Alpha-particle Reactions Research Articles

Investigation of Lithium Deposition in Tri-Layer Llzo Garnet Structure As a Function of Cell Cycling Using Nuclear Reaction Analysis Method

A key challenge of lithium metal batteries is the volumetric expansion of battery after several charging cycles due to the non-uniform deposition of lithium on anode. This leads to lithium dendrite formation compromising battery safety, and poor lifetime. We adapted tri-layer (porous-dense-porous) Al-doped Lithium Lanthanum Zirconium Oxide (LLZO) host (separator) via tape casting. During cycling lithium is deposited in the porous structure preventing dendrite formation. XRD analysis of annealed host structure confirmed presence of cubic phase LLZO which provides higher ionic conductivity. We measured Li distribution on LLZO host structure before and after different cell cycling conditions and investigated the failure mechanism. We performed concentration depth profiles of 7Li and 6Li isotopes by Nuclear Reaction Analysis (NRA) using two different methods: Proton Induced Gamma-ray Emission (PIGE) and Proton Induced Alpha-particle Reaction (Particle-Particle reaction) and compared the results for accuracy. Depth profile of 7Li confirmed 33 at % Li at 0.44µm thickness before cycling which was increased after cycling. The Gaussian distribution of NRA data indicated a uniform Li depth profile in the dense layer. Through electrochemical testing, we measured that Li capacity loss after 5 and 25 charging cycles with 0.1C rate, 1.51mAh and 2.89mAh, respectively, in tri layered LLZO separator.

Deuteron and alpha sub-libraries of JENDL-5

JENDL-5, the latest version of the Japanese evaluated nuclear data library, includes several sub-libraries to contribute to various applications. In this paper, we outline the evaluation and validation of the deuteron reaction sub-library developed mainly for the design of accelerator-based neutron sources and the alpha-particle reaction sub-library developed mainly for use in the back-end field. As for the deuteron sub-library, the data for 6,7Li, 9Be, and 12,13C from JENDL/DEU-2020 were partially modified and adopted. The data up to 200 MeV for 27Al, 63,65Cu, and 93Nb, which are important as accelerator structural materials, were newly evaluated based on the calculations with the DEURACS code. As for the alpha-particle sub-library, the data up to 15 MeV for 18 light nuclides from Li to Si isotopes were evaluated based on the calculations with the CCONE code, and then only the neutron production cross sections were replaced with the data of JENDL/AN-2005. Validation on neutron yield by Monte Carlo transport simulations was performed for both sub-libraries. As a result, it was confirmed that the simulations based on the sub-libraries showed good agreement with experimental data.

Empirical evidence for cosmogenic 3He production by muons

Cosmic ray muons penetrate deeply into rock where they interact with atoms to produce cosmogenic nuclides. Incorporation of the muon contribution to the production rates of cosmogenic nuclides increases the accuracy of exposure dates, burial ages, and erosion rates inferred from measured nuclide concentrations. In the absence of empirical evidence, it is generally assumed that muons do not produce 3He, a cosmogenic nuclide commonly used for exposure dating. Here we assess whether muons produce 3He by measuring He isotope concentrations in pyroxene and ilmenite from a ∼300 m deep drill core and other subsurface samples of the mid-Miocene Columbia River Basalt in Washington, USA. 3He concentrations in our samples exhibit an exponential decline with depth with an e-folding length of 32.4 m, which corresponds to an attenuation length for 3He production of 8780 g cm−2. The deeply penetrating exponential is diagnostic of 3He production by cosmic ray muons. Assuming no erosion, we constrain the minimum surface muonogenic production rate to be 0.23 atom g−1 pyroxene yr−1, whereas when incorporating erosion the production rate is 0.45 atom g−1 pyroxene yr−1. 3He concentrations in samples deeper than ∼100 meters are consistent with model-based estimates of depth-independent nucleogenic production from the capture by 6Li of neutrons produced by alpha particle reactions on light elements. Measurements in other subsurface samples indicate that muon-produced 3He is prevalent across the Columbia Plateau. The penetration depth of muonogenic 3He production is substantially deeper, and the ratio of muon- to spallation-produced 3He is substantially lower, than found for other cosmogenic nuclides. Our results provide the first definitive empirical evidence for 3He production by muons, which has several implications for quantifying the timing and rates of Earth surface change and interpreting He isotope ratios. Importantly, despite the low production rates, landforms in the Channeled Scablands, which were formed by incision of the Columbia River Basalt by the late-Pleistocene Missoula floods, have high concentrations of 3He inherited from post-Miocene muon exposure. Hence 3He production by muons must be considered, particularly when dating rapid erosional events in old bedrock. Our findings indicate samples with less than several tens of meters of shielding by overlying rock will contain cosmogenic 3He that elevates 3He/4He ratios. Hence caution should be used when using 3He/4He ratios from samples at shallower depths to infer mantle sources of basalt.

