Resonant Nuclear Reaction Research Articles

Study of the cross sections for the resonant nuclear reactions induced by 6Li + 2H collisions based on ab initio computations of characteristics of highly excited states of 8Be spectrum

Study of the cross sections for the resonant nuclear reactions induced by ⁶Li + ²H collisions based on ab initio computations of characteristics of highly excited states of ⁸Be spectrum

A Novel Cancer Therapy Using Proton Beam: An Integrated Proton-Dynamic Therapy, iPDT

[Background and Aims]A super-aged society, the prime example of which is Japan, is being flooded with increasing in numerous numbers of aged cancer patients, who often take anti-coagulant medicines to prevent the attacks of ischemic heart diseases and/ or strokes. Since they show bleeding tendency induced by the medicines, it’s hard for them to receive surgical operations. Thus, low invasive cancer treatments without bleedings are abundantly desired. In this study, the applicant will establish a new proton therapy, in which a resonance nuclear reaction (RNR) induced by collision of a proton with a stable nitrogen isotope (15N), can be a clue to injure cancer-cells specifically. The LET of the product ions (12C6+, 4He2+) of the 15N RNR is above 50 times in comparison with the LET of proton. To establish the cancer-specific 15N delivery, 15N-aminolevulinic acid (15N-ALA) will be used. This reagent has been already used and obtained regulatory approvals as a diagnostic medicine for the location of the glioblastoma in Japan.[Methods]In this study, a pair of rat gastric epithelial cells, one is normal cell RGM1, and another is cancerous characteristics cells RGK1 were used. The authors treated these cells with both 1mM 15N-ALA and 14N-ALA. Thereafter, we measured and compared porphyrin fluorescent intensity of these cells. Moreover, these cells will be irradiated with 4 nc proton beam generated by an electrostatic accelerator, then 4.43 MeV gamma-rays will be measured to demonstrate the amount of 15N collected specifically in the tumour cells. After these proton irradiations, cells were stained with hoechest33258 and dapi to observe cellular apoptosis.[Results] Cancer cells accumulated 9 folds of 15N in comparison with normal epithelial cells. After 3hours of proton irradiation, both cancer cells and normal cells were not injured. However, almost all cancer cells were died with apoptosis while normal cells showed few cellular injuries after 24 hours.[Conclusions] Cancer cells were completely killed by RNR involved with imM 15N-ALA and 4nc proton irradiation whereas this dose of proton showed few effects of ionizing radiation on normal cells. Thus, iPDT should be an ideal treatment for cancer. Moreover, the quantitative analysis of 15N in the tumour cells can be a new pre-diagnosis for iPDT.

Calculation of Cross Sections for Resonance Nuclear Reactions Based on Ab Initio Computations of Spectral Characteristics of Light Nuclei Levels

Calculation of Cross Sections for Resonance Nuclear Reactions Based on Ab Initio Computations of Spectral Characteristics of Light Nuclei Levels

In Plasma ion beam analysis of polymer layer and adsorbed H monolayer etching

We present two experiments where a layer is plasma-etched while monitoring its evolution by in plasma ion beam analysis. First, we etch a photoresist with a diffuse O2 plasma at low pressure. Using a 4.335 MeV He beam, Rutherford Backscattering Spectrometry and Elastic Recoil Detection spectra are acquired every minute during 8 h. Etching of most elements follows a linear trend, but H desorbs faster at the beginning of the plasma process, which we ascribe to the ion beam-induced desorption. In addition, we observe a thin Mo layer building up at the surface, likely due to the sputtering of an electrode in the plasma source. Secondly, we etch in HF a crystalline Si (c-Si) sample with <100> surface orientation, which should leave 14 H/nm2 bonded to the c-Si surface. The sample is then introduced in the chamber and exposed to a diffuse Ar plasma at low pressure. During plasma processing, the H surface concentration is monitored using a resonant nuclear reaction with a 15N beam at 6.385 MeV. The initial H concentration is 11.7±1.1 H/nm2, and it decreases over a 3-minute timescale to an equilibrium concentration of 6.0±0.8 H/nm2. Over the range of experimental conditions investigated, the diffuse Ar plasma is therefore not able to entirely sputter the H from the c-Si surface.

