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Building English Writing Confidence in Adult Learners: A Pilot Study on a Telegram-Based Text Detective Game
No full textInteractive narrative games are used in language education as a more engaging alternative to traditional reading activities. In addition, playing AI-driven narrative games can be a low-stake way to practice foreign-language writing.
This study introduces a pilot version of a text-based detective game with AI-powered characters, aimed at enhancing engagement and reducing writing anxiety in adult English learners. The characters adjust their language difficulty level (from A2 to B2) depending on the player’s choice. The game also provides in-context vocabulary explanation and on-demand feedback.
Seven participants of different language levels (A2–C1) tested the game and completed questionnaires about their experience, and three of them participated in semi-structured interviews. The questionnaire and the interview results suggest that mystery solving made the writing process more engaging for the participants, though no statistically significance was found in the anxiety effect. Although for some participants writing tasks seemed too open-ended, in-game writing was not perceived as more stressful than everyday writing. The participants’ feedback will help to further adapt the game for writing-anxious English learners
Design and analysis of Piezoelectric MEMS Varactor loaded on QMSIW filter for 5G Communication
No full textThis paper presents the design and simulation of Piezoelectric MEMS varactor for 5G communication. The piezoelectric MEMS varactor is utilized for the tuning of the RF structure in the form of Quarter Mode Substrate Integrated Waveguide (QMSIW). Piezoelectric MEMS varactor is positioned above the QMSIW resonator. The QMSIW is a second order resonator built on the high resistive silicon substrate having dielectric constant 11.7 having a thickness of 254 μm. Piezoelectric MEMS varactor is designed for Aluminium Nitride and Lithium Niobate as the piezoelectric material. Aluminium Nitride based varactor is actuated to – 11.8 V compared to – 20 V for Lithium Niobate based varactor to achieve a displacement of 450 μm displacement. With this upward displacement of the piezoelectric diaphragm, the resonant frequency bandwidth of the QMSIW filter vary up-to 800 MHz from 29.4 GHz to 30.2 GHz. The transmission zero to the right side of the passband shifts itself towards the passband by 1 GHz, making the passband narrower. Thus, making the structure suitable for 5G Communication
Diamond nano-patterning by graphitization induced by ion implantation
No full textIrradiation of diamond surface by energetic ion beams has represented a useful and flexible technique to modify the material properties to comply with quantum technology needs. Ion implantation is a reliable process to create color centers in diamond, due to its ability to define their concentration and three dimensional location1.
Besides that, ion implantation can also permanently modify the crystallographic phase of diamond, by damaging the diamond lattice. Thermal annealing can convert the irradiated areas to graphite2. The diamond graphitization via ion implantation combined with a selective etching3 could be a useful approach for diamond surface nano-patterning4, enabled by a lower fluence than direct milling, achieving a high lateral resolution if a focused ion beam (FIB) system is used.
We report a systematic experiment to nano-pattern the surface of an ‘electronic-grade’ diamond inducing graphitization using a multi-species FIB and removing the graphite by wet etching. The installed liquid metal alloy ion source (LMAIS)5 enables to implant Au++, Ge++ and Si++ species with maximum energy of 70 keV, allowing the tuning of the graphitic thicknesses and thus the depth of the nanostructures. For instance, for 70 keV irradiations the graphite layer thicknesses ranged from 40-90 nm. The process window was defined for each ion species in terms of ion fluence and thermal annealing, identifying the carbon phases by Raman spectroscopy and measuring by atomic force microscopy the swelling after ion irradiation, the etched thicknesses, and the minimum lateral resolution after the wet etching. Moreover, the fabrication of suspended nano-structure by the formation of buried graphite layer is investigated by exploiting the ions energy distribution in the diamond
New generation of TSV-enabled SiPM technologies for medical imaging and industrial applications
No full text2.5D and 3D integration enable high-density, low-latency interconnects by routing signals vertically through
the highly doped silicon bulk using Through-Silicon Vias (TSVs). These technologies support FBK’s
development of TSVs, micro TSVs, and Backside-Illuminated SiPMs, enabling compact architectures with
high segmentation while preserving the NUV-HD sensors’ electro-optical and timing performance.
TSVs will ensure a very compact SiPM packaging when arranged in arrays and will allow achieving the best
alignment when the tile is coupled with a scintillation crystal matrix or a hodoscope. With the glass-less TSV
technology, the sensor does not need a glass support wafer, which would create an additional optical
diffusing interface, negatively affecting light collection from the scintillator, the optical crosstalk between
neighboring channels and, thus, the overall timing performance
Formation of group IV-vacancy color centers in diamond by FIB: role of graphitization
No full textThe wide bandgap of diamond enables the engineering of photoluminescent defects, allowing controlled photon emission in the visible range, even at the single-photon level. Fabricating color centers (CC) in diamond is crucial for quantum technologies, including sensing, metrology, and computing.
