This study investigates the response of n-type Low Gain Avalanche Detectors (nLGADs) to local ion beam irradiation with low-penetrating 1.285 MeV gallium ions, focusing on charge collection efficiency (CCE) and gain degradation. Using the Transient Current Technique (TCT), we present charge collection maps before and after local irradiation. A 404 nm blue laser was used in postcharacterization, with no signal detected in the damaged zones after irradiation, suggesting significant charge trapping. The results reveal a pronounced vulnerability of nLGADs, with significant gain loss observed at fluences as low as 4 x 10 (9 )ions/cm( 2). This study confirms that a donor removal mechanism occurs at low fluences, and we hypothesize that this effect is linked to vacancy-mediated mechanism. Additionally, we report a global reduction in CCE, suggesting a long-range impact on electric field triggered by local defects. This phenomenon is referred to as the global gain quenching (GGQ). Simulations of the electric field provide further confirmation of GGQ's occurrence.

Nitrogen-Vacancy (NV) centers in diamond are promising systems for quantum technologies, including quantum metrology and sensing. A promising strategy for the achievement of high sensitivity to external fields relies on the exploitation of large ensembles of NV centers, whose fabrication by ion implantation is upper limited by the amount of radiation damage introduced in the diamond lattice. In this works we demonstrate an approach to increase the density of NV centers upon the high-fluence implantation of MeV N2+ ions on a hot target substrate (>550 {\deg}C). Our results show that, with respect to room-temperature implantation, the high-temperature process increases the vacancy density threshold required for the irreversible conversion of diamond to a graphitic phase, thus enabling to achieve higher density ensembles. Furthermore, the formation efficiency of color centers was investigated on diamond substrates implanted at varying temperatures with MeV N2+ and Mg+ ions revealing that the formation efficiency of both NV centers and magnesium-vacancy (MgV) centers increases with the implantation temperature.

Silicon carbide (SiC), thanks to its material properties similar to diamond and its industrial maturity close to silicon, represents an ideal candidate for several harsh-environment sensing applications, where sensors must withstand high particle irradiation and/or high operational temperatures. In this study, to explore the radiation tolerance of SiC sensors to multiple damaging processes, both at room and high temperature, we used the Ion Microprobe Chamber installed at the Ruđer Bošković Institute (Zagreb, Croatia), which made it possible to expose small areas within the same device to different ion beams, thus evaluating and comparing effects within a single device. The sensors tested, developed jointly by STLab and SenSiC, are PIN diodes with ultrathin free-standing membranes, realized by means of a recently developed doping-selective electrochemical etching. In this work, we report on the changes of the charge transport properties, specifically in terms of the charge collection efficiency (CCE), with respect to multiple localized proton irradiations, performed at both room temperature (RT) and 500 °C.

The energy loss of protons, in the range between 1.6 MeV and 6 MeV, in a 3.5 mu m thick single-crystal diamond membrane was determined by the transmission method. The thickness and surface uniformity of the target were checked by two independent techniques before ion beam irradiation. The stopping power of diamond was evaluated from these data and compared with SRIM Monte Carlo simulations of ion transport, showing a slight overestimate of the simulated values over the experimental stopping powers. In addition, a comparison was made with theoretical calculations based on the Bethe formula to extract the mean ionization potential, I, of carbon atoms in diamond. The obtained I-value was 81 +/- 4 eV. A discussion and comparison with results of other authors is given.

In recent times, ion implantation has received increasing interest for novel applications related to deterministic material doping on the nanoscale, primarily for the fabrication of solid-state quantum devices. For such applications, precise information concerning the number of implanted ions and their final position within the implanted sample is crucial. In this work, we present an innovative method for the detection of single ions of MeV energy by using a sub-micrometer ultra-thin silicon carbide sensor operated as an in-beam counter of transmitted ions. The SiC sensor signals, when compared to a Passivated Implanted Planar Silicon detector signal, exhibited a 96.5% ion-detection confidence, demonstrating that the membrane sensors can be utilized for high-fidelity ion counting. Furthermore, we assessed the angular straggling of transmitted ions due to the interaction with the SiC sensor, employing the scanning knife-edge method of a focused ion microbeam. The lateral dimension of the ion beam with and without the membrane sensor was compared to the SRIM calculations. The results were used to discuss the potential of such experimental geometry in deterministic ion-implantation schemes as well as other applications.

