Installation of temperature sensors at the bottom of the cryostat A. - - PowerPoint PPT Presentation

Installation of temperature sensors at the bottom of the cryostat

ProtoDUNE-SP Installation and Integration meeting 13/07/2017

• A. Cervera, M. Antonova, P

. Fernández, A. Izmaylov, M. Sorel, P . Novella, P . Bernabeu, J.V. Civera, P . Leon

IFIC - (CSIC & Univ. Valencia)

• Cables run attached to the pipes all the way to port 9.3
• Pipes in purple, cables in white

Sensor map and cabling

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T T

SIDE view TOP view

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9.3

T T T T T T T T T T T T

9.3

M M M M M

T

M M M M M M M M M M

9.3

T

T T

T T T T T T T T

M M T M M M M M M M M M M

6 12 24+6 6 12 6 6 6 6

The box with a number indicates the number of cables in each section

M T

membrane sensors pipe sensors The vertical pipe should hold 24 sensors from the bottom plus ~6 from the wall In principle the flange at port 9.3 should have 5 SUBD-25 connectors

• 2 for pipes
• 2 for floor
• 1 for wall

Grounding loops ?

• Cables have a teflon jacket
• Since teflon and copper have different linear expansion coefficients

there is risk of breaking the jacket when in cold

• QUESTION: Is there a grounding loop problem if the metallic

shields of two contiguous cables touch each other ?

• I guess there is no problem if those two shields are connected to the same

ground (same flange or same SUBD-25 connector on flange ?)

• QUESTION: Is there a grounding loop problem if the metallic

shield touches the pipe ?

• I guess so but need confirmation. If this is the case we need to put cables
• n the sides of the pipes and not above.
• In the next slides assume cables should not touch each othe

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Cable supports

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stainless steel screws aluminum or stainless steel stainless steel teflon or FR4

QUESTION: can this piece be made of aluminum ? QUESTION: can we use teflon without additional derogation ?

Teflon is preferred because it is easier to machine at IFIC and it will be less aggressive with the cables

homemade external

External support

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• The idea is to use a similar system to the one used to hold the pipes
• We got the technical drawings for those supports from D. Montanari
• Investigating the option of buying similar ones to the same company.

QUESTION: Do we have any answer from the company?

For 6 cables in 4 horiz. pipes

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pipe sensors floor sensors

• Separate pipe and floor cables

4 2 . 4 m m

• Each group of 6 cables to a different SUBD-25 connector
• Separate pipe sensors from floor sensors

12 cables in large horiz. pipe

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pipe sensors floor sensors

1 1 4 . 3 m m

• Different supports for pipe and floor sensors
• Each group of 6 cables to a different SUBD-25 connector

24 cables in vertical pipe

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pipe sensors pipe sensors floor sensors floor sensors

1 1 4 . 3 m m 1 1 4 . 3 m m

sensor support

• The whole design is oriented to homemade production, except for the

external support.

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FR4

Kinematic joint to avoid tension due to shrinkage (material transition) Press the cable and connector with the fr4 plates Sensor separation: 103 mm in this design

Cable lengths

• 500 m of cables will arrive to Valencia at the end of July, 500 m at the

beginning of August and another 300 m in September

• We will measure the length of each cable based on the 3D models (we

need an stripped version of the last one), account for shrinkage and leave an extra tolerance to account for measurement error (~10%)

• Then we will sold the cables to SUBD-25 connectors on the flange side

and IDC-4 on the sensor side

• With this we can do calibration with the “almost final” cable length
• Once at CERN, cable length will have to be fine tuned by cutting at the

sensor part and re-soldering to the IDC-4 connectors

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Installation plan

• The plan is to install first cables and supports and put sensors as late

as possible (more time for calibration, less risks of damaging sensors, etc)

• Sensor installation should take … minutes, … hours, (?), but certainly it

can be done in one day. It is just plugging in 12 IDC-4 male connectors into their corresponding female connectors, and probably tightening some screws. And then check that all sensors are readout correctly.

• In order to understand the timing for sensor/cable support production

we should know:

• QUESTION: what is the best time window for the installation of the

supports and the cables ?

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Summary of Questions

• 1. Can we use teflon for sensor/cables supports without additional

derogation ?

• 2. Is there any problem in using SS in contact with aluminum ?
• 4. Is there a grounding loop problem if the external teflon jacket of the

cable is broken and the metallic shield of two contiguous cables touch each other ?

• 5. Is there a grounding loop problem if the external teflon jacket of the

cable is broken and the metallic shield touches the pipe ?

• 7. What is the best two weeks time window for installation of cables and

cable/sensor supports on bottom pipes?

• 8. What is the best day for installation of bottom sensors ?

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Answers

• 1. Can we use teflon for sensor/cables supports without additional derogation ?
• Filippo thinks so, but he will ask
• 2. Is there any problem in using SS in contact with aluminum ?
• Jack Fowler: apart of the obvious difference in shrinkage, there is risk of corrosion.

Avoid that when possible

• 3. Is there a grounding loop problem if the external teflon jacket of the cable is broken and

the metallic shield of two contiguous cables touch each other ?

• Linda Bagby: they need a full schematics of the system
• 4. Is there a grounding loop problem if the external teflon jacket of the cable is broken and

the metallic shield touches the pipe ?

• Linda Bagby: They need a full schematics of the system
• 5. What is the best two weeks time window for installation of cables and cable/sensor

supports on bottom pipes?

• Roberto Acciarri: Pipes will be installed from August 15th to September 7th, while the

first APA will be installed at the beginning of November. So there are almost two months for the installation. To agree with Roberto on a specific time window

• 6. What is the best day for installation of bottom sensors ? Easy !!!

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