The Neel IRAM KIDs Array (NIKA) is a fully integrated measurement system based on kinetic inductance detectors (KIDs) currently being developed for millimeter wave astronomy. The instrument includes ...dual-band optics allowing simultaneous imaging at 150 GHz and 220 GHz. The imaging sensors consist of two spatially separated arrays of KIDs. The first array, mounted on the 150 GHz branch, is composed of 144 lumped-element KIDs. The second array (220 GHz) consists of 256 antenna-coupled KIDs. Each of the arrays is sensitive to a single polarization; the band splitting is achieved by using a grid polarizer. The optics and sensors are mounted in a custom dilution cryostat, with an operating temperature of ~70 mK. Electronic readout is realized using frequency multiplexing and a transmission line geometry consisting of a coaxial cable connected in series with the sensor array and a low-noise 4 K amplifier. The dual-band NIKA was successfully tested in 2010 October at the Institute for Millimetric Radio Astronomy (IRAM) 30 m telescope at Pico Veleta, Spain, performing in-line with laboratory predictions. An optical NEP was then calculated to be around 2 X 10--16 W Hz--1/2 (at 1 Hz) while under a background loading of approximately 4 pW pixel--1. This improvement in comparison with a preliminary run (2009) verifies that NIKA is approaching the target sensitivity for photon-noise limited ground-based detectors. Taking advantage of the larger arrays and increased sensitivity, a number of scientifically relevant faint and extended objects were then imaged including the Galactic Center SgrB2 (FIR1), the radio galaxy Cygnus A, and the NGC1068 Seyfert galaxy. These targets were all observed simultaneously in the 150 GHz and 220 GHz atmospheric windows.
•We reviewed the literature on experience and management of intracranial chordoma.•The weighted mean estimate of 5-year OS was 77.4% (95% CI, 72.9–81.7%).•The weighted mean estimate of 5-year PFS was ...49.4% (95% CI, 41.6–57.3%).•A wide variety of surgical approaches were utilised.•The total complication rate was 28.5% (95% CI, 18.4–39.8%).
Chordomas are rare neoplasms of the axial skeleton, with a predilection for the clival region. The lack of data about intracranial chordomas has led to inconsistent reporting of their clinical behavior and management principles. We performed a systematic review and meta-analysis with the aim of reporting on clinical behavior and management in the literature. We performed an electronic search of the MEDLINE, EMBASE, LILACS, Web of Science, Cochrane, and CINAHL databases. We included studies of patients with intracranial chordoma that had undergone surgical management with 5-year data available. The weighted mean estimate of 5-year OS was 77.4% (95% CI, 72.9–81.7%) whilst the 5-year PFS estimate was 49.4% (95% CI, 41.6–57.3%). A wide variety of surgical approaches were utilised, with transcranial approaches being the commonest. Surgeons achieved gross total resection in 29.4% of cases (95% CI, 17.6–43.0%), Sub-total resection in 60.9% of cases (95% CI, 40.2–79.8%) and partial resection in 19.7% (95% CI; 11.9 to 28.9%). The total complication rate was 28.5% (95% CI, 18.4–39.8%), with the commonest being new cranial nerve palsy (weighted mean 11.1%, 95% CI, 7.11–15.7%). Our review demonstrates that a wide range of management options exist in the literature. These should be tailored to each patient based on factors including tumoral location, local involvement and capabilities of the surgical team. The outcomes of chordoma management have largely been stable with no improvement despite improvements in modern surgical techniques.
The STEREO experiment Allemandou, N.; Almazán, H.; Sanchez, P. del Amo ...
Journal of instrumentation,
07/2018, Letnik:
13, Številka:
7
Journal Article
Recenzirano
Odprti dostop
The STEREO experiment is a very short baseline reactor antineutrino experiment aiming at testing the hypothesis of light sterile neutrinos as an explanation of the deficit of the observed neutrino ...interaction rate with respect to the predicted rate, known as the Reactor Antineutrino Anomaly. The detector center is located 10 m away from the compact, highly 235U enriched core of the research nuclear reactor of the Institut Laue Langevin in Grenoble, France. This paper describes the STEREO site, the detector components and associated shielding designed to suppress the external sources of background which were characterized on site. It reports the performances in terms of detector response and energy reconstruction.
Context.
Wide-field spectrometers are needed to deal with current astrophysical challenges that require multiband observations at millimeter wavelengths. An example of these is the KIDs ...Interferometer Spectrum Survey (KISS), which uses two arrays of kinetic inductance detectors (KIDs) coupled to a Martin-Puplett interferometer (MPI). KISS has a wide instantaneous field of view (1 deg in diameter) and a spectral resolution of up to 1.45 GHz in the 120–180 GHz electromagnetic band. The instrument is installed on the 2.25 m Q-U-I JOint TEnerife telescope at the Teide Observatory (Tenerife, Canary Islands), at an altitude of 2395 m above sea level.