Gamma-ray emission in alpha-particle reactions with C, Mg, Si, Fe

Cross sections for the strongest γ-ray emission lines produced in α-particle reactions with C, Mg, Si, Fe have been measured in the range E α = 50-90 MeV at the center for protontherapy at the Helmholtz-Zentrum Berlin. Data for more than 60 different γ-ray lines were determined, with particular efforts for lines that are in cross section compilations/evaluations with astrophysical purpose, and where data exist at lower projectile energies. The data are compared with predictions of a modern nuclear reaction code and cross-section curves of the latest evaluation for gamma-ray line emission in accelerated-particle interactions in solar flares.

RESEARCH OF ALPHA-PARTICLE TRANSFER REACTIONS

This paper presents the capabilities of nuclear physics for the development of nuclear cluster physics. Frequencies of several nucleons, acting as component clusters, are one of the key aspects of the nuclear device. Therefore, the basis for the clustering was helium nuclei (α-particles). This article explores the different types of cluster ensembles and different types of unmanaged nuclei as the fundamental components of new quantum environments. The experimental results of the α-particle transfer reactions under the complete synthesis of some of the cluster nuclei show the formula for those reactions. Specifically, this work focuses on the so-called "cluster nucleus model" - a model that describes the excited states of the nuclei, ie helium nuclei. One of the most important goals of this work is to carefully analyze the author's available data on research of alpha-particle reactions and to compare them with today's promising models of nuclei, to identify and explain new patterns. The author of the article received experimental data from various publications in journal articles and "personal contact". Relevant sources in the article have reference to sources.

A suspended boron foil multi-wire proportional counter neutron detector

Three natural boron foils, approximately 1.0cm in diameter and 1.0µm thick, were obtained from The Lebow Company and suspended in a multi-wire proportional counter. Suspending the B foils allowed the alpha particle and Li ion reaction products to escape simultaneously, one on each side of the foil, and be measured concurrently in the gas volume. The thermal neutron response pulse-height spectrum was obtained and two obvious peaks appear from the 94% and 6% branches of the 10B(n,α)7Li neutron reaction. Scanning electron microscope images were collected to obtain the exact B foil thicknesses and MCNP6 simulations were completed for those same B thicknesses. Pulse-height spectra obtained from the simulations were compared to experimental data and matched well. The theoretical intrinsic thermal–neutron detection efficiency for enriched 10B foils was calculated and is presented. Additionally, the intrinsic thermal neutron detection efficiency of the three natural B foils was calculated to be 3.2±0.2%.

The Risky Road to Mars

In their Report “Measurements of energetic particle radiation in transit to Mars on the Mars Science Laboratory” (31 May, p. [1080][1]), C. Zeitlin et al. try to assess the radiation risks to astronauts from exposure to galactic cosmic rays and solar flares during a manned expedition to Mars. They conclude that astronauts will receive about two-thirds of the lifetime exposure limit for humans during the round trip. I believe the dose could be even higher. ![Figure][2] Astronaut on Mars (artist's conception) CREDIT: DIETER SPEARS/INHAUS CREATIVE/ISTOCKPHOTOS Zeitlin et al. did not consider the secondary effects of radiation-induced nuclear reactions in the human body. Nuclear reactions of protons and alpha particles with carbon, nitrogen, and oxygen nuclei lead to formation of lithium, beryllium, and boron nuclei. These reactions are most likely to happen for incident protons and alphas with energies between 5 and 100 MeV, particularly those between 10 and 50 MeV ([ 1 ][3]). The lithium, beryllium, and boron nuclei produced in such reactions are low in energy and much more heavily ionizing (i.e., more dangerous) than higher-energy protons or alphas. Thus, this type of radiation, below 100 MeV, is most likely to produce significant damage in human tissue. This radiation comes not only from the primary flare and galactic cosmic ray fluxes studied by Zeitlin et al. , but also from the secondary flux of protons and alphas originating in the space capsule shielding, as well as from nuclear reactions. In the event of a significant solar flare event while an astronaut is outside the space capsule, the radiation effects would be further magnified, because the reaction probabilities are highest at energies corresponding to the solar flare spectrum. 1. [↵][4] 1. S. M. Read, 2. V. E. Viola , Atomic Data and Nuclear Data Tables 31, 359 (1984). [OpenUrl][5][CrossRef][6][Web of Science][7] [1]: /lookup/doi/10.1126/science.1235989 [2]: pending:yes [3]: #ref-1 [4]: #xref-ref-1-1 View reference 1 in text [5]: {openurl}?query=rft.jtitle%253DAtomic%2BData%2Band%2BNuclear%2BData%2BTables%26rft.volume%253D31%26rft.spage%253D359%26rft_id%253Dinfo%253Adoi%252F10.1016%252F0092-640X%252884%252990009-3%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [6]: /lookup/external-ref?access_num=10.1016/0092-640X(84)90009-3&link_type=DOI [7]: /lookup/external-ref?access_num=A1984ADL7000001&link_type=ISI

