordinator Run CoordinatorRun Coordinator

Parasitic RunParasitic RunParasitic RunParasitic Run

Full RunFull RunFull RunFull Run

12 Hr Shifts:12 Hr Shifts: 1 DAY SHIFT (Beam Group) 10:00 – 22:001 DAY SHIFT (Beam Group) 10:00 – 22:00 1 NIGHT SHIFT max. 22:00 – 10:00 1 NIGHT SHIFT max. 22:00 – 10:00

1 Shift Leader Nights1 Shift Leader Nights Manned by Detector ExpertsManned by Detector Experts

12 Hr Shifts:12 Hr Shifts: 1 DAY SHIFT (Beam Group) 10:00 – 22:001 DAY SHIFT (Beam Group) 10:00 – 22:00 1 NIGHT SHIFT max. 22:00 – 10:00 1 NIGHT SHIFT max. 22:00 – 10:00

1 Shift Leader Nights1 Shift Leader Nights Manned by Detector ExpertsManned by Detector Experts

8 Hr Shifts:8 Hr Shifts: 1 DAY SHIFT 07:00 – 15:301 DAY SHIFT 07:00 – 15:30 1 EVENING SHIFT 15:00 – 23:301 EVENING SHIFT 15:00 – 23:30 1 NIGHT SHIFT 23:00 – 07:301 NIGHT SHIFT 23:00 – 07:30

1 Shift Leader + 1 Crew Member1 Shift Leader + 1 Crew Member

8 Hr Shifts:8 Hr Shifts: 1 DAY SHIFT 07:00 – 15:301 DAY SHIFT 07:00 – 15:30 1 EVENING SHIFT 15:00 – 23:301 EVENING SHIFT 15:00 – 23:30 1 NIGHT SHIFT 23:00 – 07:301 NIGHT SHIFT 23:00 – 07:30

1 Shift Leader + 1 Crew Member1 Shift Leader + 1 Crew Member

to allow for flexibility + continuity:to allow for flexibility + continuity:

Staggered & Overlapping shift systemStaggered & Overlapping shift system Daily Run Meetings (on-site)Daily Run Meetings (on-site) Weekly Video Run Meeting (Collaboration-wide) Weekly Video Run Meeting (Collaboration-wide) later, weekly Video Physics Analysis Group Meetinglater, weekly Video Physics Analysis Group Meeting Web-based Schedule + Shift list + “On-call” ListWeb-based Schedule + Shift list + “On-call” List


Organization In PracticeOrganization In PracticeDetailed Information AccessDetailed Information Access• • “ “How to” information database for shift crews on MEGWikiHow to” information database for shift crews on MEGWiki

Shift List

Shift List

Shift List

Shift List

Schedule

Schedule

Schedule

Schedule

EXAMPLES

EXAMPLES

• comprehensive electronic Hardware/Softwarecomprehensive electronic Hardware/Software check-list for shift crews check-list for shift crews

• fully searchable & cross-referenced Electronic fully searchable & cross-referenced Electronic Logbooks for all sub-detectors & Run shift-crewsLogbooks for all sub-detectors & Run shift-crews

5 Sheets

5 Sheets

• easy web-based experiment/instrument easy web-based experiment/instrument control for shift-crews control for shift-crews (e.g. Beam Line – magnets, separator)(e.g. Beam Line – magnets, separator) push-button changing of rate with autopush-button changing of rate with auto magnet/slits hysteresis cyclingmagnet/slits hysteresis cycling


Detector Synopsis Detector Synopsis

TCsTCs DCsDCs

Calo.Calo. NaINaI

Calo:Calo:• HV feedthroughs replacedHV feedthroughs replaced• Liquid & Gaseous purificationLiquid & Gaseous purification success LY-behaviour needs success LY-behaviour needs further study + PM gain stabilityfurther study + PM gain stability

Calo:Calo:• HV feedthroughs replacedHV feedthroughs replaced• Liquid & Gaseous purificationLiquid & Gaseous purification success LY-behaviour needs success LY-behaviour needs further study + PM gain stabilityfurther study + PM gain stability

DCs:DCs:• HV instability problems with HV instability problems with air-doping still persist!!!air-doping still persist!!!

DCs:DCs:• HV instability problems with HV instability problems with air-doping still persist!!!air-doping still persist!!!

TCs:TCs:• Fibres working, problemFibres working, problem DAQ control of DS fibresDAQ control of DS fibres• Laser temp. control problemsLaser temp. control problems

TCs:TCs:• Fibres working, problemFibres working, problem DAQ control of DS fibresDAQ control of DS fibres• Laser temp. control problemsLaser temp. control problems

C-W:C-W:• proved “Essential Tool”proved “Essential Tool”Li (17.6, 14.6 MeV)Li (17.6, 14.6 MeV)+ B (4.4, 11.7, 16.1 MeV)+ B (4.4, 11.7, 16.1 MeV)lines – Energy + Timinglines – Energy + Timing

C-W:C-W:• proved “Essential Tool”proved “Essential Tool”Li (17.6, 14.6 MeV)Li (17.6, 14.6 MeV)+ B (4.4, 11.7, 16.1 MeV)+ B (4.4, 11.7, 16.1 MeV)lines – Energy + Timinglines – Energy + Timing

