[PPT] - Dual-Phase status: progress on 3x1x1 prototype L. Molina Bueno on PowerPoint Presentation

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Dual-Phase status: progress on 3x1x1 prototype

L. Molina Bueno on behalf of WA105 collaboration

DUNE monthly collaboration meeting, 14th July 2017

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The WA105 collaboration

22 institutes 138 physicists, 10 countries

demonstrate the capabilities of the dual phase technology at the kton scale

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Goals of Dual-phase LAr TPC prototype at CERN

Demonstrate technical feasibility for O(10kton) detectors

Large surface charge readout in dual-phase scalable to O(10kton) scale

detectors

Charge readout with 3mm pitch in two collection views
Long drift distances
High voltage to generate drift field
Production and QA/QC chains for all detector elements
Validation of installation sequence in view of underground detector

assembly Conceptual design for DUNE dual-phase 10kton LAr TPC is described in DUNE CDR Vol. 4 arXiv:1601.02984 Operation and measured performance of the prototype at CERN informs DUNE TDR (CD2 review in 2019)

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Two dual phase liquid argon detectors

11 m 5 m

in commissioning in construction 3x1x1 m3 protoDUNE-DP Common aspects ✓ LEMs and anode: design, purchase, cleaning and QA ✓ chimneys, FT and slow control sensors ✓ membrane tank technology ✓ Accessible cold front-end electronics and DAQ system ✓ amplification in pure Ar vapour on large areas Same technology→different sizes→different goals

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The 3x1x1 m3 Dual phase LAr TPC

✓ First GTT constructed cryostat for LAr ✓ Fully engineered versions of many detector components with pre-production and direct implementation (installation details and ancillary services) ✓ First overview of the complete system integration: set up full chains for Quality Assessment, construction, installation and commissioning ✓ Anticipate legal and practical aspects related to procurement, costs and schedule verification ✓ short term data taking with cosmics

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The role of CERN: Neutrino Platform

3x1x1-DP large support from CERN Neutrino platform

cryostat cryogenic installation (piping+ monitoring) infrastructure (clean room, structures,..) & safety handling, lifting operations,.. DCS

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The role of CERN

anode+LEM: EP-DT-EF photogrammetry + survey EN-ACE-SU drift cage profile bending: EN-MME-FW main workshop polymers: TE-MSC-MDT PMT coating and qualification EP-DT-EF cold bath test, cryolab TE-CRG-CI SEM observations: EN-MME-MM LEM thickness measurements EP-UAT cabling manufacturing EN-EA-CT cabling and grounding installation EP-DT-DI SMD soldering TE-MPE-EM

in addition to the support from Neutrino Platform, important assistance from many CERN groups and labs

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Detector installation- on schedule

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Detector commissioning and first results

Dec Jan Feb 2017 2016

Beginning

f purge:

purging of main pipes Purge in closed loop Purge in

pen loop

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Detector commissioning and first results

Dec Jan Feb 2017 2016

Beginning

f purge:

purging of main pipes Purge in closed loop Purge in

pen loop

RMS pedestal measured at 1.74 ADC PMTs synchronised with CRTs trigger. Data in GAr was subsequently acquired. All HV connections and sensors tested before cool down systematic check of noise Online display to constantly monitor the different sensors. A Slack account for the collaboration was created with different channels to report the daily activities. pulsing to check detector response

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Light measurements in GAr and trigger

2 Cosmic Ray Tagger pannels with a trigger rate of 0.3 Hz

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Detector commissioning and first results

Mar

1st cool down trial 45 temperature sensors along the insulation space

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Filling process: The filling of the detector started progressively and the evolution of cold regions was monitored in the process. Cryostat works ongoing in the meantime to understand the source of cold spots.

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Detector commissioning and first results

3rd cool down trial

Apr

Inspections inside to ensure there were no leaks. GTT started inspecting the insulation and drilling holes.

Mar

Measurement of the gradient of temperature in the gas during cool down

May

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Filling process: The filling of the detector started progressively and the evolution of cold regions was monitored in the process. Cryostat works ongoing in the meantime to understand the source of cold spots

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Detector commissioning and first results

3rd cool down trial

Apr

Inspections inside to ensure there were no leaks. GTT started inspecting the insulation and drilling holes.

Mar

Measurement of the gradient of temperature in the gas during cool down

May Jun Jul The source of cold spots was identified by CERN and GTT. Due to an anomalous convection produced in gaps between the insulation panels the heat load of the cryostat was 4.5 kW. After injecting a double component foam in several places the heat load was significantly reduced. The injection finished at the beginning of July.

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Detector commissioning and first results

Mar May

Very high voltage tests performed in May at different LAr levels. Cathode and field cage powered up to 50 kV in stable conditions. Total resistance of the field cage:

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Detector commissioning and first results

Mar Jun

On June 9th CRP position adjusted to its nominal level. On June 12th recirculation started. By June 15th a total

f 7 volumes had

been recirculated.

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Evidence for extraction and electroluminescence

~200 V/cm ~1ms drift ~500 V/cm ~640us drift

ne muon crossing the entire volume at two different drifts

electroluminescence (“S2") electroluminescence (“S2") preliminary preliminary Time (200µs/div) PMT raw signal PMT raw signal prompt (“S1”) prompt (“S1”)

Long runs (several 10’s

ktriggers per run) - data being analysed.

