<html><body><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000"><div data-marker="__QUOTED_TEXT__"><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000" data-mce-style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000;"><div>Hello,<br></div><br><div>This afternoon, Mindy, Amanda, and I tested three additional spots on Mirror 4 with the reflectivity test station. <br></div><br><div>The location of the three additional spots are noted in the updated "Mirror 4 reflectivity test locations.JPG" that is attached. We were not able to measure any spots where the worst smudges are on the bottom of the mirror surface due to the placement of the test station's optics and the size of the darkbox.<br></div></div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000" data-mce-style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000;"><br data-mce-bogus="1"></div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000" data-mce-style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000;">Attached are the excel sheets for all five spots: two from yesterday and three from today.<br data-mce-bogus="1"></div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000" data-mce-style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000;"><br><div>Spot 3 was on an area of the mirror that looked smudged. However, the results for this mirror unexpectedly gave a reflectivity of 92% - 94% for wavelengths 420 nm to 650 nm. This was higher than spots 4 (89% - 91%) and spot 5 (88% - 90%).<br></div><div><br data-mce-bogus="1"></div><div>Best regards,<br data-mce-bogus="1"></div><div>Tyler<br data-mce-bogus="1"></div><br><br><hr id="zwchr"><div><b>From: </b>"Tyler Lemon" <tlemon@jlab.org><br><b>To: </b>"dsg-rich" <dsg-rich@jlab.org><br><b>Sent: </b>Thursday, August 17, 2017 5:00:00 PM<br><b>Subject: </b>[Dsg-rich] RICH spherical mirror 4 reflectivity test<br></div><br><div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000" data-mce-style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000;"><div>Hello,<br></div><br><div>This morning Mindy and I took reflectivity measurements for RICH spherical Mirror 4.<br></div><br><div>As the mirror will soon be shipped to CMA, we wanted to finish taking reflectivity measurements for Mirror 4 to give us a reference for the mirror when it returns to JLab.<br></div><br><div>We measured Mirror 4's reflectivity in two spots. The location of these spots are noted in the attached "Mirror 4 reflectivity test locations.JPG".<br></div><br><div>Just looking at the data, Mirror 4's reflectivity for spot 1 is between 87% - 89%.</div><br><div>For spot 2 the reflectivity is between 79% and 81%. The lower reflectivity for spot 2 could be from an area of poor surface quality or a misalignment in the test station optics.<br></div><br><div>Best regards,<br></div><div>Tyler<br></div></div><br>_______________________________________________<br>Dsg-rich mailing list<br>Dsg-rich@jlab.org<br>https://mailman.jlab.org/mailman/listinfo/dsg-rich</div></div><br></div></div></body></html>