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Mapping millimetre continuum emission has become a key issue in modern multi-wavelength astrophysics. In particular, spectrum imaging at low-frequency resolution is an asset for characterising the clusters of galaxies via the Sunyaev–Zel’dovich effect. In this context, we have built a ground-based spectrum-imager named KIDs Interferometer Spectrum Survey (KISS). This instrument is based on two 316-pixel arrays of Kinetic Inductance Detectors (KID) cooled to 150 mK by a custom dilution refrigerator-based cryostat. By using Ti–Al and Al absorbers, we can cover a wide frequency range between 80 and 300 GHz. In order to preserve a large instantaneous field of view ∼ 1 ∘ , the spectrometer is based on a Fourier transform interferometer. This represents a technological challenge due to the fast scanning speed that is needed to overcome the effects of background atmospheric fluctuations. KISS is installed at the QUIJOTE 2.25 m telescope in Tenerife since February 2019 and is currently in its commissioning phase. In this report, we present an overview of the instrument and the latest results.

Clusters of galaxies are used to map the large-scale structures in the universe and as probe of universe evolution. They can be observed through the Sunyaev-Zel’dovich (SZ) effect. In this respect the spectro-imaging at low resolution frequency is an important tool, today, for the study of cluster of galaxies. We have developed KISS (KIDs Interferometer Spectrum Survey), a spectrometric imager dedicated to the secondary anisotropies of the Cosmic Microwave Background (CMB). The multi-frequency approach permits to improve the component separation with respect to predecessor experiments. In this paper, firstly, we provide a description of the scientific context and the state of the art of SZ observations. Secondly, we describe the KISS instrument. Finally, we show preliminary results of the ongoing commissioning campaign.

New IRAM KID array 2 (NIKA2) is a camera dedicated to millimeter-wave astronomy based upon kilopixel arrays of kinetic inductance detectors [ 1 ] (KID). The pathfinder instrument, NIKA [ 2 ], has already shown state-of-the-art detector performance. NIKA2 builds upon this experience but goes one step further, increasing the total pixel count by a factor ∼ 10 while maintaining the same per pixel performance. For the next decade, this camera will be the resident photometric instrument of the Institut de Radio Astronomie Millimetrique (IRAM) 30 m telescopes in Sierra Nevada (Spain). In this paper, we give an overview of the main components of NIKA2 and describe the achieved detector performance. The camera has been permanently installed at the IRAM 30 m telescope in October 2015. It will be made accessible to the scientific community at the end of 2016, after a 1-year commissioning period. When this happens, NIKA2 will become a fundamental tool for astronomers worldwide.

We describe the preliminary on-sky results of the KIDs Interferometer Spectrum Survey (KISS), a spectral imager with a 1 deg field of view (FoV). The instrument operates in the range 120–180 GHz from the 2.25m Q-U-I JOint TEnerife telescope in Teide Observatory (Tenerife, Canary Islands), at 2 395m altitude above sea level. Spectra at low resolution, up to 1.45 GHz, are obtained using a fast (3.72 Hz mechanical frequency) Fourier transform spectrometer, coupled to a continuous dilution cryostat with a stabilized temperature of 170mK that hosts two 316-pixel arrays of lumped-element kinetic inductance detectors. KISS generates more than 3 000 spectra per second during observations and represents a pathfinder to demonstrate the potential for spectral mapping with large FoV.We give an overall description of the spectral mapping paradigm and we present recent results from observations, in this paper.

A Forward Calorimeter (FoCal) has been proposed as part of the ALICE upgrades for data taking from 2029 onwards. The FoCal will feature a sampling electromagnetic calorimeter segmented into 110 towers supplemented by a hadron calorimeter. The electromagnetic calorimeter will be composed of 20 passive layers of tungsten absorber interleaved with 18 active layers of low-granularity silicon pad sensors and two layers of high-granularity pixel detectors. Each pad layer will be read out by 110 silicon pad sensors of 72 channels, amounting to a total of 1980 sensors. This paper describes, from front-end to back-end, the electronics developed to instrument a tower prototype composed of 18 silicon pad sensors as well as a design proposal for the full-detector readout system.

