NIKA January 20th, 2014 / S1
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2014-01-21
- Cryostat Temperature: 150mK (regulated, RMS ripple 0.03mK).
- Arrays status tonight: 128 pixels 2mm - 1Hz noise; 196 pixels 1mm 3-5Hz noise
Modulation frequency: 8kHz 1mm, 5kHz 2mm
Opacity is measured with the new taumeter at 225 GHz
Nasmyth offsets : 0, 0
Set pointing : 0, 0
Set Focus : -2.40 mm
Preliminary remark:
- We are afraid that the minimal background is actually not the best radio alignment, indeed if the NIKA pupil is misaligned such that it sees the sky next to M2 it's possible that the background is lower than seeing only M2 (the other hypothesis with the pupil misalignment is that it sees the edge of M1 diffraction the 300K from the ground, so increase the background on the array). Only way to know now is to look at a source (Uranus) with M5 on the "best laser (alignment) position", then look at the source with M5 on the "minimal background" position and compare the beams: the stronger and narrower beam is the one with the best illumination of the telescope pupil.
- Quick description of the session: Test an upgrade of data acquisition. Try to find if the radio alignment was correct. Choose reference detector. Pointing and Focus on Ref det. Pointing session.
Scan |
UT |
Source |
Command |
Az |
El |
Pointing X, Y, Focus |
Tau225 |
Comment |
176 |
16h45 |
Uranus |
Track |
180 |
56 |
0,0,-2.4 |
0.28 |
Track30 |
177 |
16h55 |
Uranus |
Track |
180 |
56 |
0,0,-2.4 |
0.28 |
Track60 |
178 |
16h57 |
Uranus |
Cross |
180 |
56 |
0,0,-2.4 |
0.28 |
Noelvin data |
179 |
16h59 |
Uranus |
Cross |
180 |
56 |
0,0,-2.4 |
0.28 |
Noelvin data |
180 |
17h00 |
Uranus |
Cross |
180 |
56 |
0,0,-2.4 |
0.28 |
|
181 |
17h03 |
Uranus |
Cross |
180 |
56 |
0,0,-2.4 |
0.28 |
source close to array edge |
182 |
17h05 |
Uranus |
Cross |
180 |
56 |
0,0,-2.4 |
0.28 |
M5 on "best laser position" (see preliminary remark above) no source |
183 |
17h07 |
Uranus |
Cross |
190 |
55 |
0,0,-2.4 |
0.28 |
no source (additional problem: sky gets cloudy) |
184 |
17h07 |
Uranus |
Cross |
190 |
55 |
0,0,-2.4 |
0.28 |
back to M5 on "minimal background position" => no source |
185 |
17h19 |
Uranus |
Cross |
193 |
55 |
0,0,-2.4 |
0.28 |
offsets 2.9 40.8 Nasmyth to get source at array center => no source |
186 |
17h19 |
Uranus |
Cross |
193 |
55 |
0,0,-2.4 |
0.28 |
offsets 0 0 Nasmyth => see source |
185 |
17h28 |
Uranus |
Cross |
193 |
55 |
0,0,-2.4 |
0.28 |
offsets -2.9 -40.8 Nasmyth to get source at array center => see source |