A new experimental setup for dual ion microbeam irradiation and analysis of materials has been designed and commissioned at the Ruđer Bošković Institute (RBI). Ion beams in the MeV energy range are provided by two tandem accelerators, a 1.0 MV Tandetron and a 6.0 MV EN tandem Van de Graaff. The dual microprobe end station is primarily dedicated for the performance of experiments where one ion microbeam is used for the irradiation, while the other ion microbeam is used for the analysis or ‘probing’ the in-situ changes induced during the target irradiation. Likewise, both microbeams can be also used independently, for experiments involving either ion beam characterization or ion beam irradiation techniques. The ion beam from the small tandem accelerator is focused with a magnetic quadrupole triplet, which is more suitable for the high spatial resolution work with light ions. The ion beam from the larger accelerator is focused by an electrostatic quadruplet that enables easier focusing of heavy ions. Details of the experimental setup, its capabilities in terms of ion beam irradiation and analysis techniques, as well as the first applications, are presented.

Telescope detectors have long been studied for their capability of discriminating the type of radiation detected. Silicon is the most widely used material for solid-state detectors. However, in many nuclear physics experiments and medical applications, diamond offers significant advantages due to its outstanding features, such as near tissue equivalence, high radiation hardness and reliable operation in harsh environments. A monolithic AE-E diamond-based telescope was fabricated. The thicknesses of the two detection stages were 2.5 mu m and 500 mu m for the AE and E stage, respectively. The device was characterised by means of IBIC (Ion Beam Induced Charge) analysis at the Ruder Bos?kovic acute accent Institute ion microbeam. The detector, irradiated with different low energy ions ranging from helium to oxygen, showed good homogeneity of the response on a well-defined sensitive volume with a charge collection efficiency close to 100%.The AE stage showed a very good linear response on a wide range of LET values in diamond (170-3140 keV/mu m). Due to its relatively low thickness, it can be successfully used as a microdosimeter. Time coincidence measurements have demonstrated the diamond telescope capability of discriminating and identifying the impinging ions. However, when the ratio between the energy deposited by the particle in the E stage and in the AE stage is small, the response of the E stage was observed to be affected by a cross-talk between the two stages of the device. A method to correct the E response for such effect was developed and successfully applied to the acquired data.

In this work the utilization of the Ion Beam Induced Charge (IBIC) technique is explored to assess the resolution a 2 MeV Li + ion microbeam raster scanning a micrometer-sized FIB-machined hollows in a silicon photodiode. The analysis of the maps crossing the FIB machined structures evidenced a drop in charge collection efficiency across the perimeter of the hollows combined with a significant recovery of the signal amplitude at the center of the microstructures, thus forming a micrometer-sized feature which can be exploited to estimate the resolution of the probing beam. The results were interpreted according to numerical simulations based on the Shockley-Ramo-Gunn as originating from a FIB-induced surface space charge density. These results offered additional information with respect to what achievable by a confocal photocurrent microscopy analysis of the same device, due to the significantly shorter focal depth of the latter with respect to the probing ion beam. This study suggests the viability of an effective method to evaluate of the resolution of ion microbeams in processes and experiments, which could be beneficial in emerging fields (deterministic implantation, micro-radiobiology, ion lithography) demanding beam spot sizes below the micrometer scale.

The development of semiconductor detectors with an increased tolerance to high radiation levels often results in devices that deviate significantly from those of the classical design with planar electrodes. Decreasing the charge drift distance and/or introducing localised charge multiplication volumes are two detector development strategies that are often used in an attempt to increase the device radiation hardness. However, such approaches result in a more complex three-dimensional distribution of electrodes and sensitive detector volumes, which presents a challenge for the microscopic characterisation of charge transport properties. IBIC (ion beam-induced charge) is one of the available microscopic characterisation techniques that utilises focused, MeV energy range ions to probe charge transport. Here we used IBIC to probe different detector depths by varying the ion energy and/or angle of incidence and to probe certain detector regions by ions of the same range but with different stopping powers. These investigations are particularly important for studying low gain avalanche diode (LGAD) detectors, where measured interpad distances change with proton energy and where an increased carrier density results in changes in the charge multiplication, which are studied in this work.

