The MuPix Telescope

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The MuPix Telescope

Tracking Low Momentum Particles at High Rate

Lennart Huthfor the Mu3e Collaboration Physikalisches Institut Heidelberg DPG Spring Meeting Hamburg 03 March 2016

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Motivation

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Motivation

What's beyond the SM?

• Charged Lepton Flavour Violation?

• Introduced by BSM theories

• Measurable branching ratios predicted

The decayµ⁺→e⁺e⁻e⁺

• SM - BR<10⁻⁵⁴

• P~p=0

• Coincident in space and time

• Emax<53 MeV Background

• Radiative decay with internal conversion: P~p 6=0

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Mu3e

The Mu3e Experiment - Searching forµ⁺→e⁺e⁻e⁺with a sensitivity of BR<10⁻¹⁶

Inner pixel layers

Scintillating

Outer pixel layers Recurl pixel layers

Scintillator tiles

μBeam Stopping Target

ﬁbres

Multiple scattering regime and high rate

→Fast and thin pixel sensor

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HighVoltage - MonolithicActivePixelSensors (HV-MAPS)

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

Design Goals

• Binary readout

• Pixel size: 80 x 80 µm²

• 256 x 256 pixel

• Time resolution<20 ns

• Efﬁciency>99 %

• 50 µm thin 0,05 % radiation

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The MuPix 7

• Latest prototype

• Fully integrated readout on the chip

• On chip PLL & VCO

• 1.25 GBit/s data≈33 MHits/s

• Details: T 72.1/2/3

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The MuPix Telescope

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The MuPix Telescope

Idea: Build a tracking detector out of Mu3e parts as integration test and ﬁll a gap in the choice of existing beam telescopes:

Tiles Test PCB MuPix

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Concept, Readout & DAQ

• Custom PCB holder with 10 µm precision

• Commercial mechanical support

• Differential high speed links: 1.25 GBit/s

• Online time sorting (T 22.4)

• GByte/s data transfer to PC

• Up to 60 MByte/s ﬁnal data storage

• User friendly control interface

• Online monitoring, tracking and efﬁciency calculation

• GPU Online Tracking and direct memory access (T 42.5/6)

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Concept, Readout & DAQ

• Differential high speed links: 1.25 GBit/s

200-260mm

max. 600 mm min 25 mm

breadboard

rail MuPix Beam

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Concept, Readout & DAQ

• Differential high speed links:

1.25 GBit/s

1 2 3 4

1.25 GBit/s LVDS link

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Concept, Readout & DAQ

1.25 GBit/s

1 2 3 4

Sorter

Time

Frames

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Concept, Readout & DAQ

1.25 GBit/s

1 2 3 4

Sorter

Time Frames

HDD

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Concept, Readout & DAQ

1.25 GBit/s

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Concept, Readout & DAQ

1.25 GBit/s

• GPU Online Tracking and direct

Time stamp correlation

Column correlations

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Testbeam Results

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Comparison of Power Settings

Maximal cooling power: 400 mW/cm²

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Efficiency Summary

Larger rotation→more signal→Higher efﬁciency at higher thresholds

0.94 0.95 0.96 0.97 0.98 0.99 1

Rotation 0o

15o

30o

45o

Eﬃciency

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Crosstalk I

Selection Criteria

• Single track

• Count hits on DUT

• Select events with only 2/3 hits

• Same column, row +/-2

Column/Row Address

0 5 10 15 20 25 30 35

Crosstalk Prob

−4 10

−3 10

−2 10

triple_hit_row

row col

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Crosstalk II

Crosstalk Prob

−4 10

−3 10

−2 10

triple_hit_row

row

col

Active Pixel Area

Digital Part

Point to Point

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Crosstalk III

Column/Row Address

0 5 10 15 20 25 30 35

Crosstalk Prob

−4 10

−3 10

−2 10

triple_hit_row

row col

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Crosstalk III

Crosstalk Prob

−4 10

−3 10

−2 10

triple_hit_row

row col

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Conclusion

• First running integrated HV-MAPS system

• High Rate capabilitiesO(1MHz)

• Important tool to test scalability

• High system efﬁciency>99 %

• Time resolution<11 ns

• Cross talk and clustering analysis ongoing

→cross talk issue, should be ﬁxed in MuPix8

Threshold [V]

0.07 0.06 0.05 0.04 0.03 0.02

0.94 0.95 0.96 0.97 0.98 0.99 1

Rotation 0o 15o 30o 45o

Eﬃciency

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Acknowledgments

The measurements leading to the rotated DUT results have been performed at the Test bEam Facility at DESY Hamburg (Germany), a member of the Helmholtz Association (HGF).

