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This work describes a tabletop (50 cm × 25 cm × 25 cm) full field X-ray pinhole camera (FF-XPC) presenting high energy- and high spatial-resolution. The FF-XPC consists of a conventional charge-coupled device (CCD) detector coupled, in a coaxial geometry, to a pinhole collimator of small diameter. The X-ray fluorescence (XRF) is induced on the samples with an external low-power X-ray tube. The use of the CCD as an energy dispersive X-ray detector was obtained by adopting a multi-image acquisition in single photon counting and by developing a processing algorithm to be applied in real-time to each of the acquired image-frames. This approach allowed the measurement of X-ray spectra with an energy resolution down to 133 eV at the reference value of 5.9 keV. The detection of the X-ray fluorescence through the pinhole-collimator allowed the two-dimensional elemental mapping of the irradiated samples. Two magnifications (M), determined by the relative sample-pinhole-CCD distances, are used in the present setup. A low value of M (equal to 0.35×) allows the macro-FF-XRF of large area samples (up to 4 × 4 cm(2)) with a spatial resolution down to 140 μm; a large magnification (M equal to 6×) is used for the micro-FF-XRF of small area samples (2.5 × 2.5 mm(2)) with a spatial resolution down to 30 μm.

At the new 3 MV Tandetron accelerator of the LABEC laboratory of INFN in Florence, an external beam facility fully dedicated to measurements of elemental composition of atmospheric aerosol has been installed. The experimental set-up hitherto used for this kind of applications has been upgraded with the introduction of a silicon drift detector and of a beam current monitor system based on the backscattering of protons on the extraction window. The new facility will be presented, together with some methodological results obtained so far for the analysis of airborne particulate matter samples collected on quartz fiber filters.

We performed high-temperature luminescence studies of silicon-vacancy color centers obtained by ion implantation in single crystal diamond. We observed reduction of the integrated fluorescence upon increasing temperature, ascribable to a transition channel with an activation energy of 180 meV that populates a shelving state. Nonetheless, the signal decreased only 50% and 75% with respect to room temperature at 500 K and 700 K, respectively. In addition, the color center is found highly photostable at temperatures exceeding 800 K. The luminescence of this color center is thus extremely robust even at large temperatures and it holds promise for novel diamond-based light-emitting devices.

Single-photon sources are a fundamental element for developing quantum technologies, and sources based on colour centres in diamonds are among the most promising candidates. The well-known nitrogen vacancy centres are characterized by several limitations, and thus few other defects have recently been considered. In the present work, we characterize, in detail, native efficient single colour centres emitting in the near infra-red (λ = 740-780 nm) in both standard IIa single-crystal and electronic-grade polycrystalline commercial chemical vapour deposited (CVD) diamond samples. In the former case, a hightemperature (T > 1000°C) annealing process in vacuum is necessary to induce the formation/activation of luminescent centres with good emission properties, while in the latter case the annealing process has marginally beneficial effects on the number and performance of native centres in commercially available samples. Although displaying significant variability in several photo-physical properties (emission wavelength, emission rate instabilities, saturation behaviours), these centres generally display appealing photophysical properties for Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. applications as single photon sources: short lifetimes (0.7-3 ns), high emission rates (∼50-500 × 10 3 photons s −1 ) and strongly (>95%) polarized light. The native centres are tentatively attributed to impurities incorporated in the diamond crystal during the CVD growth of high-quality type-IIa samples, and offer promising perspectives in diamond-based photonics.Single photon sources represent a key element for developing quantum technologies [1][2][3][4]. Diamond offers a promising platform for the implementation of single-photon-emitter architectures, due to the vast range of available luminescent defects [5,6] with suitable emission properties that can be allocated in a broadly transparent crystal structure. The nitrogenvacancy (NV − ) complex has established a prominent role as a single photon emitter in several pioneering works [7-9], due to its ubiquity, quantum efficiency and well-understood electronic transition structure [10]. In the last decade, single NV − emitters were successfully employed to implement quantum cryptography schemes [11][12][13][14] as well as more fundamental demonstrations of quantum complementarity and entanglement [15][16][17][18]. At the same time, the research in diamond-based single-photon sources has broadened to new types of defects, with the goal of overcoming some inherent limitations in the NV − centre, namely its strong phonon coupling, relatively long lifetime and charge-state blinking. In particular, the identification of centres emitting in the near-infrared (NIR) offers the perspective of combining diamond colour centres with Si-based photodetectors in the spectral range where they are maximally efficient...