Synthetic single crystal diamond grown using the chemical vapor deposition technique constitutes an extraordinary candidate material for monitoring radiation in extreme environments. However, under certain conditions, a progressive creation of space charge regions within the crystal can lead to the deterioration of charge collection efficiency. This phenomenon is called polarization and represents one of the major drawbacks associated with using this type of device. In this study, we explore different techniques to mitigate the degradation of signal due to polarization. For this purpose, two different diamond detectors are characterized by the ion beam-induced charge technique using a nuclear microprobe, which utilizes MeV energy ions of different penetration depths to probe charge transport in the detectors. The effect of polarization is analyzed by turning off the bias applied to the detector during continuous or discontinuous irradiation, and also by alternating bias polarity. In addition, the beneficial influence of temperature for reducing the effect of polarization is also observed. Finally, the effect of illuminating the detector with light is also measured. Our experimental results indicate that heating a detector or turning off the bias, and then applying it during continuous irradiation can be used as satisfactory methods for recovering the CCE value close to that of a prepolarized state. In damaged regions, illumination with white light can be used as a standard method to suppress the strength of polarization induced by holes.

The capability of single crystal diamonds to maintain their unique electronic properties even at high temperatures is, in particular, relevant for its applications as a radiation detector. In order to explore characteristics of charge transport at high temperatures (up to 450 ∘C), diamond was exposed to MeV energy ions, both, to induce radiation damage and to probe subsequent influence on detector’s properties. Dependence of mobility-lifetime product with temperature has been obtained for electrons and holes. For holes, mu-tau displays a linear degradation with rising temperature, while for electrons, change with temperature is less evident. Furthermore, deep trapping levels induced in the material by radiation damage, were studied through time-resolved charge signals. Detrapping time was extracted from this data. Hole trap level, with the activation energy of 0.53 ± 0.01 eV has been detected in the regions of the diamond detector previously irradiated by 5 MeV damaging proton beam, but not in the pristine regions. This indicates that the trap was formed due to defect induction during radiation damage exposure. Activation of this deep level is important for charge transport performance in diamond detectors operating at high temperatures and high radiation conditions.

Diamond detectors are increasingly being used in many multidisciplinary areas due to their good spectroscopy properties. However, in certain cases of diamond employment as a nuclear detector, a significant deterioration of the signal properties due to the trapping of free charge carriers by defects can be observed. This phenomenon is known as polarization. Experimentally, a good understanding of the free carrier transport mechanisms can be obtained from direct measurements of the Charge Collection Efficiency (CCE) using the ion beam induced charge technique (IBIC). In this work IBIC was performed by focused proton and carbon ion beams of different energies in the MeV range, to probe the polarization induced changes of the CCE. The detectors being used in this study include a thin scCVD membrane detector (thickness 6 mu m) and a scCVD crystal of 65 mu m thickness. Furthermore, the detectors have been damaged with transmitted protons to study the influence of defects on polarization. The results that are presented show that the ion microprobe technique IBIC can be successfully used to fully characterize the polarization development in terms of time evolution in scCVD diamonds. More specifically, we show for the thin membrane detectors at high count rates and longer time irradiation a clear dependence of the pulse height signal decrease, induced by the polarization effect, with levels of radiation damage. A significant deterioration of the signal was observed in regions damaged with fluences between 10 (12) and 10(14) ions/cm(2) for both types of charge carriers. The results have shown that the energies used for the probing ion beams allow us to explore the electronic features from shallow to deeply penetration range and that has an effective impact on the temporal evolution of the build-up space charge. The experiments carried out have also shown that light can be used to suppress or amplify the polarization phenomena in damaged regions depending on the dominant type of charge carriers.

