Flobber Space Constraints:Resolution Options

James Mott, Eric Hazen, Dan Gastler

Tracker Meeting

08/20/15

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Introduction• Last week I outlined some space conflicts with the boards

inside the flobber

• We’ve now thought about this a bit more and made a rough attempt to cost two different options for fixing these conflicts:

1. Enlarging the flobber, and re-working the feedthrough board to increase the space between boards

2. Changing the design of the TDC and TDC motherboards to remove the problematic connector

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Option 1: Feedthrough Board – General Idea

Increase snout & flobber height

Increase board-to-board spacing

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Option 1: Feedthrough Board – Inner Traces

8 layer design is fairly complicated

Comparatively easy to increase this distance

We’re not confident that we can do this without starting again with routing after moving connectors

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Option 1: Feedthrough Board – Cost• FNAL to say how big flobber can get ~ 1 d, $?

• Re-design board at BU ~ 3.5 d, $1.2k

• Prototype new feedthrough board ~ 2d, $1.4k

• Re-design flobber at UCL ~ 1.5 d?, $?

• Re-design snout at Liverpool ~ 1 d?, $? (already reqd.)

• Prototype new mechanical connections ~ 3 d? $?

• Totals: 10 – 12 person-days? $2.6k + $?

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Remove programming connector, which is causing conflict.

Also remove two more TDC board connectors.

Enlarge connector to match one on ASDQ to accommodate extra signals (may not be necessary).

This removes need for separate cables which are currently a pain.

Requires much easier changes to TDC motherboard and TDC board than feedthrough option.

Option 2: TDC Board – General Idea

Two of these would also be removed - inserting/removing the boards much easier

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Option 2: TDC Board – Cost• Re-design TDC mother board at BU ~ 1.5 d, $0.5k

• Re-design TDC board (Newgrange electronics) ~ 1 d, $0.7k

• Prototype new TDC board & motherboard ~ 2d, $3.2k

• Savings on cables and connectors (200 TDC boards) ~ $-3.5k

• Totals: 3.5 person-days; $0.9k

• N.B. times here do not mean we could order prototype in 4 days!

• We need to finish testing electronics for test beam fall-out first, but that’s the same in both options.

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Conflict Resolution Preference• We favour option 2 – it’s easier for us and saves a lot of effort

in re-coordinating the interface between BU, Liverpool & UCL.

• Removing all the cables is a great advantage.

• The money it saves us offsets the cost of two prototypes and it also removes a lot of hassle we had in assembly (they often un-plug or lose their connection).

• If we also remove the connectors at the back of the motherboard we can add a hole to use a tool to remove the boards.