Daily Reports
Contents
Feb 1st, Tuesday
16:00-21:00; Ioannis: During maintenance, SN worked with MC on the problem of Ar1 resonances that show peaks around 3 Hz, 6 Hz and 9 Hz. They identified the Ar1 synthesizer as the source of the problem (by swapping the Ar1 and Ar3 synthetizers) and then replaced the faulty synthesizer with the last spare one. The problem is not visible anymore in the traces. We start the NIKA2 tuning after maintenance at 16:30 but we have a problem with Ar3 resonances. We restart several times the acquisition but we cannot tune Ar3 most of the times. After investigating numerous factors with JLS and contacting SN, we suspect that the increased temperature in the receiver cabin (up to 24 ºC) may be causing these problems. We turn off the Ar3 synthesizer, restart the temperature control in the cabin and use a fan for additional cooling of the crates (mainly 3). Around 20:30 the temperature in the cabin drops around 20 ºC. We restart the acquisition and Ar3 behaves normally (bad kids: 43/7/48 for Ar1/Ar2/Ar3), so we start with the observations. After pointing on Uranus we stop at 21:15 due to high wind. Observations restart at 22:00. Pointing and focus on Uranus but the beam is a bit elongated (17"x20" at 2mm and 11"x14" at 1mm), most likely because the antenna temperature evolution shows that the cooling of the structure is slower than usual today (highest temperature peak in the last few weeks). Will have to wait a bit longer for the antenna to fully relax.
21:00-03:00; Guilaine: Exceptional tau (0.15) but very bad shift. Electronic problems at the beginning. Then windy. Start observing Uranus at 22:10. Series of pointing/focus. Beams way too bad (today was the hottest day since 1 month). Change source to the very bright 0316+413 (since Uranus at too low elevation). New series of pointing/focus. Skydip [20220201s158]. 23:28, beams of 12.13 – 17.92 – 12.29. Launch 1 repet on source NGC1333-C7 (18 minutes), which is very close to 0316+413. Then again series of pointing/focus. Although the focus was at expected value, very degraded beams. 1:06: do a "retune". And restarting the whole acquisition (too much bad KIDS in array1). 2:00: pointing scan on 0552+398. Beams of 12.78, 18.33, 12.90. Got to project 137-21 to observe a low priority target (WB89-640). Scan 14 aborted at 03:12 since array 3 was lost (lost before 03:05, I don’t know exactly when, cannot see the acquisition screen remotely; scan 12 reduced with nk_rta and doesn’t seem weird).
03:00-09:00; Juan: At the beginning of the shift array 3 showed problems again -operator went up to the cabin to restart and cool down the synthetizer. We finally manage to observe for 2 hours or so, 2.5 repetions on PSZ2G122
Feb 2nd, Wednesday
Feb 3rd, Thursday
Feb 4th, Friday
Feb 5th, Saturday
Feb 6th, Sunday
Feb 7th, Monday