NaI:NaI:• New APD preampsNew APD preamps• automated moverautomated mover• temp. contolled APDstemp. contolled APDs• E/E ~5-6% (E/E ~5-6% ())

NaI:NaI:• New APD preampsNew APD preamps• automated moverautomated mover• temp. contolled APDstemp. contolled APDs• E/E ~5-6% (E/E ~5-6% ())

C-WC-W


Trigger + DAQTrigger + DAQ Trigger+ Splitters Trigger+ Splitters

Online ClusterMegonxx

Online ClusterMegonxx Multi-trigger implementation:Multi-trigger implementation:

Final Complement of 29 Triggers implementedFinal Complement of 29 Triggers implemented multiple & pre-scaled (MEG=11, RMD=5)multiple & pre-scaled (MEG=11, RMD=5)

Single & Coincidence detector triggers crucialSingle & Coincidence detector triggers crucial for monitoring/Calibrationfor monitoring/Calibration e.g. e.g. 77Li, Li, 1111B C-W, B C-W, , CR, LED – RMD, , CR, LED – RMD, 00,,00-Dalitz-Dalitz

CEX software collimators LXe responceCEX software collimators LXe responce Direction matching Direction matching mmee (planned TC fibres)(planned TC fibres)

too slow too slow still still XEC PMT-index + TC-bar(index,z) XEC PMT-index + TC-bar(index,z) where z from bar charge-ratiowhere z from bar charge-ratio

Trig. Monitoring via (cyclic-buffers)Trig. Monitoring via (cyclic-buffers)

Multi-trigger implementation:Multi-trigger implementation:

Final Complement of 29 Triggers implementedFinal Complement of 29 Triggers implemented multiple & pre-scaled (MEG=11, RMD=5)multiple & pre-scaled (MEG=11, RMD=5)

Single & Coincidence detector triggers crucialSingle & Coincidence detector triggers crucial for monitoring/Calibrationfor monitoring/Calibration e.g. e.g. 77Li, Li, 1111B C-W, B C-W, , CR, LED – RMD, , CR, LED – RMD, 00,,00-Dalitz-Dalitz

CEX software collimators LXe responceCEX software collimators LXe responce Direction matching Direction matching mmee (planned TC fibres)(planned TC fibres)

too slow too slow still still XEC PMT-index + TC-bar(index,z) XEC PMT-index + TC-bar(index,z) where z from bar charge-ratiowhere z from bar charge-ratio

Trig. Monitoring via (cyclic-buffers)Trig. Monitoring via (cyclic-buffers)lcmeg05lcmeg05lcmeg05lcmeg05

lcmeg04lcmeg04lcmeg04lcmeg04




OfflineClusterlcmeg

OfflineClusterlcmeg

Limits:Limits:• DAQ/DRS readout limited by VME (83MB/s)DAQ/DRS readout limited by VME (83MB/s) ~ 30 events/s full waveforms (threading)~ 30 events/s full waveforms (threading)• Online (backend) 2TB storageOnline (backend) 2TB storage• Offline (lcmeg) 64 CPUs + 104TB disk Offline (lcmeg) 64 CPUs + 104TB disk • “ “Lazylogger” autocopy Online Lazylogger” autocopy Online Offline Offline factor 2 compression offlinefactor 2 compression offline

DRS3 – partly implemented DRS3 – partly implemented (clock signals, temp eff. Etc.)(clock signals, temp eff. Etc.)

DRS v2 + part v3DRS v2 + part v3


Arsenal of Standard Calibration ToolsArsenal of Standard Calibration ToolsLEDLED

PMT Gain

Higher V with light att.

Can be repeated frequently

alphaalpha

PMT QE & Att. L

Cold GXe

LXe

LaserLaser

Laser

(rough) relative timing calib.

< 2~3 nsec< 2~3 nsec

Nickel GeneratorNickel Generator

9 MeV Nickel γ-line

NaI

Polyethylene

0.25 cm Nickel plate

3 cm 20 cm

quelle

on

off

Illuminate Xe from the back

Source (Cf) transferred by comp air on/off

Proton AccProton Acc Li(p,)Be

LiF target at COBRA center

17.6MeV

~daily calib.

Can be used also for initial setup

KBi

TlF

Li(p, 0) at 17.6 MeV

Li(p, 1) at 14.6 MeV

m radiative decaym radiative decay

0 0 - + p 0 + n

0 (55MeV, 83MeV)

- + p + n (129MeV)

10 days to scan all volume precisely

(faster scan possible with less points)

LH2 target

e+

e-

ee

mm

Lower beam intensity < 107

Is necessary to reduce pile-ups

Better t, makes it possible to take data with higher beam intensity

A few days ~ 1 week to get enough statistics

MEG DetectorMEG DetectorStandardStandard

CalibrationsCalibrations

MEG DetectorMEG DetectorStandardStandard

CalibrationsCalibrations

NOT YET S

TANDARD

NOT YET S

TANDARD

NO

T YE

T ST

AND

ARD

NO

T YE

T ST

AND

ARD


New & Improved Calibration TechniquesNew & Improved Calibration TechniquesMultiple calibration techniques proved Multiple calibration techniques proved Essential Essential for deconvoluting complex effects for deconvoluting complex effects Multiple calibration techniques proved Multiple calibration techniques proved Essential Essential for deconvoluting complex effects for deconvoluting complex effects

