Aluminum-Titanium Bilayer for Near-Infrared Transition Edge Sensors

Transition-edge sensors (TESs) are single photon detectors attractive for applications in quantum optics and quantum information experiments owing to their photon number resolving capability. Nowadays, high-energy resolution TESs for telecommunication are based on either W or Au/Ti films, demonstrating slow recovery time constants. We report our progress on the development of an Al/Ti TES. Since bulk aluminum has a critical temperature (Tc) of ca. 1.2 K and a sufficiently low specific heat (less than 10(-4) J/cm³K²), it can be employed to produce the sensitive material for optical TESs. Furthermore, exploiting its high Tc, Al-based TESs can be trimmed in a wider temperature range with respect to Ti or W. A first Al/Ti TES with a Tc ≈ 142 mK, investigated from a thermal and optical point of view, has shown a response time constant of about 2 μs and single photon discrimination with 0.34 eV energy resolution at telecom wavelength, demonstrating that Al/Ti films are suitable to produce TESs for visible and NIR photon counting.Transition-edge sensors (TESs) are single photon detectors attractive for applications in quantum optics and quantum information experiments owing to their photon number resolving capability. Nowadays, high-energy resolution TESs for telecommunication are based on either W or Au/Ti films, demonstrating slow recovery time constants. We report our progress on the development of an Al/Ti TES. Since bulk aluminum has a critical temperature (Tc) of ca. 1.2 K and a sufficiently low specific heat (less than 10(-4) J/cm³K²), it can be employed to produce the sensitive material for optical TESs. Furthermore, exploiting its high Tc, Al-based TESs can be trimmed in a wider temperature range with respect to Ti or W. A first Al/Ti TES with a Tc ≈ 142 mK, investigated from a thermal and optical point of view, has shown a response time constant of about 2 μs and single photon discrimination with 0.34 eV energy resolution at telecom wavelength, demonstrating that Al/Ti films are suitable to produce TESs for visible and NIR photon counting

Quantum characterization of superconducting photon counters

We address the quantum characterization of photon counters based on transition-edge sensors (TESs) and present the first experimental tomography of the positive operator-valued measure (POVM) of a TES. We provide the reliable tomographic reconstruction of the POVM elements up to 11 detected photons and M=100 incoming photons, demonstrating that it is a linear detector.Comment: 3 figures, NJP (to appear

Micro-SQUIDs based on MgB2 nano-bridges for NEMS readout

We show the results obtained from the fabrication and characterisation of MgB2 loops with two nano-bridges as superconducting weak links. These ring structures are made to operate as superconducting quantum interference devices and are investigated as readout system for cryogenics NEMS resonators. The nano-constrictions are fabricated by EBL and ion beam milling. The SQUIDs are characterised at different temperatures and measurements of the noise levels have been performed. The devices show high critical current densities and voltage modulations under applied magnetic field, close to the critical temperatures

Randomised phase II trial of CAPTEM or FOLFIRI as SEcond-line therapy in NEuroendocrine CArcinomas and exploratory analysis of predictive role of PET/CT imaging and biological markers (SENECA trial): A study protocol

Introduction Patients with metastatic or locally advanced, non-resectable, grade 3 poorly differentiated gastroenteropancreatic (GEP) and lung neuroendocrine carcinomas (NECs) are usually treated with in first-line platinum compounds. There is no standard second-line treatment on progression. Accurate biomarkers are needed to facilitate diagnosis and prognostic assessment of patients with NEC. Methods and analysis The SEcond-line therapy in NEuroendocrine CArcinomas (SENECA) study is a randomised, non-comparative, multicentre phase II trial designed to evaluate the efficacy and safety of folinic acid, 5-fluorouracil and irinotecan (FOLFIRI) or capecitabine plus temozolomide (CAPTEM) regimens after failure of first-line chemotherapy in patients with lung NEC and GEP-NEC. Secondary aims are to correlate the serum miRNA profile and primary mutational status of MEN1, DAXX, ATRX and RB-1 with prognosis and outcome and to investigate the prognostic and predictive role of the Ki-67 score and 18-fluorodeoxyglucose positron emission tomography/computed tomography (18 F-FDG PET/CT) or 68 Ga-PET/CT. The main eligibility criteria are age ≥18 years; metastatic or locally advanced, non-resectable, grade 3 lung or GEP-NECs; progression to first-line platinum-based chemotherapy. A Bryant and Day design taking into account treatment activity and toxicity was used to estimate the sample size. All analyses will be performed separately for each treatment group in the intention-to-treat population. A total of 112 patients (56/arm) will be randomly assigned (1:1) to receive FOLFIRI every 14 days or CAPTEM every 28 days until disease progression or unacceptable toxicity or for a maximum of 6 months. Patients undergo testing for specific biomarkers in primary tumour tissue and for miRNA in blood samples. MiRNA profiling will be performed in the first 20 patients who agree to participate in the biological substudy. Ethics and dissemination The SENECA trial, supported by Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST), was authorised by the locals Ethics Committee and the Italian Medicines Agency (AIFA). Results will be widely disseminated via peer-reviewed manuscripts, conference presentations and reports to relevant authorities. The study is currently open in Italy. Trail registration number NCT03387592; Pre-results. EudraCT-2016-000767-17. Protocol version Clinical Study Protocol Version 1, 7 November 2016

