Search

The aim of the SIDDHARTA-2 experiment is to perform the first measurement ever of the width and shift induced by the strong interaction to the 2 p → 1 s energy transition of kaonic deuterium. This ambitious goal implies a challenging task due to the very low X-ray yield of kaonic deuterium, which is why an accurate and thorough characterization of the experimental apparatus is mandatory before starting the data-taking campaign. Helium-4 is an excellent candidate for this characterization since it exhibits a high yield in particular for the 3 d → 2 p transition, roughly 100 times greater than that of the kaonic deuterium. The ultimate goal of the work reported in this paper is to study the performances of the full experimental setup in view of the kaonic deuterium measurement. This is carried out by measuring the values of the shift and the width for the 3 d → 2 p energy transition of kaonic helium-4, induced by the strong interaction. The values obtained for these quantities, for a total integrated luminosity of ∼31/ p b , are ε 2 p = 2.0 ± 1.2 (stat) ± 1.5 (syst) eV and Γ 2 p = 1.9 ± 5.7 (stat) ± 0.7 (syst) eV . The results, compared to the value of the shift measured by the SIDDHARTA experiment ε 2 p = 0 ± 6 (stat) ± 2 (syst) eV , show a net enhancement of the resolution of the apparatus, providing strong evidence of the potential to perform the challenging measurement of the kaonic deuterium. [ABSTRACT FROM AUTHOR]

The aim of the SIDDHARTA-2 experiment is to perform the first measurement ever of the width and shift induced by the strong interaction to the 2p→1s energy transition of kaonic deuterium. This ambitious goal implies a challenging task due to the very low X-ray yield of kaonic deuterium, which is why an accurate and thorough characterization of the experimental apparatus is mandatory before starting the data-taking campaign. Helium-4 is an excellent candidate for this characterization since it exhibits a high yield in particular for the 3d→2p transition, roughly 100 times greater than that of the kaonic deuterium. The ultimate goal of the work reported in this paper is to study the performances of the full experimental setup in view of the kaonic deuterium measurement. This is carried out by measuring the values of the shift and the width for the 3d→2p energy transition of kaonic helium-4, induced by the strong interaction. The values obtained for these quantities, for a total integrated luminosity of ∼31/pb, are ε2p=2.0±1.2(stat)±1.5(syst)eV and Γ2p=1.9±5.7(stat)±0.7(syst)eV. The results, compared to the value of the shift measured by the SIDDHARTA experiment ε2p=0±6(stat)±2(syst)eV, show a net enhancement of the resolution of the apparatus, providing strong evidence of the potential to perform the challenging measurement of the kaonic deuterium.

In this paper, we present the first tests performed after the full installation of the SIDDHARTA-2 experimental apparatus on the interaction region of the DAΦNE collider at the INFN National Laboratories of Frascati. Before starting the first measurement of the kaonic deuterium 2p → 1s transition, an accurate evaluation of the background rejection was required, mainly achieved with the kaon trigger system. This run, performed in the period 04--26/05/2022 with a 4He gaseous target, confirmed the 105 order of magnitude of the rejection factor obtained with the reduced version of the setup and different machine conditions in 2021. This important outcome motivated the filling of the target cell with deuterium and the start of the measurement campaign of the kaonic deuterium 2p → 1s transition. [ABSTRACT FROM AUTHOR]

In this study, we present a procedure to optimize a set of finite impulse response filter (FIR) coefficients for digital pulse-amplitude measurement. Such an optimized filter is designed using an adapted digital penalized least mean square (DPLMS) method. The effectiveness of the procedure is demonstrated using a dataset from a case study on high-resolution X-ray spectroscopy based on single-photon detection and energy measurements. The energy resolutions of the K α and K β lines of the Manganese energy spectrum have been improved by approximately 20 % , compared to the reference values obtained by fitting individual photon pulses with the corresponding mathematical model. [ABSTRACT FROM AUTHOR]

The SIDDHARTINO experiment at the DAΦNE collider of INFN-LNF, the pilot run for the SIDDHARTA-2 experiment which aims to perform the measurement of kaonic deuterium transitions to the fundamental level, has successfully been concluded in July 2021. The paper reports the main results of this run, including the optimization of various components of the apparatus, among which the degrader needed to maximize the fraction of kaons stopped inside the target, through measurements of kaonic helium transitions to the 2p level. The obtained shift and width values are ε 2p = E exp âˆ' E e.m = 0.2 ± 2.5(stat) ± 2.0(syst) eV and Î"2p = 8 ± 10 eV (stat), respectively. This new measurement of the shift, in particular, represents the most precise one for a gaseous target and is expected to contribute to a better understanding of the kaonâ€"nuclei interaction at low energy. The results obtained in this pilot run, combined with the foreseen additional veto systems and projected for the total 48 SDD arrays of the SIDDHARTA-2 final setup, represent a solid starting point for the successful measurement of the kaonic deuterium 2p â†' 1s transition, main goal of the experiment. [ABSTRACT FROM AUTHOR]

