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Friday 14th February 2014

10h00. Xavier and Alessandro arrive at the telescope. Among the NIKA2 collaboration, Philippe André too is on the mountain. Made a new parameter file FOR THE 2MM array ONLY (definitely need the sky for the 1mm).

Old configuration (2mm): DAC gains: 20-23-20-28-35. General niveau: 5.

New configuration (2mm): DAC gains: 20-23-20-38-55. General niveau: 5. Pixels 17-25: niv 6. Pixels 55 to 56: niv 6. Pixels 73 to 78: niv 4. Pixels 96 to 108: niv 6.

Figure. Left: old config (2mm), right: new config (2mm). MADE WITH WINDOW ON CRYOSTAT, TO BE CONFIRMED (see tomorrow) WITH LN2. DON'T USE THIS BRAIN!!

Strong (strange) 12Hz noise on some (e.g. 4-5) pixels. See tomorrow daily report for more on that.

Saturday 15th February 2014

8h00. Theoretical start of the run. Winds peaking at 40m/s, telescope stopped probably the whole morning. The ski station is closed due to the wind.

It's so windy:

9h00. LN2 in front of the cryostat window to play at least with the resonances. "Decalage" found by the new "restore tones" is good. -22kHz and -1KHz at 1 and 2mm respectively, indicating that the param file run8.txt is well representative of LN2 temperature.

NEW PARAM FILE MADE ON LN2

LN2 configuration (1mm): DAC gains: 20-23-20-30-40. General niveau: 6. Individual levels to be adjusted on the sky but it'll be difficult. Bad pixels: too difficult, see offline data analysis.

LN2 configuration (2mm): DAC gains: 20-23-20-33-50. General niveau: 5. Pixels KB021,30,41,42,111 at niv. 6. Pixels KB073-80,83,88,111,114-116,119-120 at niv.4. Bad pixels: KB033,75,76,88,109,110.

Parameter file made on LN2 on 15-Feb-2014

Figure. Top: 1mm new config (LN2). Bottom: 2mm new config (LN2). MADE WITH LN2 close to pupil, TO BE CONFIRMED ON THE SKY. When we can get it.

13h00. Wind hits 42m/s (150km/h). The telescope basement is a block of ice. Put again the window on the cryostat, "restore tones" works very well. Found a shift of -393kHz and 100kHz.

15h00. Went to the cabin to try understanding the monochromatic lines (e.g. 8Hz, 12Hz) on some pixels. Difficult to conclude since it apperars that even with the window closed (but without Al tape) you see large signals due to reflections of body temperature through the HDPE then onto the curved inner surface of the window and into the cryostat.

For comparison with the previous run7, we show below the noise spectra measured with the window on (equivalent rto roughly 180K background).

Figure. Left: 1mm noise. Right: 2mm noise. MADE WITH WINDOW ON CRYOSTAT.

Here is a photo of NIKA ready to observe (courtesy of Bilal Ladjelate)

Sunday 16th February 2014

11h00. Our theoretical slot begins. Wind, snow, fog. Nothing is going to happen today. New SW version uploaded by Alain.