Malte Hildebrandt

MEG Review Meeting, 14th February 2007

Report of Run Coordinator

Run 2006 Summary

Malte Hildebrandt MEG Review Meeting, 14th February 2007

Malte Hildebrandt

MEG Review Meeting, 14th February 2007

Pre-Commissioning Run 2006

beam and detector operation: 16th – 22nd December 2006 (continuously around-the-clock)

goals: • run pressure control system to flush COBRA and dc

• find beam settings for very low, low and high beam rate

• start operation and data taking with dc and tc

• perform neutron background measurement

• take data with NaJ and plastic scintillator

realisation: • daily run meeting • summarise past 24 h • collect requests, wishes, requirements

• organise upcoming 24 h

daily run plan for anefficient usage and sharingof the rare beam time:

Malte Hildebrandt

MEG Review Meeting, 14th February 2007

Beam Line

First measurement of muon beam rate in center of COBRA with complete set of beam line elements, in particular with:

• degrader• correction coils on BTS

degrader beam transport solenoid (BTS)correction coils for BTS

Malte Hildebrandt

MEG Review Meeting, 14th February 2007

COBRA, End-Caps and Insertion System

COBRA • field stability ~0.05 % (FWHM)• 2 quenches: reasons not completely understood

nevertheless: quick recovery (< 3 h) due to newlyinstalled turbo molecular pump

End-Caps • both end-caps installed• insertion system installed and operated successfully

upstream end-cap downstream end-cap with insertion system

Malte Hildebrandt

MEG Review Meeting, 14th February 2007

Gas Distribution and Supply

He volume inside COBRA

• improved He distribution system inside both end-caps and along dc cable duct

→ He fraction >95 % after a few hours

Drift Chamber

• PSI safety requirements fullfilled to operate with 10 l bottle C2H6

stainless steel tubing oxygen sensor ethane sensor

downstream end-cap

Malte Hildebrandt

MEG Review Meeting, 14th February 2007

„MEG“-targetin parking position

„MEG“-targetin measuring position

• phase 2: „MEG“-target in measuringposition

Target

• phase 1: during beam commissioning„APD“-target („MEG“-target parked)

Target

„APD“-target

Malte Hildebrandt

MEG Review Meeting, 14th February 2007

Drift Chamber

• installation:

8 dc modules (8 out of 16)

gas manifolds (us and ds)

pressure gauges

gas tubing

• 7 (out of 2*8) planes operational problems: leaks, HV, LV?, ...

• tasks: HV conditioning without beamHV conditioning with beamIanode = Ianode (beam rate)

data taking:Ranode = Ranode (r-coordinate)

waveform analysis, tracking...

dc04dc05

dc06dc07dc08

dc09

dc11dc10

flange to BTS dc support gas manifold us

differential pressure gauge

gas manifold dsand gas tubing

„MEG“ target

Malte Hildebrandt

MEG Review Meeting, 14th February 2007

Pressure Control System

Pressure control system worked stable and reliable!

inlet gas manifold

oulet gas manifold

-1.0

-1.2

10:00 11:00time [h]

PDC – PCOBRA

[Pa]

drift chamber

Malte Hildebrandt

MEG Review Meeting, 14th February 2007

Timing Counter

• installation:

nitrogen bags (us and ds)

N2 distribution system

all tc bars: 15 tc bars us15 tc bars ds

no tc fibres

• tasks: gain calibrationcosmics with / without Brate tcus vs tcds

data taking:waveform analysis

charge ratio studies

event distribution...

N2 bag

us end-cap flange to BTScopper collar to sealN2 bag vs end-cap

PMT of tc bars N2 flushing tubes

Malte Hildebrandt

MEG Review Meeting, 14th February 2007

Supplementary Components

NaJ and plastic scintillator

• tasks: studies of radiative muon decaybackground studies for later LXe

Bonner Sphere System and 3He detector

• tasks: neutron background measurementwith final beam line elements and final beam settings

→ previous measurements confirmed→ no concerns about neutron background

in LXe calorimeter

Malte Hildebrandt

MEG Review Meeting, 14th February 2007

Trigger, DAQ, Logging and Central MIDAS

Trigger 36 Type 1 boards 5 Type 2 boards 4 Ancillary boardsall cablingFirmware version 0

DAQ DRS chips + cables for:DC: 864 channelsTC: 60 channelsNaJ: 9 channels

Logging and Central MIDAS

installedand

operational(except for dc_trigger)

data taking withall channels of installed

sub-detectorcomponents

Malte Hildebrandt

MEG Review Meeting, 14th February 2007

Beam Tuning and Data Taking

data taking • all channels of installed sub-detector components recorded

• 285 runs taken at different beam rates and HV settings → in total ~600 GB recorded

MEG Review Meeting February 2007:

• not only technical talks • but also talks about analysis of „real“ data

beam tuning settings for very low beam rate 3 %low beam rate 25 %high beam rate 100 %

of ≥ 6 · 107 / s

• at center of COBRA• Iproton = 1.8 mA

• 6 cm target E