A traveling wave parametric amplifier has been integrated in the haloscope of the QUAX experiment. A search for dark matter axions has been performed with a high-Q dielectric cavity immersed in an ...8 T magnetic field and read by a detection chain having a system noise temperature of about 2.1 K at the frequency of 10.353 GHz. Scanning has been conducted by varying the cavity frequency using sapphire rods immersed into the cavity. At multiple operating frequencies, the sensitivity of the instrument was at the level of viable axion models.
The DARTWARS project has the goal of developing high-performing innovative traveling wave parametric amplifiers with high gain, large bandwidth, high saturation power, and nearly quantum-limited ...noise. The target frequency region for its applications is 5–10 GHz, where the expected noise temperature is below 600 mK. The development follows two different approaches, one based on Josephson junctions and one based on kinetic inductance of superconductors. This contribution mainly focuses on the Josephson traveling wave parametric amplifier, presenting its design, preliminary measurements and the test of homogeneity of arrays of Josephson junctions.
CYGNO is an international collaboration with the aim of operating a Image 3 optical time projection chamber (TPC) for directional Dark Matter (DM) searches and solar neutrino spectroscopy, to be ...deployed at the Laboratori Nazionali del Gran Sasso (LNGS). A Image 1/Image 2 (60/40) mixture is used, along with a triple Gas Electron Multiplier (GEM) cascade to amplify the ionisation signal. The scintillation produced in the electron avalanches is read out using a scientific complementary metal–oxide–semiconductor (sCMOS) camera. This solution has proven to provide very high sensitivity to interactions in the few Image 4 energy range. The inclusion of a hydrogen-based gas will offer an even lighter target, resulting in a more efficient energy transfer in a DM particle collision, and consequently, a lower detection threshold. Additionally, longer track lengths of light nuclear recoils are easier to detect with a clearer direction. However, the addition of such gas will contribute to quenching the scintillation, jeopardizing the TPC performance. In this work, we demonstrate the feasibility of adding 1% to 5% isobutane to the Image 1/Image 2 (60/40) mixture by measuring the respective absolute scintillation yield output. The overall scintillation produced in the charge avalanches is not drastically suppressed by quenching due to the isobutane addition. The presence of Penning transfer from excited He atoms to isobutane molecules increases the number of electrons in the avalanches, partially compensating for the loss of scintillation due to quenching. For the highest applied GEM voltage, the total number of photons produced in the avalanche per Image 4 deposited in the absorption region presents a decrease of only a factor of about three, from 2.30(20)×104 to 8.2(4)×103 Image 5, as the isobutane content increases from 0 to 5%. The quantification of the visible component of the scintillation shows that isobutane quenches both visible and ultraviolet (UV) photons emitted by Image 1/Image 2.
CYGNO is an international collaboration with the aim of operating a ▪ optical time projection chamber (TPC) for directional Dark Matter (DM) searches and solar neutrino spectroscopy, to be deployed ...at the Laboratori Nazionali del Gran Sasso (LNGS). A ▪/▪ (60/40) mixture is used, along with a triple Gas Electron Multiplier (GEM) cascade to amplify the ionisation signal. The scintillation produced in the electron avalanches is read out using a scientific complementary metal–oxide–semiconductor (sCMOS) camera. This solution has proven to provide very high sensitivity to interactions in the few ▪ energy range. The inclusion of a hydrogen-based gas will offer an even lighter target, resulting in a more efficient energy transfer in a DM particle collision, and consequently, a lower detection threshold. Additionally, longer track lengths of light nuclear recoils are easier to detect with a clearer direction. However, the addition of such gas will contribute to quenching the scintillation, jeopardizing the TPC performance. In this work, we demonstrate the feasibility of adding 1% to 5% isobutane to the ▪/▪ (60/40) mixture by measuring the respective absolute scintillation yield output. The overall scintillation produced in the charge avalanches is not drastically suppressed by quenching due to the isobutane addition. The presence of Penning transfer from excited He atoms to isobutane molecules increases the number of electrons in the avalanches, partially compensating for the loss of scintillation due to quenching. For the highest applied GEM voltage, the total number of photons produced in the avalanche per ▪ deposited in the absorption region presents a decrease of only a factor of about three, from 2.30(20)×104 to 8.2(4)×103▪, as the isobutane content increases from 0 to 5%. The quantification of the visible component of the scintillation shows that isobutane quenches both visible and ultraviolet (UV) photons emitted by ▪/▪.
