Harvard-Smithsonian Center for Astrophysics
XRT E2E Test
Day 20050608 Shift A
Test Conductor B. Podgorski
Shift Scientist J. Cirtain
VLI Focus Determination
The VLI focus measurements were completed along with the X-ray / VLI optical axis alignment tests. The VLI has been found to have a large depth of field, as is evidenced by the plot below that shows the RSS sigma widths of the VLI image as a function of focus position. This result is in line with the predictions of the engineering models. A number of images of the VLI spot are provided below.VLI and XRO Optical Axis Alignment
The X-ray / VLI optical axis alignment was found by first locating the centroid of the x-ray and visible light spots on the CCD. These two CCD positions were XRO (952, 1202) and VLI (935,1239).The offset of these two spots was determined and a correction for the distance between the visible light and x-ray source was applied. This was found to be 32.4 in x and 42.3 in y. Having made these calculations the alignment has been determined to be offset by 17.0 arcseconds.
VLI Focus position 0000.00 microns from initial configuration
VLI Focus position -2500.00 microns from initial configuration
VLI Focus position +2500.00 microns from initial configuration
This plot is of the RSS values of the gaussian widths at several focus positions (in units of focus steps).
