The Silicon Tracker of AMS02
● The AMS02 Experiment and its Goals● The Silicon Tracker of AMS02
Design & Overview Production and Assembly (Silicon, Frontend, Readout) Testbeam Results & Performance
● Outlook & Conclusions
Daniel HaasDPNC Geneva
6th International Conferenceon Large Scale Applications
and Radiation Hardnessof Semiconductor Detectors
Firenze, 29 Sep - 1 Oct 2003
The AMS02 Experiment
D. Haas Firenze, 29 Sep - 1 Oct 2003, page 2
Acceptance ~ 0.45 m2srWeight ~ 6 tons
Power ~ 2 kW
AMS02 - Physics Goals
● Search for Antimatter Improve Limits of AMS01 Increased Sensitivity Energy Range of O(1-10 TV/c) Anti-Helium Cosmic Antimatter Anti-Carbon Anti-Stars
● Search for Dark Matter High statistics for e, Antiprotons and Spectra
● Cosmic Ray Studies Precision measurements of light isotopes
● Sources of High Energy Photons● AMS02 is foreseen on ISS in November 2005
D. Haas Firenze, 29 Sep - 1 Oct 2003, page 3
Silicon Tracker – Overview...● 2264 Sensors
Doublesided Silicon ~ 6.4m2 total 1024 channels each Combined into Ladders of 7-15 sensors,
around 200k channels● 8 layers on support planes
2 external planes - 1 layer each 3 internal planes - 2 layers each
● Goals: Track charged particles Measure rigidities p/Z up to O(10 TV)
with (p)/p ~ 1.5 % Identify elements via dE/dx
D. Haas Firenze, 29 Sep - 1 Oct 2003, page 4
Silicon Tracker – Collaboration
● University of Geneva, Switzerland● INFN - University of Perugia, Italy● RWTH-I Aachen, Germany● National Central University, Taiwan● CERN, Switzerland● University of Turku, Finland● NIKHEF, Netherlands● NLR, Netherlands
D. Haas Firenze, 29 Sep - 1 Oct 2003, page 5
...Silicon Tracker – Ladders
Two-sided silicon is used
K-side (n) has 384 channelsS-side (p) has 640 channels
Ladder is reinforced with Airex
Channels are bonded to Frontend
Pitch S-side K-side Implantation Readout
27.5 m 104 m110 m 208 m
D. Haas Firenze, 29 Sep - 1 Oct 2003, page 6
...Silicon Tracker – Ladders
D. Haas Firenze, 29 Sep - 1 Oct 2003, page 7
...Silicon Tracker – Frontend
● Frontend produced by IDEas, Norway
● AC coupling with PreAmp via Capacitors
● 64 channel PreAmp/Shaper● Multiplexed analog readout
Upilex foil is used on K-sideto connect to Frontend
Daisy chained on S-side
~11.000 bonds for 12-sensor ladder
D. Haas Firenze, 29 Sep - 1 Oct 2003, page 8
...Silicon Tracker – Assembly
D. Haas Firenze, 29 Sep - 1 Oct 2003, page 9
...Silicon Tracker – Electronics
Tracker Data Reduction Board (TDR)● Collect analog data and digitize it● Perform online data compression
Remove Pedestals Calculate and Remove Common Noise Search Clusters
Tracker Bias Supply (TBS)Power Supply for FrontEnd (TPSFE)
D. Haas Firenze, 29 Sep - 1 Oct 2003, page 10
Testbeam Evaluation● Testbeam at CERN SPS, Oct 2002
20 GeV/c Protons and Fragmented Ions 1 week of DAQ, ~107 events on disk Study of Resolution, dE/dx etc...
● Testbeam at CERN PS, Jun 2003 10 GeV/c Protons Study of Shaping Time, Resolution etc...
Under Preparation:● Testbeam at CERN SPS, Oct 2003
New quasi final electronics● Testbeam at GSI Darmstadt, Nov 2003
Dedicated Ion runs (12C etc...)
D. Haas Firenze, 29 Sep - 1 Oct 2003, page 11
D. Haas Firenze, 29 Sep - 1 Oct 2003, page 12
Testbeam Evaluation – Setup...
D. Haas Firenze, 29 Sep - 1 Oct 2003, page 13
Testbeam Evaluation – ...Setup
6 Silicon Ladders(connected to Tracker Electronics)
Beam
line
← NIM-Crate
← DC/DC-Converter
← Tracker Electronics
← DAQ PC
(connected to Control
Room Run Control)
Testbeam Results – Shaping Time● K-Side
Best shaping time around 4-5 s
● S-Side Best shaping time
around 2.5-3.5 s
Electronics can handle different shaping times
Bill BurgerPre
limin
a
ry
D. Haas Firenze, 29 Sep - 1 Oct 2003, page 14
Prelim
ina
ry
Testbeam Results – Signal to Noise
Bill Burger
Signal to Noise of ~8 on S-Side and ~6.5 on K-side for Protons
D. Haas Firenze, 29 Sep - 1 Oct 2003, page 15
Testbeam Results – Resolution
Resolution around 20-30 m in x (K-side) and 8-10 m in y (S-side)(this corresponds to the expected resolution of 110 m/12 and 27.5 m/12)
Prelim
ina
ry
Bill Burger
D. Haas Firenze, 29 Sep - 1 Oct 2003, page 16
Testbeam Results – Raw Data● Raw Data:
4He is cut away Different dynamic
behaviour of S and K Side
● Correct charge integral: for center-of-gravity for each Z for each PreAmp Calculate truncated
charge for S and K
Bill Burger
Prelim
ina
ry
D. Haas Firenze, 29 Sep - 1 Oct 2003, page 17
K-Side
Testbeam Results – Center-of-Gravity
Apply Correction
Philipp Azzarello
Prelim
ina
ry
D. Haas Firenze, 29 Sep - 1 Oct 2003, page 18
Testbeam Results – corrected...
Philipp Azzarello
Prelim
ina
ry
D. Haas Firenze, 29 Sep - 1 Oct 2003, page 19
Testbeam Results – ...corrected
Philipp Azzarello
Prelim
ina
ry
Prelim
ina
ry
D. Haas Firenze, 29 Sep - 1 Oct 2003, page 20
Conclusions● AMS02 silicon tracker is on schedule
Ladder Production nearly finished Assembly of planes has started and is going well Production of readout electronics is ongoing
● Silicon ladders show excellent performance Good Signal to Noise Resolution of ~20-30 m for x and ~8-10 m for y
confirm expected performance● dE/dx results outperform expectations
Elements up to Nickel could be identified BUT: careful study of corrections is necessary
● More studies on upcoming testbeams...
D. Haas Firenze, 29 Sep - 1 Oct 2003, page 21
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