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| We observed from 9:00UT to 13:00pm, but the wind is too strong so we stopped observation several times. We performed few pointing and one off_geometry on Venus and on DR21OH, 1 skydip. The skydip seems to work well. Here and example (with TAU 225GHz 0.24). [Do we know the scaling relation between the opacity from the NIKA skydip at 1mm with its large bandpass and the taumeter value at 225GHz with its narrow bandpass of only 500MHz ? (CK)] [From my calculation, the scaling relation between tau NIKA1mm and IRAM tau225 changes versus mmwv. Considering a measured tau1mm=0.29 from skydips, the scaling relation with tau225 (tau225/tau1mm) is about 0.65 (AC)] |
We observed from 9:00UT to 13:00pm, but the wind is too strong so we stopped observation several times. We performed few pointing and one off_geometry on Venus and on DR21OH, 1 skydip. The skydip seems to work well. Here and example (with TAU 225GHz 0.24). [Do we know the scaling relation between the opacity from the NIKA skydip at 1mm with its large bandpass and the taumeter value at 225GHz with its narrow bandpass of only 500MHz ? (CK)] [From my calculation, the scaling relation between tau NIKA1mm and IRAM tau225 changes versus mmwv. Considering a measured tau1mm=0.29 from skydips, the scaling relation with tau225 (tau225/tau1mm) is about 0.65 (AC)] |
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Contents
January 20th 2015
9h00 UT: Santiago stars operations to cool down the NIKA cryostat in contact with Andrea and Martino from Grenoble
STATUS OF THE INSTRUMENT
9h00 UT: Connection with automate restored. It does not work well, we lost connection few times in the morning. We probably need to change but for the moment we choose to continue.
9h00 UT: Status of the Camera pulse tube : J5=352mbar
09h30 UT: Santiago connected the cryostat to the leak detector.
10h00 UT: Pumped the dilution circuit (until Jpi=8x10e-3mbar). Trap pumped and emptied.
10h30 UT: Warm impedance test: about 30mbar/min at 3bar. Consistent with the last cooling down.
11h00 UT: Circulation throught the capillar starts.
12h00 UT: Leak test: OK
13h30 UT: M5 and M6 mounted. Optical alignment of the cryostat with Santiago, OK.
14h00 UT. Pulse Tube on. Low pressure and High pressure OK. Mixture circulates at 2.95bar (J4) and 950mbar (J2 with preref on).
16h20 UT: Lowering to 850mbar. Keep this value for the night.
17h40 UT: T4K=272K. Tstill=280K.
January 21st 2015
Cooling down still going on. Tests on acquisition software in Grenoble still going on.
STATUS OF THE INSTRUMENT
06h00 UT: T4K=43K. Tstill=47K.
06h00 UT: Lowering to 550mbar.
08h20 UT: T4K=23.6K. Tstill=30K. Flux set at 360mbar
10h00 UT: T4K=11K. Tstill=18K. Flux at 280mbar
11h30 UT: T4K=7K. Tstill=8K. Flux at 200mbar. We pump directly from ev17 (ev17, ev19,ev1,ev6 open, ev5 closed). The slope is much better.
12h30 UT: T4K=5.5K. Tstill=4.5K. Ready to condensate, but we lost connection with the automate. Waiting the end of the lunch at IRAM to call somebody.
13h30 UT: T4K=5.4K. Tstill=4.27K, R_BM=1.35kOhm Flux at 170mbar. Condensation Started.
15h50 UT: Turbo on. ev11 closed with 40mbar on J5.
17h00 UT: 84mK!!!
18h00 UT: Stop compressor. Injection pressure very low.
January 22nd 2015
Nothing happened. The cryostat is still cold at 84mK with injection pressure low.
January 23rd 2015
- Martino, Nicolas and Andrea arrived to the telescope. The control room is arranged with all the NIKA computers. Mini mac 2 seems to work weel so we chose to put all the instruments here (nikel1, nikel2, antenna, elvin, control).
- Arrays are connected. Tuning is not working well for the moment so we optimized detectors with traditional balayage procedure.
- Mppsync is connected.
- 150mK stage regulated at 150mK
- We got the telescope at 7pm and started to observe almost right away. We could find the focus in two iterations:
- We then derived a first OTF geometry to compute kid offsets. Then, choosing kid 494 as the reference detector (like in the previous run), we could derive the Nasmyth offsets required to center the planet on this reference kid, and redo a geometry.
- We could check on a bright quasar that we were indeed centered and that our reduction scripts were still ok.
- We also did two skydips that went fine as far as acquisition is concerned. We'll look at them in detail tomorrow.
January 24th 2015
We observe from 9:00UT to 13:00pm. The opacity is 0.1-0.2, the wind is strong close to the telescope limit. We installed the polarisation facilities choosing to dedicate the observations to polarisation. Few warnings:
1) Sincronisation of nikels is very low.
2) Sincronisation between nikels and mppsync seems not to work correctly. It takes a lot of time and the shift changes in time.
3) Need to cut at least 2x2cmm the aluminium plate of the noise in order to be able to plug the canon connector on pol modulator.
4) Tuning procedure: From a tuning to an other the bad pixels could increase (o decrease) a lot, especially for the 1mm channel.
5) Tuning procedure: even without "tuning auto" a tuning can be sent.....why?
January 25th 2015
We observed from 9:00UT to 13:00pm, but the wind is too strong so we stopped observation several times. We performed few pointing and one off_geometry on Venus and on DR21OH, 1 skydip. The skydip seems to work well. Here and example (with TAU 225GHz 0.24).
[Do we know the scaling relation between the opacity from the NIKA skydip at 1mm with its large bandpass and the taumeter value at 225GHz with its narrow bandpass of only 500MHz ? (CK)]
[From my calculation, the scaling relation between tau NIKA1mm and IRAM tau225 changes versus mmwv. Considering a measured tau1mm=0.29 from skydips, the scaling relation with tau225 (tau225/tau1mm) is about 0.65 (AC)]
