Operations: Oops all Modes!
Machine modes are the backbone to the PPS rack and ACS system. If you want to send beam anywhere in the facility you must first make sure the PPS rack is in the correct machine mode. There are five total modes from Mode 0 (M0) to M4. What separates Machine modes from other modes is that machine modes are tied directly to PPS controlled beam inhibit devices. Each mode is linked to a specific area in the facility and inhibit devices that prevent beam from being sent past the specified area. We will go through each machine mode and their specifics.
This machine mode restricts the beam itself, while in this mode neither source HV can be turned on.
This machine mode restricts beam to ULEBT by controlling the beam stop located at FE_LEBT:BD_D0824, before E-Bend D0833 but after FC D0814, and the power supplies for both VLEBT E-Bends. When in this mode both E-Bends are off and beam stop D0824 is inserted, blocking beam from entering the tunnel. In this mode the Linac cannot be secured, put into Beam Permit, or put into Power Permit; but all other areas can be secured.
This machine mode restricts beam to the tunnel by controlling the BDS dipole power supplies (D5578). When in this mode the BDS dipole cannot be turned on limiting beam to the tunnel and front end only. In order to secure the tunnel, put the tunnel into Beam Permit, or put the tunnel into Power Permit you must have the PPS in M2. It is a prerequisite for all these Linac states. As M1 all other areas can be secured.
This machine mode restricts beam to the Target and Transfer Hall by controlling the S3 and N4 beam stops. This mode is a prerequisite for putting the Target Facilities into Ready for Beam.
This machine mode allows for beam to be sent into the user vaults. There is no BID for this mode as there is no need to limit beam destinations after the user end stations. The S3 and N4 beam stops are still able to be inserted to allow for some destination control, it is also important to note that if a vault is unsecured the wall plug and beam stop will be inserted.
Beam inhibit modes are different from machine modes in one important way, they do not inhibit the beam in any meaningful way. At their core beam inhibit modes are checklists that help you make sure that you are in the correct configuration of devices before sending beam to a specific destination. There are 13 total modes, with some sub-modes for Mode 2 and Mode 6 (source and FSEE modes), that contain configuration directions to send beam from ULEBT to BTS19.
We really don't ever use these. They exist and there is documentation about how to use them here, but it is common practice to use mode 08 FE commissioning.