Quantum Beam Science

20 pages, 7839 KiB

Open AccessArticle

High Energy Pulsed Laser Beam to Produce a Thin Layer of Crystalline Silver without Heating the Deposition Substrate and Its Catalytic Effects

by Alexandru Cocean, Georgiana Cocean, Cristina Postolachi, Silvia Garofalide, Daniela Angelica Pricop, Bogdanel Silvestru Munteanu, Georgiana Bulai, Nicanor Cimpoesu, Iuliana Motrescu, Vasile Pelin, Razvan Vasile Ababei, Dan-Gheorghe Dimitriu, Iuliana Cocean and Silviu Gurlui

Quantum Beam Sci. 2024, 8(2), 16; https://doi.org/10.3390/qubs8020016 - 19 Jun 2024

Viewed by 1191

Abstract

Crystalline silver thin layers were obtained using high-energy pulsed laser ablation without the heating of the deposition substrate. The fluid Plateau–Rayleigh (PRI), Rayleigh–Taylor (RTI), and Richtmyer–Meshkov (RMI) instabilities, as well as the crown splash induced during the pulsed laser deposition (PLD) in the [...] Read more.

Crystalline silver thin layers were obtained using high-energy pulsed laser ablation without the heating of the deposition substrate. The fluid Plateau–Rayleigh (PRI), Rayleigh–Taylor (RTI), and Richtmyer–Meshkov (RMI) instabilities, as well as the crown splash induced during the pulsed laser deposition (PLD) in the high energy regime, resulting in ring and pearl-shaped structures, offer the benefit of an increased sorption surface. These morphological structures obtained for the silver thin layers make them of interest for catalytic applications. This study addresses both fundamental and applied issues on the morphological structures obtained for the silver thin layers and their catalytic function in organic processes. In this sense, the catalytic action of the thin silver layer was highlighted by modifications of the Reactive Blue 21 dye (C.I.) in an aqueous solution with sodium bicarbonate. Specific investigations and analyses were carried out using electron microscopy and elemental analysis (SEM-EDX), atomic force microscopy (AFM) and profilometry, mass spectrometry, ablation plasma diagnosis, diffractograms (XRD), as well as IR spectroscopy (FTIR). In addition to the experimental investigation and analyses, the simulation of the ionization energy threshold was conducted in COMSOL for complementary evaluation on the involved processes and phenomena. Full article

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12 pages, 2813 KiB

Open AccessArticle

Analysis of Avoided Level Crossing Muon Spin Resonance Spectra of Muoniated Radicals in Anisotropic Environments: Estimation of Muon Dipolar Hyperfine Parameters for Lorentzian-like Δ₁ Resonances

by Iain McKenzie, Victoria L. Karner and Robert Scheuermann

Quantum Beam Sci. 2024, 8(2), 15; https://doi.org/10.3390/qubs8020015 - 17 Jun 2024

Viewed by 760

Abstract

Avoided level crossing muon spin resonance (ALC-

μ

SR) is used to characterize muoniated free radicals. These radicals are used as probes of the local environment and reorientational motion of specific components in complex systems. The parameter that provides information about the anisotropic [...] Read more.

Avoided level crossing muon spin resonance (ALC-

μ

SR) is used to characterize muoniated free radicals. These radicals are used as probes of the local environment and reorientational motion of specific components in complex systems. The parameter that provides information about the anisotropic motion is the motionally-averaged muon dipolar-hyperfine coupling constant (

⟨D_{μ}^{‖}⟩

). The ALC-

μ

SR spectra of muoniated radicals in anisotropic environments frequently have Lorentzian-like

Δ_{1}

resonances, which makes it challenging to extract

⟨D_{μ}^{‖}⟩

. In this paper, we derive a means to estimate

| ⟨D_{μ}^{‖}⟩ |

from ALC-

μ

SR spectra with Lorentzian-like resonances by measuring the amplitude, width, and position of the

Δ_{1}

resonance and the amplitude, width, and position of a

Δ_{0}

resonance. Numerical simulations were used to test this relationship for radicals with a wide range of muon and proton hyperfine parameters. We use this methodology to determine

| ⟨D_{μ}^{‖}⟩ |

for the Mu adducts of the cosurfactant 2-phenylethanol in

C_{12}

E₄ bilayers. From this we determined the amplitude of the anisotropic reorientational motion of the cosurfactant. Full article

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9 pages, 3130 KiB

Open AccessArticle

Effect of Collimation on Diffraction Signal-to-Background Ratios at a Neutron Diffractometer

by Dunji Yu, Yan Chen, David Conner, Kevin Berry, Harley Skorpenske and Ke An

Quantum Beam Sci. 2024, 8(2), 14; https://doi.org/10.3390/qubs8020014 - 30 May 2024

Viewed by 976

Abstract

High diffraction signal-to-background ratios (SBRs), the ratio of diffraction peak integrated intensity over its background intensity, are desirable for a neutron diffractometer to acquire good statistics for diffraction pattern measurements and subsequent data analysis. For a given detector, while the diffraction peak signals [...] Read more.

