3.1 Beam Shutter and Interlocks on GEM

The Shutter

The beam shutter on GEM may be controlled either from a box in the cabin, or from a second duplicate box located outside the cabin.

The two square buttons on the left may be used to open the shutter (upper button) or close the shutter (lower button). It is necessary to raise the flap on these buttons before they can be pressed. The circular button between these two buttons is for testing the display bulbs.

The shutter is a very heavy piece of steel and it takes some time for it to be raised or lowered. If another ISIS instrument is already opening or closing their shutter, then your open/close request will be put into a queue until they have finished. This is because the power supply for the shutter motors has enough power to run only one motor at a time.

The Interlocks

The interlocks must be made before the shutter can be opened.

Last updated on 31 Jul 2002 by Alex Hannon (a.c.hannon@rl.ac.uk)