Krishna & Hugh

The attached 30 day plot shows the DRIFTMON Channel.  This indicates the DC position of the Hanging Beam in the BRS assembly.  The data are the relected position of the Diffraction Lines on the linear CCD array.  The range of operation is +-16000 and it drifted bad over the weekend.  Krishna arrived Tuesday AM and completed adjustment around noon.  The adjustment is made by shifting (yawing) an 8gram bar, maybe a couple inches long, attached at one end.  This is in vacuum so I don't have any photos.  In this case, the adjustment to put the drift back at a good position for the continued drift expected, was at most a few 10s of um at the end of the bar.  It took many tries and lots of patience.

It looks like Krishna got it into a pretty good place and we hope to tolerate the drift for a few weeks before this is again necessary.  It is suttle but it looks like the drift is abating but albeit quite slowly.