Adsorption interaction of carrier-free thallium species with gold and quartz surfaces

Abstract The adsorption interactions of thallium and its compounds with gold and quartz surfaces were investigated. Carrier-free amounts of thallium were produced in nuclear fusion reactions of alpha particles with thick gold targets. The method chosen for the studies was gas thermochromatography and varying the redox potential of the carrier gases. It was observed that thallium is extremely sensitive to trace amounts of oxygen and water, and can even be oxidized by the hydroxyl groups located on the quartz surface. The experiments on a quartz surface with O2, He, H2 gas in addition with water revealed the formation and deposition of only one thallium species – TlOH. The adsorption enthalpy was determined to be Δ H SiO2 ads(TlOH) = −134 ± 5 kJ mol−1. A series of experiments using gold as stationary surface and different carrier gases resulted in the detection of two thallium species – metallic Tl (H2 as carrier gas) and TlOH (O2, O2+H2O and H2+H2O as pure carrier gas or carrier gas mixture) with Δ H Au ads(Tl) = −270 ± 10 kJ mol− and Δ H Au ads(TlOH) = −146 ± 3 kJ mol−1. These data demonstrate a weak interaction of TlOH with both quartz and gold surfaces. The data represent important information for the design of future experiments with the heavier homologue of Tl in group 13 of the periodic table – element 113 (E113).

A simulation of neutron interaction from Am–Be source with the CR-39 detector

Abstract Presented in this paper is a simulation of the interaction of neutrons emitted from a cylindrical Am–Be source with a CR-39 detector. A Fortran90 program, called Neutron.f90, has been written to determine the specifications of secondary particles (alpha particle or proton) and the kinematics of the interactions. A Monte Carlo method was used to simulate which interactions occurred with the constituents of the CR-39 detector, H, C and O atoms. Due to the detector composition, elastic and nonelastic scattering of neutrons is possible. In this paper, nonelastic scattering includes: inelastic scattering; the emission of an alpha particle (n,α) reaction and the emission of a proton (n,p) reaction. Cross sections of other reactions are very small and negligible in comparison with the above mentioned. The energy deposited per unit mass per one neutron was calculated. In addition the contribution to the energy deposited by the alpha particles and protons were determined separately. The program Neutron.f90 computes the coordinates of points in which interactions occur i.e. where secondary particles appear. The energy and angular distributions of protons are also represented in this paper. Another Fortran90 program, called Track_Visibility.f90, was written to calculate the number of visible proton tracks and to calculate the energy deposited per one neutron per one visible track.

Delayed X‐ and Gamma‐Ray Line Emission from Solar Flare Radioactivity

We have studied the radioactive line emission expected from solar active regions after large flares, following the production of long-lived radioisotopes by nuclear interactions of flare-accelerated ions. This delayed X- and gamma-ray line emission can provide unique information on the accelerated particle composition and energy spectrum, as well as on mixing processes in the solar atmosphere. Total cross sections for the formation of the main radioisotopes by proton, 3-He and alpha-particle reactions are evaluated from available data combined with nuclear reaction theory. Thick-target radioisotope yields are provided in tabular form, which can be used to predict fluxes of all of the major delayed lines at any time after a gamma-ray flare. The brightest delayed line for days after the flare is found to be the 511 keV positron-electron annihilation line resulting from the decay of several beta+ radioisotopes. After ~2 days however, the flux of the 511 keV line can become lower than that of the 846.8 keV line from the decay of 56-Co. Our study has revealed other delayed gamma-ray lines that appear to be promising for detection, e.g. at 1434 keV from the radioactivity of both the isomer and the ground state of 52-Mn, 1332 and 1792 keV from 60-Cu, and 931.1 keV from 55-Co. The strongest delayed X-ray line is found to be the Co Kalpha at 6.92 keV, which is produced from both the decay of the isomer of 58-Co by the conversion of a K-shell electron and the decay of 57-Ni by orbital electron capture. Prospects for observation of these lines with RHESSI or future space instruments are discussed.