(1)(1) New Lithium TetraborateTarget (LiNew Lithium TetraborateTarget (Li22BB44OO77) for C-W: - advantage both Li- & B-lines ) for C-W: - advantage both Li- & B-lines

simultaneously available without large X-section of F (~ 6-7 MeV), from LiFsimultaneously available without large X-section of F (~ 6-7 MeV), from LiF

>16.1 MeV >11.7 MeV

4.4 MeV

11.7 & 4.4 MeV 11.7 & 4.4 MeV s Coincident in time (94%)s Coincident in time (94%) & no angular correlation& no angular correlation11.7 & 4.4 MeV 11.7 & 4.4 MeV s Coincident in time (94%)s Coincident in time (94%) & no angular correlation& no angular correlation

Li used for E-calibration, B can be used for Li used for E-calibration, B can be used for ΔΔtabstabs(LXe-TC) (LXe-TC)

or or ΔΔt(TC-TC(inter-bar)t(TC-TC(inter-bar)))

Li used for E-calibration, B can be used for Li used for E-calibration, B can be used for ΔΔtabstabs(LXe-TC) (LXe-TC)

or or ΔΔt(TC-TC(inter-bar)t(TC-TC(inter-bar)))

(2) New timing calibration technique during CEX: - use Dalitz decay for (2) New timing calibration technique during CEX: - use Dalitz decay for intercalibrating LXe & TC detectors by tracking eintercalibrating LXe & TC detectors by tracking e+ + in DCsin DCs ((00 → e→ e++ee-- )) used successfully for measuring absolute used successfully for measuring absolute ΔΔt(t(LXe-TC) of reference TC-bar, canLXe-TC) of reference TC-bar, can then intercalibrate bar using Boron e.g.then intercalibrate bar using Boron e.g.

“Energy” deposit in TC

Ene

rgy

dep

osit

in X

EC

4.4 and 11.6 MeVCompton Edges

(3) Am/Be – neutron source as a source of 4.44 MeV Gammas from 2+ state of 12C*

via 9Be(α,n)12C

Am/Be Am/Be ≡ Li≡ Li

LY


Calibration Techniques cont.Calibration Techniques cont.(4) Use of tuned monochromatic positron beam being investigated as a means of e.g. studying our positron spectrometer tracking efficiency vs. emission angle or momentum, with high statistics, in a momentum range equivalent to real MEG- conditions!!!

MechanismMechanism:: positron-Nucleus elastic scattering from light nuclei at aroundpositron-Nucleus elastic scattering from light nuclei at around PPee ~ 50 MeV/c “Coherent” ~ 50 MeV/c “Coherent”

nuclear recoil, spin-effects, magnetic terms all ~ negligablenuclear recoil, spin-effects, magnetic terms all ~ negligablenuclear form-factor introduces a small effectnuclear form-factor introduces a small effectX-sections “well known” X-sections “well known” basically “Mott-scattering”basically “Mott-scattering”

MechanismMechanism:: positron-Nucleus elastic scattering from light nuclei at aroundpositron-Nucleus elastic scattering from light nuclei at around PPee ~ 50 MeV/c “Coherent” ~ 50 MeV/c “Coherent”

nuclear recoil, spin-effects, magnetic terms all ~ negligablenuclear recoil, spin-effects, magnetic terms all ~ negligablenuclear form-factor introduces a small effectnuclear form-factor introduces a small effectX-sections “well known” X-sections “well known” basically “Mott-scattering”basically “Mott-scattering”

Reality:• MEG beam can be tuned to give ~ 50 MeV/c e+ with a max. rate of ~ 8· 108 e+/s at 2mA proton current with ΔP/P ~ 7% FWHM obviously would reduce ΔP/P to achieve “monochromaticity” though at the cost of rate.• Wien-filter does not work at this momentum to sufficiently separate e+ from m+

but a 2mm CH2-degrader at the collimator system in front of BTS DOES!

Carbon target Carbon target ρρ ~ 2.1 g/cm ~ 2.1 g/cm3 3 t < 1cm thick, and 10t < 1cm thick, and 1077 e e++/s /s Integrated X-section: 30Integrated X-section: 30°° < < ΔθΔθ < 120 < 120°° & & ΔφΔφ = = 2.5 mbarn 2.5 mbarn ~ 1300 events/s ~ 1300 events/sCarbon target Carbon target ρρ ~ 2.1 g/cm ~ 2.1 g/cm3 3 t < 1cm thick, and 10t < 1cm thick, and 1077 e e++/s /s Integrated X-section: 30Integrated X-section: 30°° < < ΔθΔθ < 120 < 120°° & & ΔφΔφ = = 2.5 mbarn 2.5 mbarn ~ 1300 events/s ~ 1300 events/s


2008 Run Conditions 2008 Run Conditions

- target - target inclinationinclinationangleangle

- target - target inclinationinclinationangleangle

(1)(1) New Target Angle:New Target Angle: - modification DC Support Structure - modification DC Support Structureoptimal @ ~ 21optimal @ ~ 21° to match beam stopping distribution etc.° to match beam stopping distribution etc.Prior 2008 limited by DC Support structure to max. 13°Prior 2008 limited by DC Support structure to max. 13°

