HV-MAPS Tracking Telescope: Alignment and Eﬃciency Analysis

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HV-MAPS Tracking Telescope: Alignment and Efficiency Analysis

Dorothea vom Bruch for the Mu3e Collaboration

DESY Telescope Workshop January 20, 2015

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Outline

The Mu3e Experiment Mupix Sensors

Telescope Setup Beam Tests Alignment

Efficiency Analysis

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The Mu3e Experiment

Mu3e searches for the charged lepton-flavour violating decay µ⁺ →e⁺e⁺e⁻ with a sensitivity better than 10^-16

E_e <53MeV

e⁺

e⁺ e^-

Signal

Coincident in time Single vertex Σ~p_i =0

Random Combinations Not coincident in time No single vertex Σ~p_i 6=0

E 6=m_µ

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The Mu3e Experiment

Mu3e searches for the charged lepton-flavour violating decay µ⁺ →e⁺e⁺e⁻ with a sensitivity better than 10^-16

E_e <53MeV

e⁺

e⁺ e^-

Signal

Coincident in time Single vertex Σ~p_i =0 E =m_µ

e⁺

e⁺ e^-

Random Combinations Not coincident in time No single vertex Σ~pi 6=0

E 6=m

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The Mu3e Detector

Requirements:

Excellent momentum resolution: <0.5 MeV/c

Good timing resolution: 100 ps for tiles, 1 ns for fibres, 20-50 ns for pixels

Good vertex resolution: 100µm

Target Inner pixel layers

Scintillating fibres

Outer pixel layers Recurl pixel layers

Scintillator tiles

μ Beam

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The Mu3e Detector

Requirements pixel detector:

Pixel size: 80µm x 80µm

Continuous readout frequency: 20 MHz Low material budget → 50µm thickness

Target Inner pixel layers

Scintillating fibres

Outer pixel layers Recurl pixel layers

Scintillator tiles

μ Beam

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High Voltage Monolithic Active Pixel Sensors

P-substrate N-well

Particle E field

Zero suppressed readout 8 bit timestamps

HV applied: 50 - 90 V Charge collection via drift

(I. Peric, P. Fischer et al., NIM A 582 (2007) 876)

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Mupix Prototypes

Mupix6

Pixel area: 103 x 80µm² Active area: 9.4 mm² Analog + digital readout Double stage amplifier

Time stamp resolution: <17 ns 250µm chip

On 100µm PCB board x/X₀ =2.5h

Thinned Mupix4

50µm sensor on 25µm Kapton foil

⇒ 0.6h radiation lengths

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Telescope Setup

4 layers of Mupix6 sensors Read out by two FPGAs

Scintillating tiles in front and back

z x y

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Telescope Setup

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Comparison with EUDET Telescope

EUDET Telescope HV-MAPS Telescope Pixel size 18.4µm x 18.4µm 103µm x 80µm

Active area 224 mm² 9.4 mm²

Material 50µm sensor 50µm sensor

50µm protective foil 25µm Kapton

in radiation lengths 0.7h 0.6h

Time resolution (115.2 /√

12)µs 17 ns

Frame rate 9 kHz 20 MHz

Maximum track rate ∼100 kHz ∼20 MHz

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Beam Tests

DESY

First test at T22 beamline with Mupix4 chips PSI

πM1 beamline 250 MeV π,µ, e

Beam trigger rate of tiles: > kHz

First test with Mupix6 chips including time stamps On one layer (DUT), scans were performed:

High Voltage Threshold Voltage

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Online Alignment

Adjust planes mechanically with help of laser Study correlations between hits on different planes

→ Improve mechanical adjustment

0 5 10 15 20 25 30

corr_col_1_col2 Entries 2732497 Mean x 16.78 Mean y 19.54 RMS x 7.406 RMS y 7.376

0 2000 4000 6000 8000 10000 corr_col_1_col2 Entries 2732497 Mean x 16.78 Mean y 19.54 RMS x 7.406 RMS y 7.376 column column correlation between 1 and 2

0 5 10 15 20 25 30 35

corr_row_1_row2 Entries 2732497 Mean x 19.05 Mean y 17.86 RMS x 10.71 RMS y 10.68

1000 2000 3000 4000 5000 6000 7000 8000 corr_row_1_row2 Entries 2732497 Mean x 19.05 Mean y 17.86 RMS x 10.71 RMS y 10.68 row row correlation between 1 and 2

