High Voltage Tests At CERN Heng-Ye Liao, Francesco Pietropaolo, - - PowerPoint PPT Presentation

High Voltage Tests At CERN

Heng-Ye Liao, Francesco Pietropaolo, Francesca Stocker, Kevin Wood HV Consortium Meeting 03/21/2018

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Motivation

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u i c k t u r n a r

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n d t e s t s

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h i g h v

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t a g e c

• mp
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e n t s f

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p r

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U N E

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e v e l

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me n t

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h i g h v

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t a g e d i a g n

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t i c s t

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Test Setup

TOP View High Voltage Cable High Voltage Cable

• Heinzinger Power Supply
• No RC filter in the load

~ 100 kV Field Cage Profiles Field Cage Profiles Ground Planes Ground Planes

• All FC profiles are at same potential

I-beams for testing I-beams for testing

10 cm drift gap

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Monitoring Instrumentation

View port for Rpi Camera View port for Rpi Camera Antenna Antenna Ground Planes Ground Planes LED illumination LED illumination ProtoDUNE Ground Plane Pick-off Board ProtoDUNE Ground Plane Pick-off Board Side View

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High Voltage Test in Air

HV Activities at 100 kV in air

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Simplified Sketch of Cryogenic Setup

Drawing by Francesca

Outer Thermal Bath Pure LAr Gas LAr 4l/h purifer

1.19bar

Heat exchanger Purifed LAr

1.22bar

Inner Vessel 200 l

HV-T est Setup

Recirculation-purification Circuit

• LAr Consumption: ~4 l/hr
• ~2 days to empty the

inner vessel

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Discharge During HV test

• Discharge around the HV cable
• Bubble formation after discharging

@ 105 kV → Live stream at CERN: http://icab04.cern.ch:18160 (See details of connection in the backup slides)

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Ramping Up

03/16/2018 60 kV 142 kV 147 kV Note: Need to scale by ~1.58 on current & voltage readout from Heinzinger (calibration issue) 55 kV Discharge on the HV Cable

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Discharge After 147 kV

Video Credit: Kevin

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Typical HV Discharge Event from the HV Cable

Software Credit: Kevin GP signal saturation because of 10 V TVS diode in the circuit

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Typical HV Discharge Event from the HV Cable

Software Credit: Kevin

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• Few candidates of the “I-beam events” from the Heinzinger readouts
• No time-correlated ground plane events associated with these candidates

Candidates of the “I-beam Events”

p.s. Need to scale by ~1.58 on Heinzinger voltage & current 100 kV 110 kV 120 kV

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Status

• Refill LAr on March, 09, 2018
• Record GP & Antenna traces after 03/12/2018 ~12:00
• Stable running HV at 100 kV

Observed no HV activities associated with I-beams

• HV at 147 kV

Observed discharge on the HV cable only

• HV at 110 kV

3 candidates of “I-beam events” on Heinzinger, no time-correlated GP traces

• Observe cosmic-ray events in the test setup
• Different polarity of GP traces, no time-correlation with Heinzinger
• Ballpark calculation of the signal size

5 tracks of cosmics are ~ 10 mV signal in the GP DAQ? (Assuming µ as MIP, dE/dx~ 2.1 MeV/cm )

• Currently running at 120 kV
• Plan to go higher

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Backup

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E-Field Simulation for the Orientation of the FC Profiles (Bo)

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Live Stream of the HV test at CERN

• Connection Inside CERN:
• Open VLC player

Media > Open Network stream > Type http://icab04.cern.ch:18160

• Connection Outside CERN:
• Make an SSH tunnel through lxplus.cern.ch

ssh -v -N -L localhost:18163:icab04.cern.ch:18160 -p 22 USERNAME@lxplus.cern.ch

• Open VLC player & type http://localhost:18183

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Events with Different Polarity & No Time Correlation with Heinzinger

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[0] Circuit in the cryo [1] Circuit outside cryo to limit the input voltage to ±10 V [2] Voltage Divider to handle the signal size

Simplified Electrical Circuit of Ground Planes Instrumentation

Ground Plane DAQ

39 V MOV 250 kΩ 50 kΩ 10 V TVS Diodes 720 kOhm resistor

[1] [2] [0] Housing in a Pomona box