High diffraction signal-to-background ratios (SBRs), the ratio of diffraction peak integrated intensity over its background intensity, are desirable for a neutron diffractometer to acquire good statistics for diffraction pattern measurements and subsequent data analysis. For a given detector, while the diffraction peak signals primarily depend on the characteristics of the neutron beam and sample coherent scattering, the background largely originates from the sample incoherent scattering and the scattering from the instrument space. In this work, we investigated the effect of collimation on neutron diffraction SBRs of Si powder measurements using one high-angle area detector bank coupled with six different collimation configurations in a large and complex instrument space at the engineering materials diffractometer VULCAN, SNS, ORNL. The results revealed that the diffraction SBRs can be significantly improved by a proper coarse collimator that leaves no gap between the detector and the collimator, and the improvement of SBRs by a fine radial collimator was remarkable with a proper coarse collimator in place but not distinguishable without one. It was also found that the diffraction SBRs were not effectively improved by adding the neutron-absorbing element boron to the fine radial collimator body, which indicates that either the absorption of secondary scattered neutrons by the added boron is insignificant or the collimator base material (resin and ABS) alone attenuates background scattering sufficiently. These findings could serve as a useful reference for diffractometer developers and/or operators to optimize their collimation to achieve higher diffraction SBRs. Full article

(This article belongs to the Section Instrumentation and Facilities)

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15 pages, 5720 KiB

Open AccessArticle

Simulation Dosimetry Studies for FLASH Radiation Therapy (RT) with Ultra-High Dose Rate (UHDR) Electron Beam

by Nick Gazis, Andrea Bignami, Emmanouil Trachanas, Melina Moniaki, Evangelos Gazis, Dimitrios Bandekas and Nikolaos Vordos

Quantum Beam Sci. 2024, 8(2), 13; https://doi.org/10.3390/qubs8020013 - 24 May 2024

Viewed by 1333

Abstract

FLASH-radiotherapy (RT) presents great potential as an alternative to conventional radiotherapy methods in cancer treatment. In this paper, we focus on simulation studies for a linear particle accelerator injector design using the ASTRA code, which permits beam generation and particle tracking through electromagnetic [...] Read more.

FLASH-radiotherapy (RT) presents great potential as an alternative to conventional radiotherapy methods in cancer treatment. In this paper, we focus on simulation studies for a linear particle accelerator injector design using the ASTRA code, which permits beam generation and particle tracking through electromagnetic fields. Space charge-dominated beams were selected with the aim of providing an optimized generated beam profile and accelerator lattice with minimized emittance. The main results of the electron beam and ultra-high dose rate (UHDR) simulation dosimetry studies are reported for the FLASH mode radiobiological treatment. Results for the percentage depth dose (PDD) at electron beam energies of 5, 7, 15, 25, 50, 100 MeV and 1.2 GeV for Poly-methyl-methacrylate (PMMA) and water phantom vs. the penetration depth are presented. Additionally, the PDD transverse profile was simulated for the above energies, delivering the beam to the phantom. The simulation dosimetry results provide an UHDR electron beam under the conditions of the FLASH-RT. The performance of the beam inside the phantom and the dose depth depends on the linear accelerator beam’s energy and stability. Full article

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17 pages, 3654 KiB

Open AccessArticle

Modification of Cu Oxide and Cu Nitride Films by Energetic Ion Impact

by Noriaki Matsunami, Masao Sataka, Satoru Okayasu and Bun Tsuchiya

Quantum Beam Sci. 2024, 8(2), 12; https://doi.org/10.3390/qubs8020012 - 10 Apr 2024

Viewed by 1291

Abstract

We have investigated lattice disordering of cupper oxide (Cu₂O) and copper nitride (Cu₃N) films induced by high- and low-energy ion impact, knowing that the effects of electronic excitation and elastic collision play roles by these ions, respectively. For high-energy [...] Read more.

