MXTPC

Pepe GülkerRD51 Mini Week Feb 2020

MAGIXperiment @ MESA

2

Electron Beam• E ≤ 105 MeV• I ≤ 1 mA

Jet Target• windowless target• from H to Xe

2 Spectrometers• Focal Plane

• 700 mm (dispersive)• 150 mm (drift)• 200 mm (depth)

MomentaAngles

Electrons & Positrons

Electron Scattering

• Elastic or inelastic

• Form factor measurements

• Proton radius

Pair Production

• e+e-

coincidence• With SM or dark

U(1) photons

Focal Plane

4

Need detector to measure• Position x and y• Angles 𝜑 and 𝜙

How?• Easiest approach: hodoscope• Multiple scattering in 1st

detector limits angular resolution• Remember: 105 MeV electrons!

Material Budget

5

type radiation thickness [X0] scattering angle [deg] @ 100 MeVdefault 0.95 % 0.7thin readout 0.38 % 0.4chromium GEMs 0.22 % 0.3

The end of the hodoscope

6

New Spectrometer Design

7

New Spectrometer Design

8

Focal Plane Size• 640 mm (dispersive)• 140 mm (non-dispersive)• 200 mm (depth)

Detector not tilted• less material to traverse• mapping not constant

TPC – Time Projection Chamber

9

10

117

Pad PCB

12

VMM

13

hans

.mul

ler@

cern

.ch

MXTPC - Numbers

14

Tripple GEM•Voltages:

•GEMs: 360 - 329 - 293•Transfer: 720 - 720 - 720

Gas•Ar:CO2 90:10•10 L/h

Readout PCB•Padsize: 2 x 8 mm^2•50 rows•12 columns•600 pads

Readout Electronics•6 VMMs @ TPC•1 VMM @ Trigger

Fieldcage•Copper rings 0.5 mm•pitch 2.5 mm•28 rings•7 cm drift

Beamtime 2019

15

Beam•Energy fixed 855 MeV•Rates up to 1 MHz

TPC•3 GEMs•7 cm drift

Readout•6 VMMs @ TPC•1 VMM @ Trigger

Beamtime 2019

16

Beam•Energy fixed 855 MeV•Rates up to 1 MHz

TPC•3 GEMs•7 cm drift

Readout•6 VMMs @ TPC•1 VMM @ Trigger

Beamtime 2019

17

Beamtime 2019

18

Beamtime 2019

19

Gas Mixture

20

70:30 80:20 90:10

double flow

data runs

Argon flow

CO2 flow

400410420430440450460

0 9 18 27 39 52

drift [t]

drift [t]

stable

time [min]

drif

t [a.

u.]

online mixture check

Beamtime 2019

21

Gas Mixture

HighRates

22

2 kHz

950 kHz

50 kHz

5 kHz

High Rates

tripoff

Beamtime 2019

23

Gas Mixture

HighRates

TPCScans

24

cathode voltagebeamrate

x-position

y-position

TPC - Scans

Beamtime 2019

25

Gas Mixture

HighRates

TPCScans

Beamtime 2019

26

0 2 4 6 8 10PadY Rows [8mm]

0

5

10

15

20

25

30

35

40

45

PadX

Col

umns

[2m

m] hit_err

Entries 52Mean x 5.004Mean y 22.24Std Dev x 3.464Std Dev y 3.785

0

200

400

600

800

1000hit_err

Entries 52Mean x 5.004Mean y 22.24Std Dev x 3.464Std Dev y 3.785

errorband

columns [2mm]rows [8mm]

drifttim

e [ns]

Trigger2VMM

27

0

20

40

60

80

100

120

140

310´

hitmap

0 5 10 15 20 25 30 35 40 45

0

2

4

6

8

10

Entries 4286529

Mean x 21.25

Mean y 5.578

Std Dev x 4.23

Std Dev y 3.475

0 0 0

04286521 8

0 0 0

hitmap

0 500 1000 1500 2000 2500 3000 3500 40000

200

400

600

800

1000

1200

1400

1600

tpc bcid spectrumEntries 4286529

Mean 2029

Std Dev 1178

Underflow 0

Overflow 0

tpc bcid spectrum

200- 100- 0 100 200 time [0.3 ns]

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

tpc tdc spectrumEntries 1814122

Mean 3.152

Std Dev 36.19

Underflow 0

Overflow 0

tpc tdc spectrum

0 200 400 600 800 10000

5000

10000

15000

20000

25000

tpc adc spectrumEntries 4286529

Mean 385.7

Std Dev 234.8

Underflow 0

Overflow 4.623e+05

tpc adc spectrum

0 500 1000 1500 2000 2500 3000 3500 40000

20

40

60

80

100

120

trigger bcid spectrumEntries 305360

Mean 2045

Std Dev 1183

Underflow 0

Overflow 0

trigger bcid spectrum

200- 100- 0 100 200 time [0.3 ns]

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

trigger tdc spectrumEntries 140545

Mean 2.861-

Std Dev 12.06

Underflow 0

Overflow 0

trigger tdc spectrum

Beamtime 2019

28

0 5 10 15 20 25 30 35 40 450

0.2

0.4

0.6

0.8

1

1.2

1.4

clusterfinder

0 5 10 15 20 25 30 35 40 450

200

400

600

800

1000

clusterfinder with weights

0 10 20 30 400

1

2

3

4

5

6

clusterfinder results

Analysis ongoing!• Time resolution ~ 1ns• Point resolution < 500 um• Track resolution?

THANK YOU FOR YOUR ATTENTION!

http://magix.kph.uni-mainz.de