D22
Large dynamic range small-angle diffractometer
D22 Interlock
This document describes how to manipulate the interlock system for the beam shutter and the access to the sample zone and selector bunker.
For other items, refer to the D22 Manual. See also the D22 documentation.
1. Philosophy of the interlock system
The role of the interlock system is to make sure that the beam is switched off whenever someone has to access one of the sensible zones (sample area and selector bunker/collimation area). The system chosen at the ILL is electro-mechanical. The key allowing to switch the beam on is kept prisoner in the beam shutter box while the beam is on.
When the beam is off, the two electro-magnetic locks at the sample zone entrance and the entrance behind the detector tube are both released.
A sound warns anyone present in the controlled area when a beam opening is attempted so that he/she can push the red emergency button situated in the sample area. Acting on the emergency button closes the beam and releases the door lock(s).
2. Beam Shutter Control
The Beam Shutter Control box (CCO D22) is situated left of the main sample zone entrance gate of D22.
The beam shutter key enters the slot horizontally (position UNLOCK GATE)
To open the beam,
Visually inspect each part of the experimental zone to ensure that no one is present and that all the radiological protections are in place. You must press the green beam opening authorisation button in each hidden zone before you can open the beam.
- Close the gate(s)
Nb: The beam opening authorisation button is activated during a short time which varies according to the instrument, so you must close the gate as soon as you have pressed the green button. - If both gates are correctly locked and the authorisation button is still active, the green LED "GATE LOCKED" on the shutter control box will come on.
- Turn the key 45 ° clockwise to the SHUTTER CLOSED/GATE LOCKED position.
- Turn the key to the shutter opening authorised position. The yellow "shutter opening authorised" light will come on.
- Press the shutter open button. The beam will open after the audible warning.
- If you close the beam and do not enter the zone equipped with the Beam opening authorisation button, you will not need to reactivate it before reopening the beam.
To close the beam,
- turn the key 45 deg. counter-clockwise to position SHUTTER CLOSED.
- wait for the green light (SHUTTER CLOSED)
3. Sample zone access
3.1. Opening the sample zone
Access to the sample zone only necessitates to turn the beam-shutter key in two steps of 45 degrees counter-clockwise from the vertical to the horizontal (UNLOCK GATE) position. As a consequence of this, the electro-mechanical locks on the sample-zone door and on the instrument back door are released.
3.2. Closing the sample zone
Follow the first steps of the procedure "To open the beam" above.
4. Access to the back door of the sample zone
Certain manipulations require access to the back door of the sample zone. As for the sample-zone gate, the beam must be closed for opening the back door. It is a good idea to take the beam-shutter key with you (but not to forget to return it after your intervention).
5. Access to the selector bunker
ATTENTION: Access to the selector bunker is restricted. The procedure is described in a note that is part of the "dossier de securite" of D22.
The bunker door is "condamnee" with a pad-lock. The opening of the selector bunker door is also included in the security loop of the instrument.
The selector bunker is reached through the back door of the sample zone.
Web document produced by Roland May, ILL Grenoble (07-Junr-2005)