Among the various techniques for introducing defects, Focused Ion Beam (FIB) implantation stands out due to its unique spatial resolution and the ability to deliver fluences of a few ions, allowing the controlled introduction of defects at the nanometer scale [1]. However, the ion implantation process damages the diamond lattice, potentially causing amorphization. Thermal annealing is required to activate CC and restore the lattice, but irreversible changes like graphitization and lattice swelling occur if the amorphization threshold is reached, reducing the formation yield of CC [2] and photoluminescence emission. In particular, the extremely focused ion beams (~15 nm spot diameters) allow to reach the amorphization threshold even for low fluences (<1000 ions).
In this study, FIB was used to implant (70 keV kinetic energy) silicon and germanium ions into electronic-grade diamonds, rastering 10×10 μm2 areas at different fluences. Graphitization and phase changes induced by implantation and annealing were analyzed for each ion species and correlated with the optical properties of silicon-vacancy (SiV) and germanium-vacancy (GeV) CC formed by introducing germanium or silicon ions by FIB. The CC optical properties were investigated through photoluminescence and Raman spectroscopy. The results were compared with those from the arrays produced via single-spot ion implantation. The amorphization of the implanted area, despite the small beam spot size, was investigated to assess its impact on CC formation and photoluminescence properties.
Our results highlight the importance of optimizing implantation conditions to balance structural damage and efficient CC formation
Fabrication of conductive graphitic layers in diamond by multi-species focused ion beam
No full textIon beam irradiation of diamond surface is a powerful technique to modify structural, electrical and optical properties to target quantum technology applications. In particular, ion implantation has been proven as a reliable and flexible process to create color centers (CC) in diamond, due to its ability to define their concentration and three dimensional location1. Ion implantation can also act on the crystal structure permanently modifying the phase of the irradiated diamond: once a certain level of lattice damage has been reached, subsequent thermal annealing can only convert the irradiated areas to graphite in an irreversible way2. This effect is clearly detrimental to the formation of CC, since the implanted ion species end up in a not-diamond phase. However, since the graphitic layers are electrically conductive, the effect can be exploited to create integrated or buried conductive layers3, supporting electrical driving of CC or even creating electrodes for photocurrent detection of magnetic resonance4, if the irradiation can be designed using a focused ion beam (FIB) system.
Figure 1 – Diagram showing the multispecies FIB process to either create graphitic layers or a nanometric patterning of diamond surface.
In this work, we report a systematic study to produce controlled layers of graphite on ‘electronic grade’ diamonds by ion implantation using a multi-species column FIB equipment. The liquid metal alloy ion source (LMAIS)5 allowed to select among Au++, Ge++ and Si++ species with implant energy of 70 keV. In particular, the process window was defined for each ion species in terms of ion fluence and thermal annealing recipe, identifying the carbon phases by Raman spectroscopy and measuring the developed topographies by atomic force microscopy, before and after a selective etching. Due to the mass difference, different graphite thicknesses were achieved, ranging from 40 to 90 nm. Another possibility is to exploit the selective etching coupled to FIB irradiation for a direct patterning of the diamond surface6, a process in principle able to create nanometric structures embedding CC.
References
1. S. Pezzagna, et al. New Journal of Physics 13(3) (2011), 035024.
2. C. Uzan‐Saguy, et al. Appl. Phys. Lett. 67(9) (1995), 1194.
3. F. Picollo, et al. New Journal of Physics 14(5) (2012), 053011.
4. G. Villaret, et al. Appl. Phys. Lett. 122(19) (2023), 194001.
5. L. Bischoff, et al. Appl. Phys. Rev. 3(2) (2016), 021101.
6. N. Kawasegi, Noritaka, et al. Diam. Relat. Mater 70 (2016), 159
Development of Sdd Array for Ultra-Fast Measurement
No full textThe performance of Silicon Drift Detectors (SDD), including the pre-amplifier, is constantly improving. Recently the energy resolution was improved even at short shaping time, allowing high throughput measurements in X-ray analysis. As a direct consequence the measurement time becomes shorter and industrial applications are expanding. To reduce the measurement time further, the active area and hence the solid angle of the detector also can be increased. However, in a SDD with large active area, the drift time of the signal charge becomes longer, and it makes the rise time of the signal longer, and then the signal processing time longer. Although using multiple detectors simultaneously is one of the good solutions, the aligned detectors have dead space in peripheral areas of the respective detectors. In a SDD array, multiple SDD elements are fabricated monolithically to achieve both high throughput and large solid angle. In such a SDD array if X-ray photons come into the boundary area between the different channels, generated charges divide and travel towards different adjacent anodes (charge sharing), or parts of the charges is not collected because of weak electric fields near the border areas. This phenomenon causes an unexpected tailing and background in the acquired spectrum. We're trying to reduce these boundary areas with weak electric fields. We add electrodes (drift rings) in these border areas on the radiation-entrance side to enhance a high electric field which drives signal charges to the read-out electrode swiftly. Our preliminary results from a single SDD prototype indicated that the added drift rings on the entrance side improve the tailing of the spectrum by 12%. Effects and technical problems of the drift rings on the entrance side will be reported and discusse