The differential cross sections of the Be-9(He-3,p)B-11 reactions for i = 0-6 were determined within the laboratory energy range 1.24-2.87 MeV and for backward angles from 107 degrees to 164 degrees with 2 degrees steps using two double sided silicon strip detectors. The obtained cross sections covered the angle and energy ranges typically used for the analysis of beryllium targets with the nuclear reaction analysis technique. The experiments were carried out at the Ruder Boskovic Institute and the determined cross sections were benchmarked with the measurement of thick target reaction yields from a pure beryllium target at two beam energies, 1.8 and 2.7 MeV. The results are presented in graphical form and for 134 degrees and 164 degrees are also given as tables in the Appendix. The correctness of the data, verified through the comparison of thick target spectra as well as the observed discrepancies with previous data are discussed and analyzed.

We report on the creation and characterization of the luminescence properties of high-purity diamond substrates upon F ion implantation and subsequent thermal annealing. Their room-temperature photoluminescence emission consists of a weak emission line at 558 nm and of intense bands in the 600–750 nm spectral range. Characterization at liquid He temperature reveals the presence of a structured set of lines in the 600–670 nm spectral range. We discuss the dependence of the emission properties of F-related optical centers on different experimental parameters such as the operating temperature and the excitation wavelength. The correlation of the emission intensity with F implantation fluence, and the exclusive observation of the afore-mentioned spectral features in F-implanted and annealed samples provides a strong indication that the observed emission features are related to a stable F-containing defective complex in the diamond lattice.

Diamond, as a wide band-gap semiconductor material, has the potential to be exploited under a wide range of extreme operating conditions, including those used for radiation detectors. The radiation tolerance of a single-crystal chemical vapor deposition (scCVD) diamond detector was therefore investigated while heating the device to elevated temperatures. In this way, operation under both high-temperature and high-radiation conditions could be tested simultaneously. To selectively introduce damage in small areas of the detector material, a 5 MeV scanning proton microbeam was used as damaging radiation. The charge collection efficiency (CCE) in the damaged areas was monitored using 2 MeV protons and the ion beam induced charge (IBIC) technique, indicating that the CCE decreases with increasing temperature. This decreasing trend saturates in the temperature range of approximately 660 K, after which CCE recovery is observed. These results suggest that the radiation hardness of diamond detectors deteriorates at elevated temperatures, despite the annealing effects that are also observed. It should be noted that the diamond detector investigated herein retained its very good spectroscopic properties even at an operation temperature of 725 K (≈2% for 2 MeV protons).

We present two new experimental arrangements designed to study time dependent processes during the irradiation of semiconductor detectors using ion microbeams. The first one is based on an upgraded pulsed beam irradiation setup of the RBI heavy ion microprobe. Controlled time-sequences of sample irradiation and intermediate IBIC probing is used to study dynamics of degradation of charge transport in detectors at different time scales. The second experimental arrangement is a dual ion microbeam irradiation setup that can accept simultaneously the ion beams from the two accelerators. In that case the first ion microbeam may be used as a damaging beam while the second one could be used as a probing beam. Probing techniques that have been used to study induced changes in crystalline materials are based on low microbeam currents and include STIM channeling, IBIC and IL.

Poluvodički detektori zračenja u mnogim eksperimentima bivaju izloženi enormnim količinama zračenja, primjerice na LHC akceleratoru čestica, dio opreme osjeti tok čestica Φ ∼ 1034 cm−2s−1. Unaprjedenje otpornosti poluvodičkih uredaja na oštećenja nastala zračenjem, u smislu traženja novih materijala i tehnika zaštite je stoga vrlo aktivno i aktuelno u fizici. U ovom radu su predstavljeni rezultati proučavanja utjecaja ionskog snopa ugljika energije 3.25 MeV na procese formiranja defekata u čistom siliciju, izvedeni u ”Laboratoriju za interakcije ionskih snopova” na IRB-u. Prilikom ozračivanja koristile su se dvije brzine kretanja snopa po površini uzorka. IBIC mikroskopijom smo provjerili vremensku skalu na kojoj defekti migriraju iz oštećenog dijela silicija, što rezultira oporavkom detektorskih sposobnosti diode (CCE se opravio s 0.4 nakon par stotina sekundi, na 0.6 nakon 19.5 sati). Nisu uočene različite promjene brzine i iznosa oporavka oštećenja za dvije ispitivane konfiguracije ozračivanja.