1. Long Bo FT and Flanges April 12, 2012 talk Hans Jostlein 12/19/2015Long Bo FT and Flanges1

2. Requested Design Changes from 4/4/2012 12/19/2015Long Bo FT and Flanges2 Based on Comments and Requirements from the April 4 presentation: 1.Increase the distance between HV Feed and TPC 1.Increase the distance between central purity monitor and TPC / HV feed 2.Raise the HV FT flange above the insulation atop the big 33 ½”) flange to diminish icing danger

3. Implementation of new Design Requirements 12/19/2015Long Bo FT and Flanges3 Move the TPC away from the Tank Center. This frees up radial space for the purity monitor and the HV Feed Raise the TPC to the same elevation as the central purity monitor, maintaining the same minimum LAr depth.

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7. Additional Design Features: Bubbles 12/19/2015Long Bo FT and Flanges7 Analyze bubble paths and Bubble Size Control Add a tight fitting seal at the bottom of the PE sleeve. It will sea when cold Conical bottom end of the PE sleeve to prevent bubble aggregation Venting of the space surrounding the 7/8” center tube to its inside Venting the 7/8 tube inside through tiny holes in the contact cup at the bottom. Hole size 0.2 mm requires 2 cm LAr head; we will use 0.5 mm or larger.

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9. Additional Design Features: Purging 12/19/2015Long Bo FT and Flanges9 Purge the space surrounding the PE sleeve into the GAr space at the top. Purge the GAr space near the top into an external purge line Purge the GAr space near the TPC Signal Feedthrough into an external purge line

10. New Feedthrough Design New Features: 1.Top Flange raised above the top insulation 2.Bubble stop insert at bottom of PE Sleeve (See later slide) 3.Inverted cup/ spring contact arrangement (see later slide) 4.Extended to great depth to avoid having an insulated support 5.Bubble and purge management (see later slide) 12/19/2015Long Bo FT and Flanges10

11. Additional Design Features: HV Contact Area 12/19/2015Long Bo FT and Flanges11 In order to minimize the TPC assembly diameter, thus maximizing the stand-off distances of HV FT and Purity monitor, We invert the usual arrangement: The spring loaded finger is attached to the TPC cathode HV tubing, while the (inverted) cup is welded to the HV FT center tube. This change turns out useful and effective for bubble control (see previous slide)

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13. Additional Design Features: Windows 12/19/2015Long Bo FT and Flanges13 We will have two windows, both existing: An 8” CF window and a 6” CF window. These will help during HV FT installation

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17. 12/19/2015Long Bo FT and Flanges17 Making the Long Bo High Voltage Fedthrough Cutting grooves into the PE:

18. 12/19/2015Long Bo FT and Flanges18 Making the Long Bo High Voltage Fedthrough Cutting grooves into the PE:

19. 12/19/2015Long Bo FT and Flanges19 Making the Long Bo High Voltage Fedthrough Cutting grooves into the PE:

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