Second flange presence in beampipe in forward direction

[rymilton]

Is your feature request related to a problem? Please describe.
Should the second flange in the beampipe in the forward direction (z = ~445 cm) be present? I've been told by multiple people in the calorimetry group that this flange is from an older beampipe design. The flange overlaps with the proposed design of the forward HCal insert.

Describe the solution you'd like
Remove the secondary flange.

Describe alternatives you've considered
Maintain the flange and adjust the design of the insert.

Additional context
Image of the beampipe:

[wdconinc]

The flange can be removed indeed. When it became clear that the flange placement was notional, we didn't have as much urgency to fix this. We just moved it 5 cm to avoid overlap with the drich. The lines 62 through 67 in https://github.com/eic/ip6/blob/master/ip6/central_beampipe.xml#L62 describe that flange.

[wdconinc]

Ah, that's the first flange and you're talking about the second flange, but the same is true there. The other aspect there is that we should also adjust the pipe itself to mate with the B0 magnet, with or without flange.

[rymilton]

For the time being, I can submit a pull request that removes both of these flanges by removing lines 63-66 & 69-72. We can then adjust the pipe further for the B0 magnet in another pull request.