In this study, we present a procedure to optimize a set of finite impulse response filter (FIR) coefficients for digital pulse-amplitude measurement. Such an optimized filter is designed using an adapted digital penalized least mean square (DPLMS) method. The effectiveness of the procedure is demonstrated using a dataset from a case study on high-resolution X-ray spectroscopy based on single-photon detection and energy measurements. The energy resolutions of the Kα and Kβ lines of the Manganese energy spectrum have been improved by approximately 20%, compared to the reference values obtained by fitting individual photon pulses with the corresponding mathematical model.

Detection of heavy elements, such as metals, in macromolecular crystallography (MX) samples by X‐ray fluorescence is a function traditionally covered at synchrotron MX beamlines by silicon drift detectors, which cannot be used at X‐ray free‐electron lasers because of the very short duration of the X‐ray pulses. Here it is shown that the hybrid pixel charge‐integrating detector JUNGFRAU can fulfill this function when operating in a low‐flux regime. The feasibility of precise position determination of micrometre‐sized metal marks is also demonstrated, to be used as fiducials for offline prelocation in serial crystallography experiments, based on the specific fluorescence signal measured with JUNGFRAU, both at the synchrotron and at SwissFEL. Finally, the measurement of elemental absorption edges at a synchrotron beamline using JUNGFRAU is also demonstrated. [ABSTRACT FROM AUTHOR]

• Test the efficacy of the GUPIX H-parameter in PIXE analysis. • Calibrate PIXE system using both analogue and digital SDDs. • Above ∼ 3 kev dependence of H upon X-ray energy is negligible. • Below ∼ 3 kev X-ray energy, H falls steeply in each case. The AXAS-A silicon drift detector that has been a part of the University of Guelph PIXE system for over a decade has recently been replaced by an AXAS-D unit. The calibration process previously performed on the AXAS-A, which uses a suite of high purity, "thick-target" single element and simple compound standards, was repeated for the AXAS-D. This allows for comparison between the analogue and digital approach to measuring PIXE spectra. The similarities between the results of the two detectors and the high accuracy found in geological applications affirm the validity of the use of an energy-dependent calibration factor within the GUPIX software. The upgrade to a digital detector offers multiple advantages. Unlike the AXAS-A, the AXAS-D contains a pre-amplifier and digital pulse processing circuitry and therefore requires significantly less supporting equipment. The improved count rate of the AXAS-D decreases the time required to complete projects. [ABSTRACT FROM AUTHOR]

The High Energy Modular Ensemble of Satellites (HERMES) project is aimed to realize a modular X/gamma-ray monitor for transient events, to be placed on-board of a nano-satellite bus (e.g. CubeSat). This expandable platform will achieve a significant impact on Gamma Ray Burst (GRB) science and on the detection of Gravitational Wave (GW) electromagnetic counterparts: the recent LIGO/VIRGO discoveries demonstrated that the high-energy transient sky is still a field of extreme interest. The very complex temporal variability of GRBs (experimentally verified up to the millisecond scale) combined with the spatial and temporal coincidence between GWs and their electromagnetic counterparts suggest that upcoming instruments require sub-microsecond time resolution combined with a transient localization accuracy lower than a degree. The current phase of the ongoing HERMES project is focused on the realization of a technological pathfinder with a small network (3 units) of nano-satellites to be launched in mid 2020. We will show the potential and prospects for short and medium-term development of the project, demonstrating the disrupting possibilities for scientific investigations provided by the innovative concept of a new "modular astronomy" with nano-satellites (e.g. low developing costs, very short realization time). Finally, we will illustrate the characteristics of the HERMES Technological Pathfinder project, demonstrating how the scientific goals discussed are actually already reachable with the first nano-satellites of this constellation. The detector architecture will be described in detail, showing that the new generation of scintillators (e.g. GAGG:Ce) coupled with very performing Silicon Drift Detectors (SDD) and low noise Front-End-Electronics (FEE) are able to extend down to few keV the sensitivity band of the detector. The technical solutions for FEE, Back-End-Electronics (BEE) and Data Handling will be also described. [ABSTRACT FROM AUTHOR]

