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11 pages, 3236 KiB

Open AccessFeature PaperArticle

Irradiation Temperature Dependence of Shape Elongation of Metal Nanoparticles in Silica: Counterevidence to Ion Hammering Related Scenario

by Hiroshi Amekura, Saif Ahmad Khan, Pawan Kumar Kulriya and Debdulal Kabiraj

Quantum Beam Sci. 2023, 7(2), 12; https://doi.org/10.3390/qubs7020012 - 07 Apr 2023

Viewed by 1307

Abstract

Irradiation temperature (IT) dependence of the elongation efficiency of vanadium nanoparticles (NPs) in SiO₂ was evaluated: The samples were irradiated with 120 MeV Ag⁹⁺ ions to a fluence of 1.0 × 10¹⁴ ions/cm² each at ITs of 300, 433, [...] Read more.

Irradiation temperature (IT) dependence of the elongation efficiency of vanadium nanoparticles (NPs) in SiO₂ was evaluated: The samples were irradiated with 120 MeV Ag⁹⁺ ions to a fluence of 1.0 × 10¹⁴ ions/cm² each at ITs of 300, 433, 515, and 591 K, while the measurements were performed at room temperature. The vanadium was selected for the NP species because of the highest bulk m.p. of 1910 °C (2183 K) among all the species of the elemental metal NPs in which the shape elongation was observed. The highest m.p. could contribute negligible size changes of NPs against inevitable exposure to high temperatures for the IT dependence measurements. The elongation of V NPs was evaluated qualitatively by transmission electron microscopy (TEM) and quantitatively by optical linear dichroism (OLD) spectroscopy. The electron microscopy studies showed a pronounced elongation of NPs with ion irradiation at the elevated temperatures. The OLD signal was almost constant, or even slightly increased with increasing the IT from 300 to 591 K. This IT dependence provides a striking contrast to that of the ion hammering (IH) effect, which predicts a steep decrease with increasing IT. Combined with the other two counterevidence previously reported, the IH-related effect is excluded from the origin of the shape elongation of metal NPs in SiO₂. Full article

(This article belongs to the Special Issue Quantum Beam Science: Feature Papers 2022)

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16 pages, 4674 KiB

Open AccessArticle

Coulomb Spike Modelling of Ion Sputtering of Amorphous Water Ice

by Jean-Marc Costantini and Tatsuhiko Ogawa

Quantum Beam Sci. 2023, 7(1), 7; https://doi.org/10.3390/qubs7010007 - 28 Feb 2023

Viewed by 1378

Abstract

The effects of electronic excitations on the ion sputtering of water ice are not well understood even though there is a clear dependence of the sputtering yield on the electronic stopping power of high-energy ions. Ion sputtering of amorphous water ice induced by [...] Read more.

The effects of electronic excitations on the ion sputtering of water ice are not well understood even though there is a clear dependence of the sputtering yield on the electronic stopping power of high-energy ions. Ion sputtering of amorphous water ice induced by electronic excitations is modelled by using the Coulomb explosion approach. The momentum transfer to ionized target atoms in the Coulomb field that is generated by swift ion irradiation is computed. Positively charged ions produced inside tracks are emitted from the surface whenever the kinetic energy gained in the repulsive electrical field is higher than the surface binding energy. For that, the energy loss of deep-lying ions to reach the surface is taken into account in the sputtering yield and emitted ion velocity distribution. Monte Carlo simulations are carried out by taking into account the interactions of primary ions and secondary electrons (δ-rays) with the amorphous water ice medium. A jet-like anisotropic ion emission is found in the perpendicular direction in the angular distribution of the sputtering yield for normal incidence of 1-MeV protons. This directional emission decreases with an increasing incidence angle and vanishes for grazing incidence, in agreement with experimental data on several oxides upon swift ion irradiation. The role of the target material’s properties in this process is discussed. Full article

(This article belongs to the Special Issue Quantum Beam Science: Feature Papers 2022)

