Yuhang and Marc

As reported in the last logbook 3084, where we found the beam size changed significantly. Fortunately, we have a reported beam parameter measurement four years ago (logbook 1079). Thus, to compare, we measured again the beam parameter (relative to the first hole after the 2-inch BS). The new measurement is shown in Fig.1. According to this new measurement, we made a comparison of beam waist positions on the scheme as Fig. 2. We note that although the beam waist position is measured to be very different, the beam waist size is the same as before.