malte hildebrandtmeg review meeting, 14th february 2007 report of run coordinator run 2006 summary...
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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