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22 pages, 915 KiB

Open AccessArticle

Clonogenic Survival RBE Calculations in Carbon Ion Therapy: The Importance of the Absolute Values of α and β in the Photon Dose-Response Curve and a Strategy to Mitigate Their Anticorrelation

by Alessio Parisi, Chris J. Beltran and Keith M. Furutani

Quantum Beam Sci. 2023, 7(1), 3; https://doi.org/10.3390/qubs7010003 - 28 Jan 2023

Cited by 3 | Viewed by 2050

Abstract

The computation of the relative biological effectiveness (RBE) is a fundamental step in the planning of cancer radiotherapy treatments with accelerated ions. Numerical parameters derived analyzing the dose response of the chosen cell line after irradiation to photons (i.e., α and β, [...] Read more.

The computation of the relative biological effectiveness (RBE) is a fundamental step in the planning of cancer radiotherapy treatments with accelerated ions. Numerical parameters derived analyzing the dose response of the chosen cell line after irradiation to photons (i.e., α and β, namely the linear and quadratic terms of the linear-quadratic model of cell survival) are generally used as input to biophysical models to predict the ion RBE. The α/β ratio for the photon exposure is generally regarded as an indicator of cell radiosensitivity. However, previous studies suggest that α/β might not be a sufficient parameter to model the RBE of relatively high linear energy transfer (LET) radiation such as carbon ions. For a fixed α/β, the effect of the absolute values of α and β on the computed RBE is underexplored. Furthermore, since α and β are anticorrelated during the fit of the photon-exposed in vitro survival data, different linear-quadratic fits could produce different sets of α and β, thus affecting the RBE calculations. This article reports the combined effect of the α/β ratio and the absolute values α and β on the RBE computed with the Mayo Clinic Florida microdosimetric kinetic model (MCF MKM) for ¹²C ions of different LET. Furthermore, we introduce a theory-based strategy to potentially mitigate the anticorrelation between α and β during the fit of the photon dose-response biological data. Full article

(This article belongs to the Special Issue Quantum Beam Science: Feature Papers 2022)

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10 pages, 3658 KiB

Open AccessArticle

Automated Pulsed Magnet System for Neutron Diffraction Experiments at the Materials and Life Science Experimental Facility in J-PARC

by Masao Watanabe, Takumi Kihara and Hiroyuki Nojiri

Quantum Beam Sci. 2023, 7(1), 1; https://doi.org/10.3390/qubs7010001 - 27 Dec 2022

Viewed by 2035

Abstract

A pulsed magnet system has been developed as a new user-friendly sample environment equipment at the Materials and Life Science Experimental Facility in Japan Proton Accelerator Research Complex. It comprises a vacuum chamber, a 4 K closed-cycle refrigerator for samples, and a nitrogen [...] Read more.

A pulsed magnet system has been developed as a new user-friendly sample environment equipment at the Materials and Life Science Experimental Facility in Japan Proton Accelerator Research Complex. It comprises a vacuum chamber, a 4 K closed-cycle refrigerator for samples, and a nitrogen bath made of a stainless-steel tube with a miniature solenoidal coil. The coil is cooled by liquid nitrogen supplied by an automatic liquid nitrogen supply system, and the sample is cooled by a refrigerator. This combination facilitates the automatic high magnetic field diffraction measurement for the user’s operation. A relatively large scattering angle 2θ is up to 42°, which is significantly wider than the previous setup. Neutron diffraction experiments were performed on a multiferroic TbMnO₃ and the field dependence of the diffraction peaks was clearly observed. The new pulsed magnet system was established for a practical high magnetic field diffraction for the user program. Full article

(This article belongs to the Special Issue Quantum Beam Science: Feature Papers 2022)

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9 pages, 836 KiB

Open AccessCommunication

A Machine for Ionizing Radiation Treatment of Bio-Deteriogens Infesting Artistic Objects

by Monia Vadrucci

Quantum Beam Sci. 2022, 6(4), 33; https://doi.org/10.3390/qubs6040033 - 16 Dec 2022

Cited by 4 | Viewed by 1525

Abstract

Precious cultural heritage has been inherited through past activities and maintained by the generations, and it includes artifacts and objects preserved in institutes or museum areas. As part of the study, the conservation of art objects and other cultural assets was carried out [...] Read more.