Accurate measurement of hydrogen concentration in transition metal hydrides utilizing electronic excitations by MeV ions

This study focuses on enhancing the accuracy of hydrogen content verification in hydrogen-rich ultrathin materials relevant for sustainable energy applications. Ion beams are used for distinctive real-space detection leveraging elastic and inelastic interactions with hydrogen atoms. However, the lack of experimental reference data on electronic interactions poses a challenge to the accuracy of analytical techniques. We investigate the effect of absorbed hydrogen on the electronic energy deposition of 15N-ions in amorphous transition metal compounds, specifically V and Zr, covering concentrations >1H/M. Employing resonant nuclear reactions and Rutherford backscattering, the energy loss is found to increase considerably with hydrogen content, in line with Bragg's additivity. The electronic energy loss cross section for 15N-ions at 6.5 MeV measured (64.55±3.38) eV cm2/1015 atoms. Results are compared to semi-empirical and theoretical models. The findings improve hydrogen profiling accuracy using 15N-nuclear reaction analysis and enable unprecedented methods for hydrogen quantification by other, commonly available ion beams.

An experimental study of hydrogen implantation to minerals: Role of the solar wind as a source of water in terrestrial bodies

The solar wind is a possible source for hydrogen and other volatiles on planetary bodies. To better understand the role of the solar wind during the volatile acquisition of planetary materials, we conducted hydrogen implantation experiments on olivine, orthopyroxene, quartz single crystals. Depth profiles of hydrogen concentration after implantation are determined by the Nuclear Resonance Reaction Analysis. We find that energetic hydrogen particles penetrate into the sample and accumulate at a certain depth. The hydrogen concentration increases with the hydrogen fluence until a “saturation level” is attained. Hydrogen saturation level (e.g., ∼10–20 at.% in olivine, equivalent to 0.5–1.2 wt%) far exceeds the equilibrium solubility in the bulk crystal at a similar thermodynamic condition (∼10−22 wt%). The results of olivine show that the hydrogen penetration depth increases whereas the saturation level decreases (weakly) with the beam energy. Hydrogen saturation level also depends on the mineral species in the order: olivine > orthopyroxene > quartz. The experimental results can be applied to explain some observations on the high surface water content of some planetary bodies including Itokawa asteroid and the Moon. We also explore the possibility of hydrogenated dusts by the solar wind implantation as a source for water on terrestrial planets. We conclude that if all dusts were exposed to the solar wind and all implanted hydrogen were converted to water, then >10 ocean masses would have been acquired for Earth by ∼100 years. However, the main part of the proto-planetary disk was not exposed to the solar wind and dusts could have been hydrogenated only when they were far from the equatorial plane of the disk. We discuss a possible mechanism to transport the hydrogenated dusts to the disk interior via turbulent mixing. Also, our experimental results and the mass dependence of the particle energies in the solar wind suggest that the D/H ratio of the dusts exposed to the solar wind will be higher than the solar wind value.

A New Cancer Therapy with a Resonance Nuclear Reaction between 15n-5-ALA and Proton Beam: iPDT

