1. BRAN: LS2-plans
TREX
M. Palm, E. Bravin, BE-BI-PM

2. Plans Remove 2 BRAN-A (ionization chambers)
IP1: 1 pcs
IP5: 1 pcs
Install 2 Cherenkov-based BRAN monitors

3. Existing BRAN prototype
Crane support
Tested at IP1L
Verified feasibility of fused silica as sufficiently radiation-hard Cherenkov media
Main drawbacks:
In case of bake-out or maintentance: entire monitor must be removed+reinstalled using crane
From experience: final position of BRAN sometimes adjusted by hand. Small items easily fall into the TAN, causing detector to tilt
Manual disconnection of all connectors (from TAN “wall side”)
⇒ Make the BRAN more “remote handling”-friendly.
PMTs at top of each tube
2x8 connectors (bayonet)
2 x 1/2 day, 6-8 people. Per IP-side.
8 x Stainless steel tubes
Climbing on TAN to be avoided during HL-LHC…
Copper sheets (15 mm)

4. Modifications Split monitor into two parts Top: Bottom: Connectors:
Top: removable PMT house
Split monitor into two parts
Top:
PMT housing, attenuation filters, etc.
Bottom:
Fused silica rods.
Copper spacers (absorption)
Connectors:
Use connector panels (non-latching connectors)
Ensure minimal impact on bake-out procedure

5. New BRAN: draft Installed by crane (as today)
Operational position
Crane support (rigid)
Installed by crane (as today)
Manual connection of coax, HV and air on “wall side”
PMT unit (green) can be removed
Mates with connector panel on back side
Remove PMT unit if needed
Leave main part in TAN permanently (no active parts)
PMT unit: removable
Connector panels (non-latching)
Handle/Robot grip
Bake-out jackets (permanent)
LEMO (mixed coax/HV)
Combitac
MCR

6. Feasibility & Open questions

7. Bake-out (1) Pull out PMT house (robot / manually)
Bake-out position
Connector panel not directly above TAN slot
Pull out PMT house (robot / manually)
Store temporarily in box below TAN
Or in bunker?
Insert dust cover for fused silica rods
Other
EDMS : “Max height over TAN 28cm (20 cm space on the top when extracting)”
Still valid?
<28 cm
Crane support
Gap for bakeout jacket (cover TAN surface)

8. Bake-out (2) New concept ok with TE-VSC (discussed with Nicolas Zelko)
Cover this part during bakeout
New concept ok with TE-VSC (discussed with Nicolas Zelko)
If needed, we can prevent heat loss during bakeout with custom- made “bake-out hat” to cover crane support
To be verified: connector panel temperature during bake-out
(Worst case: we can install a fan during bake-out to cool the connector panel)

9. Remote handling Robot handling of PMT-unit is feasible Pending
Robot gripper compatibility for installing/removing PMT unit
Two solutions for connector panels:
Combitac: ~200 N to engage
LEMO “all-in-one” connector (coax + HV): ~150 N to engage
Max robot push force: ~130 N
→ Lever mechanism needed to fully engage connector panels
Advantage Combitac: patch cable connectors (e.g. LEMO 00, LEMO Y) can be integrated directly in connector panel.
Robot handling of PMT-unit is feasible
Lifting PMT-unit ok (few kg)
Pull-push to engage/disengage connectors ok
Add guide rails/support plate to facilitate insertion of PMT unit

10. Integration: IP1 Seems feasible
TAN IP1 Left
Integration: IP1
Seems feasible
HL-LHC: Alignment cable on tunnel side of TAN will be installed (space reserved) → Avoid cables on this side.
HL-LHC: space reserved for alignment.
IP1 Left: View from wall side

11. Integration: IP5 (1)
More difficult
Crane
BRAN-A

12. BRAN connector panel should not collide with this
Integration: IP5 (2)

13. Summary, open questions
Any preferences on which BRAN-A to replace at IP1 & IP5: Left or right?
If not, we will keep the BRAN-As with best signal
Bakeout
Connector temperature during bakeout?
[N. Zelko: worst case: use a fan to cool connector during bakeout]
Can we temporarily store PMT housing below TAN/TAXN during bakeout?
Robot
PMT housing: ~5 kg weight not a problem
Grip to be defined
Push/pull force not enough to engage connector panels. Lever needed.
Integration
Max height of BRAN if left in TAB durin bake-out: 28 cm
Still valid?
IP5 crane compatibility
Space restrictions RP
Crane support remains above TAN surface during bake-out procedure. Any issues?
…anything else that we missed?