Procedure for direct beam measurement

It's very easy to take a direct beam. Just turn the filter wheel in the mirror box (AXIS SELECTOR on the focusing mirror controls set to position 4) to the .06 filter. Then move the readout system to a sample-to-IP distance of 100mm. Next, start the R-AXIS control software and choose direct beam adjustment, you'll get a picture of direct beam.

You can use R-AXIS display software to blow up the direct beam spot. If the maximum pixel is located at the center of the oval shaped spot with an intensity close to or above 100,000, and a light shawdow at top-right corner of the direct sopt with an intensity less than 5% of the peak intensity, you are getting a good beam. Otherwise, you may consider aligning the beam and/or aligning the goniometer stage again. If a complaint "direct beam too strong" pops up on the terminal, the filter wheel must have been set to open position. If you do not see direct beam at all, you must have chosen too thick a filter.