-- Obsolete -- Status of Polarizer - new cooling system

Both the He and Na cells are ready to be turned on when required. The Na cell has a new cooling system for the trap and collector. Instead of air cooling, we now use an oil circulator set at 105 deg C and it is now running. This should give much more stable operation of the trap and collector temperatures. Note that there is negligible heat load on the trap and collector until the Na vapour flow becomes large, starting at around Tnozzle = 380 deg C.

The Na cell relies on radiative heating by the "reservoir".  The radiant heat is absorbed by the "nozzle".  As indicated by the quotation marks, the EPICS labels "reservoir" and "nozzle" no longer accurately reflect de real functions of those components, due to a constantly improving design.

The nominal operating point for the Na cell is Tnozzle = 400 deg C. The heater temperatureTres has to be larger thanh this, probably about 440 deg C, to provide enough heating power.