ADTC
ALPHA: Chris showed the anticipated works during YETS, which include operation of the 2 traps, working around the power cuts (secured tests on 8th Jan, AUG tests on 11-12th Jan and AUL tests on 13th Jan), and the water + lHe disruption (24-28th Feb). Minor crane operations anticipated.
AEgIS: Gosia explained that the YETS works will focus on repairing the heat leak. The magnet will probably not be cooled down before end of April. The positronium trap is cooled down with tap water in an open loop, that is not concerned by demi water disruption. This suboptimal system will have to be addressed during LS3 (not considered yet).
BASE: Barabara explained that the YETS time is of outmost importance for the precision measurements. Therefore, it is required to limit as much as possible any disturbance, such as crane movements, magnetic field ramps, or magnet lHe filling (causing pressure rise in the gHe return line). It is therefore asked to all actors in the AD hall to try to concentrate these operations in the maintenance periods of BASE: Monday, Wednesday and Friday from 8:30 to 14:30. Outside of these periods, all operations can be disruptive for precision measurements. This will reman valid till the restart of AD recommissioning with beam (09th April)
It is also mentioned that the vibrations in GBAR Linac cooling pipes, beyond the discomfort that they cause, are expected to be detrimental to the accuracy of measurements. It is therefore requested that CV changes the pressure reducer to limit the noise, Action: Nicolas Roget.
ASACUSA: Eric indicates that the access to laser room is presently problematic. Bertrand will check the situation. More lasers are being added in the laser room. ASACUSA2 will be partly dismantled, involving crane movements, and cool down is expected to take place in March. Care will be taken to respect requests from BASE as much as possible.
PUMA: Clara shows that the trap magnet will be cooled (cryocoolers) at some point, but probably not be powered before the end of the YETS. Minor craning activities expected. All activities can be done working around the planned services disruptions. The installation of the connectors on the supply cables require the UPS to be in its final position. Date to be communicated later.
GBAR: Jean-Yves indicates that the pbar and positron traps will be moved and reinstalled during the YETS, and the second laser room will be connected electrically. The maintenance of the LINAC will necessitate cooling water, but as the small pump will be in operation at this stage, not much noise is expected. It would be ideal if the pressure reducer is replaced before the big pump comes back in operation during W9. GBAR will then operate with Hminus as of the restart of ELENA around the 3rd of March.
Low Voltage Substation replacement: Mickael shows the numerous consequences of the works that are ongoing and will be pursued on the LV substation. In principle, no impact is expected in the experimental areas, nor on the machine networks, but rather on general services in technical zones. Among the main disturbances, the main AD cranes will be off service on 18-20th Feb, and the AD hall lighting will be reduced to the minimal safety level on 19th Feb. No visit will be allowed on that day. This schedule will be reminded in the next meetings and reminders on power cuts will be sent in advance.