0 5 10 15 20 25 30

0 500 1000 1500 2000 2500 3000 3500 corr_col_1_col3 Entries 1245382 Mean x 15.72 Mean y 20.84 RMS x 7.639 RMS y 7.46 column column correlation between 1 and 3

0 5 10 15 20 25 30 35

200 400 600 800 1000 1200 1400 1600 1800 2000 corr_row_1_row3 Entries 1245382 Mean x 18.25 Mean y 19.14 RMS x 10.86 RMS y 10.96 row row correlation between 1 and 3

0 5 10 15 20 25 30

0 1000 2000 3000 4000 5000 6000 corr_col_2_col37000 Entries 1745551 Mean x 15.21 Mean y 21.26 RMS x 7.021 RMS y 7.013 column column correlation between 2 and 3

0 5 10 15 20 25 30 35

500 1000 1500 2000 2500 3000 3500 4000 4500 corr_row_2_row3 Entries 1745551 Mean x 17.36 Mean y 19.6 RMS x 10.51 RMS y 10.8 row row correlation between 2 and 3

0 5 10 15 20 25 30

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 corr_col_3_col4 Entries 2229456 Mean x 17.62 Mean y 19.7 RMS x 7.419 RMS y 7.501 column column correlation between 3 and 4

0 5 10 15 20 25 30 35

1000 2000 3000 4000 5000 6000 corr_row_3_row4 Entries 2229456 Mean x 16.06 Mean y 20.97 RMS x 10.32 RMS y 10.44 row row correlation between 3 and 4

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Straight Track Fit

Simple straight track:

~x(z) =~x₀+~a·z

~x: x and y position

~a: two dimensional slope

Loop over all possible hit combinations and fit tracks with 1 hit in each plane

∆t<250 ns Hot pixels removed Calculate residuals

Adjust alignment manually in several iterations

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Fit: Position and Slope

h1 Entries 120787 Mean 0.01106 RMS 0.01028

−0.030 −0.02 −0.01 0 0.01 0.02 0.03 0.04 0.05 1000

2000 3000 4000 5000 6000 7000 8000

h1 Entries 120787 Mean 0.01106 RMS 0.01028

Slope x

h2 Entries 120787 Mean 0.001612− RMS 0.009754

−0.040 −0.03 −0.02 −0.01 0 0.01 0.02 0.03 0.04 1000

2000 3000 4000 5000 6000 7000 8000

h2 Entries 120787 Mean 0.001612− RMS 0.009754

Slope y

h3 Entries 120787 Mean 4494 RMS 780.1

25000 3000 3500 4000 4500 5000 5500 6000µ6500 500

1000 1500 2000 2500 3000 3500 4000

4500 h3

Entries 120787 Mean 4494 RMS 780.1 X Intersect

h4 Entries 120787 Mean 1435 RMS 812.4

500 µ

−0 0 500 1000 1500 2000 2500 3000 3500 500

1000 1500 2000 2500 3000 3500 4000 4500

h4 Entries 120787 Mean 1435 RMS 812.4 Y Intersect

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Residuals

Run number

360 380 400 420 440

Residuals x mean [um]

-30 -20 -10 0 10 20 30

Residuals in x for plane 0 Residuals in x for plane 1 Residuals in x for plane 2 Residuals in x for plane 3

Run number

360 380 400 420 440

Residuals y mean [um]

-30 -20 -10 0 10 20 30

Residuals in y for plane 0 Residuals in y for plane 1 Residuals in y for plane 2 Residuals in y for plane 3

Run number

360 380 400 420 440

RMS of residuals x mean [um]

0 10 20 30 40 50 60 70

RMS of residuals in x for plane 0 RMS of residuals in x for plane 1 RMS of residuals in x for plane 2 RMS of residuals in x for plane 3

Run number

360 380 400 420 440

RMS of residuals y mean [um]

0 10 20 30 40 50 60 70

RMS of residuals in y for plane 0 RMS of residuals in y for plane 1 RMS of residuals in y for plane 2 RMS of residuals in y for plane 3

