3x1x1 results obtained so farLaura Manenti University College London

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Gained experience for ProtoDUNE-DP design, installation, and operation.

For first time extraction efficiency over 3 m2 area and LEM amplification over 50x50 cm demonstrated (gain of 5 at 28 kV/cm)

Purity in the ms electron lifetime range

Excellent performance of the LAr pump for recirculation and the cryogenic system

Stable operation at 500 V/cm (HVFT at -56 kV)

Good S/N ratio for both collection views even without software noise removal

Infrastructure for data transfer set up and tested with 140 k events recorded and being analysed so far

Results achieved

Goal/purpose:DP TPC technology works at large scale

311 detector served as test bench for protoDUNE-DP

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Roadmap of the 3x1x1July 2017

2015

Sebastien Murphy ETHZ TPC Symposium 2016 Paris December 5-717

Themembranecryostat

Insulation:• 1 meter made from blocks of 30 cm thick

Polyurethane+plywood.• 45 temperature sensors to measure temperature

gradient.Membrane:• corrugated steel panels welded together.• Tightness of welds tested to 1e-9 mbar l/s.

FirstmembranecryostatbuiltatCERN

MembranecryostatusedforLNGtransportationLicensedbyGTT/France

2015 - Cryostat constructed

2016 - Detector installation completed

Jan 2017 - Commission started

Mar 2017 - Operation ‘frozen’ due to cryostat issues

Jun 12th 2017 - Recirculation started

Jun 21st 2017 - First track seen!

Recirculation of LAr with cryo pump

Detector slow control system

Online processing and storage

LAr level measurement

CRP mechanical frame and suspension system

High voltage system

FE electronics

Performance of the muon trigger system

PMTs

LEM anode and extraction grid

Results achieved

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LAr recirculation

Goal is to achieve a purity at the ppt level

Jun 12th: LAr recirculation startedJun 15th: a total of 7 volumes had been recirculatedPump and cartridges have been running continuously for 2 monthsWe would like to thank CERN cryogenic team for their daily support

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Slow control system Online display to constantly monitor the different pressure and temperature sensors inside the detector and in side insulation space. A dedicated ELOG for the 3x1x1 with more than 400 entriesA Slack account for the collaboration was created with different channels to report the daily activities.

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SW activities: online processing and storage

We already have more than 140k events!Summary of all the runs recorded with the main details and number of events.Online storage and processing for protoDUNE-DP ➡Being tested on the 3x1x1. Files transferred to a local EOS and then moved to the CERN computing centre.All the necessary codes for 3x1x1 operation including online monitoring processes are functioning well and has been tested.

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LAr level measurement

• The level is adjusted and constantly monitored using 7 capacitive level meters on the CRP, and 5 along the drift cage. Since mid June, this information is also sent to the cryogenic system to constantly regulate the system to keep the level stable.

• 4 cryogenic cameras are recording pictures continuously.

DC level meters

Evolution over one month

Not real drops, we lost slow control information

CRP level meters

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Very high voltage system

Mar

Total resistance of the field cage:

C. Cantini et al., “First test of a high voltage feedthrough for liquid Argon TPCs connected to a 300 kV power Supply”, JINST 12 P03021 arXiv:1611.02085

• Very high voltage tests performed in May at different LAr levels.

• Cathode and field cage powered up to 50 kV in stable conditions with the field cage terminated to ground.

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Trigger1)Two Cosmic Ray Tagger (CRTS) panels installed in the short sides of the cryostat.

• Each panel made in scintillation bars in x-y to provide 2D coordinates

• Trigger rate of 0.3 Hz

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Trigger

2)Photomultipliers: Since beginning of July, the charge can receive also a trigger produced by the PMTs

• Threshold trigger on the scintillation light received by the 5 PMTs.

• Trigger rate 3 Hz.

From this trigger, we can also perform additional measurements:• The rate of e—ion recombination depends on the drift field.

