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

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...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

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...Silicon Tracker – Assembly

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...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)

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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...)

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Testbeam Evaluation – Setup...

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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

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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