(1)(1) New Target Angle:New Target Angle: - modification DC Support Structure - modification DC Support Structureoptimal @ ~ 21optimal @ ~ 21° to match beam stopping distribution etc.° to match beam stopping distribution etc.Prior 2008 limited by DC Support structure to max. 13°Prior 2008 limited by DC Support structure to max. 13°

Target Inclination 2008 Target Inclination 2008 = (20.5 = (20.5 ± 0.3)°± 0.3)°Target Inclination 2008 Target Inclination 2008 = (20.5 = (20.5 ± 0.3)°± 0.3)°

• Conventional = (20.6 Conventional = (20.6 ± 0.2)°± 0.2)°• PhotogrammetricPhotogrammetric (outside COBRA) = (outside COBRA) = (20.4 (20.4 ± 0.2)°± 0.2)°• PhotogrammetricPhotogrammetric (inside COBRA) = (inside COBRA) = (20.3 (20.3 ± 0.3)°± 0.3)°

• Conventional = (20.6 Conventional = (20.6 ± 0.2)°± 0.2)°• PhotogrammetricPhotogrammetric (outside COBRA) = (outside COBRA) = (20.4 (20.4 ± 0.2)°± 0.2)°• PhotogrammetricPhotogrammetric (inside COBRA) = (inside COBRA) = (20.3 (20.3 ± 0.3)°± 0.3)°

(2)(2) Beam Intensities:Beam Intensities: - apart from “Normal” beam intensity 2 further tunes were - apart from “Normal” beam intensity 2 further tunes were optimized optimized based on standard degrader 300based on standard degrader 300mmm Mylar – “Ultra-low” & “High”m Mylar – “Ultra-low” & “High”(2)(2) Beam Intensities:Beam Intensities: - apart from “Normal” beam intensity 2 further tunes were - apart from “Normal” beam intensity 2 further tunes were optimized optimized based on standard degrader 300based on standard degrader 300mmm Mylar – “Ultra-low” & “High”m Mylar – “Ultra-low” & “High”

Measured values at 7% air contaminationMeasured values at 7% air contamination1% Air ~ 101% Air ~ 10mmm Mylar degrader - Not compensated for in 2008!!!m Mylar degrader - Not compensated for in 2008!!!

ModeMode RRmm Measured Rate COBRA at 2mAMeasured Rate COBRA at 2mA RRstopstop Stopping Rate at 2mA (Stopping Rate at 2mA (εεSTOPSTOP= 0.794)= 0.794)

““High”High” 8.48.410107 7 mm++ss-1-1 6.76.710107 7 mm++ss-1-1

““Normal”Normal” 3.53.5101077 mm++ss-1-1 ~ 2.8~ 2.8101077 mm++ss-1-1

““Ultra-low”Ultra-low” 1.51.5101066 mm+s+s-1-1 ~ 1.2~ 1.2101066 mm++ss-1-1


Run Conditions cont.Run Conditions cont.(3)(3) COBRA He-Concentration:COBRA He-Concentration: - - for DC HV-stability reasons air-doping of COBRAfor DC HV-stability reasons air-doping of COBRAEnvironment was necessaryEnvironment was necessary(3)(3) COBRA He-Concentration:COBRA He-Concentration: - - for DC HV-stability reasons air-doping of COBRAfor DC HV-stability reasons air-doping of COBRAEnvironment was necessaryEnvironment was necessary

6363 7070 6161

6262 6060

DS-ECDS-EC US-ECUS-EC

COBRACOBRA

Mean Air-doping (Physics Run Part1 + 2) = 6%Mean Air-doping (Physics Run Part1 + 2) = 6%Mean Air-doping (Physics Run Part1 + 2) = 6%Mean Air-doping (Physics Run Part1 + 2) = 6% 1% Air ~ 101% Air ~ 10mmm Mylar degraderm Mylar degraderNot compensated for!!!Not compensated for!!!

P61 blueP61 blueP70 greenP70 greenP63 redP63 redP60 lightP60 light blueblue

P61 blueP61 blueP70 greenP70 greenP63 redP63 redP60 lightP60 light blueblue

OO22-sensor-sensor

Part1:Part1: 11/9 (0111/9 (010000) – 20/10 (01) – 20/10 (010000) )

35 days35 days

Part1:Part1: 11/9 (0111/9 (010000) – 20/10 (01) – 20/10 (010000) )

35 days35 days

Physics Run Classification:Physics Run Classification: MEG Data ONLY(before/after DC COBRA test)MEG Data ONLY(before/after DC COBRA test)Physics Run Classification:Physics Run Classification: MEG Data ONLY(before/after DC COBRA test)MEG Data ONLY(before/after DC COBRA test)

P61,P61,P70, P70, P63P63P61,P61,P70, P70, P63P63

96%96% HeHe

92%92%

95%95% HeHe

93%93%

Part 1Part 1 Part 2Part 2Part2:Part2:

27/10 (1127/10 (114949) – 06/11 (23) – 06/11 (235959) – 23/12 ) – 23/12 11 + 32.5 days11 + 32.5 days

Part2:Part2: 27/10 (1127/10 (114949) – 06/11 (23) – 06/11 (235959) – 23/12 ) – 23/12

