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X9 User Guide |
The X7C (X9) beam is a tertiary particle beam that provides hadrons, electrons or
muons of energies between 5 and 75 GeV. It is a prolonged version of the
X7 beam,
directing particles to the CHORUS experiment. This beam is a part of the
West Area test beam complex, that is derived from the H3 secondary beam.
For more detailed information the users are referred to one
of the
West Area
liaison physicists.
Note that from 1997 on this prolongation has been integrated into the X7 beam.
Please check also the X7 User Guide.
Please nothe that in June 1998, when the CHORUS calibration runs have come to an end, the prolongation will be dismounted.
1. General information about the beam
As stated above the X9 prolongation to the Chorus experiment is now considered part of
the X7 beam. tThe operation of the X7 beam in general is described in the
X7 User Guide.
As the X7 beam is upgraded in the 1997-1998 shutdown, the prolongation to Chorus had to
be redesigned as well. A description of the new prolongation, both design and operation,
is available on the Web.
For completeness, the old X9 User Guide has still be left available.
2. Control of the beam
The X7 beam is controlled through the Experimental Areas computers. The control system is based on an emulation of the NODAL language, implemented in C and Unix on HP/UX computers. The user interface is a tree structure, which comes up automatically when you boot the beam X-terminal in the WA95 control room. It can also be started 'manually' from the nodal environment by typing
RUN <212>TREE
Please note that the control system recognises (normally) only upper case.
To escape from the tree program, you may type Ctrl-C.
3. Access to the beam
Frequently you will need access to the region of the beam in order to modify, adjust, move or repair your apparatus. This is done through the command
Type in your name when the program asks for it. Then go to the door marked PPE097, wait till the lights 'ACCESS WITH KEY' start flashing, push the button with a key on it, take the key for which the red diode lights up and use it to open the door and enter the zone.
When you come out of the zone you should put back the key and turn it into its normal position. When the last person has finished, check that nobody is left in the zone, put back the last key, push the red button marked 'END OF ACCESS' (do not forget - otherwise you will not get beam!) and go back to your barrack. Then go to your beam terminal and type
type in your name (you are responsible for persons left in the zone!) and wait till beam comes back. It is wise to check that all magnet currents are OK by typing
If the magnets do not switch on properly, then try "ACCESS/BEAM ON" again or try to set them to their BIM.0 value by TUNE / SET. If the problem persists, call the CRW operators.
This access procedure should be used whenever somebody wants to approach the beam axis or whenever the beam is sent to the displaced calorimeter position without the calorimeter being displaced. The exact conditions are described in a memo by G.R. Stevenson/TIS to WA95. The responsibility for respecting this procedure is with the WA95 experiment.
Important : In the door itself, next to the door knob, there is a round 'pastille' with a dim red light in it, which should be pushed in emergency cases only! Whenever this button is pushed, it requires an operator to come over and reset the emergency stop manually. This may cause significant loss of beam time, in particular when the operators are working on another problem elsewhere!
| The rules for access to experimental areas at the SPS (recently modified) are defined by the SL Radiation Safety Officer. They are available on the Web. Also available is a detailed and illustrated description of how to take and end an access. |
4. Further problems