Precious cultural heritage has been inherited through past activities and maintained by the generations, and it includes artifacts and objects preserved in institutes or museum areas. As part of the study, the conservation of art objects and other cultural assets was carried out at the ENEA Frascati Research Center and attention was paid to the biodegradation aspect caused by microorganisms that cause the loss of information and artistic characteristics contained in the artifacts, for example, through covering them, the loss of color and the smearing of decorative or writing strokes. A non-chemical and non-toxic, completely ecological approach is used as an alternative bio-removal treatment to control the pathogens: these are the disinfection procedures that were applied using the REX machine. The beams of photons and electrons produced by this facility carried out anti-biodegradation activities for the control of deteriogens isolated from multi-material works. This communication concerns the REX machine, which is framed in the context of ENEA and in the panorama of activities carried out for the conservation of cultural heritage, presenting its application to case studies in which the developed technique was demonstrated as a non-invasive treatment for bio-degradation removal. Full article

(This article belongs to the Special Issue Quantum Beam Science: Feature Papers 2022)

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12 pages, 318 KiB

Open AccessArticle

Polarimetric Quantum-Strong Correlations with Independent Photons on the Poincaré Sphere

by Andre Vatarescu

Quantum Beam Sci. 2022, 6(4), 32; https://doi.org/10.3390/qubs6040032 - 29 Nov 2022

Cited by 1 | Viewed by 1375

Abstract

Controllable, quantum-strong correlations of polarization states can be implemented with multi-photon independent states. Polarization-based photonic quantum correlations can be traced back to the overlap of the polarization Stokes vectors on the Poincaré sphere between two polarization filters. The quantum Rayleigh scattering prevents a [...] Read more.

Controllable, quantum-strong correlations of polarization states can be implemented with multi-photon independent states. Polarization-based photonic quantum correlations can be traced back to the overlap of the polarization Stokes vectors on the Poincaré sphere between two polarization filters. The quantum Rayleigh scattering prevents a single photon from propagating in a straight line inside a dielectric medium, and it also provides a mechanism for the projective measurement of polarization. Complexities associated with single-photon sources and detectors can be eliminated because the quantum Rayleigh scattering in a dielectric medium destroys entangled photons. Entanglement-free, identical sources and processing devices give rise to correlations rather than these being caused by “quantum nonlocality”. These analytic developments were prompted by the vanishing expectation values of the Pauli spin vector for a single photon of maximally entangled photonic Bell states. Full article

(This article belongs to the Special Issue Quantum Beam Science: Feature Papers 2022)

13 pages, 937 KiB

Open AccessArticle

Instantaneous Quantum Description of Photonic Wavefronts and Applications

by Andre Vatarescu

Quantum Beam Sci. 2022, 6(4), 29; https://doi.org/10.3390/qubs6040029 - 30 Sep 2022

Cited by 2 | Viewed by 1740

Abstract

Three physical elements are missing from the conventional formalism of quantum photonics: (1) the quantum Rayleigh spontaneous and stimulated emissions; (2) the unavoidable parametric amplification; and (3) the mixed time-frequency spectral structure of a photonic field which specifies its duration or spatial extent. [...] Read more.

