Energy-Dependent Proton Damage in Silicon

Non Ionizing Energy Loss (NIEL) in the sensor bulk is a limiting factor for the lifetime of silicon detectors. In this work, the proton-energy dependent bulk-damage is studied in n- and p-type silicon pad diodes. The samples are thin (200 μm thick), and oxygen enriched (bulk material types: MCz, standard or deep-diffused FZ). Irradiations are performed with 23 MeV, 188 MeV and 23 GeV protons; the 1 MeV neutron equivalent fluence assumes selected values in the range [0.1, 3]·10$^{14}$cm$^{−2}$. In reverse bias, Current-Voltage (IV) and Capacitance-Voltage (CV) measurements are performed to electrically characterise the samples; in forward bias, IV and CV measurements point out the transition from lifetime to relaxation-like semiconductor after irradiation. By means of Thermally Stimulated Current (TSC) measurements, 13 bulk defects have been found after proton irradiation. Firstly, TSC spectra are analysed to obtain defect concentrations after defect filling at the conventional temperature T$_{fill}$ = 10 K. Secondly, temperature dependent capture coefficients of bulk defects are explained, accordi (T$_{fill}$ < 130 K). Thirdly, a new method based on the SRH statistics and accounting for cluster-induced shift in activation energy is proposed; it allows to fully characterise bulk defects (in terms of activation energy, concentration and majority capture cross-section) and to distinguish between point- and cluster-like defects. A correlation is noted between the leakage current and the concentration of three deep defects (namely the V$_2$, V$_3$ and H(220K) defects), for all the investigated bulk materials and types, and after all the considered proton energies and fluences. At least five defects are found to be responsible for the space charge, with positive contributions from the E(30K) and B$_i$O$_i$ defects, or negative contributions from three deep acceptors H(116K), H(140K) and H(152K)

Study of point- and cluster-defects in radiation-damaged silicon

Non-ionising energy loss of radiation produces point defects and defect clusters in silicon, which result in a significant degradation of sensor performance. In this contribution results from TSC (Thermally Stimulated Current) defect spectroscopy for silicon pad diodes irradiated by electrons to fluences of a few  1014 cm −2 and energies between 3.5 and 27 MeV for isochronal annealing between 80 and 280 ∘ C, are presented. A method based on SRH (Shockley–Read–Hall) statistics is introduced, which assumes that the ionisation energy of the defects in a cluster depends on the fraction of occupied traps. The difference of ionisation energy of an isolated point defect and a fully occupied cluster, ΔEa , is extracted from the TSC data.Non-ionising energy loss of radiation produces point defects and defect clusters in silicon, which result in a signifcant degradation of sensor performance. In this contribution results from TSC (Thermally Stimulated Current) defect spectroscopy for silicon pad diodes irradiated by electrons to fluences of a few $10^{14}$ cm$^{-2}$ and energies between 3.5 and 27 MeV for isochronal annealing between 80 and 280{\deg}C, are presented. A method based on SRH (Shockley-Read-Hall) statistics is introduced, which assumes that the ionisation energy of the defects in a cluster depends on the fraction of occupied traps. The dfference of ionisation energy of an isolated point defect and a fully occupied cluster, $\Delta E_a$, is extracted from the TSC data. For the VOi (vacancy-oxygen interstitial) defect $\Delta E_a = 0$ is found, which cofirms that it is a point defect, and validates the method for point defects. For clusters made of deep acceptors the $\Delta E_a$ values for different defects are determined after annealing at 80{\deg}C as a function of electron energy, and for the irradiation with 15 MeV electrons as a function of annealing temperature. For the irradiation with 3.5 MeV electrons the value $\Delta E_a = 0$ is found, whereas for the electron energies of 6 to 27 MeV $\Delta E_a > 0$. This agrees with the expected threshold of about 5 MeV for cluster formation by electrons. The $\Delta E_a$ values determined as a function of annealing temperature show that the annealing rate is different for different defects. A naive diffusion model is used to estimate the temperature dependencies of the diffusion of the defects in the clusters

Beam Instrumentation Performance During Commissioning of the ESS RFQ, MEBT and DTL