• To understand if the drift field had an impact on the trigger rate, we evaluate the trigger rate as a function of the drift field up to 60 kV

see Alberto’s talk

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accessible cold amplifiers at 150 K.Sealed in chimney separate from main argon volume

uTCA crate

cold ASICs

ASICs insertion via 2 m blade

Test pulse at warm and at cold: 17 (1.3%) dead or problematic channels.Low noise condition at cold: 1.66 adc counts (1600 e-) RMS noise

Chan

nel

050

100

150

200

250

300

Pedestal RMS [ADC] 123

1000

2000

Pedestal RMS [# e-]

Channel650 700 750 800 850 900 950Pe

desta

l RM

S [A

DC]

1

2

3

1000

2000

Pedestal RMS [# e-]

Channel350 400 450 500 550 600Pe

desta

l RM

S [A

DC

]

1

2

3

1000

2000

Pedestal RM

S [# e-]

Channel0 50 100 150 200 250 300Pe

desta

l RM

S [A

DC]

1

2

3

1000

2000

Pedestal RMS [# e-]

(20adc=3fC)

Noise and dead channels in warm and cold

Induction field

LEM field

Extraction field

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HV system configuration

Ext grid

All measurements in mm

20

55

FFS

LEMup

LEMdown

Anode

21

cathode

980

-56 kV

-7.6 kV

-6.5 kV-4.0 kV-1.0 kV

0 kV

shieldingPMTs

Nominal values

Drift field 500 V/cm

> 2 kV/cm

30 kV/cm

5 kV/cm 1-1.5 kV/cm

28-29 kV/cm

1-2.3 kV/cm

500-700 V/cm

Values reached

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76 4 DLAR DETECTOR COMPONENTS

LEM field [kV/cm]24 26 28 30 32 34 36

effe

ctiv

e ga

in

0

20

40

60

80

100

reso

lutio

n

0

0.1

0.2

0.3

0.4

0.5

resolution view 0

resolution view 1

effective gain

Extraction field [kV/cm]0 0.5 1 1.5 2 2.5 3 3.5 4

effe

ctiv

e ga

in

0

10

20

30

40

reso

lutio

n

0

0.1

0.2

0.3

0.4

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resolution view 0

resolution view 1

effective gain

Induction field [kV/cm]0 1 2 3 4 5 6 7 8

effe

ctiv

e ga

in

0

10

20

30

40

reso

lutio

n0

0.1

0.2

0.3

0.4

0.5

resolution view 0

resolution view 1

effective gain

FIG. 51: E↵ective gain and resolution of the charge deposition measurements on both view as a function of theLEM electric field.

event acquired with a gain of 15. Further studies will be performed to check wether the chamber can

be continuously operated at larger LEM fields and if higher gains in stable conditions can be reached.

FIG. 52: Event display of a cosmic track with a gain of ∼ 15 obtained in the 3 liter chamber. (top): the rawwaveform showing the amplitude of the signals on both views. (bottom): drift time versus channel number ofthe reconstructed hits.

Based on those studies in Table IV we summarise the typical high voltages applied across each stage

of the detector equipped with the new anode and operated in the single grid configuration. An electric

1

10

100

1000

100 1000

(s)

electric field (V/cm)

A exp(B E1/2) / E

A = 1.20x105 s V/cm

B = -0.062 (cm/V)1/2

0

0.2

0.4

0.6

0.8

1

1.2

0 0.5 1 1.5 2 2.5 3 3.5 4

extra

ctio

n ef

ficie

ncy

electric field (kV/cm)

fastfast + slow

Induction Field [kV/cm]0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

Colle

ctio

n Ef

ficie

ncy

0.4

0.5

0.6

0.7

0.8

0.9

1

linear dependanceinterpolation assuming

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HV system configuration

In green the field values scanned so far.In orange the field values at most stable conditions.

hdQds iview = Fshare ⇥Gain⇥ E↵extr ⇥ E↵ind ⇥dQds

hdQds iview ⇠ 0.5⇥ 5⇥ 0.9⇥ 0.5⇥ 10 fC/cm = 11.5 fC/cm

Gushchin et al, Sov. Phys. JETP 55 (1982) 860-862

see Laura Z.’s talk

LBNO TDR, CERN-SPSC-2014-013, 1409.4405

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