Three physical elements are missing from the conventional formalism of quantum photonics: (1) the quantum Rayleigh spontaneous and stimulated emissions; (2) the unavoidable parametric amplification; and (3) the mixed time-frequency spectral structure of a photonic field which specifies its duration or spatial extent. As a single photon enters a dielectric medium, the quantum Rayleigh scattering prevents it from propagating in a straight-line, thereby destroying any possible entanglement. A pure dynamic and coherent state composed of two consecutive number states, delivers the correct expectation values for the number of photons carried by a photonic wave front, its complex optical field, and phase quadratures. The intrinsic longitudinal and lateral field profiles associated with a group of photons for any instantaneous number of photons are independent of the source. These photonic properties enable a step-by-step analysis of the correlation functions characterizing counting of coincident numbers of photons or intensities with unity visibility interference, spanning the classical and quantum optic regimes. Full article

(This article belongs to the Special Issue Quantum Beam Science: Feature Papers 2022)

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16 pages, 6887 KiB

Open AccessArticle

A Solar-Rechargeable Radiation Dosimeter Design for Radiation Hazard Zone Located with LoRa Network

by Cheng-Yan Guo, Tzu-Lu Lin and Tung-Li Hsieh

Quantum Beam Sci. 2022, 6(3), 27; https://doi.org/10.3390/qubs6030027 - 19 Sep 2022

Cited by 2 | Viewed by 2507

Abstract

Since the nuclear energy leakage that occurred at the Fukushima nuclear power plant in Japan, people have paid more attention to the danger of environmental radiation. Environmental radiation is monitored using Geiger counters, which are not easy to obtain in some areas. Therefore, [...] Read more.

Since the nuclear energy leakage that occurred at the Fukushima nuclear power plant in Japan, people have paid more attention to the danger of environmental radiation. Environmental radiation is monitored using Geiger counters, which are not easy to obtain in some areas. Therefore, this research proposes an open-source and low-cost handheld Geiger counter that uses solar energy to charge lithium-ion batteries. Our design can provide a low-cost environmental radiation monitoring platform and effectively enhance the public’s scientific education awareness of radiation hazards. The measured dose rate can be output through the serial port, allowing a LoRa wireless network to transmit data to a database. When the sensing network deployed by the radiometer detects that the radiation value of the area is abnormally increased, it can issue an alarm to the government for the first time. Moreover, the low-power radiometer design can reduce energy consumption, reduce the burden on the ecological environment caused by the deployment of the sensing network, and provide sustainability for the environment. Full article

(This article belongs to the Special Issue Quantum Beam Science: Feature Papers 2022)

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Review

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28 pages, 1625 KiB

Open AccessReview

Overall Review on Recent Applications of Raman Spectroscopy Technique in Dentistry

by Iulian Otel

Quantum Beam Sci. 2023, 7(1), 5; https://doi.org/10.3390/qubs7010005 - 01 Feb 2023

Cited by 2 | Viewed by 2644

Abstract

The present paper reviews the applications of Raman spectroscopy in dentistry in the past two decades. This technique is considered a highly promising optical modality, widely used for the chemical identification and characterization of molecular structures, providing detailed information on the structural arrangement, [...] Read more.

The present paper reviews the applications of Raman spectroscopy in dentistry in the past two decades. This technique is considered a highly promising optical modality, widely used for the chemical identification and characterization of molecular structures, providing detailed information on the structural arrangement, crystal orientations, phase, and polymorphism, molecular interactions and effects of bonding, chemical surrounding environment, and stress on samples. Raman spectroscopy has been appropriate to investigate both organic and inorganic components of dental tissues since it provides accurate and precise spectral information on present minerals through the observation of the characteristic energies of their vibrational modes. This method is becoming progressively important in biomedical research, especially for non-invasiveness, non-destructiveness, high biochemical specificity, low water sensitivity, simplicity in analyzing spectral parameters, near-infrared region capability, and in vivo remote potential by means of fiber-optics. This paper will address the application of Raman spectroscopy in different fields of dentistry, found to be the most relevant and prevalent: early recognition of carious lesions; bleaching products performance; demineralizing effect from low-pH foods and acidic beverages; and efficiency of remineralization agents. Additionally, this review includes information on fiber-optic remote probe measurements. All described studies concern caries detection, enamel characterization, and assessment indicating how and to what extent Raman spectroscopy can be applied as a complementary diagnostic method. Full article

(This article belongs to the Special Issue Quantum Beam Science: Feature Papers 2022)

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