11 + 32.5 days11 + 32.5 days


2008 Beam Time Influences2008 Beam Time Influences

(1) (1) Calorimeter:Calorimeter: 2007 Light-yield << expected both for s & s (Q/A)/(Q/A)~ 1.25 expect LP~ 1.92!!! Contamination? new purifier installed 2008Significant time was invested with monitoring/understanding of LY vs. purification timeUsing C-W Li, CR, s & LEDs Liquid & Gaseous & No purification scenarios studied

(1) (1) Calorimeter:Calorimeter: 2007 Light-yield << expected both for s & s (Q/A)/(Q/A)~ 1.25 expect LP~ 1.92!!! Contamination? new purifier installed 2008Significant time was invested with monitoring/understanding of LY vs. purification timeUsing C-W Li, CR, s & LEDs Liquid & Gaseous & No purification scenarios studied

Liq.P → Induced Noise on electronics→ Induced Noise on electronicsGas.P → minimal Noise → minimal Noise Liq.P → Induced Noise on electronics→ Induced Noise on electronicsGas.P → minimal Noise → minimal Noise

Questions to answer: • can one survive without Liq.P for 3 weeks between inter-accelerator shutdowns and only rely on GasP?• What happens to LY without any purifications?

- 0.7%/5 days- 0.7%/5 days

Gas.PGas.PLiq.PLiq.P

Initial Purification May 2008Initial Purification May 2008Initial Purification May 2008Initial Purification May 2008

ss

ss

also CR same response!also CR same response!

L-YL-Y

3 Major factors influenced the maximizing of the available beam time for Physics 3 Major factors influenced the maximizing of the available beam time for Physics Data-taking – such that substantial extra investigation time was necessary Data-taking – such that substantial extra investigation time was necessary

3 Major factors influenced the maximizing of the available beam time for Physics 3 Major factors influenced the maximizing of the available beam time for Physics Data-taking – such that substantial extra investigation time was necessary Data-taking – such that substantial extra investigation time was necessary

No.PNo.P

• Calorimeter – Calorimeter – Light-yield + PMT gain drift• Electronics - Noise + Baseline stabilityElectronics - Noise + Baseline stability• Drift Chambers - HV stabilityDrift Chambers - HV stability

• Calorimeter – Calorimeter – Light-yield + PMT gain drift• Electronics - Noise + Baseline stabilityElectronics - Noise + Baseline stability• Drift Chambers - HV stabilityDrift Chambers - HV stability


Beam Time Influences Calo.- cont.Beam Time Influences Calo.- cont.• Variations in no Photo-electrons seen…LY changing + ?Variations in no Photo-electrons seen…LY changing + ?• PMT- Gain variation seen vs. Beam rate drastic during CEXPMT- Gain variation seen vs. Beam rate drastic during CEX changes of several % possible!! Stable at low ratechanges of several % possible!! Stable at low rate• PMT Gain well monitored using LEDs …Reason for instability?PMT Gain well monitored using LEDs …Reason for instability? in principle effect already compensated for “zener diodes”!!!in principle effect already compensated for “zener diodes”!!! could this be aging?could this be aging?• Thus frequent LED calibrations used as gain normalization forThus frequent LED calibrations used as gain normalization for light/energy measurementslight/energy measurements• time constants for rate-changes measured (beam-blocker) time constants for rate-changes measured (beam-blocker) • therefore in principle all ingredients available for corrections therefore in principle all ingredients available for corrections

• Variations in no Photo-electrons seen…LY changing + ?Variations in no Photo-electrons seen…LY changing + ?• PMT- Gain variation seen vs. Beam rate drastic during CEXPMT- Gain variation seen vs. Beam rate drastic during CEX changes of several % possible!! Stable at low ratechanges of several % possible!! Stable at low rate• PMT Gain well monitored using LEDs …Reason for instability?PMT Gain well monitored using LEDs …Reason for instability? in principle effect already compensated for “zener diodes”!!!in principle effect already compensated for “zener diodes”!!! could this be aging?could this be aging?• Thus frequent LED calibrations used as gain normalization forThus frequent LED calibrations used as gain normalization for light/energy measurementslight/energy measurements• time constants for rate-changes measured (beam-blocker) time constants for rate-changes measured (beam-blocker) • therefore in principle all ingredients available for corrections therefore in principle all ingredients available for corrections

20072007LevelLevel

CEXCEX

NormNormBeamBeam

OffOff

1/21/2

CEX CEX --PM GainPM Gain

LY nearly reached optimal value LY is constant LY >

LY nearly reached optimal value LY is constant LY >

How does this affect our energy scaleHow does this affect our energy scaleExtrapolated for low-energy low-rate?Extrapolated for low-energy low-rate?How does this affect our energy scaleHow does this affect our energy scaleExtrapolated for low-energy low-rate?Extrapolated for low-energy low-rate?


Effect on Energy ScaleEffect on Energy Scale

~30 mins.~30 mins.