We would like to thank the PSI for providing high rate test beams under excellent conditions.

We owe our SPS test beam time to the SPS team and our LHCb colleagues, especially Heinrich, Kazu and Martin.

We thank the Institut für Kernphysik at the JGU Mainz for giving us the opportunity to take data at MAMI.

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Backup

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Track Model

Trackmodel: Straight track without scattering

~x(z) =x~0+~a·z

→ X²can be analytically minimized X²=

n

X

i=1

(xi−(x0+ax·zi))² σ_x²

mi

+(yi−(y0+ay·zi))² σ²_y

mi

!

assumingσ_x/y_mi =pixel resolution= pixel size√ 12

→Fast and robust track model!

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Alignment @ DESY

Run number

600 800 1000 1200 1400

Residuals x mean [um]

−15

−10

−5 0 5 10 15

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

600 800 1000 1200 1400

Residuals y mean [um]

−15

−10

−5 0 5 10 15

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

600 800 1000 1200 1400

RMS of residuals x mean [um]

20 30 40 50 60 70 80 90 100

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

600 800 1000 1200 1400

RMS of residuals y mean [um]

20 30 40 50 60 70 80 90 100

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

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Telescope Timing @ DESY

Threshold [V]

0.73 0.735 0.74 0.745 0.75 0.755 0.76 0.765 0.77 0.775

) [ns]σTime Resolution (1

14 14.5 15 15.5 16 16.5 17 17.5 18

Time Resolution

00 deg 15 deg 30 deg 45 deg

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MuPix7 Spatial Resolution

µm]

X Residual [

−100−80−60−40−20 0 20 40 60 80 100

m]µY Residual [

−100

−80

−60

−40

−20 0 20 40 60 80 100

1 10 102 103 104

µm]

Residual of matched hit [

−300 −200 −100 0 100 200 300

Entries [1/run]

0 50 100 150 200 250

103

×

µm 19.8+-0.2 σ X Residual

µm 18.3+-0.2 σ Y Residual

• Resolution is dominated by the pixel size!

• Multiple Scattering small enough for 4 GeV/c electrons

• Resolution in x slightly worse than in y: Feature of pixel size

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Analysis Concept

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Analysis Procedure

• Align the system

• Extrapolate track and check hits on DUT

• Match DUT hits

• Analyze cut-effects

• Extract the relevant

parameters ⁰ ¹⁰⁰ ²⁰⁰ ³⁰⁰ Matching Radius [mum]⁴⁰⁰ ⁵⁰⁰

Eﬃciency of ROI

0.88 0.9 0.92 0.94 0.96 0.98 1 1.02

Chi2 Cuts 1 2 4 6 8 10 14 20

Eﬃciency for diﬀerent chi2 cuts as function of the matching radius

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Efficiency Analysis

Column

0 5 10 15 20 25 30

Row

0 5 10 15 20 25 30 35

0 100 200 300 400 500 600 Matched Map

# Matched

/

Column

0 5 10 15 20 25 30

Row

0 5 10 15 20 25 30 35

# Tracks

0 100 200 300 400 500 600 Track Map

=

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Efficiency Analysis

Column

0 5 10 15 20 25 30

Row

0 5 10 15 20 25 30 35

0 100 200 300 400 500 600 Matched Map

# Matched

/

Column

0 5 10 15 20 25 30

Row

0 5 10 15 20 25 30 35

# Tracks

0 100 200 300 400 500 600 Track Map

=

Eff= ^{# matched}_{# tracks}

Column

0 5 10 15 20 25 30

Row

0 5 10 15 20 25 30 35

0.80.82 0.840.86 0.880.9 0.920.94 0.96 Eﬃciency Map 0.98

Eﬃciency

Noiseratepixel= ^#hits_{# runtime}⁻^{# matched}_·_{# pixel}

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Efficiency Analysis

Column

0 5 10 15 20 25 30

Row

0 5 10 15 20 25 30 35

0 100 200 300 400 500 600 Matched Map

# Matched

/

Column

0 5 10 15 20 25 30

Row

0 5 10 15 20 25 30 35

# Tracks

0 100 200 300 400 500 600 Track Map

=

Eff= ^{# matched}_{# tracks}

Column

0 5 10 15 20 25 30

Row

0 5 10 15 20 25 30 35

0.80.82 0.840.86 0.880.9 0.920.94 0.96 Eﬃciency Map 0.98

Eﬃciency

ROI

EffROI=^{# matched}_{# tracks} ^ROI

ROI

Noiseratepixel= ^#hits_{# runtime}⁻^{# matched}_{# pixel}