International audienceIn late 2021 through mid 2022, the first protons were accelerated and transported through the European Spallation Source (ESS) Radio Frequency Quadrupole and Medium Energy Transport line at 3.6 MeV, and finally through the first Drift Tube Linac tank at 21 MeV. To enable these achievements, the following beam instrumentation systems were deployed: Ion Source power supply monitors, beam chopping systems, Faraday Cups, Beam Current Monitors (BCM) and Beam Position Monitors (BPM) that also measured phase. Additional systems were deployed for dedicated studies, including Wire Scanners, a slit and grid Emittance Measurement Unit, neutron Beam Loss Monitors and fast BCM and BPM systems. The instrumentation deployment is the culmination of efforts by a partnership of the ESS beam diagnostics section, multiple ESS groups and institutes across the globe. This paper summarizes the beam tests that characterized the performance of the instrumentation systems and verified the achievement of commissioning goals

First Beam Matching and Transmission Studies on the ESS RFQ

International audienceThe European Spallation Source will be driven by a 5 MW linear accelerator, producing 2.86 ms long proton beam pulses with a peak current of 62.5 mA at 14 Hz. Following the source commissioning in 2018 and 2019, the RFQ was successfully conditioned and subsequently commissioned with beam in 2021. In this paper, we will present results of studies on beam matching to the RFQ, both for low and high current beam modes, and will compare these results to model predictions

The prognostic power of inflammatory indices and clinical factors in metastatic castration-resistant prostate cancer patients treated with radium-223 (BIO-Ra study)

Purpose: To combine peripheral blood indices and clinical factors in a prognostic score for metastatic castration-resistant prostate cancer (mCRPC) patients treated with radium-223 dichloride ([223Ra]RaCl2). Patients and methods: Baseline neutrophil-to-lymphocyte ratio (NLR), derived NLR (donor), lymphocyte-to-monocyte ratio (LMR), platelet-to-lymphocyte ratio (PLR), systemic inflammation index (SII), Eastern Cooperative Oncology Group performance status (ECOG PS), Gleason score (GS) group, number of bone metastases, prostate-specific antigen (PSA), alkaline phosphatase (ALP), line of therapy, previous chemotherapy, and the presence of lymphadenopathies were collected from seven Italian centers between 2013 and 2020. Lab and clinical data were assessed in correlation with the overall survival (OS). Inflammatory indices were then included separately in the multivariable analyses with the prognostic clinical factors. The model with the highest discriminative ability (c-index) was chosen to develop the BIO-Ra score. Results: Five hundred and nineteen mCRPC patients (median OS: 19.9 months) were enrolled. Higher NLR, dNLR, PLR, and SII and lower LMR predicted worse OS (all with a p &lt; 0.001). The multivariable model including NLR, ECOG PS, number of bone metastases, ALP, and PSA (c-index: 0.724) was chosen to develop the BIO-Ra score. Using the Schneeweiss scoring system, the BIO-Ra score identified three prognostic groups (36%, 27.3%, and 36.6% patients, respectively) with distinct median OS (31, 26.6, and 9.6 months, respectively; hazard ratio: 1.62, p = 0.008 for group 2 vs. 1 and 5.77, p &lt; 0.001 for group 3 vs. 1). Conclusions: The BIO-Ra score represents an easy and widely applicable tool for the prognostic stratification of mCRPC patients treated with [223Ra]RaCl2 with no additional costs

Efficient Implementation of Application-Aware Spinlock Control in MPSoCs

Recent years have seen considerable progress in epidemiological and molecular genetic research into environmental and genetic factors in schizophrenia, but methodological uncertainties remain with regard to validating environmental exposures, and the population risk conferred by individual molecular genetic variants is small. There are now also a limited number of studies that have investigated molecular genetic candidate gene-environment interactions (G × E), however, so far, thorough replication of findings is rare and G × E research still faces several conceptual and methodological challenges. In this article, we aim to review these recent developments and illustrate how integrated, large-scale investigations may overcome contemporary challenges in G × E research, drawing on the example of a large, international, multi-center study into the identification and translational application of G × E in schizophrenia. While such investigations are now well underway, new challenges emerge for G × E research from late-breaking evidence that genetic variation and environmental exposures are, to a significant degree, shared across a range of psychiatric disorders, with potential overlap in phenotyp