A super-aged society, the prime example of which is Japan, is being flooded with increasing in numerous numbers of aged cancer patients, who often take anti-coagulant medicines to prevent the attacks of ischemic heart diseases and/ or strokes. Since they have diseases with bleeding tendency induced by the medicines, it’s hard for them to receive surgical operations. Thus, low invasive cancer treatments without bleedings are abundantly desired. In this study, the applicant will establish a new proton therapy, in which a resonance nuclear reaction (RNR) induced by collision of a proton with a stable nitrogen isotope (15N), can be a clue to injure cancer-cells specifically. The LET of the product ions (12C6+, 4He2+) of the 15N RNR is above 50 times in comparison with the LET of proton. To establish the cancer-specific 15N delivery, 15N-aminolevulinic acid (15N-ALA) will be used. This reagent has been already used and obtained regulatory approvals as a diagnostic medicine for the location of the glioblastoma in Japan.In this study, a pair of rat gastric epithelial cells, one is normal cell, and another is cancerous characteristics cells were used, 15N-ALA treated porphyrin fluorescent intensity of these cells will be compared with 14N-ALA treatment. The cells will be irradiated with a proton beam generated by an electrostatic accelerator and 4.43 MeV gamma-rays will be measured to demonstrate the amount of 15N collected specifically in the tumour cells. Such quantitative analysis of 15N in the tumour cells can be a new pre-diagnosis of iPDT.

Study of fluorine-doped tin oxide thin films deposited by pneumatic spray pyrolysis and ultrasonic spray pyrolysis: a direct comparison

A comparative analysis was performed of fluorine-doped tin oxide (FTO) thin films deposited through two different systems: pneumatic spray pyrolysis and ultrasonic spray pyrolysis. The films were deposited on glass substrates at 460 °C, with varying weight ratios of fluorine to tin (F/Sn = 0.35, F/Sn = 0.50, and F/Sn = 0.65). The investigation focuses on the evolution of the film’s crystallinity, structural, morphological, transmittance, optical, and electrical properties. Resonant nuclear reaction (RNR) and energy dispersive spectroscopy (EDS) techniques were used to confirm the presence of fluorine in the FTO samples. The results show that the sample with F/Sn = 0.50 deposited through pneumatic spray pyrolysis, with a figure of merit of 34.5 × 10−3 Ω−1, exhibits the best characteristics for use as electrodes in optoelectronic devices, particularly in the fabrication of solar cells.

Laboratory electron screening in nuclear resonance reactions

Laboratory electron screening in nuclear resonance reactions

An experimental study of proton implantation in olivine

Implantation of ions in minerals by high energy radiation is an important process in planetary and materials sciences. For example, the solar wind is a multi-ion flux that progressively modifies the composition and structure of near-surface domains in solar objects, like asteroids. A bombardment of a target by different elements like hydrogen (H) at various energies causes, among other things, the implantation of these particles in crystalline and amorphous materials. It is important to understand the mechanisms and features of this process (e.g., how much is implanted and retained), to constrain its contribution to the chemical budget of solar objects or for planning various material-science applications. Yet, there has been no detailed study on H implantation into olivine (e.g., the quantification of maximum retainable H), a major mineral in this context. We performed experiments on H implantation in San Carlos olivine at 10 and 20 keV with increasing fluences (up to 3×1018 at/cm2). Nanoscale H profiles that result from implantation were analyzed using Nuclear Resonance Reaction Analysis after each implantation to observe the evolution of the H distribution as a function of fluence. We observed that after a systematic growth of the characteristic, approximately Gaussian shaped, H profiles with increasing fluences, a maximum concentration at H ~ 20 at% is attained. The maximum concentration is approximately independent of ion energy, but the maximum penetration depth is a function of beam energy and is greater at higher energies. The shapes of the profiles as well as the maximum concentrations deviate from those predicted by currently available models and point to the need for direct experimental measurements. We compared the depth profiles with predictions by SRIM. Based on observations from this study, we were able to constrain the maximum retainable H in olivine as a function of ion energy.

