The level to which the LPL should turned off is dependent on the several variables such as when does the system need to be turned on again, is the system being used for beamtime experiments or is it being used for chamber apparatus alignment, or is the system needed daily or needed only for a short period of time with days/weeks between needs. Several levels of the Turn Off/On procedure have been constructed to accommodate several different sets of circumstances. The levels are:
Short term LPL Turn off procedure-(critical): this procedure should be used when the LPL laser is being used for beam time experiments that have consecutive days of use. The laser turn off is minimal and the associated electronics and chillers remain on so that the laser oscillator, amplifiers, chillers, and power supplies maintain a thermal equilibrium. Total turn off time is a single Python command.
Short term LPL Turn off procedure (non-critical): This procedure should be used when the LPL is being used in consecutive days but not during beam time experiments. Examples of this may be when the LPL is used for 10Hz alignment operation, LPL laser maintenance, high energy shot testing for a variety of purposes, and/or any other circumstances that require frequent but not critical use. The laser turn off is more extensive, as chillers and power supplies are turned off. Total turn off time is approx 1 minute.
Long term LPL Turn off procedure-This procedure should be used when the anticipated periods between LPL use are days/weeks. There isn't a big difference in terms of steps and time to perform these steps from the steps noted in the Short term, non critical procedure above. The main difference in this procedure is the corresponding Turn on procedure. More steps and checks are made during the turn on if the LPL has been off for a period of time. Note that this is not a supplement procedure for the LPL Full Power shut down procedure that is typically used when there are planned power outages, holiday breaks, and other circumstances that require total shut down.