Differences

This shows you the differences between two versions of the page.

--- on_sky_testing [2025/11/06 20:41] – holtz
+++ on_sky_testing [2025/11/21 15:46] (current) – holtz
@@ Line 1: / Line 1: @@
+====November 2025====
+Enclosure box installed 11/18-29. Required taking ferrule out to run through box, so location of traces, etc. changed. Installed 4 temperature sensors inside the box. Cleaned up room and put spare parts on shelf and in drawers.  Installed pass-thrus for cables on FPUs. Connected big dome fan to outlet #10.
+Spectrograph refocussed.
 ====Guiding tests====
@@ Line 15: / Line 21: @@
 {{:test:throughput.png?direct&400}}
-Clearly, there is some variation in the throughput, which is expected because of variations in transparency and also variations in seeing, leading to different fiber losses at the focal plane. However, the exposures with iodine are clearly significantly lower than those without iodine by a factor of roughly 2-3 (we've been using 2.5x the exposure time for iodine, and you can see in the middle panel that this roughly brings observed fluxes to be the same); i.e., iodine throughput is  ~40% of the non-iodine throughput.
+Clearly, there is some variation in the throughput, which is expected because of variations in transparency and also variations in seeing, leading to different fiber losses at the focal plane. However, the exposures with iodine (+ symbols) are clearly significantly lower than those without iodine (squares) by a factor of roughly 2-3 (we've been using 2.5x the exposure time for iodine, and you can see in the middle panel that this roughly brings observed fluxes to be the same); i.e., iodine throughput is  ~40% of the non-iodine throughput.
 The horizontal lines represent throughput achieved at the Tenerife SONG node for several different stars (median of many observations), I believe through iodinec cell, from some paper....