Abstract 1106: A novel cancer therapy using proton beam; an integrated proton dynamic therapy, iPDT

Abstract A super-aged society, the prime example of which is Japan, is being flooded with increasing in numerous numbers of aged cancer patients, who often take anti-coagulant medicines to prevent the attacks of ischemic heart diseases and/or strokes. Since they show bleeding tendency induced by the medicines, it’s hard for them to receive surgical operations. Thus, low invasive cancer treatments without bleedings are abundantly desired. In this study, the applicant will establish a new proton therapy, in which a resonance nuclear reaction (RNR) induced by collision of a proton with a stable nitrogen isotope (15N), can be a clue to injure cancer-cells specifically. The LET of the product ions (12C6+, 4He2+) of the 15N RNR is above 50 times in comparison with the LET of proton. To establish the cancer-specific 15N delivery, 15N-aminolevulinic acid (15N-ALA) will be used. This reagent has been already used and obtained regulatory approvals as a diagnostic medicine for the location of the glioblastoma in Japan. In this study, a pair of rat gastric epithelial cells, one is normal cell, and another is cancerous characteristics cells were used. 15N-ALA treated porphyrin fluorescent intensity of these cells will be compared with 14N-ALA treatment. The cells will be irradiated with a proton beam generated by an electrostatic accelerator and 4.43 MeV gamma-rays will be measured to demonstrate the amount of 15N collected specifically in the tumor cells. Such quantitative analysis of 15N in the tumor cells can be a new pre-diagnosis of iPDT. Citation Format: HIrofumi Matsui. A novel cancer therapy using proton beam; an integrated proton dynamic therapy, iPDT [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1106.

Parameterization of Direct and Doorway Processes in R-Matrix Formalism

R-matrix formalism is extended beyond compound nuclear (CN) resonant reactions to include parameterization of direct as well as doorway processes. Direct processes in the R-matrix exterior are parameterized by a unitary matrix that introduces mixing among wave function coefficients of the incoming and outgoing wave function components at the R-matrix channel surface. Doorway processes are parameterized by separating the Hilbert space of the interior R-matrix region into its doorway and CN subspaces, from which doorway state eigenenergies, reduced width amplitudes, and the strengths of their coupling to CN levels appear as new R-matrix parameters. Parameterization of generalized as well as the conventional Reich–Moore approximation for eliminated capture channels in the presence of direct, doorway, and CN processes is presented along with a complex-valued scattering length with contributions from direct, doorway, and CN capture processes. Derivation of Brune’s alternative R-matrix parameters is extended to include doorway states. This work suggests how R-matrix formalism could be extended further by adopting the concepts from related reaction formalisms.

Control of nanosecond proton bunches in a magnetically insulated ion diode by resonant nuclear reactions of radiative proton capture

To calibrate the detection efficiency of a plastic scintillator that detects prompt gamma quanta from the 19F(p,αγ)16O resonant reaction of radiative proton capture and is used to control the dynamics of the arrival of protons with an energy of about 340 keV accelerated by a magnetically isolated pulsed ion diode, a change the polarity of the diode electrodes to the reverse was used, at which electron bunches were accelerated in the geometry of the Luce diode, forming virtual cathodes. The virtual cathodes in the Luce diode collectively accelerated protons to an energy of about 500 keV, the value of which was determined from the drift velocity of these virtual cathodes, while the number of such protons was determined from the activity of the 13N radionuclide induced by the 457 keV resonance of the 12C(p,γ)13N reaction. Keywords: intense pulsed ion beam, organic scintillator, prompt gamma spectrometry.

Hydrogen Diffusion in Clinopyroxene at Low Temperatures (195°C–400°C) and Consequences for Subsurface Processes

AbstractStudying diffusion of hydrogen in nominally anhydrous minerals, like clinopyroxene, at low temperatures is a challenging task due to experimental and analytical difficulties. In this study, to overcome these problems we have produced H concentration gradients in single crystals of natural diopsidic clinopyroxene by ion implantation and measured the nanoscale profiles before and after diffusion anneals using Nuclear Resonance Reaction Analysis. These steps allowed us to conduct experiments at temperatures between 195°C and 400°C. Obtained diffusion rates show a consistent Arrhenius relation DH= 5.47(±13.98) · 10−8 · exp (−115.64(±11.5) kJ mol−1/RT) m2s−1. Notably, our results lie well within the range of extrapolations from high temperature experiments (≥600°C) of previous studies. This implies that fast diffusion of hydrogen (compared to other elements) extends to low temperatures. We used these results in a non‐isothermal diffusion model that simulates the ascent of crystals (0.5, 1.0, and 2.0 mm) along two representative P‐T‐paths from 600°C to 100°C, to assess potential re‐equilibration of H contents in clinopyroxene at low temperatures. Our model highlights the need to carefully consider boundary conditions, which are a function of P‐T‐fO2, that control the concentration gradient at the crystal's rim. The results from this model help to assess, as a function of crystal size and cooling rate, when re‐equilibration must be considered.

