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Contents

  1. Run80 data processing
    1. Focus difference between the three arrays
    2. Beam maps analysis
    3. Study of the Ar1 and Ar2 beams at different focus values

Run80 data processing

Here we include the preliminary data reduction results of the re-commissioning NIKA2 run 80, as obtained at the telescope during this week (2026/03/24-31).

Focus difference between the three arrays

As of 2026/03/25 @01:25 UT.
The focus difference Ar1-Ar2 is roughly +1.00 mm.
The focus difference Ar3-Ar1 is roughly -0.05 mm.

Ar2 focus, scans 153-157 Ar1 focus, scans 153-157 Ar3 focus, scans 153-157

Ar2 focus, scans 163-167 Ar1 focus, scans 158-162 Ar3 focus, scans 158-162

Ar1 focus, scans 206-210 Ar3 focus, scans 206-210

Beam maps analysis

We have a new Ar3 and we need to characterize its geometry and its flat field. To this aim, on 2026/03/24 we took two beam maps focused on Ar1 (scans 20260324s169 and 177). The idea and hope is that the focus of Ar3 is roughly the same of that of Ar1, thanks to the March 10 intervention, and these beam maps will be good for our purpose.

We reduce the beam maps during the night between 2026/03/24 and 25.
Ar2 is out of focus and in order to be able to reduce it, we need to relax completely the constraints on its beam size and shape.
Ar1 is well on focus. The best beam map is 177. The other (169) has some problems at the lower edge for unknown reasons.
The Ar3 focus is decent. The array is missing Box S, as already known, and also several KIDs in Boxes M, N O (supposedly).

Below here you can see the geometry of the three Arrays as derived from the average of these two beam maps.

Ar2 beam maps 169 and 177 Ar1 beam maps 169 and 177 Ar3 beam maps 169 and 177

Study of the Ar1 and Ar2 beams at different focus values

On 2026/03/25, we carried out a series of calib_1scan with different focus values, starting from the Ar1 optimal focus to the Ar2 optimal focus, in steps of 0.2 mm. The aim was to study the change of MB flux (because the CAL is based on main beams), % of flux in the side lobes of the beam, and FWHM of the minor/major axes of the beam, as a function of focus (distance from the optimal position). Below here you find a table that summarizes our measurements and a series of plots produced by the PIIC monitors for Ar1 and Ar2.