HV bus issues and ideas: Mind the gap From Vic Guarino's - - PowerPoint PPT Presentation

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HV bus issues and ideas: Mind the gap

From Vic Guarino's presentation at ProtoDUNE SP CPA and Field Cage meeting Wednesday https://indico.fnal.gov/conferenceDisplay.py?confId=11862

• Design Challenges:

– Thermal contraction results in .9mm gap between CPAs – Offset loading from FC results in significant rotation of frame

• Looking at connecting two CPA’s together at top and bottom bars of

frame so that they act as one.

– Balanced loading – Requires top supports to beam to be able to slide .9mm for thermal contraction.

• Need flexible connection to beam to accommodate roof distortion.

[Roof distortion is 3 mm.]

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Mind the gap

• Need flexible HV bus connection that can

accommodate 3 mm roof motion, changes in gap width, survives dynamic changes during FC swing out.

• Also want to avoid exposing connection points

to field in gap

• Known problem, various ideas.

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1 6 t a l k : H V B u s I n t e g r a t e d i n t

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This concept needs to be modifjed to allow for a few mm of vertjcal relatjve movement between CPA modules to accommodate roof defmectjon:

• Change the circular pin and socket into rectangular ones
• Or use screw and wire lug to connect the bus

together.

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A Variant to Allow Vertjcal Movement

The pin and slot connectjon should allow a few mm of vertjcal movement between CPAs caused by roof motjon without breaking electrical contact.

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A n

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h e r i d e a

Loose but captured protruding magnetic plug, fixed recessed magnetic socket

Mated, on-axis with 9mm gap Mated, 4 mm gap, 3 mm vertical shift Resistive material Embedded magnet near contacts

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Another thought

• Resistive strips around

frame should cover gap

• Large strip on one CPA

could cover gap and frame of next CPA over.

• Then we could have

bigger gap, shielded region in which to run bus wires.

Fiberglass channel (63x63x6mm) Resistjve panel (3mm thick) Resistjve strips with a difgerent bias

1.15 m

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Fiberglass channel (63x63x6mm) Resistjve panel (3mm thick) Resistjve strips with a difgerent bias

1.15 m

Fiberglass channel (63x63x6mm) Resistjve panel (3mm thick) Resistjve strips with a difgerent bias

1.15 m