Possible solution to the triple alpha fine-tuning problem: Spallation reactions during planet formation

Carbon is produced during the helium burning phase of sufficiently massive stars through the triple alpha process. The 0+ energy level of the carbon nucleus allows for resonant nuclear reactions, which act to greatly increase the carbon yields compared to the non-resonant case. Many authors have argued that small changes to the energy level of this resonance would lead to a significantly lower carbon abundance in the universe, and this sensitivity is often considered an example of fine-tuning. By considering spallation reactions occurring during the process of planet formation, this paper presents a partial solution to this triple alpha fine-tuning problem. Young stellar objects generate substantial luminosities of particle radiation (cosmic rays) that can drive nuclear reactions through spallation. If the standard triple alpha process is inoperative, stars tend to synthesize oxygen (and other alpha elements) rather than carbon. Cosmic rays can interact with oxygen nuclei to produce carbon while planets are forming. The resulting carbon abundances are significant, but much smaller than those observed in our universe. However, for a range of conditions – as delineated herein – spallation reactions can result in carbon-to-oxygen ratios roughly comparable to those found on Earth and thereby obviate the triple alpha fine-tuning problem.

Measurements of Energy Loss of Charded Particles Travelling in Crystalline Materials along the Channeling Directon

A method for determining the energy loss and mean dechanneling distance of light charged particles traveling along a low index axis of a crystal in the backscattering geometry, is presented. The method is based on nuclear resonance reactions which act as a marker for the range in the backscattering spectra. Computer simulations based on the assumption of an exponential rate of dechanneling of the incoming particles in the crystalline material, are in good agreement with measured spectra. The results of applying this method to protons and alphas in crystals of Si, SiO2, SiC and MgO are discussed and possible improvements are indicated.

Detection, Structural Elucidation, and Biological Effects of Diverse N-Acyl-homoserine Lactone Signaling Molecules in the Plant-Promoting Endophytic Bacterium Rhizobium oryzihabitans M15.

Quorum sensing (QS), usually performed by N-acyl-homoserine lactones (AHLs) in Gram-staining-negative bacteria, plays an important role in plant-bacteria interactions. Rhizobium oryzihabitans M15 is a plant-growth-promoting rhizobacterium (PGPR) isolated from rice roots. In this study, we found a QS system in the endogenous plasmid of R. oryzihabitans M15 and detected the activity of AHLs by a bioassay method. We identified five AHL analogues in R. oryzihabitans M15 using liquid chromatography-tandem mass spectrometry (LC-MS). The most dominant AHL analogue was N-(3R-hydroxy-7-cis-tetradecanoyl)-l-homoserine lactone according to nuclear magnetic resonance (NMR) and Mosher's reactions. Furthermore, the rosI mutant abolished AHL production and significantly decreased growth, exopolysaccharide (EPS) production, biofilm formation, and motility compared to the wild-type strain. These results lay the foundation for further investigating the QS regulation mechanism and signal pathway of R. oryzihabitans M15 and its interactions with the host plant.