Alpha-particle clustering in nuclear reactions

There is extensive evidence that nucleons in the nucleus can sometimes form clusters and, of these, alpha-particle clusters are the most likely. This is illustrated by considering alpha-particle emission, transfer and capture reactions, and also the interactions of electrons, pions and kaons with nuclei. Present knowledge of the probability of clustering as a function of atomic number and position in the nucleus is summarized.

Evaluation of The (α, n) Reaction Nuclear Data for Light Nuclei

Nuclear data of emitted neutrons by the reactions of alpha particles incident on light nuclei: 6,7Li, 9Be, 10,11B, 12,13C, 14,15N and 17,l8O have been evaluated in the alpha particle energy Eα (lab.) below 15 MeV.

Alpha-particle reactions

Recent work using the concept of alpha-clustering in studies of nuclear structure and nuclear reactions is reviewed. The high symmetry and binding energy of the alpha-particle makes it likely that nucleons inside the nucleus can condense into alpha particles and live long enough to affect many properties of nuclei and also the cross-sections of nuclear reactions, particularly those with alpha-particles as the projectile or ejectile. The alpha-particles inside the nucleus may escape, and the resulting alpha decay is now quite well understood. An incident projectile may collide with a transient alpha-particle in the nucleus and knock it out, thus providing information on the degree of clustering. This model enables the direct part of the cross-sections of (n, α) reactions to be calculated. The alpha-particle mean field unifies many of the characteristics of alpha-particle structure and alpha-particle scattering. Many properties of light nuclei may be simply explained using the concept of alpha-clustering.

SiC particles from asymptotic giant branch stars - MG burning and the s-process

The question of whether isotopically anomalous SiC particles found in meteorites originate in AGB stars is addressed. It is shown that if the peak helium shell flash temperatures of massive (6-9 solar masses) stars are about 10 percent larger than they are normally assumed to be, alpha particle reactions with the magnesium will become significant. Then the (Mg-29)(alpha, n)Si-29 reaction produces a large excess of Si-29. With a light element nuclear reaction network, the evolution of the silicon isotopic composition during AGB evolution is calculated. It is found that the experimentally determined correlation between excess Si-29 and excess Si-30 in SiC particles from carbonaceous chondrites can indeed be naturally produced in this way. It is suggested that if the large isotopically anomalous SiC particles carrying nearly pure-process krypton and xenon do indeed originate in AGB stars, those stars were massive and had peak shell flash temperatures near 450 KM.

Some nuclear data needs in astrophysics

Abstract In this paper we discuss a number of astrophysical environments and how improved nuclear data could facilitate a better understanding of them. One area of interest includes proton and alpha-particle reactions with unstable nuclei which are necessary for understanding the nucleosynthesis and energy generation in hot hydrogen-burning environments. Efforts underway at LLNL and elsewhere to develop the technology for the measurement of these reaction rates are discussed. Heavy-element nucleosynthesis in the late stages of red-giant stars and supernovae requires a complete network of neutron capture rates and beta-decay rates for nuclei near and far from stability. Experimental and theoretical efforts at LLNL to supply the input data and to model the nucleosynthetic environments will be outlined. Suggestions are made as to which nuclear data are most critical for the various scenarios.

Direct evidence for mixing of two-quasiproton and two-quasineutron configurations in 172Yb

The 175Lu(p,α)172Yb reaction has been studied using beams of 17 MeV protons from the McMaster University tandem Van de Graaff accelerator. The alpha particle reaction products were analyzed with a magnetic spectrograph and detected with photographic emulsions. Levels up to an excitation energy of 2.8 MeV were studied with a resolution of 20 keV FWHM. The spin 3, 4, 5, and 6 members of the Kπ = 3+ band at 1172 keV were populated appreciably, indicating the existence of a significant two-quasiproton admixture in this band. The measured angular distributions and relative intensities within the band are consistent only with a Kπ = 3+, {7/2+ [404] − 1/2+ [411]} configuration for this admixture, and the absolute intensities indicate that it makes up (27 ± 10)% of the state. This observation provides a quantitative explanation for the observed magnetic moment of the 1172 keV level and also for the observed E2–M1 mixing ratios within the band. It may also be important in the explanation of other anomalous properties of this band. The present measurements also show large Kπ = 3+, {7/2+ [404] − 1/2+ [411]} admixtures in the previously assigned Kπ = 2+ band at 1609 keV and the Kπ = 3+ band at 1663 keV. In addition, the assignment of the 2073 and 2192 keV levels as Iπ = 4+ and 5+ members of a Kπ = 4+, {7/2+ [404] + 1/2+[411]} band has been confirmed.