The detection module of the ARDESIA spectrometer, an SDD-based, multichannel X-ray detector is presented. The detector design and experimental characterization are discussed. ARDESIA has been optimized for synchrotron radiation applications that require high-rate (>1-Mcps per channel) and high-resolution (better than 200 eV at 6 keV) X-ray detection. The main target applications considered in this development are X-ray fluorescence and X-ray absorption fine structure spectroscopy, in particular for the DAFNE-Light DXR1 beamline at LNF (Frascati, Italy). This detector is based on a compact unit (16 mm $\times16$ mm) that can be replicated and juxtaposed with several units, thus easily covering different detection configurations. The detector consists of a four-channel monolithic array of SDDs, produced by Fondazione Bruno Kessler (Trento, Italy) connected to a four-channel monolithic CUBE preamplifier mounted on the same carrier. The CUBE preamplifier, compatible with both analog and digital pulse processing, enables reaching high count rates (1-Mcps per channel), while keeping good spectroscopic performances. It is extremely low white series noise guarantees good energy resolution, even at short pulse processing times (below 200 ns). [ABSTRACT FROM AUTHOR]

In this paper, an application of silicon drift detectors (SDDs) as photodetectors for large inorganic scintillators is presented. In particular, a $2.3\times 2.3\times 1.5$ cm3 CdWO4 crystal has been coupled to a $3\times 2$ matrix of $8\times 8$ mm2 SDDs both cooled at 125 K, obtaining a scintillation detector whose performances are tested by measuring the $\gamma $ rays emitted by a 228Th source. The SDDs, characterized by high quantum efficiency and low electronic noise, are suitable candidates as photodetectors for high-resolution gamma-ray spectroscopy detectors. On the other hand, CdWO4 is an interesting crystal for the study of rare nuclear decays, such as the possible neutrinoless double beta decay ( $0\nu \beta \beta $ ) of 116Cd. With this prototype, a full-width at half-maximum resolution of 3.09 ± 0.05% at 2615 keV has been measured. This result provides a first validation of the application of this technology to rare event searches. [ABSTRACT FROM AUTHOR]

FLARES is an innovative project in the field of rare events searches, such as the search for the neutrinoless double beta decay. It aims at demonstrating the high potential of a technique that combines ultra-pure scintillating crystals with arrays of high performance silicon drift detectors, operated at about 120 K, to reach a 1% level energy resolution. The proposed technique will combine in a single device all the demanding features needed by an ideal experiment looking for rare events. The performance of a first production of matrices of silicon drift detectors as well as first measurements of the low temperature light yield of a selection of high purity scintillating crystals will be presented and discussed. [ABSTRACT FROM AUTHOR]

After the manufacture and delivery of a state-of-the-art detection system for the XRF-XAFS beamline of the synchrotron light source SESAME, a new and improved detection system was realized. This new multichannel modular detection system based on Silicon Drift Detectors consists of 8 monolithic multipixel arrays, each comprising 8 SDD cells with a total area of 570 mm 2. As the previous one, this 64 channels integrated detection system includes ultra-low-noise front-end electronics, dedicated acquisition system, digital filtering, temperature control and stabilization. With respect to the SESAME version, the new instrument implements a tungsten collimation system yielding a total collimated sensitive area of 500 mm 2. Optimized to work in an energy range of 3–30 keV, the system shows an overall energy resolution (sum of its 64 cells) below 180 eV FWHM at the 5.9 Mn K α line at room temperature. We highlight the system performance and in particular the peak to background ratio, before and after the collimation of the sensors. [ABSTRACT FROM AUTHOR]

We present the first experimental results achieved with a monolithic array of 166 Silicon Drift Detectors (SDD). This detector was developed for the TRISTAN experiment, targeting the search for a sterile neutrino in the keV mass range by means of accurate Beta spectroscopy of the Tritium decay. We briefly report on the design and characterization with X-rays of the full signal chain: from the SDD array, operated in a planar configuration with all the components of the final system, to the acquisition platform simultaneously acquiring all 166 channels. The average energy resolution is better than 250eV FWHM at 5.9keV at a temperature of 0 °C, a 6 μ s shaping time, and an average count rate of 1kcps per channel, 100 times smaller than the final experiment one. [ABSTRACT FROM AUTHOR]

