The AGS snake magnet will be used this weekend, however there are some operations requirements that are associated with it. The Magnet cannot hold liquid Helium level with all cryo coolers running and the super conducting level probe tends to make discrete jumps in reading rather than indicating a steady decrease in Helium level. These issues are under investigation but we can still operate.
· Testing indicates the magnet level reading holds at about 85% for about 24 hours following a refill, then the level quickly drops to 74% in nearly one jump. An 85% reading indicates the magnet is filled.
· The magnet was filled today at 4 PM and there is currently one nearly full 500 liter dewar connected to the fill line.
· The magnet must not be powered if the level indicated is below 80%. If the level drops below 80% refill using the helium dewar stationed near the A18 house. See refill procedure in CCR
· Do not refill while the magnet is operating. If a refill is needed while the snake is operating contact MCR and request they power down. Once the refill is complete contact MCR and inform them they can resume powering.
· If the level drops below 80% when the magnet is not operating, immediately begin a refill. Inform MCR they cannot power the magnet until the refill is complete.
· If the magnet quenches, the relief valves in the tunnel will lift. Heaters installed on these valves will warm them back up and they will reseal. When it appears on the camera display in the control room that the valves have resealed, begin to refill using the Helium dewar. Contact MCR when the refill is complete. See quench recovery procedure in CCR
If there are any questions, contact myself Bill or Andy