Bremsstrahlung%20Monitor%20@%20Dafne%20Bhabha%20Monitor%20@%20Dafne%20Upgrade

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Bremsstrahlung Monitor_at_ DafneBhabha Monitor_at_
Dafne Upgrade
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Gas Electron Multiplier
A Gas Electron Multiplier (F.Sauli, NIM A386 531
1997) is made by 50 ?m thick kapton foil, copper
clad on each side and perforated by an high
surface-density of bi-conical channels
70 µm
140 µm
50 µm
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A Triple GEM luminometer
10 cm
2.4 cm
2.4 cm
64 pads
10 cm
A triple GEM 10x10 cm2 has been built with a 64
pixel 3 x3 mm2
The read out has been realized using 8 chip ASDQ
(8 channel each) Actually non more than 64
channel readout is possible
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3GEM lumi setup
The 3GEM chamber has been put at 0 degrees,
between the two Dafne Beampipes
The chamber was misaligned due to dimension of
FEE mother board (the mother board touches the
positron beam pipe)
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Number of photon vs luminosity
Number of photon vs time ( MHz/cm2)
Photon beam spot
Finuda luminosity vs time
Online Display
24 mm
24 mm
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Analysis GEMlumi vs Finuda Lumi
Data taking of 2007 05 08
1030 cm-2 s-1
Finuda Luminosity
1030 cm-2 s-1
Time
Nhit 10000
Nhit 10000
Time (day of May)
GEM Monitor
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Analysis G3lumi vs Finuda Lumi
Data taking of 2007 05 09
1030 cm-2 s-1
1030 cm-2 s-1
Nhit 10000
Nhit 10000
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Analysis GEMlumi vs Finuda Lumi
Data taking of 2007 05 10
1030 cm-2 s-1
1030 cm-2 s-1
Nhit 10000
Nhit 10000
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Analysis GEMlumi vs Finuda Lumi
Comparisons between the two luminosity
slumi (1030 cm-2 s-1)
GEMlumi Finuda Lumi
slumi 5.8 x 1030
Finuda lumi 0
Dlumi (1030)
time (days of May)
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Analysis photon beam profile
Data taking of 2007-05-09
x position (mm)
x position (mm)
y position (mm)
y position (mm)
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Analysis photon beam position
A resolution of about 100 mm has been obtained
both on x and y coordinate
6 m from IP
0.80 0.74
x position (mm)
x position (mrad)
0.80 0.70
y position (mm)
y position (mrad)
time (days of May)
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Analysis photon beam position
The monitor has been active for all the last
period of Dafne RUNS This is the photon beam
postion during month of May
x position (mm)
y position (mm)
time (days of May)
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Bhabha Monitor _at_ DAFNE UPG
Bhabha luminometer
Siddharta Exp
3GEM Luminometers for Bhabha events
Lumi Calorimeter
Two tracker luminometers in front of calorimeters
realized with GEM technology will be mounted on
November 07 in the new interaction region of
DAFNE Upgrade
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New Gem foil layout
A new design of 370x340 mm2 GEM foils have been
design to stretch and glue at the same time all
three frames (thickness of 3, 2 and 1 mm).
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Pads readout and assembling
The pads PCB has been realized with 4 semi rings
and 8 phi sectors for a total of 32 channel per
detector. The global tracker luminometer
foreseen 4 detectors.
The framed GEMs will be assembled using two
ALCOA planes with 6 holes for referencepins
insertion
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Front End Electronics
Each detector is readout with 2 FEE based on
Carioca GEM chip directly assembled on the back
side of PCB. The Carioca GEM is a modification
of Carioca chip developed for the Wire Chambers
ofMuon LHCB system readout. The new
electronic card (3x6 cm2) mount 2 chips (one per
side) for a total of 16 channels (roughly 1
ch/cm2). It foreseen one connector for the analog
incoming signal and two connectors for 16 LVDS
output signals (one on the upper side and the
other one on the lower side) to allow the use for
other type of readout.