A Silicon Drift Detector with 3 × 3 mm 2 sensitive area was designed by INFN of Trieste and built by FBK-Trento. It represents a single-pixel precursor of a monolithic matrix of multipixel Silicon Drift Detectors and, at the same time, a model of one cell Fluorescence Detector System (XAFS) for SESAME. The point-by-point mapping tests of the detector were carried out in the X-ray facilities at INAF-IAPS in Rome, equipped with a motorized two-axis micrometric positioning system. High precision characterization of this detector was done with a radioactive 55Fe source and a collimated Ti X-ray tube equipped with a Bragg crystal monocromator. The mapping in different positions and bias condition was specifically-aimed to the detailed analysis of the charge collection efficiency at the edge of the detector. The result is important to understand and verify the aspects related to the collection of the signal with respect to the position of interactions of the photons, especially in consideration of the new design and development of monolithic multipixel detectors. • High precision mapping of single-pixel Silicon Drift Detector. • The point by point mapping test allows to verify the charge collection. • The mapping is way to verify the efficiency at the edge of the detector. • Four different bias conditions are used for the measurements. • The mapping fosters the progress in the design and development of new detectors. [ABSTRACT FROM AUTHOR]

SESAME (Synchrotron-light for Experimental Science and Application in the Middle East) is a "third-generation" synchrotron light source. The Middle East's first major international research centre, established as cooperative venture by the scientists and governments of the region, is situated in Jordan. On the basis of the agreement signed between INFN and SESAME, our collaboration has designed and is building a Fluorescence Detector System based on 64 SDDs, each having a 9 mm 2 non-collimated sensitive area, realized with eight monolithic arrays for a total collimated sensitive area of 499 mm 2. The instrument will be used at the beamline dedicated to x-ray absorption spectroscopy in the energy range 3–30 keV with the capability of reaching a maximum counting rate of at least 3.2 Mcps. The energy resolution required for this application is below 150 eV FWHM @5.9 keV. We plan to have the system completely operative by July 2018. We report on the main building blocks of this system, dedicated to SESAME, and describe the experimental performances measured in the lab and on the XAFS beamline of ELETTRA Sincrotrone Trieste, Italy. In the very first tests the system was successfully operated up to 8 Mcounts/s. The energy resolution below 150 eV @5.9 keV was measured using a 1. 6 μ s peaking time with the detector cooled to 10 °C. • Novel spectroscopic system for XAFS beamlines features 64 SDDs. • Each SDD has a 9 mm 2 non-collimated sensitive area. • The energy resolution is below 150 EV FWHM @5.9 kEV using 1.6 us peaking time. • The Output Count Rate of the complete system results in 8 Mcounts/s. [ABSTRACT FROM AUTHOR]

Silicon Drift Detectors (SDDs) are a promising technology for electron spectroscopy, due to their excellent energy resolution and capability to sustain high interaction rate. We present a model based on a Geant4 simulation for the electron response. We then investigate the possibility to use a SDD as a versatile and compact β spectrometer that can be operated with standard technologies. [ABSTRACT FROM AUTHOR]

A 7.24 × 12.03 cm 2 sensor, Silicon Drift Detector (SDD), has been developed for the enhanced X-ray Timing and Polarimetry (eXTP) mission of the Chinese Academy of Science, with a large contribution by a European consortium inherited from the ESA-M3 LOFT mission study. In the frame of the project X-ray Observatories (XRO), active in the National Scientific Commission 2 of the INFN, we report the details of the qualification procedure to select from the mass production the 640 sensors that will equip the Large Area Detector (the eXTP instrument dedicated to the X-ray spectroscopy in the range 2-30 keV), with energy resolution below 240 eV FWHM at 6 keV during the entire mission duration of at least 5 years. This stringent requirement dictates the need to thoroughly verify the characteristics of each single sensor before integration in the final layout. We describe the dedicated testing facilities that have been developed. We report on the detector selection criteria and test results obtained in the pre-series production. [ABSTRACT FROM AUTHOR]

FLARES is a project for an innovative detector technology to be applied to rare event searches, and in particular to neutrinoless double beta decay experiments. Its novelty is the enhancement and optimization of the collection of the scintillation light emitted by ultra-pure crystals through the use of arrays of high performance silicon photodetectors cooled to 120 K. This would provide scintillation detectors with 1% level energy resolution, with the advantages of a technology offering relatively simple low cost mass scalability and powerful background reduction handles, as requested by future neutrinoless double beta decay experimental programs. The performances of a first production of matrices of Silicon Drift Detectors are presented and discussed in this paper. [ABSTRACT FROM AUTHOR]