We present the data-processing algorithms and the performance of CONCERTO (CarbON CII line in post-rEionisation and ReionisaTiOn epoch) in continuum by analysing the data from the commissioning and scientific observations. The beam pattern is characterized by an effective FWHM of 31.9 \\(\\pm\\) 0.6\" and 34.4 \\(\\pm\\) 1.0\" for high-frequency (HF) and low-frequency (LF) bands. The main beam is slightly elongated with a mean eccentricity of 0.46. Two error beams of \\(\\sim\\)65\" and \\(\\sim\\)130\" are characterized, enabling the estimate of a main beam efficiency of \\(\\sim\\)0.52. The field of view is accurately reconstructed and presents coherent distortions between the HF and LF arrays. LEKID parameters were robustly determined for 80% of the read tones. Cross-talks between LEKIDs are the first cause of flagging, followed by an excess of eccentricity for \\(\\sim\\)10% of the LEKIDs, all located in a given region of the field of view. On the 44 scans of Uranus selected for the absolute photometric calibration, 72.5% and 78.2% of the LEKIDs are selected as valid detectors with a probability >70%. By comparing Uranus measurements with a model, we obtain calibration factors of 19.5\\(\\pm\\)0.6 [Hz/Jy] and 25.6\\(\\pm\\)0.9 [Hz/Jy] for HF and LF. The point-source continuum measurement uncertainties are 3.0% and 3.4% for HF and LF bands. The RMS of CONCERTO maps is verified to evolve as proportional to the inverse square root of integration time. The measured NEFDs for HF and LF are 115\\(\\pm\\)2 mJy/beam\\(\\cdot\\)s\\(^{1/2}\\) and 95\\(\\pm\\)1 mJy/beam\\(\\cdot\\)s\\(^{1/2}\\), obtained using CONCERTO data on the COSMOS field for a mean precipitable water vapour and elevation of 0.81 mm and 55.7 deg. CONCERTO demonstrates unique capabilities in fast dual-band spectral mapping with a \\(\\sim\\)18.5' instantaneous field-of-view. CONCERTO's performance in continuum is perfectly in line with expectations.

We present the performance of a full-length prototype of the ALICE Forward Calorimeter (FoCal). The detector is composed of a silicon-tungsten electromagnetic sampling calorimeter with longitudinal and transverse segmentation (FoCal-E) of about 20\\(X_0\\) and a hadronic copper-scintillating-fiber calorimeter (FoCal-H) of about 5\\(\\lambda_{\\rm int}\\). The data were taken between 2021 and 2023 at the CERN PS and SPS beam lines with hadron (electron) beams up to energies of 350 (300) GeV. Regarding FoCal-E, we report a comprehensive analysis of its response to minimum ionizing particles across all pad layers. The longitudinal shower profile of electromagnetic showers is measured with a layer-wise segmentation of 1\\(X_0\\). As a projection to the performance of the final detector in electromagnetic showers, we demonstrate linearity in the full energy range, and show that the energy resolution fulfills the requirements for the physics needs. Additionally, the performance to separate two-showers events was studied by quantifying the transverse shower width. Regarding FoCal-H, we report a detailed analysis of the response to hadron beams between 60 and 350 GeV. The results are compared to simulations obtained with a Geant4 model of the test beam setup, which in particular for FoCal-E are in good agreement with the data. The energy resolution of FoCal-E was found to be lower than 3% at energies larger than 100 GeV. The response of FoCal-H to hadron beams was found to be linear, albeit with a significant intercept that is about factor 2 larger than in simulations. Its resolution, which is non-Gaussian and generally larger than in simulations, was quantified using the FWHM, and decreases from about 16% at 100 GeV to about 11% at 350 GeV. The discrepancy to simulations, which is particularly evident at low hadron energies, needs to be further investigated.

The CONCERTO spectral-imaging instrument was installed at the Atacama Pathfinder EXperiment (APEX) 12-meter telescope in April 2021. It has been designed to look at radiation emitted by ionised carbon atoms, [CII], and use the \"intensity Mapping\" technique to set the first constraints on the power spectrum of dusty star-forming galaxies. The instrument features two arrays of 2152 pixels constituted of Lumped Element Kinectic Inductance Detectors (LEKID) operated at cryogenic temperatures, cold optics and a fast Fourier Transform Spectrometer (FTS). To readout and operate the instrument, a newly designed electronic system hosted in five microTCA crates and composed of twelve readout boards and two control boards was designed and commissioned. The architecture and the performances are presented in this paper.

This paper reports the development and testing of n-type silicon pad array detectors targeted for the Forward Calorimeter (FoCal) detector, which is an upgrade of the ALICE detector at CERN, scheduled for data taking in Run~4~(2029-2034). The FoCal detector includes hadronic and electromagnetic calorimeters, with the latter made of tungsten absorber layers and granular silicon pad arrays read out using the High Granularity Calorimeter Readout Chip~(HGCROC). This paper covers the Technology Computer-Aided Design (TCAD) simulations, the fabrication process, current versus voltage (IV) and capacitance versus voltage (CV) measurements, test results with a blue LED and \\(^{90}\\)Sr beta source, and neutron radiation hardness tests. IV measurements for the detector showed that 90\\% of the pads had leakage current below 10~nA at full depletion voltage. Simulations predicted a breakdown voltage of 1000~V and practical tests confirmed stable operation up to 500~V without breakdown. CV measurements in the data and the simulations gave a full depletion voltage of around 50~V at a capacitance of 35~pF. LED tests verified that all detector pads responded correctly. Additionally, the 1\\(\\times\\)1 cm\\(^2\\) pads were also tested with the neutron radiations at a fluence of \\(5\\times10^{13}\\) 1~MeV~n\\(_{eq}\\)/cm\\(^2\\).