Aligned to within 10µm

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Residuals Versus Position

µm]

x [ 3000 3500 4000 4500 5000 5500 6000

m]µResiduals in x [

−30

−20

−10 0 10 20 30

Plane 1: Residuals in x versus x Plane 1: Residuals in x versus x

µm]

y [ 0 500 1000 1500 2000 2500 3000

m]µResiduals in y [

−30

−20

−10 0 10 20 30

Plane 1: Residuals in y versus y Plane 1: Residuals in y versus y

µm]

x [ 3500 4000 4500 5000 5500 6000 6500

−30

−20

−10 0 10 20 30

µm]

y [ 0 500 1000 1500 2000 2500 3000

−30

−20

−10 0 10 20 30

µm]

x [ 3500 4000 4500 5000 5500 6000 6500

−30

−20

−10 0 10 20 30

µm]

y [ 0 500 1000 1500 2000 2500 3000

−30

−20

−10 0 10 20 30

µm]

x [ 4000 4500 5000 5500 6000 6500 7000

−30

−20

−10 0 10 20 30

µm]

y [

−5000500 1000 1500 2000 2500

−30

−20

−10 0 10 20 30

Threshold = 0.68 V, HV = 60 V, single run

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Efficiency Analysis

Fit tracks from three hits without DUT Extrapolate tracks onto DUT

Match extrapolated tracks to hits on DUT

0 1 2 3 4 5 6 7 8 9 10

0 200 400 600 800 1000 1200 1400

2 of fit with three hits χ

χ² < 2

µm]

Difference [

0 100 200 300 400 500 600 700 800

0 100 200 300 400 500

Extrapolated track - hit position on DUT

Difference < 400µm

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Efficiency Analysis

Columns

0 5 10 15 20 25 30

Rows

0 5 10 15 20 25 30 35

0 100 200 300 400 500 600 700 800 900 Matched Hits

Columns

0 5 10 15 20 25 30

Rows

0 5 10 15 20 25 30 35

0 100 200 300 400 500 600 700 800 900 Total Hits

/

Columns

0 5 10 15 20 25 30

Rows

0 5 10 15 20 25 30 35

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 Efficiency

=

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Efficiency Analysis

Columns

0 5 10 15 20 25 30

Rows

0 5 10 15 20 25 30 35

0 100 200 300 400 500 600 700 800 900 Matched Hits

Columns

0 5 10 15 20 25 30

Rows

0 5 10 15 20 25 30 35

0 100 200 300 400 500 600 700 800 900 Total Hits

/

Columns

0 5 10 15 20 25 30

Rows

0 5 10 15 20 25 30 35

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 Efficiency

=

Columns

0 5 10 15 20 25 30

Rows

0 5 10 15 20 25 30 35

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 Efficiency

Threshold = 0.7 V, HV = 60 V

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High Voltage Scan

Threshold = 0.65 V

High voltage [-V]

0 10 20 30 40 50 60 70 80

Efficiency

0.3 0.4 0.5 0.6 0.7 0.8

by Jan Repenning

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Signal Wave Form

0.8

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Threshold Scan

HV = 60 V

Threshold voltage [V]

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

Efficiency

0 0.2 0.4 0.6 0.8 1

by Jan Repenning

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Conclusions

First test of Mupix6 telescope Achieved alignment:

to within 10µm

minimized rotations of planes Straight track model works

Efficiency of Mupix6 determined to

> 94 %

Voltage and threshold dependency studied

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Outlook

Improve mechanics:

Adjust y-position more precisely

Integrate tiles as triggers with movable posts

Possibly use software for minimization of residuals and alignment, such as Millepede

Next beam test at DESY in March:

Further measurements at other thresholds

Test new prototype Mupix7 Final goal: Working telescope with online reconstruction, streaming readout

⇒ Test Mu3e DAQ

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Thank you for your attention!

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Backup Slides

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Time Resolution

trigger_ts_s_diff

Entries 6910482

Mean 1.238

RMS 16.43

/ ndf

χ2 8741 / 17

Constant 3.257e+05 ± 2.058e+02

Mean -1.931 ± 0.005

Sigma 7.162 ± 0.006

-100 -50 0 50 100

0 50 100 150 200 250 300

103

× trigger_ts_s_diff

Entries 6910482

Mean 1.238

RMS 16.43

/ ndf

χ2 8741 / 17

Constant 3.257e+05 ± 2.058e+02

Mean -1.931 ± 0.005

Sigma 7.162 ± 0.006

Trigger TimeStamp Difference Distribution for Single Events