B-B “opened”B-B “opened”

B-B “closed”B-B “closed”

C-WC-W

CEXCEX

For our Photon Energy-scale we extrapolate from For our Photon Energy-scale we extrapolate from ““Low-energy” “Low-rate” C-W data toLow-energy” “Low-rate” C-W data to““High-energy” “High-rate” CEX pion dataHigh-energy” “High-rate” CEX pion data

What is the rate dependency at CEX-rates?What is the rate dependency at CEX-rates?Not enough LED data taken during intial CEXNot enough LED data taken during intial CEX

Hence new “mini-CEX” run at end of DecemberHence new “mini-CEX” run at end of December

For our Photon Energy-scale we extrapolate from For our Photon Energy-scale we extrapolate from ““Low-energy” “Low-rate” C-W data toLow-energy” “Low-rate” C-W data to““High-energy” “High-rate” CEX pion dataHigh-energy” “High-rate” CEX pion data

What is the rate dependency at CEX-rates?What is the rate dependency at CEX-rates?Not enough LED data taken during intial CEXNot enough LED data taken during intial CEX

Hence new “mini-CEX” run at end of DecemberHence new “mini-CEX” run at end of December

Rate-dependent effect

~ 4% discrepancy from~ 4% discrepancy fromExtrapolation to CEX energiesExtrapolation to CEX energiesbeforebefore correction from “Mini-CEX” correction from “Mini-CEX”After?After? better but not perfect! More work neededbetter but not perfect! More work needed

Before CorrectionBefore Correction


Beam Time Influences – cont.Beam Time Influences – cont. (2) (2) ElectronicsElectronics: : baseline instability as well higher noise content on DRS i/psbaseline instability as well higher noise content on DRS i/ps 2 reasons found – (i) i/p stages (diodes + resistors)of splitter damaged by sparking from 2 reasons found – (i) i/p stages (diodes + resistors)of splitter damaged by sparking from defective Calorimeter feed-thro’s. defective Calorimeter feed-thro’s. all boards modified with new higher rated all boards modified with new higher rated diodes & resistors changeddiodes & resistors changed

(ii) burst-noise suppressed with external shielding of flat-band(ii) burst-noise suppressed with external shielding of flat-band calorimeter cables between splitter & DRScalorimeter cables between splitter & DRS external shielding added to all calo-cables between splitter & DRSexternal shielding added to all calo-cables between splitter & DRS

(2) (2) ElectronicsElectronics: : baseline instability as well higher noise content on DRS i/psbaseline instability as well higher noise content on DRS i/ps 2 reasons found – (i) i/p stages (diodes + resistors)of splitter damaged by sparking from 2 reasons found – (i) i/p stages (diodes + resistors)of splitter damaged by sparking from defective Calorimeter feed-thro’s. defective Calorimeter feed-thro’s. all boards modified with new higher rated all boards modified with new higher rated diodes & resistors changeddiodes & resistors changed

(ii) burst-noise suppressed with external shielding of flat-band(ii) burst-noise suppressed with external shielding of flat-band calorimeter cables between splitter & DRScalorimeter cables between splitter & DRS external shielding added to all calo-cables between splitter & DRSexternal shielding added to all calo-cables between splitter & DRS

(3) (3) Drift ChambersDrift Chambers:: HV-stability of chambers persists, seems to be a time HV-stability of chambers persists, seems to be a time

dependencydependency before onset & seems worsened by CEX pion beam then worsensbefore onset & seems worsened by CEX pion beam then worsens with time. with time. Gives a complicated time-dependent e+ detector efficiencyGives a complicated time-dependent e+ detector efficiency Air doping + overpressure + gas-mixture investigated during dedicated Air doping + overpressure + gas-mixture investigated during dedicated combined electronics/Calo./DC maintenance weekcombined electronics/Calo./DC maintenance week

(3) (3) Drift ChambersDrift Chambers:: HV-stability of chambers persists, seems to be a time HV-stability of chambers persists, seems to be a time

dependencydependency before onset & seems worsened by CEX pion beam then worsensbefore onset & seems worsened by CEX pion beam then worsens with time. with time. Gives a complicated time-dependent e+ detector efficiencyGives a complicated time-dependent e+ detector efficiency Air doping + overpressure + gas-mixture investigated during dedicated Air doping + overpressure + gas-mixture investigated during dedicated combined electronics/Calo./DC maintenance weekcombined electronics/Calo./DC maintenance week

He-ConHe-ConCC.

ΔΔP(DC-COBRA)P(DC-COBRA).

Anode Hit-mapAnode Hit-map.

0%

100%


Beam Time/DataBeam Time/DataIn view of the complex & overlapping problems that were studied & monitored during the In view of the complex & overlapping problems that were studied & monitored during the ““Parasitic” & Part 1 Phase of the “Full Run” the following schedule evolved Parasitic” & Part 1 Phase of the “Full Run” the following schedule evolved necessitating necessitating a mini-CEX at the end of the period to evaluate the rate dependency during the full CEX, a mini-CEX at the end of the period to evaluate the rate dependency during the full CEX, so that the Calorimeter Energy-scale could be fully determined:so that the Calorimeter Energy-scale could be fully determined:

In view of the complex & overlapping problems that were studied & monitored during the In view of the complex & overlapping problems that were studied & monitored during the ““Parasitic” & Part 1 Phase of the “Full Run” the following schedule evolved Parasitic” & Part 1 Phase of the “Full Run” the following schedule evolved necessitating necessitating a mini-CEX at the end of the period to evaluate the rate dependency during the full CEX, a mini-CEX at the end of the period to evaluate the rate dependency during the full CEX, so that the Calorimeter Energy-scale could be fully determined:so that the Calorimeter Energy-scale could be fully determined:

