A Pyrex capillary of either 1 mm or 2 mm internal diameter is used to transfer the radiation from the exit slit to the experiment. Details of the Mirrors and gratings available are given below. As the length and diameter of the capillary is changed for each individual experiment these figures should be viewed as guides only. Other important properties of the monochromator output are polarisation and higher order contamination. Recent measurements of these can be found in the station manual.
Some filters are available to reduce the higher order contamination.
The benchmark figures are measurements taken under standard conditions. When this is not possible a day is scheduled for 'changeover' - this allows the physical removal of apparatus to take place. Optical alignment of users' apparatus and the pumping of the exit slit housing and users' equipment are counted in the allocation of beamtime and should not take more than one or two days. Users should note that if they let their chambers up to atmospheric pressure then it will take up to 12 hours for the exit slit housing to pump down to acceptable pressures and the station will be considered operational during this time even if the users apparatus can achieve working pressures faster. Last update 12 July 1996.