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Processing of the June 2025 NIKA2 Re-Commissioning

PIIC reduction of the 20250612s43 beam-map

During the first half of run 73, only one beam map was taken.

SB, 2025/06/12 @18:20 LT: The beam map is scan 20250612s43. Results of a quick analysis of the beam map: the quality of the beam map (sky, telescope, focus, etc.) is unfortunately not good enough for making new (preliminary) Ar1 and Ar3 DAFs. Below you see the classic FOV beam-map figure. Ar3 is much worse than Ar1 likely because the best focus difference that affects it. Nevertheless, also Ar1 is unusable.

On the bright side: the central KID (Ar2, KC016, PIIC id 363) is definitely back! Yay!

20250612s43, Ar2 20250612s43, Ar1 20250612s43, Ar3

PIIC reduction of the 20250616-18 beam-maps

During the second half of run 73, six beam maps have been taken, namely:

20250616s179

focus Ar2-1

3C273

20250616s181

focus Ar3

3C273

20250617s49

focus Ar2-1

2251+158

20250617s51

focus Ar3

2251+158

20250618s83

focus Ar2-1

2251+158

20250618s90

focus Ar3

2251+158

SB reduces them of 2025/06/24-....

Impressions:

The plots below show the best beam map for each of the three arrays. For Ar3, I inlcude both the "best" beam maps of run 73. As you can see the result of Ar3 is still sub-optimal.

My feeling is that the focus offset of Ar3 wrt the other reached now a critical level, provided that this is the only problem and that there are no other issues with some other optical element (the polarizer? the arrays "z" angle wrt their optical axis? else?). If confirmed, I think that this should be fixed.

Therefore, I decide that I do not apply any change sto the DAFs RPPs. In practice, we only have one decent Ar1 beam map in this run 73. The Ar2 RPPs are already in good and centered on the central KID (Ar2 RPPs of NIKA2 run 68). For Ar3 I do not have any good beam map to make good RPPs refereed to the same central KID.

Therefore, I decide to keep the same RPP scheme used during run 73: Ar2 centered on the good old central KID; Ar1 and Ar3 produced in run 72 and affected by an offset wrt Ar2. When there will be good beam maps for Ar1 and Ar3 (at least 2 beam maps each), I will make again the RPPs for Ar1 and Ar3, centered on the good central KID. For now we keep the offset between Ar2 and Ar1/3. When you'll see this offset at the telescope DO NOT PANIC. It's all ok, and it's on purpose. For further explanations see these notes in the run 73 daily report, as well as the emails exchange of 2025/06/10.

2025/05/26 I have therefore installed this mixed set of DAFs as default, keeping the pure-run-72 version as backup (write me if needed).

20250618s83, Ar2 20250618s83, Ar1 20250617s51, Ar3 20250618s90, Ar3

Run73processing (last edited 2025-06-26 14:09:49 by NikaBolometer)