Duchenne's muscular dystrophy involves a defective transsulfuration pathway activity

Duchenne muscular dystrophy (DMD) is the most frequent X chromosome-linked disease caused by mutations in the gene encoding for dystrophin, leading to progressive and unstoppable degeneration of skeletal muscle tissues. Despite recent advances in the understanding of the molecular processes involved in the pathogenesis of DMD, there is still no cure. In this study, we aim at investigating the potential involvement of the transsulfuration pathway (TSP), and its by-end product namely hydrogen sulfide (H2S), in primary human myoblasts isolated from DMD donors and skeletal muscles of dystrophic (mdx) mice. In myoblasts of DMD donors, we demonstrate that the expression of key genes regulating the H2S production and TSP activity, including cystathionine γ lyase (CSE), cystathionine beta-synthase (CBS), 3 mercaptopyruvate sulfurtransferase (3-MST), cysteine dioxygenase (CDO), cysteine sulfonic acid decarboxylase (CSAD), glutathione synthase (GS) and γ -glutamylcysteine synthetase (γ-GCS) is reduced. Starting from these findings, using Nuclear Magnetic Resonance (NMR) and quantitative Polymerase Chain Reaction (qPCR) we show that the levels of TSP-related metabolites such as methionine, glycine, glutathione, glutamate and taurine, as well as the expression levels of the aforementioned TSP related genes, are significantly reduced in skeletal muscles of mdx mice compared to healthy controls, at both an early (7 weeks) and overt (17 weeks) stage of the disease. Importantly, the treatment with sodium hydrosulfide (NaHS), a commonly used H2S donor, fully recovers the impaired locomotor activity in both 7 and 17 old mdx mice. This is an effect attributable to the reduced expression of pro-inflammatory markers and restoration of autophagy in skeletal muscle tissues. In conclusion, our study uncovers a defective TSP pathway activity in DMD and highlights the role of H2S-donors for novel and safe adjuvant therapy to treat symptoms of DMD.

Novel approach to study diffusion of hydrogen bearing species in silicate glasses at low temperatures

Diffusion of hydrogen bearing species in glasses plays a significant role in numerous applications in commercial as well as scientific domains. The investigation of diffusion of water in glasses at low temperatures led to experimental and analytical difficulties in the past. We present a new approach that lets us overcome these complications. Diffusion couples of An50Di50 glass (mol %, NBO/T = 0.67) were produced by coating anhydrous glass substrates with thin films of hydrated glass (~200 nm, ~2 wt% H2O) using pulsed laser deposition (PLD). Bonding the diffusant to the glass matrix of the thin film instead of using free water at the interface during experiments precludes other glass altering processes such as dissolution and precipitation. This allows us to confidently interpret the measured profiles to be a result of diffusion only. Nanoscale concentration profiles that result from diffusion at low temperatures on experimentally feasible time scales were measured with the Nuclear Resonance Reaction Analysis (NRRA, 1H(15N,αγ)12C). The non-destructive nature of NRRA enables us to observe and better understand the evolution of diffusion profiles with time within one sample. Evaluation of the sample quality by EPMA, SEM, optical microscopy, Rutherford backscattering spectroscopy (RBS), and NRRA was performed and confirmed the suitability of the samples for diffusion studies. Experiments at 1 atm in a box furnace and at 2 kbar in a CSPV (pressure medium = water) and an IHPV (pressure medium = Argon) prove that the diffusion couples can be used under various experimental conditions. We present diffusion profiles that were measured in experiments carried out in these devices and discuss the distinct features of each that result from different boundary conditions in the experiments.

Hydrogen induced lattice expansion and site occupation analyzed by ion beam methods

We study the absorption of H in ultrathin crystalline Fe/V stacks using elastic recoil detection (ERD) and resonant nuclear reaction analysis (NRA) combined with Rutherford backscattering spectrometry (RBS). Probing with the resonant 1H (15N,αγ) 12C nuclear reaction allows us to profile the hydrogen concentration with high depth resolution, while ERD permits us to quantify the integral hydrogen inventory while minimizing possible ion-beam induced hydrogen desorption. We perform angular scans in order to directly identify the interstitial site occupancy. A detailed analysis of channeling patterns permits us the deduction of crystal strain in as-deposited films as well as H-loaded targets. We observe tetragonal strain formation resulting in c/a = 1.06 and find qualitative indications for tetrahedral site occupation.