The TRILL project: increasing the technological readiness of Laue lenses

Hard X-/soft Gamma-ray astronomy (> 100 keV) is a crucial field for the study of important astrophysical phenomena such as the 511 keV positron annihilation line in the Galactic center region and its origin, gamma-ray bursts, soft gamma-ray repeaters, nuclear lines from SN explosions and more. However, several key questions in this field require sensitivity and angular resolution that are hardly achievable with present technology. A new generation of instruments suitable to focus hard X-/soft Gamma-rays is necessary to overcome the technological limitations of current direct-viewing telescopes. One solution is using Laue lenses based on Bragg's diffraction in a transmission configuration. To date, this technology is in an advanced stage of development and further efforts are being made in order to significantly increase its technology readiness level (TRL). To this end, massive production of suitable crystals is required, as well as an improvement of the capability of their alignment. Such a technological improvement could be exploited in stratospheric balloon experiments and, ultimately, in space missions with a telescope of about 20 m focal length, capable of focusing over a broad energy pass-band. We present the latest technological developments of the TRILL (Technological Readiness Increase for Laue Lenses) project, supported by ASI, devoted to the advancement of the technological readiness of Laue lenses. We show the method we developed for preparing suitable bent Germanium and Silicon crystals and the latest advancements in crystals alignment technology.Comment: arXiv admin note: text overlap with arXiv:2211.1688

Evaluation of biomimetic hyaluronic-based hydrogels with enhanced endogenous cell recruitment and cartilage matrix formation

Biomaterials play a pivotal role in cell-free cartilage repair approaches, where cells must migrate through the scaffold, fill the defect, and then proliferate and differentiate facilitating tissue remodeling. Here we used multiple assays to test the influence of chemokines and growth factors on cell migration and cartilage repair in two different hyaluronan (HA)-based hydrogels. We first investigated bone marrow Mesenchymal Stromal Cells (BMSC) migration in vitro, in response to different concentrations of platelet-derived growth factor-BB (PDGF-BB), chemokine ligand 5 (CCL5/RANTES) and stromal cell-derived factor 1 (SDF-1), using a 3D spheroid-based assay. PDGF-BB was selected as most favourable chemotactic agent, and MSC migration was assessed in the context of physical impediment to cell recruitment by testing Fibrin-HA and HA-Tyramine hydrogels of different cross-linking densities. Supplementation of PDGF-BB stimulated progressive migration of MSC through the gels over time. We then investigated in situ cell migration into the hydrogels with and without PDGF-BB, using a cartilage-bone explant model implanted subcutaneously in athymic mice. In vivo studies show that when placed into an osteochondral defect, both hydrogels supported endogenous cell infiltration and provided an amenable microenvironment for cartilage production. These processes were best supported in Fibrin-HA hydrogel in the absence of PDGF-BB. This study used an advanced preclinical testing platform to select an appropriate microenvironment provided by implanted hydrogels, demonstrating that HA-based hydrogels can promote the initial and critical step of endogenous cell recruitment and circumvent some of the clinical challenges in cartilage tissue repair. Statement of significance: The challenge of articular cartilage repair arises from its complex structure and architecture, which confers the unique mechanical behavior of the extracellular matrix. The aim of our research is to identify biomaterials for implants that can support migration of endogenous stem and progenitor cell populations from cartilage and bone tissue, in order to permanently replace damaged cartilage with the original hyaline structure. Here, we present an in vitro 3D spheroid-based migration assay and an osteochondral defect model, which provide the opportunity to assess biomaterials and biomolecules, and to get stronger experimental evidence of the not well-characterized dynamic process of endogenous cells colonization in an osteochondral defect. Furthermore, the delicate step of early cell migration into biomaterials towards functional tissue engineering is reproduced. These tests can be used for pre-clinical testing of newly developed material designs in the field of scaffold engineering

Optical design and performance simulations for the 1.49 keV beamline of the BEaTriX X-ray facility

The BEaTriX (Beam Expander Testing X-ray) facility, now operational at INAF-Brera Astronomical Observatory, will represent a cornerstone in the acceptance roadmap of Silicon Pore Optics (SPO) mirror modules, and will so contribute to the final angular resolution of the ATHENA X-ray telescope. By expansion and collimation of a microfocus X-ray source via a paraboloidal mirror, a monochromation stage, and an asymmetric crystal, BEaTriX enables the full-aperture illumination of an SPO mirror module with a parallel, monochromatic, and broad (140 mm × 60 mm) X-ray beam. The beam then propagates in a 12 m vacuum range to image the point spread function of the mirror module, directly on a focal plane camera. Currently the 4.51 keV beamline, based on silicon crystals, is operational in BEaTriX. A second beamline at 1.49 keV, which requires a separate paraboloidal mirror and organic crystals (ADP) for beam expansion, is being realized. As for monochromators, the current design is based on asymmetric quartz crystals. In this paper, we show the current optical design of the 1.49 keV beamline and the optical simulations carried out to predict the achievable performances in terms of beam collimation, intensity, and uniformity. In the next future, the simulation activity will allow us to determine manufacturing and alignment tolerances for the optical components

