PHENIX & The Beam Pipe
1) Overview of the drawings
2) I will break down the beam pipe going from MuID-S to MuID-N piece by piece.
3) Important Information
4) Overview of the planned changes to the PHENIX beampipe.
PHENIX w/ focus on the beampipe
This is from an Autocad drawing done by Richie and Don: 026.pdf
Part F no longer exists. This was a stand used before the South Magnet was installed.
South Piston Hole Beampipe
This is from an Autocad drawing done by Richie and Don.
A pdf copy is available: 047.pdf
Zoom-in’s and explanations will follow.
North Piston Hole Beampipe
This is from an Autocad drawing done by Richie and Don.A pdf copy is available: 038.pdfZoom-in’s and explanations will follow.
And there’s a bellows, but it doesn’t have a “Bellows Spreader” on it. The South’s “bellows spreader” increases the South’s keep out zone.
South Mu ID
Valve – isolates PHENIX from the rest of the ring. Close the valve, and we can break vacuum without affecting the ring.
Bellows – I & 2
BPM – beam position monitor
Vacuum Pump
Fixed support – no longer exists. Taken out with installation of South Magnet
Sliding Beam Pipe SupportShown in Section C of 026.pdf
Flange and BellowsShown in Detail D of 026.pdf & in 047.pdf
Conversion from 5” ID to 3” ID steel beam pipe
South Muon Magnet
Beam pipe conversion from steel to beryllium. This is a rigid joint. I believe the transition from beryllium to steel is inside the central magnet steel
Central Region
V – Shaped support : The steel beam pipe is not rigidly held here. Nor can it roll. It can scrape through the V.
Flange and Bellows
Conversion from 3” ID to 5” ID steel beam pipe
North Muon Magnet
Sliding Beam Pipe SupportShown in Section C of 026.pdf
North MuID
Very similar to the South case. Valve, flanges, vacuum pump…
Important Information
There must be a bellows between any two fixed points to give the beam pipe room to expand/contract in the z-direction.
Fixed Point
Rolling Support
Bellows
From 026.pdf it looks like this is a non-sliding support, positioned just before the transition to beryllium. This seems to break the rule. I will follow up with Don tomorrow.Sliding Support
Three Beam Pipes
Beryllium section is rigidly connect to steel piece.
Planned Changes
Both the beampipe thickness and inner diameter will be decreased. Time frame unknown, but it is connected with the Nose Cone Calorimeter upgrade.
The plan is to have beryllium up to the nose cone, have a bellows there and make the transition to steel. It’s difficult to tell, but it looks like the current beampipe makes the steel-beryllium transition inside the central magnet
We could make the argument that we are moving the south bellows from the magnet hole to the south nose cone.
What would this give us?
Bellows Spreader Diameter – 6.50”
Flange Diameter – 4.62”
We’d reduce the keep out zone radius by almost an inch so… we’d be at the keep out zone of the North MPC… 4 5/8”
The south drawings are in pdf’s 043, 044, 045, 046 & 047.
Numbers Explained (i)
6.5”
6.5” is diameter of spreaders
5.5” is the diameter of the circle formed by the bellow spreader rods
Numbers Explained (ii)
4.62” is the flange diameter. – This would make out keep out diameter the same as the NMPC.