Example of event acquired

with scope:

-1kV on bottom LEM, -3

kV on the grid, -20 kV on the cathode → drift, extraction, drift in gas, EL inside LEM holes

Observe millisecond drift

in scope trace → evidence for good liquid argon purity and long drift.

prompt (“S1”) electroluminescence (“S2")

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Light-CRT synchronised events

1kV on bottom LEM, -3.5 kV on the grid, -50 kV on the cathode

preliminary

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Detector commissioning and first results

Mar Jun

On June 9th CRP position adjusted to its nominal level. On June 12th recirculation started. On June 20th first track

One of the very first events with un-optimized field parameters: Drift field 0.32 kV/cm, extraction field 0.6 kV/cm, induction field 1 kV/cm. Amplification field in the LEM 29kV/cm (gain ~5).

Raw data- no noise filtering

By June 15th a total

f 7 volumes had

been recirculated.

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Noise and dead channels in warm and cold

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

Channel

50 100 150 200 250 300

Pedestal RMS [ADC]

1 2 3

1000 2000

Pedestal RMS [# e-]

Channel

650 700 750 800 850 900 950 1000 2000

Pedestal RMS [# e-]

Channel

350 400 450 500 550 600

Channel

50 100 150 200 250 300

Pedestal RMS [ADC]

1 2 3

(20adc=3fC)

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Detector commissioning and first results

Mar Jun Jul

The condenser and phase separator were not well regulated We activate an interlock on the HV system to switch it off in case this happens again

We identify liquid level variations due to instabilities in the cryogenic system

Level meter measurement Time periodic variation

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LAr level

Camera’s movies provide very useful information!

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LAr level

The level is adjusted and constantly

monitored using 7 capacitive level meters

n the CRP, and 5 along the drift cage.

Since middle 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.

CRP level meters DC level meters RMS of the fluctuations 0.1 mm

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Detector commissioning and first results

Mar Jun Jul

Since beginning of this week, we have implemented the possibility of sending a trigger performed by the PMTs to the charge. Beginning of HV tests and data taking.

Trigger rate of 3 Hz Raw data- no noise filtering

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HV configuration

Anode LEM up LEM down Extraction grid Induction Field 5 kV/cm Extraction field in liquid > 2 kV/cm LEM field

Current reached values

Plot from TDR

Cathode

. . .

1 m PMTs

56 kV
7.5 kV
6.5 kV

First Field shaper (FFS) 2 cm

4 kV
1 kV

0 kV Drift field 500V/cm LEM Field 30 kV/cm Current reached values

LEM field: 29 kV/cm
Extraction field in

liquid: 0.9-1.5 kV

Induction Field 1-1.5 kV/cm Gain ~6 Extraction efficiency 0.4-0.8

Several HV tests and data taking campaigns performed since beginning of June at different configurations and different LAr levels. During operations we have always stayed below the nominal operating voltages as the extraction grid trips before reaching its nominal value. This limits the extraction efficiency, the induction field and the field across the LEMs.

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Preliminary stability of data taking

Voltage stable over 5 hours

More than 15 runs taken at different configurations. The average run

duration is 100 minutes mainly due to instabilities of the grid voltage. This was also because the purpose of some of these runs was to test a determined HV configuration and not to take data continuously.

LEM up LEM down and grid

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Software activities - online processing and storage

Online storage and processing for protoDUNE-DP. Being tested on the 3x1x1. The online processing has been tested during the different campaigns of noise and data measurements in the 3x1x1: files transferred to a local EOS and then moved to the CERN computing center. All the necessary codes for 3x1x1 operation including online monitoring processes are functioning well and has been tested.

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Preliminary reconstruction of 3x1x1 data

Qscan and LArsoft packages available to reconstruct 3x1x1 data
Waveforms Qscan-LArSoft

comparison - identical

Raw hit finding

Threshold for fitting: 5 ADC counts. More noise is fitted but tuning of other parameters (see previous slide) and noise filtering should get rid of this.

Reconstruction of cosmic track

in LArSoft (PRELIMINARY)

Standard LArSoft reconstruction

works fairly well for DP and is a good starting point for further developments.

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Time [tdc] ADC LEM down voltages

Preliminary reconstruction of 3x1x1 data

Raw data- no noise filtering 3m view

From channel 0 to160 From channel 160-320

3 m view 1 m view

Problematic channels removed from the reconstruction

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Preliminary reconstruction of 3x1x1 data

Qscan and LArsoft packages available to reconstruct 3x1x1 data
Qscan reconstruction of cosmic tracks:

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Black points are registered hits in view 0 Long tracks traversing the detector are triggered by CRT Short tracks are fragments of other cosmics entering detector within +/- readout window

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Event Gallery

Raw data- no noise filtering

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Conclusion

Significant progress has been made:

We are already in operations/commissioning phase.
Some delay on the operation has been accumulated during cryogenic installation and

commissioning phase and more recently due to the defect in the insulation.

Large experience has been gained for protoDUNE-DP design, installation and

commissioning.

First time, extraction efficiency over 3m2 area and LEM amplification demonstrated on the

50x50 cm2, which is the final design for DUNE, consistent with a LEM gain of 6 at 28 kV/cm.

Currently, the performance is limited by the sparks of the grid at 4 kV (nominal is 6.5 kV). Possible

causes which can explain this issue:

Non-planarity of the CRP.
We disfavour a problem with the liquid level stability.
It could be a problem with the HV kapton cable inside, the connector itself or the SHV

connector of the flange.

Preliminary results indicate a purity compatible with ms electron lifetime.
Full infrastructure for data transfer has been set up and tested in the 3x1x1
Several runs with thousand of events already recorded and being analysed.
Integration of dual phase geometries into LArSoft and studies ongoing.

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THANK YOU

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