Gamma-Ray Burst observations by the high-energy charged particle detector on board the CSES-01 satellite between 2019 and 2021

In this paper we report the detection of five strong Gamma-Ray Bursts (GRBs) by the High-Energy Particle Detector (HEPD-01) mounted on board the China Seismo-Electromagnetic Satellite (CSES-01), operational since 2018 on a Sun-synchronous polar orbit at a $\sim$ 507 km altitude and 97$^\circ$ inclination. HEPD-01 was designed to detect high-energy electrons in the energy range 3 - 100 MeV, protons in the range 30 - 300 MeV, and light nuclei in the range 30 - 300 MeV/n. Nonetheless, Monte Carlo simulations have shown HEPD-01 is sensitive to gamma-ray photons in the energy range 300 keV - 50 MeV, even if with a moderate effective area above $\sim$ 5 MeV. A dedicated time correlation analysis between GRBs reported in literature and signals from a set of HEPD-01 trigger configuration masks has confirmed the anticipated detector sensitivity to high-energy photons. A comparison between the simultaneous time profiles of HEPD-01 electron fluxes and photons from GRB190114C, GRB190305A, GRB190928A, GRB200826B and GRB211211A has shown a remarkable similarity, in spite of the different energy ranges. The high-energy response, with peak sensitivity at about 2 MeV, and moderate effective area of the detector in the actual flight configuration explain why these five GRBs, characterised by a fluence above $\sim$ 3 $\times$ 10$^{-5}$ erg cm$^{-2}$ in the energy interval 300 keV - 50 MeV, have been detected.Comment: Accepted for publication in The Astrophysical Journal (ApJ

First light of BEaTriX, the new testing facility for the modular X-ray optics of the ATHENA mission

Aims: The Beam Expander Testing X-ray facility (BEaTriX) is a unique X-ray apparatus now operated at the Istituto Nazionale di Astrofisica (INAF), Osservatorio Astronomico di Brera (OAB), in Merate, Italy. It has been specifically designed to measure the point spread function (PSF) and the effective area (EA) of the X-ray mirror modules (MMs) of the Advanced Telescope for High-ENergy Astrophysics (ATHENA), based on silicon pore optics (SPO) technology, for verification before integration into the mirror assembly. To this end, BEaTriX generates a broad, uniform, monochromatic, and collimated X-ray beam at 4.51 keV. The beam collimation is better than a few arcseconds, ensuring reliable tests of the ATHENA MMs, in their focus at a 12 m distance. Methods: In BEaTriX, a micro-focus X-ray source with a titanium anode is placed in the focus of a paraboloidal mirror, which generates a parallel beam. A crystal monochromator selects the 4.51 keV line, which is expanded to the final size by a crystal asymmetrically cut with respect to the crystalline planes. An in-house-built Hartmann plate was used to characterize the X-ray beam divergence, observing the deviation of X-ray beams from the nominal positions, on a 12-m-distant CCD camera. After characterization, the BEaTriX beam has the nominal dimensions of 170 mm × 60 mm, with a vertical divergence of 1.65 arcsec and a horizontal divergence varying between 2.7 and 3.45 arcsec, depending on the monochromator setting: either high collimation or high intensity. The flux per area unit varies from 10 to 50 photons/s/cm2 from one configuration to the other. Results: The BEaTriX beam performance was tested using an SPO MM, whose entrance pupil was fully illuminated by the expanded beam, and its focus was directly imaged onto the camera. The first light test returned a PSF and an EA in full agreement with expectations. As of today, the 4.51 keV beamline of BEaTriX is operational and can characterize modular X-ray optics, measuring their PSF and EA with a typical exposure of 30 min. Another beamline at 1.49 keV is under development and will be integrated into the current equipment. We expect BEaTriX to be a crucial facility for the functional test of modular X-ray optics, such as the SPO MMs for ATHENA

X-ray tests of the ATHENA mirror modules in BEaTriX: from design to reality

The BEaTriX (Beam Expander Testing X-ray) facility is now operative at the INAF-Osservatorio Astronomico Brera (Merate, Italy). This facility has been specifically designed and built for the X-ray acceptance tests (PSF and Effective Area) of the ATHENA Silicon Pore Optics (SPO) Mirror Modules (MM). The unique setup creates a parallel, monochromatic, large X-ray beam, that fully illuminates the aperture of the MMs, generating an image at the ATHENA focal length of 12 m. This is made possible by a microfocus X-ray source followed by a chain of optical components (a paraboloidal mirror, 2 channel cut monochromators, and an asymmetric silicon crystal) able to expand the X-ray beam to a 6 cm × 17 cm size with a residual divergence of 1.5 arcsec (vertical) × 2.5 arcsec (horizontal). This paper reports the commissioning of the 4.5 keV beam line, and the first light obtained with a Mirror Module