Deuteron and alpha-particle total reaction cross sections for nuclei with A∼50

The total reaction cross sections for the target nuclei 45Sc, 48Ti, 51V and 52,53,54Cr induced by 13.6 MeV deuterons and 27.2 MeV alpha particles were measured. The deuteron-induced total reaction cross sections for 48Ti and 52,54Cr are well reproduced by optical-model calculations. Ambiguity of parameters for these nuclei is reduced considerably. The total reaction cross sections corresponding to alpha particles are analysed in the quasiclassical approximation. It is shown that isotopic-isotonic effects may be explained quantitatively if one assumes that the diffuseness of the nuclear density distribution for the nucleus 52Cr is less than that for 51V by Delta a=0.28+or-0.11 fm, and the diffuseness of the isotope 54Cr is greater than that for 52Cr by Delta a=0.13+or-0.11 fm. The optical-model analysis of elastic scattering and total reaction cross sections for the nuclei 45Sc, 48Ti and 51V was carried out concurrently. The experimental data are explained successfully using a six-parameter optical potential.

Alpha-particle breakup at incident energies of 20 and 40 MeV/nucleon

The breakup of alpha particles at incident energies of 20 and 40 MeV/nucleon on $^{27}\mathrm{Al}$, $^{58}\mathrm{Ni}$, $^{90}\mathrm{Zr}$, and $^{209}\mathrm{Bi}$ has been studied. It was found that the breakup cross section decreases rapidly with increasing angles and increases with increasing target mass and incident energy. The total breakup yield, summed over all charged fragments, is \ensuremath{\sim}15-35% of the alpha-particle total reaction cross section, and has an approximate ${A}^{\frac{1}{3}}$ dependence. The ratios of breakup yields among different fragments are approximately $p:d:t:^{3}\mathrm{He}\ensuremath{\approx}13:3:1:2$, and are roughly independent of the incident energy and the target nucleus. These features suggest that the alpha-particle fragmentation is a peripheral process and is dominated by the properties of the incident projectile. A simple plane-wave alpha-particle breakup model gives a rather good description to the experimental data. In addition to the breakup deuteron peak at half of the beam energy, a second peak at quarter of the beam energy (or the same energy as the breakup proton peak) is observed. This peak might be due to a two-step breakup-pickup process.NUCLEAR REACTIONS $^{27}\mathrm{Al}$, $^{58}\mathrm{Ni}$, $^{90}\mathrm{Zr}$, $^{209}\mathrm{Bi}$($\ensuremath{\alpha}$,$\mathrm{xp}$), ($\ensuremath{\alpha}$,$\mathrm{xd}$), ($\ensuremath{\alpha}$,$\mathrm{xt}$), ($\ensuremath{\alpha}$, $x^{3}\mathrm{He}$,) ${E}_{\ensuremath{\alpha}}=80, 160$ MeV; $\ensuremath{\theta}=6\ifmmode^\circ\else\textdegree\fi{}\ensuremath{-}30\ifmmode^\circ\else\textdegree\fi{}$, measured $\frac{{d}^{2}\ensuremath{\sigma}}{d\ensuremath{\Omega}\mathrm{dE}}$, deduced alpha-particle breakup yield, Comparisons with alpha-particle breakup model.

Production of Li and B in proton and alpha-particle reactions onN14at low energies

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Proton Spectra from 54.8-MeV Alpha-Particle Reactions: Precompound Emission

An experimental survey of 54.8-MeV ( alpha ,p) proton spectra is undertaken for studying pre-equillbrium emission; such deexcitation yields on the average cross sections about 250 mb, the average value measured for all the investigated reactions. Different quantitative formulations are discussed in tenns of exciton state mean lifetimes: the exciton and hybrid mcdels are found to give a good interpretation of the proton emision cross sections. A geometrical distinction between the equilibrium and nonequilibrium processes may be attempted. Odd-even effects appear in ( alpha ,p) reactions by means of partial state density: Odd-Z targets require an initial exciton number n/sib I/ equal to five (3p-2n-Oh) and even-Z targets equal to four (2p-2n-Oh). This result may be attributed to a pairing effect according to the odd-even character of residual nuclei.