The Time Projection Chamber (TPC) is an ideal candidate to finely study the charged particle ionization in a gaseous medium. Large volume TPCs can be readout with a suitable number of channels ...offering a complete 3D reconstruction of a charged particle track, that is the sequence of its energy releases in the TPC gas volume. Moreover, He-based TPCs are very promising to study keV energy particles as nuclear recoils, opening the possibility for directional searches of Dark Matter (DM) and the study of Solar Neutrinos (SN).
In this paper we report the analysis of the data acquired with a small TPC prototype (named LEMOn) built by the CYGNO collaboration that was exposed to a beam of 450 MeV electrons at the Beam Test Facility of National Laboratories of Frascati. LEMOn is operated with a He-CF4 mixture at atmospheric pressure and is based on a Gas Electron Multipliers amplification stage that produces visible light collected by the high granularity and very good sensitivity of scientific CMOS camera. This type of readout – in conjunction with a fast light detection – allows a 3D reconstruction of the electrons tracks. The electrons are leaving a trail of clusters of ionizations corresponding to a few keV energy release each. Their study leads to predict a keV energy threshold and 1–10 mm longitudinal and 0.1–0.3 mm transverse position resolution (sigma) for nuclear recoils, very promising for the application of optically read out TPC to DM searches and SN measurements.
Progress in the development of a KITWPA for the DARTWARS project Borghesi, M.; Barone, C.; Borghesi, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
February 2023, 2023-02-00, Letnik:
1047
Journal Article
Recenzirano
Odprti dostop
DARTWARS (Detector Array Readout with Traveling Wave AmplifieRS) is a three years project that aims to develop high-performing innovative Traveling Wave Parametric Amplifiers (TWPAs) for low ...temperature detectors and qubit readout (C-band). The practical development follows two different promising approaches, one based on the Josephson junctions (TWJPA) and the other one based on the kinetic inductance of a high-resistivity superconductor (KITWPA). This paper presents the advancements made by the DARTWARS collaboration to produce a first working prototype of a KITWPA.
DNA-triggered asymmetric ZnO nanoparticles Zimbone, M.; Musumeci, P.; Contino, A. ...
Colloids and surfaces. A, Physicochemical and engineering aspects,
01/2016, Letnik:
489
Journal Article
Recenzirano
Display omitted
•ZnO nanoparticles are obtained by using a DNA-templated synthesis.•The Zn2+ ion/DNA base pairs ratio has been used to tune the particles size and morphology.•DLS and SEM ...characterization highlights the formation of ZnO nanorods.
DNA/ZnO nanoparticles were obtained by using a biopolymer-assisted chemical bath growth process. A dynamic light scattering (DLS) technique was used to investigate the size and the growth kinetics of the nanoparticles and scanning electron microscopy (SEM) was used to characterize their morphology. The obtained nanoparticles were larger than the original DNA molecules indicating that DNA acted as a template for the growth of asymmetric DNA/ZnO nanoparticles. The growth kinetics and the particle size were tuned with the solution temperature and composition. Thus, the DNA characteristics can be used to build up different supra-molecular objects by covering with nano ZnO the different polynucleotide structures present in solution. The implications of this process have several positive benefits for building nano-scale device.
Objectives Biomarkers for psychiatric disorders are critical for patient stratification, premorbid diagnosis and personalized treatment. Our aim is to identify protein biomarkers for anxiety ...disorders by comparing the synaptic proteomes of a well-established mouse model of high (HAB), normal (NAB) and low (LAB) anxiety-related behavior. Methods We have compared protein expression levels using15 N metabolic labeling and quantitative proteomics. Mice were metabolically labeled through feeding with a15 N-enriched diet. Synaptosomes from unlabeled HAB and LAB mice were then compared with synaptosomes from15 N labeled NAB mice by quantitative mass spectrometry. Protein expression differences were validated with Western blots, enzymatic assays and in silico pathway analysis. Results We have identified numerous protein expression differences between HAB and LAB synaptosome proteomes. We observed alterations in energy metabolism pathways such as the Krebs cycle as well as in mitochondrial function. Furthermore, we detected changes in transport and phosphorylation processes. Conclusions We present an accurate proteomics platform for biomarker discovery in psychiatric disorders. We identified candidate biomarkers and pathways involved in anxiety pathophysiology. Our data provide the basis for the establishment of a biomarker panel that will shed light on anxiety pathophysiology and can be applied for optimal therapeutic intervention.
PDF
