It is an accepted fact among the community of synchrotron users that about half of the data they collect on the synchrotrons for X-ray absorption or other spectroscopies is discarded. The main reason for this data rejection is the instability of the beam, which results from the orbital and angular changes in the ring, frequency dependent position and intensity fluctuations and long term drifts and sudden jumps in the beam. During our Phase I experiments, we found that we can compensate for the position fluctuations, keeping the sample in the beam within +-3O microns peak to peak, and up to 1 Hz fluctuation frequency. We are planning to use five of these instruments at SSRL (Stanford Synchrotron Radiation Laboratory, CA) NSLS (National Synchrotron Light Source, Brookhaven National Labs, Upton, L.I.) and the Photon Factory in Japan. To make the instrument universal, we will add dynode voltage feedback and high frequency vacuum compatible choppers to improve the range of the compensation frequency. The vacuum tests are necessary to check the performance of this instrument before any X-ray optical devices in the beam line. This way the fluctuations are due to the source only, and the output can be used to feedback the magnets for adjustments.