Parasitic RunParasitic Run:: 1919thth May- 3 May- 3rdrd July ~ July ~ 7 weeks7 weeks Beam Tests/Tuning (Beam Tests/Tuning (4.5 weeks4.5 weeks))Full Run Part 1Full Run Part 1:: 1111thth July – 31 July – 31stst August ~ August ~7 weeks7 weeks CEX 21CEX 21stst July – 31 July – 31stst August ( August (6 weeks6 weeks))Full Run Part 2Full Run Part 2:: 11stst September – 23 September – 23rdrd December ~ December ~16 weeks16 weeks Pre-Physics Data (~ Pre-Physics Data (~ 3 weeks3 weeks)) Physics Data Part1 35 DaysPhysics Data Part1 35 Days MEG Maintenance/Repair ~ 7 DaysMEG Maintenance/Repair ~ 7 Days Physics Data Part 2 43.5 DaysPhysics Data Part 2 43.5 Days Mini-CEX ~ 7 DaysMini-CEX ~ 7 Days

Parasitic RunParasitic Run:: 1919thth May- 3 May- 3rdrd July ~ July ~ 7 weeks7 weeks Beam Tests/Tuning (Beam Tests/Tuning (4.5 weeks4.5 weeks))Full Run Part 1Full Run Part 1:: 1111thth July – 31 July – 31stst August ~ August ~7 weeks7 weeks CEX 21CEX 21stst July – 31 July – 31stst August ( August (6 weeks6 weeks))Full Run Part 2Full Run Part 2:: 11stst September – 23 September – 23rdrd December ~ December ~16 weeks16 weeks Pre-Physics Data (~ Pre-Physics Data (~ 3 weeks3 weeks)) Physics Data Part1 35 DaysPhysics Data Part1 35 Days MEG Maintenance/Repair ~ 7 DaysMEG Maintenance/Repair ~ 7 Days Physics Data Part 2 43.5 DaysPhysics Data Part 2 43.5 Days Mini-CEX ~ 7 DaysMini-CEX ~ 7 Days

Normal Physics Data-taking:Normal Physics Data-taking:• MEG 11-mixed trigger MEG 11-mixed trigger 6.5Hz Trigger Rate, LT~ 80-83%6.5Hz Trigger Rate, LT~ 80-83% • Daily LED-calibration beam “off”Daily LED-calibration beam “off”• 3/week Full-calibration LED beam “on” +LED beam “off”3/week Full-calibration LED beam “on” +LED beam “off” + C-W (Li) + C-W (B) + + C-W (Li) + C-W (B) + ss• 1/week 24Hrs RMD 5-mixed trigger data1/week 24Hrs RMD 5-mixed trigger data

Normal Physics Data-taking:Normal Physics Data-taking:• MEG 11-mixed trigger MEG 11-mixed trigger 6.5Hz Trigger Rate, LT~ 80-83%6.5Hz Trigger Rate, LT~ 80-83% • Daily LED-calibration beam “off”Daily LED-calibration beam “off”• 3/week Full-calibration LED beam “on” +LED beam “off”3/week Full-calibration LED beam “on” +LED beam “off” + C-W (Li) + C-W (B) + + C-W (Li) + C-W (B) + ss• 1/week 24Hrs RMD 5-mixed trigger data1/week 24Hrs RMD 5-mixed trigger data

DATADATAMEG (MEG (Runs# 23987- 40997)Runs# 23987- 40997) 10859 Runs a 2k events10859 Runs a 2k events 22.4 M Triggers22.4 M Triggers Time 49:18:50:49Time 49:18:50:49RMD (Runs# 23017 – 39963)RMD (Runs# 23017 – 39963) 1059 Runs a 3k events1059 Runs a 3k events 2.99 M Triggers2.99 M Triggers Time 7:05:33:39Time 7:05:33:39

DATADATAMEG (MEG (Runs# 23987- 40997)Runs# 23987- 40997) 10859 Runs a 2k events10859 Runs a 2k events 22.4 M Triggers22.4 M Triggers Time 49:18:50:49Time 49:18:50:49RMD (Runs# 23017 – 39963)RMD (Runs# 23017 – 39963) 1059 Runs a 3k events1059 Runs a 3k events 2.99 M Triggers2.99 M Triggers Time 7:05:33:39Time 7:05:33:39

TBytesTBytes

MEG 2008 Run DATA TakenMEG 2008 Run DATA TakenMEG 2008 Run DATA TakenMEG 2008 Run DATA Taken

139 TB139 TB 139 TB139 TB

Total of 139 TB DataTotal of 139 TB DataTaken 2008Taken 2008

Total of 139 TB DataTotal of 139 TB DataTaken 2008Taken 2008


Physics Data PreparationPhysics Data PreparationAnalysis SchemeAnalysis Scheme: (Physics Analysis Working Group)

• Data Reduction in form of “Pre-selectionPre-selection” - use very lose cuts ““ConservativeConservative Criteria” Criteria” (ensure non-biasing) reduces data to 16% of triggered events16% of triggered events

• Incorporate “Blinding” “Blinding” in “pre-selected” datain “pre-selected” data use “use “Hidden” Signal-boxHidden” Signal-box on parameters on parameters EE & & TTe e

directly via MEGAnalyzerdirectly via MEGAnalyzer with widths with widths

~ ~ ± 4.8 MeV & ±± 4.8 MeV & ± 1.5 ns 1.5 ns respectivelyrespectively

• Perform Perform Likelihood AnalysisLikelihood Analysis on “final revealed data” on “final revealed data” after optimized background study outside “signal-box”after optimized background study outside “signal-box” “ “side-bands”side-bands”

• Probability Density Functions (PDFs) for Likelihood AnalysisProbability Density Functions (PDFs) for Likelihood Analysis obtained partially direct from measurement & partially from MC.obtained partially direct from measurement & partially from MC.

