The EPS is associated with E-300.

There are some files here (e.g. wiring drawing):

https://drive.google.com/drive/folders/1vGu9A1lhCVARxQv3Bn1h_7BTHzFGNyTj

POC is Christine Clarke

The currently installed firmware version is 5.1. Files are located on the V drive:

V:\TF\Facet II\Experiment Protection System  

Management

Machine Protection System (MPS) and Experiment Protection System (EPS) are non-credited controls as defined in SLAC ESH Manual. They are managed by the FACET facility.

System

Technical System Owner

Hazard Control System Owner

Accelerator Systems

Jerry Yocky

Lauren Alsberg

Experiment Systems

Carsten Hast

Christine Clarke

The Technical System Owners ensure that the hazards have been properly analyzed in their area and the correct risk-based controls have been specified to mitigate the hazards. The Technical System Owners ensure the integrity of the hazard control system. They designate hazard control system owners as appropriate to manage the systems.

EPS and MPS are checked out prior to use. These are common practices for FACET and have historically required coordination for the tests. Each system has its own checkout procedure. The procedure for the EPS is in the E-300 folder on the google drive:

https://drive.google.com/drive/folders/1Zx4V9V1z7fs-jBB2Zytv-ieNKolbR2HE

EPS Functions

Logic is shown below. In words... the EPS shuts the oven down (turns off heater, closes oven gate valves) in the event of

  • Pressure in oven too high
  • Pressure in oven too low
  • Loss of oven cooling water (over-temperature ~75 deg C)
  • Loss of beamline valve enable from MPS which may be due to one or more of:
    • Pressure high in FACET beamline
    • Differential Pumping System failure
    • Sector 19/20 access

The EPS closes the valve on the gas (helium bottle) when the pressure is too high.


The EPS only allows the EPICS shutter (note: there are two shutters- LSS and EPICS) in the S20 laser room to be open if

  • Position is Bypass line (as indicated by a mechanical limit switch) or
  • Position is Oven line (as indicated by a mechanical limit switch) and the oven gate valves are open

If neither of these conditions are not fulfilled, the EPICS shutter will close and not be able to be opened without putting the oven into one of those states.



The EPS has an interface to the MPS. The EPS only allows the electron beam if

  • Position is Bypass line (as indicated by a mechanical limit switch) or
  • The oven gate valves are open

Note: MPS already has its own mechanical limit switches, independent of the EPS, that will prevent electron beam if the position is not bypass or oven.

Expert Mode

An Expert mode is available for testing the control system and interlocks. This will be able to bypass conditions that allow the testing to proceed. There are no circumstances where it is foreseen that Expert mode will be entered during beam. Expert mode is controlled administratively. If you see the system in Expert mode and you did not expect this, stop. It is not safe to perform the experiment in Expert mode.


EPICS

LI20-Experiment and then click the E-300 button.


That brings you to this panel.

You can hit the reset button here. If there is a latched fault but the faulting condition no longer exists, hitting reset will clear the fault and should give permits back. If the faulting condition continues, the inputs will tell you which it is (in combination with the logic diagram above, this should be all you need to troubleshoot).

It's always ok to hit Reset. This will never cause an issue. 





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