Shutters

2-BM has two x-ray shutters:

• Front End shutter upstream of 2-BM-A

• Mono shutter upstream of 2-BM-B

If you are not able to open the 2-BM-A or 2-BM-B shutters check the following:

• Shutter permit is enabled

• To open the B shutter: A and B stations are searched

• To open the A shutter: A station is searched

If you still cannot open the shutters check that the Equipment Protection System (EPS) is clear of errors. The EPS most frequent trips are caused by:

• Low He flow caused by low He pressure

• Vacuum bump casued by filter A moving with A shutter open

• Mirror high temperature caused by A slits too wide vertically or mirror to high in the beam