PhD Progress ReportCharacterisation, irradiation and design optimisation of silicon micro-strip modules for

the ATLAS Phase-II tracker upgrade

First Year

04/05/2017Edoardo Rossi

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ATLAS Authorship Qualification Task

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Introduction

> Beam cleaning losses: originates from protons that are lost on limiting apertures, typically the tertiary collimators (situated 150 m from the IP)

> Interaction beam-gas: elastic (small deflections, effects similar to TCT losses) or inelastic (showers of secondary particles with production of a few high energy muons)

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Space Points vs. Clusters (Z Asymmetry)

The Z asymmetry using the space points is larger and cleaner

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Mapping With Space Points

Clusters essentially provide a 1-dimensional measurement, while Space Points provide 2-dimensional points with granularity of the order of 10x10 μm2:

using Space Points we can map the Beam Induced Background in the SCT

Run 298771 (pressure bump at 150 m), LB 267 Beam C-A, End-cap A, Disk 6

Transition between inner and middle modules: they are separated by 3.5 mm

Transition between middle and outer modules: they overlap for 16.5 mm

The BIB density decreases linearly with the radius

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Mapping With Space Points

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ITk Strip Test Beam Analyses

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Testbeams and Devices Under Test (DUTs)

DUT Name FacilityMonth

Strip Length Irradiated?

Full Barrel Module LS4 DESYMay

5 and 2.5 cm No

End-Cap DAQLoad13 DESYMay

1 cm Sensors: neutrons @ 2 ∙ 1015 neq

/cm2

ASIC: one unirrad., one X-rays @ 4 Mrad

Full Barrel Module LS3 CERNJuly

5 and 2.5 cm Protons @ 7.8 ∙ 1014 neq

/cm2

Not annealed

Long Strips (5 cm)

Hybrid with 10 ABC130 (ATLAS Binary Chip)

Short Strips (2.5 cm)

n+ on p technology (electron signal)Pitch = 74.5 μmThickness = 300-320 μmBinary Read-out (3 time bins)

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Test Beam Plots in the TDR

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Test Beam Plots in the TDR

● Test beam curves obtained using only particles passing at less than 15 μm from the center of a strip (only leading strip)● Source curves obtained considering the total charge in a cluster

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Test Beam Plots in the TDR

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Test Beam Plots in the TDR

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Charge (efficiency) loss at the interstrip position

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Bond Pad Region

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Looking back at analog (Alibava) test beams

Multiple scattering of soft (MeV) electrons in the silicon. Leading strip behavior not analyzable with sources (with 300 μm thickness)

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Leading Strip Anomaly

~20% of the leading strip spectrum extends to lower charges with respect to the expected Landau distribution

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Leading Strip Anomaly (Annealing)

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Leading Strip Anomaly (Bias Voltage)

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Plans for the Future

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Varying Implant Sensors

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Varying Implant Sensors

> Sensors have been ordered (they will arrive in the summer)

> Probe station measurements

> Irradiation (protons and neutrons, mixed irradiation if we have enough sensors)

> Probe station measurements after irradiation

> Edge TCT

> Test beam(s) with analog (Alibava) read-out

> Lorentz angle data

In the meanwhile...

> Internal note on test beam work

> Learn TCT

Par

alle

l

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Talks and Schools

> Talk at the ATLAS Upgrade Week (15/11/2016, CERN)

Results from the ITk Strip 2016 Test Beams

> Contribution to a talk at Testbeam workshop (27/01/2017, Barcelona)

> Talk at the DPG (29/03/2017, Munster)

Test Beam Results of an Unirradiated and an Irradiated Prototype Module for the ATLAS ITk Strip Detector

> Attended the Terascale Detector Workshop (10-13/04/2017, DESY)

Planned

> Applied for the 2017 European School of HEP (6-19/09/2017, Portugal)

> Pier courses on writing and presenting in Academia

> Conference (NSS or similar)

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Leading Strip Anomaly

~20% of the leading strip spectrum extends to lower charges with respect to the expected Landau distribution

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Leading Strip Anomaly

~20% of the leading strip spectrum extends to lower charges with respect to the expected Landau distribution

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Pulse Shapes