Aims.
This work presents an original readout modulation method developed to improve the sky signal reconstruction accuracy for types of instruments for which a fast sampling frequency is required, both to remove atmospheric fluctuations and to perform full spectroscopic measurements on each sampled sky position.
Methods.
We first demonstrate the feasibility of this technique using simulations. We then apply such a scheme to on-sky calibration.
Results.
We show that the sky signal can be reconstructed to better than 0.5% for astrophysical sources, and to better than 2% for large background variations such as in “skydip”, in an ideal noiseless scenario. The readout modulation method is validated by observations on-sky during the KISS commissioning campaign.
Conclusions.
We conclude that accurate photometry can be obtained for future KID-based interferometry using the MPI.
Abstract
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 Kinetic 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.
A prototype of digital frequency multiplexing electronics allowing the real time monitoring of microwave kinetic inductance detector (MKIDs) arrays for mm-wave astronomy has been developed. It ...requires only 2 coaxial cables for instrumenting a large array. For that, an excitation comb of frequencies is generated and fed through the detector. The direct frequency synthesis and the data acquisition relies heavily on a large FPGA using parallelized and pipelined processing. The prototype can instrument 128 resonators (pixels) over a bandwidth of 125 MHz. This paper describes the technical solution chosen, the algorithm used and the results obtained.
Context. We have developed a dual-band (140 and 220 GHz) mm-wave imaging camera based on superconducting kinetic inductance detector (KID) arrays. Each array contains 132 superconducting resonators ...whose resonant frequencies are shifted by mm-wave photons absorption. The read out is achieved with a single electronics chain per band, taking advantage of the intrinsic KID frequency-domain multiplexability. The arrays are easily scalable and well adapted for future large format focal plane instruments. NIKA (formerly Néel IRAM KID Array, now New IRAM KID Array) has been specifically designed for the IRAM 30 m telescope at Pico Veleta, and is one of the first instruments using KIDs to have made measurements of astronomical sources. Aims. In this Letter we describe the solutions adopted to improve the calibration accuracy and the sensitivity of the instrument, and we report on the outcome of the 3rd NIKA observing run of October, 2011. Methods. We use a fast electronic modulation of the readout tone for each KID pixel in order to linearize the instrument calibration, which we track with measurements of planets. We also adopt a new design of the KIDs, sensitive to both polarizations, to increase the amount of radiation absorbed and thus the optical efficiency of the system. Results. We measured an average sensitivity on the sky of 21 mJys0.5 per beam at 140 GHz and 140 mJys0.5 at 220 GHz in the best observing conditions (τ220 ≃ 0.2) after atmospheric noise decorrelation. The sensitivity at 220 GHz was limited by the atmospheric attenuation and loading as well as a reduction in the spectral bandwidth due to a misplaced filter. We found the repeatability in the photometry over the entire observing run to be better than 10% in both bands, thus demonstrating a significant improvement over the previous runs. We also find good agreement between NIKA measurements of faint astronomical sources and previous measurements of the same sources.
Experiments aiming at measuring the neutron electric dipole moment (nEDM) are at the forefront of precision measurements and demand instrumentation of increasing sensitivity and reliability. In this ...paper, we report on the development of a dedicated acquisition and control electronics board for the nEDM experiment at the Paul Scherrer Institute (PSI) in Switzerland. This multifunction module is based on a FPGA (Field Programmable Gate Array) which allows an optimal combination of versatility and evolution capacities.
Drought events may induce mangrove mortality and dieback events worldwide as a result of climate extremes. As mangroves sequester large quantities of carbon, quantifying the losses of these stocks ...following climate disturbances may guide wetland governance strategies globally. In Southeast Brazil, we determined the total ecosystem carbon stocks (TECS) of pristine mangroves that were up to 1851 Mg of carbon per hectare (Mg C ha−1), which are the highest stocks measured from South American and raising estimates of Brazil's mangrove TECS to 0.52 Pg C. A mangrove mortality event in the same estuary resulted in a 14.6 % decrease in TECS (270.5 Mg C ha−1) and loss of 20 % of mangrove soil carbon within less than 2-years. Carbon dioxide emissions from this impact were 992.8 Mg CO2e ha−1, which are slightly lower than emissions from land use disturbances on mangroves worldwide. Our results suggest that climate effects on mangroves can become significant sources of greenhouse gases globally.
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•The pristine mangroves in SE Brazil stock over 1851 Mg C ha−1.•Climate-relate impacts resulted in 14.6 % decrease in total ecosystem carbon stock.•The mangrove dieback lead to 40.4 % of carbon losses on the 0–30 cm soil.•Carbon dioxide emissions from the climate-relate impact was 992.8 Mg CO2e ha−1.•The Brazilian mangroves hold 5 % (0.52 Pg C) of the global mangrove ecosystem stock.
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.
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