• MC substantially advanced e.g. RMD + radiative corrections etc.MC substantially advanced e.g. RMD + radiative corrections etc.

““Blinding”Blinding”

Simulatio

n

Simulatio

n

Simulatio

n

Simulatio

n


ConclusionsConclusions• With a consolidated effort made by the “whole” collaboration, as well as basically With a consolidated effort made by the “whole” collaboration, as well as basically starting from ”scratch” at the beginning of the 2008 we were able to achieve our goalstarting from ”scratch” at the beginning of the 2008 we were able to achieve our goal of taking “True” Physics Data!of taking “True” Physics Data!

• despite many detector/electronics problems that were encountered we were able todespite many detector/electronics problems that were encountered we were able to dedicate dedicate 12 weeks12 weeks out of the expected 16 weeks to out of the expected 16 weeks to “pure (MEG+RMD) Physics Data“pure (MEG+RMD) Physics Data

• a vast amount of a vast amount of calibration datacalibration data was taken during the whole 2008 period which was taken during the whole 2008 period which served a as vital input to understanding encountered effects during the runserved a as vital input to understanding encountered effects during the run – – this however will continue to serve as a basis for a better understanding of our this however will continue to serve as a basis for a better understanding of our detector with on-going analysisdetector with on-going analysis• several factors concerning our hardware led to a non-optimal MEG Detector in 2008several factors concerning our hardware led to a non-optimal MEG Detector in 2008 the main issues have been addressed ( DC: HV-stability, Calorimeter: LXe-purity,the main issues have been addressed ( DC: HV-stability, Calorimeter: LXe-purity, PMT gain-stability, TC: fibre incorporation in trigger)PMT gain-stability, TC: fibre incorporation in trigger)

• the most worrying issue is that of the DC HV-stability – this however is the most worrying issue is that of the DC HV-stability – this however is being tackled being tackled with a large and dedicated effort by the “detector group” – the experts!with a large and dedicated effort by the “detector group” – the experts! and as has and as has been shown before, especially with “forefront” detector technology such problems been shown before, especially with “forefront” detector technology such problems CAN BE SOLVED!CAN BE SOLVED!• we still have a lot of work to do & a lot of improvements are still necessarywe still have a lot of work to do & a lot of improvements are still necessary butbut !!! !!! the following “Expert” talks will show that the MEG Collaboration has the following “Expert” talks will show that the MEG Collaboration has a lot of dedicated & resourceful means at it’s disposala lot of dedicated & resourceful means at it’s disposal

• With a consolidated effort made by the “whole” collaboration, as well as basically With a consolidated effort made by the “whole” collaboration, as well as basically starting from ”scratch” at the beginning of the 2008 we were able to achieve our goalstarting from ”scratch” at the beginning of the 2008 we were able to achieve our goal of taking “True” Physics Data!of taking “True” Physics Data!

• despite many detector/electronics problems that were encountered we were able todespite many detector/electronics problems that were encountered we were able to dedicate dedicate 12 weeks12 weeks out of the expected 16 weeks to out of the expected 16 weeks to “pure (MEG+RMD) Physics Data“pure (MEG+RMD) Physics Data

• a vast amount of a vast amount of calibration datacalibration data was taken during the whole 2008 period which was taken during the whole 2008 period which served a as vital input to understanding encountered effects during the runserved a as vital input to understanding encountered effects during the run – – this however will continue to serve as a basis for a better understanding of our this however will continue to serve as a basis for a better understanding of our detector with on-going analysisdetector with on-going analysis• several factors concerning our hardware led to a non-optimal MEG Detector in 2008several factors concerning our hardware led to a non-optimal MEG Detector in 2008 the main issues have been addressed ( DC: HV-stability, Calorimeter: LXe-purity,the main issues have been addressed ( DC: HV-stability, Calorimeter: LXe-purity, PMT gain-stability, TC: fibre incorporation in trigger)PMT gain-stability, TC: fibre incorporation in trigger)

• the most worrying issue is that of the DC HV-stability – this however is the most worrying issue is that of the DC HV-stability – this however is being tackled being tackled with a large and dedicated effort by the “detector group” – the experts!with a large and dedicated effort by the “detector group” – the experts! and as has and as has been shown before, especially with “forefront” detector technology such problems been shown before, especially with “forefront” detector technology such problems CAN BE SOLVED!CAN BE SOLVED!• we still have a lot of work to do & a lot of improvements are still necessarywe still have a lot of work to do & a lot of improvements are still necessary butbut !!! !!! the following “Expert” talks will show that the MEG Collaboration has the following “Expert” talks will show that the MEG Collaboration has a lot of dedicated & resourceful means at it’s disposala lot of dedicated & resourceful means at it’s disposal

Documents

MEG 2008 Run Run Coordinator’s view