We have investigated lattice disordering of cupper oxide (Cu₂O) and copper nitride (Cu₃N) films induced by high- and low-energy ion impact, knowing that the effects of electronic excitation and elastic collision play roles by these ions, respectively. For high-energy ion impact, degradation of X-ray diffraction (XRD) intensity per ion fluence or lattice disordering cross-section (Y_XD) fits to the power-law: Y_XD = (B_XDS_e)^NXD, with S_e and B_XD being the electronic stopping power and a constant. For Cu₂O and Cu₃N, N_XD is obtained to be 2.42 and 1.75, and B_XD is 0.223 and 0.54 (kev/nm)⁻¹. It appears that for low-energy ion impact, Y_XD is nearly proportional to the nuclear stopping power (S_n). The efficiency of energy deposition, Y_XD/S_e, as well as Y_sp/S_e, is compared with Y_XD/S_n, as well as Y_sp/S_n. The efficiency ratio R_XD = (Y_XD/S_e)/(Y_XD/S_n) is evaluated to be ~0.1 and ~0.2 at S_e = 15 keV/nm for Cu₂O and Cu₃N, meaning that the efficiency of electronic energy deposition is smaller than that of nuclear energy deposition. R_sp = (Y_sp/S_e)/(Y_sp/S_n) is evaluated to be 0.46 for Cu₂O and 0.7 for Cu₃N at S_e = 15 keV/nm. Full article

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19 pages, 1763 KiB

Open AccessArticle

Estimating Lung Volume Capacity from X-ray Images Using Deep Learning

by Samip Ghimire and Santosh Subedi

Quantum Beam Sci. 2024, 8(2), 11; https://doi.org/10.3390/qubs8020011 - 28 Mar 2024

Cited by 1 | Viewed by 2042

Abstract

Estimating lung volume capacity is crucial in clinical medicine, especially in disease diagnostics. However, the existing estimation methods are complex and expensive, which require experts to handle and consequently are more error-prone and time-consuming. Thus, developing an automatic measurement system without a human [...] Read more.

Estimating lung volume capacity is crucial in clinical medicine, especially in disease diagnostics. However, the existing estimation methods are complex and expensive, which require experts to handle and consequently are more error-prone and time-consuming. Thus, developing an automatic measurement system without a human operator that is less prone to human error and, thus, more accurate has always been a prerequisite. The limitation of radiation dose and various medical conditions in technologies like computed tomography was also the primary concern in the past. Although qualitative prediction of lung volume may be a trivial task, designing clinically relevant and automated methods that effectively incorporate imaging data is a challenging problem. This paper proposes a novel multi-tasking-based automatic lung volume estimation method using deep learning that jointly learns segmentation and regression of volume estimation. The two networks, namely, segmentation and regression networks, are sequentially operated with some shared layers. The segmentation network segments the X-ray images, whose output is regressed by the regression network to determine the final lung volume. Besides, the dataset used in the proposed method is collected from three different secondary sources. The experimental results show that the proposed multi-tasking approach performs better than the individual networks. Further analysis of the multi-tasking approach with two different networks, namely, UNet and HRNet, shows that the network with HRNet performs better than the network with UNet with less volume estimation mean square error of 0.0010. Full article

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33 pages, 27060 KiB

Open AccessReview

Lithium-Ion Batteries under the X-ray Lens: Resolving Challenges and Propelling Advancements

by Mahdieh Samimi, Mehran Saadabadi and Hassan Hosseinlaghab

Quantum Beam Sci. 2024, 8(2), 10; https://doi.org/10.3390/qubs8020010 - 27 Mar 2024

Viewed by 2272

Abstract

The quest for high-performance lithium-ion batteries (LIBs) is at the forefront of energy storage research, necessitating a profound understanding of intricate processes like phase transformations and thermal runaway events. This review paper explores the pivotal role of X-ray spectroscopies in unraveling the mysteries [...] Read more.

The quest for high-performance lithium-ion batteries (LIBs) is at the forefront of energy storage research, necessitating a profound understanding of intricate processes like phase transformations and thermal runaway events. This review paper explores the pivotal role of X-ray spectroscopies in unraveling the mysteries embedded within LIBs, focusing on the utilization of advanced techniques for comprehensive insights. This explores recent advancements in in situ characterization tools, prominently featuring X-ray diffraction (XRD), X-ray tomography (XRT), and transmission X-ray microscopy (TXM). Each technique contributes to a comprehensive understanding of structure, morphology, chemistry, and kinetics in LIBs, offering a selective analysis that optimizes battery electrodes and enhances overall performance. The investigation commences by highlighting the indispensability of tracking phase transformations. Existing challenges in traditional methods, like X-ray absorption spectroscopy (XAS), become evident when faced with nanoscale inhomogeneities during the delithiation process. Recognizing this limitation, the review emphasizes the significance of advanced techniques featuring nanoscale resolution. These tools offer unprecedented insights into material structures and surface chemistry during LIB operation, empowering researchers to address the challenges posed by thermal runaway. Such insights prove critical in unraveling interfacial transport mechanisms and phase transformations, providing a roadmap for the development of safe and high-performance energy storage systems. The integration of X-ray spectroscopies not only enhances our understanding of fundamental processes within LIBs but also propels the development of safer, more efficient, and reliable energy storage solutions. In spite of those benefits, X-ray spectroscopies have some limitations in regard to studying LIBs, as referred to in this review. Full article

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Quantum Beam Sci., Volume 8, Issue 2 (June 2024) – 7 articles

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