ProtoDUNE-SP Installation and Integration meeting 13/07/2017 Installation of temperature sensors at the bottom of the cryostat A. Cervera, M. Antonova, P . Fernández, A. Izmaylov, M. Sorel, P . Novella, P . Bernabeu, J.V. Civera, P . Leon IFIC - (CSIC & Univ. Valencia)
2 Sensor map and cabling • Cables run attached to the pipes all the way to port 9.3 SIDE view • Pipes in purple, cables in white 9.3 TOP view 9.3 T T M M M M T T M M M M T T T T T T T T T T T M T M M M M M M
24+6 12 6 12 6 9.3 The box with a number indicates the number of cables in each section 6 6 6 6 The vertical pipe should hold 24 sensors from the T T M M M M bottom plus ~6 from the wall In principle the flange at port 9.3 should have 5 SUBD-25 connectors M T T M M M • 2 for pipes • 2 for floor • 1 for wall M membrane sensors T pipe sensors T T T T M M M M T T T T
4 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 on the sides of the pipes and not above. • In the next slides assume cables should not touch each othe
5 Cable supports QUESTION: can this homemade piece be made of aluminum ? stainless steel screws teflon or FR4 aluminum or stainless steel stainless steel 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 external
6 External support • 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?
7 For 6 cables in 4 horiz. pipes • Separate pipe and floor cables m pipe sensors floor sensors m 4 . 2 4
8 12 cables in large horiz. pipe • Each group of 6 cables to a different SUBD-25 connector • Separate pipe sensors from floor sensors m m pipe sensors floor sensors 3 . 4 1 1
9 24 cables in vertical pipe • Different supports for pipe and floor sensors • Each group of 6 cables to a different SUBD-25 connector pipe sensors floor sensors floor sensors m m m 3 m . 4 1 3 1 . 4 1 1 pipe sensors
10 sensor support • The whole design is oriented to homemade production, except for the external support. Sensor separation: 103 mm in this design Press the cable and FR4 connector with the fr4 plates Kinematic joint to avoid tension due to shrinkage (material transition)
11 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
12 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 ?
13 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 ?
14 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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