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In this mode, the fridge level should be maintained above the 'Heat Exchanger Bottom' (see the Purple curve on the top-left graph of the screenshot below), and the separator is kept at cold with 20slm return flow. IMPORTANT: If you see the Heat-Ex Top resistance (purple curve) starts increasing, then reduce the number of turns on the fridge run-valve using the "Fridge Valve Panel" VI on the CCP

If the system is currently on Hold Mode, then you can follow the steps for Transitioning from the Hold mode to the Production Mode

Configuration / Things to maintain

Microwaves	ON (see Microwave Operation page for instructions how to maintain the polarization)
NMR	It should be on "Take Data" (check with the Target Expert on Shift if there are issues)
Fridge	The entire pump system should be running See Roots pumps PLC interface page Maintain the fridge LHe level at the Heat-Ex Bottom by adjusting the fridge-run-valve. See these links (a) Fridge Fill Procedure (you will have to plan ahead of time to set the separator flow to 20slm 30 mins before you expect to fill the fridge) (b) How to identify the fridge LHe level is at Heat-Ex Bottom The fridge pressure should be below 1 Torr because all roots should be ON. Discuss with the Target Expert when to switch from the Production Mode to the Hold Mode: Transitioning from the Production Mode to Hold Mode
Magnet	Ensure the magnet has enough LHe. Ensure Magnet LN2 level is above 50%, if not refill it.
QT System	Ensure the purifier LN2 level and the magnet shield LN2 levels are above 50%, if not refill it. See Helium Liquefier (QT) System Summary page to identify where to look at for those LN2 levels. Ensure both liquefiers produce LHe with the rate of ~ 4 L/ hr (with an uncertainty +/- 0.3). If not, then contact the Target Expert on shift. You can use https://e906-gat1.fnal.gov/data-summary/e1039/target-par-preset/target-LHe-prod-rate.php Check LCW outlet Temperatures from the cold-head compressors and ensure all those temperatures are below 95 F. If any of those are. > 100 F then, report to the Target Expert immediately and follow Target Expert's instructions.

Outlet FlowsOutlet Flows (nominal)

	Outlet Flow (in slm)	Run Valve / Bypass Valve	How to check and control
Fridge	Nominal 45slm (can be higher (depends on the microwave power + beam)	Fridge Run valve → 1 turn0.5 turns Bypass valve → CLOSED	How to control the Fridge Return flow
Separator	20	N/A	How to control the Separator Return flow
Magnet	~7 (on pressure PID at 0.9 psi)	N/A	(link to a page)

Other useful instructions:

Steps for Transitioning from the Production Mode to the Hold Mode

Space shortcuts

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Old Version 4

New Version Current

Key

A sample screenshot of the fridge in the Production Mode

################# I think the links below are too much information for the Target Operator manual, can be suitable for the target expert manual ####

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