MEG Summary

February 9, 2005

T. Mori for MEG Collaboration

Spokespersons: T.Mori, A.BaldiniTechnical Coordinator: S.Ritt

Detectors:• Beam line: PSI P.-R.Kettle• COBRA: KEK/Tokyo W.Ootani • Drift Chamber: PSI J.Egger• Timing Counter: Genova/Pavia/Roma G. Cecchet• Photon Detector: Tokyo/Pisa/KEK S.Mihara• Trigger: Pisa M.Grassi• DAQ/Elec.: PSI S.Ritt• Offline: C.Gatto/S.Yamada/F.Cei

The MEG Collaboration

Highlights in developments sine July 2004

Beam line Separator, BTS in construction

COBRA Fringing field problem ~solved

LXe Beam test w/ new PMTs, waveform digitizers, and wire alpha sourcesDetector cryostat in construction

5

Absolute time of LXe55 M

eV

high gainnormal gain

110 psec 103 psec

110 - 64 - 61 = 65 = 56 + 33 psec

LYSO targetIntrinsic from LR analysis depth

Background and Sensitivity

Jan 2004 Jan 2005Gamma Energy (%) 4.5-5.0*e+ Timing (nsec) 0.1*Gamma Timing <0.23* ~0.15**Gamma Position (mm) 4.5-9.0*Gamma acceptance >0.4*Muon rate (108/sec) 0.2-0.3 0.25-0.35Running Time (107sec) 4.0Accidental Rate (10-14) 2.3-3.5 1.9-3.0# Accidental Events 0.6 0.690% CL Limit (10-13) 1.2-1.7 0.9-1.4

* Measured **w/ new PMTs

More detailed calculation necessary

Schedule

Changes (~delays) in schedule

Beam line BTS construction

LXe Detector cryostat constructionPMT delivery

new problem arising -- solution foreseen

DC Troubles with cathode foil production

Noise from Zener diode

2005 2006J F M A M J J A S O N D J F M A

Beam Time Shutdown MEG MEG Shutdown

COBRATests

P

F

Field

MapBeam

Line

BTS

Test

Commiss.

Part 2Tgt Full Test

Drift

Chamber

Proto

Inst

Full

InstallationTiming

Counter

BG

TestTstInst

Full

Installation

LPT PMT testing + calibration

Full

Calorimeter

Cryogenics

Installation

Assembly +

TestTest

Trigger

Inst Inst

DAQDC

Electr.

Inst Inst

Manpower

Mostly in healthy situation

except:

beam line + targetMonte Carlo

Budget

We now have enough money for PMTs!

a new budget for construction in Japan ~400 PMTsadditional budget for ~110 PMTs in Italy

Then new problems arising…

LXe for last 300literselectronicsLXe calibration equipment proton beam?

PSI

1982 !!

PREVIOUS e EXPERIMENT

NOW: GLAST SPACE EXPERIMENTCRYSTAL CALORIMETER CALIBRATION

It is the old VDG of the Crystal Ball experiment ! !they have some problems: old device, max. VDG p-energy is 400 KeVout of resonance: -rate reduced by factor 5000

180 cm target-pipe