1. November technical stop activities:
General Plan
SDD: check connections of pressure regulators (Monday 7th morning)
SSD: 2 Temperature sensors disconnection (Tuesday 8th)
SPD: replace the faulty pump and test the new one (Monday and Tuesday)
SPD: clean sectors in PP4:
mechanical filters surface cleaning (Stainless steel twisted wire)
+ C6F14 cleaning
ultrasound piezo-ceramic probes + C6F14 cleaning

2. SSD temp sensors disconnection
2 inlet temperature sensors show an offset of about 2-3 degrees due to an electrical problem: this can trigger an interlock and switch off the plant.
Our plan is to switch off the SDD and SSD Tuesday (8/11) early morning, then:
mask the alarm of T sensors disconnection (plant running)
disconnect the power supply of the 2 T sensors (plant running)
The water temperature setpoint (without heaters) will be 0,5 -1 degree below the nominal one. No impact on the detector operation.
The water temperature will be monitored by the temperature sensors installed before the detector. In case of problem the interlock will close an relevant loop.

3. SPD Pump replacement Spare pump to be prepared before the TS.
The pump will be installed on Monday afternoon after RP results (procedure agreed with Sebastien Roussee).
New pump (17b): tests could start Monday late afternoon: leave the pump running for 24 hours with some loops open.
Recovery can start again from Tuesday afternoon.
The plant can be restarted on Thursday morning after having vacuumed all the loops.

4. SPD Sectors cleaning strategy
Mechanical cleaning:
Stainless steel twisted wire 2 mm: “tap” the filter in PP3 while cleaning with
C6F14 in counter flow
Time needed: minutes per sector
following
Ultrasounds piezo-ceramic probes + C6F14 cleaning (still validating the procedure
Time needed: 12 hours per sector
Possible sequence: 6,7 9,3,5 (starting Monday afternoon, the last sector will be cleaned Wednesday night).

5. Cleaning equipment Higher platform in PP4 In front of the L3 magnet
Normal power supply needed: install an extension from the cleaning machine position to power the piezo-ceramic probes.
Higher platform in PP4
In front of the L3 magnet
40 W
1000 W