Most air quality studies on particulate matter (PM) are based on 24-h averaged data; however, many PM emissions as well as their atmospheric dilution processes change within a few hours. Samplings of PM with 1-h resolution can be performed by the streaker sampler (PIXE International Corporation), which is designed to separate the fine (aerodynamic diameter less than 2.5 μm) and the coarse (aerodynamic diameter between 2.5 and 10 μm) fractions of PM. These samples are efficiently analyzed by Particle Induced X-ray Emission (PIXE) at the LABEC laboratory of INFN in Florence (Italy), equipped with a 3 MV Tandetron accelerator, thanks to an optimized external-beam set-up, a convenient choice of the beam energy and suitable collecting substrates. A detailed description of the adopted set-up and results from a methodological study on the detection limits for the selection of the optimal beam energy are shown; the outcomes of the research on alternative collecting substrates, which produce a lower background during the measurements, and with lower contaminations, are also discussed. [ABSTRACT FROM AUTHOR]

This work describes the development of a gamma detector based on silicon drift detectors (SDDs) to read out large \LaBr_3:\Ce scintillators for gamma-ray astronomy applications, within an activity supported by the European Space Agency (ESA). SDDs, characterized by high quantum efficiency and low electronic noise, when coupled with a scintillator are good candidates for gamma-ray spectroscopy applications in a wide energy range, e.g., from 150 keV to 15 MeV. The gamma-ray detector prototype presented here is composed of a 2^\prime^\prime\times2^\prime^\prime \LaBr_3:\Ce scintillator coupled with four SDD arrays arranged in a 2 \times 2 format (a total of 36 SDDs). This detection system is operated with custom readout application specific integrated circuits (ASICs) and a data acquisition (DAQ) system. With this prototype gamma-camera, an energy resolution of 3.4% FWHM at 662 keV has been measured. Spectroscopy measurements have been carried out between 300 keV and 1800 keV and the achieved results are consistent with the electronic noise of the SDD technology. In this work, we report on the SDD based detection head’s design, its X-ray characterization, readout electronics, experimental setups and gamma-ray spectroscopy results. Finally, perspectives with the possible use of an improved SDD technology are discussed. [ABSTRACT FROM AUTHOR]

In this paper we report a novel process to fabricate high-ohmic resistors using pure boron (PureB) depositions to create a p-type conductive layer on n-type silicon substrate. Sheet resistance values in the 100 kΩ/□ range are achieved using a reproducible and IC compatible process. The resistors made in this material are linear, bias-independent for the voltage ranges as high as 100 V, low temperature coefficients of a few hundred ppm/°C and less than 1% tolerances. As an application, these resistors are integrated in the silicon drift detectors fabrication flow as voltage divider for the drift of electrons, successfully. [ABSTRACT FROM AUTHOR]

In this work we present the results of the experimental characterization of Silicon Drift Detectors (SDDs) readout by CUBE preamplifiers for X-ray spectroscopy measurements. One specific goal of the work was to characterize SDDs of different sizes cooled at low temperature in view of their use in the upgrade of the SIDDHARTA nuclear physics experiment. Beside the target application, the results of this work are also of interest for a more extended use of the SDDs in other X-ray spectroscopy applications. The SDDs have been designed as single units with square shape of different areas, 64 mm^2 (8~\mm \times 8~\mm) and 144 mm^2 (12~\mm \times 12~\mm), and also as monolithic array of 3 \times 3 elements of the 8~\mm \times 8~\mm unit (total area 26~\mm \times 26~\mm). The read-out of the SDDs is based on a CMOS (Complementary Metal Oxide Semiconductor) preamplifier (CUBE) both for the single unit and for the 3 \times 3 array. For the readout of the array, an Application Specific Integrated Circuit (ASIC) has been used. An energy resolution better than 124 eV at the Mn - K\alpha line has been measured with a 64 mm^2 SDD cooled at the temperature of 50 K. The energy resolution remains good ( < 130 eV) also at short shaping time (250 ns) thanks to the noise feature of the CUBE preamplifier. Results of measurements on SDDs of different format and also on arrays of SDDs are presented in this work. [ABSTRACT FROM PUBLISHER]

The SIDDHARTA experiment measured the kaonic He and He 3 d →2 p X-ray transitions using gaseous targets for the first time. The strong-interaction shift both of the kaonic He and He 2 p states was determined with a precision of a few eV. The shift of kaonic He is much smaller than the values obtained in the experiments performed in 70's and 80's, while it is consistent with the recent result of the KEK E570 experiment, as well as the theoretical calculated values. Therefore, the problem on kaonic helium (the 'kaonic helium puzzle') was definitely solved. The first observation of the kaonic He X-rays was also achieved in the SIDDHARTA experiment. The shift both of kaonic He and He was found to be as small as a few eV. [ABSTRACT FROM AUTHOR]