Radioactive Nuclei Research Articles

Equation of Weak Nuclear Force

We present new approach and new equation of treating and calculating weak nuclear force depends on the main physical parameters responsible of forming the weak force. The nucleons (protons & neutrons) with certain masses (1.7 x 10-27 kg) of each particle at very short certain distance ((10-17 m - 10-18 m)) is main condition of producing weak nuclear force. So, the weak nuclear force can be calculated by using the two main physical parameters responsible for its existence (mass, distance) in addition to the time of ejecting the particles and radiations from nucleus to enable an unstable nucleus to become energetically stable nucleus which is the main role of the weak nuclear force. The calculated value of weak nuclear force for two nucleons (proton & neutron) to be U 3 x 10-5 Newton and consequently the weak nuclear force with increasing number of nucleons is linearly additive as binding energy of atomic nucleus.

New tests of quantum mechanics with unstable nuclei

New tests of quantum mechanics with unstable nuclei

Feedback from low-to-moderate-luminosity radio-active galactic nuclei with MaNGA

Context. Spatially resolved spectral studies of galaxies hosting a radio-active galactic nucleus (radio-AGN) have shown that these systems can impact ionised gas on galactic scales. However, it is still unclear whether jet and radiation-driven feedback occurs simultaneously. The relative contribution of these two mechanisms in driving feedback in the AGN residing in the Local Universe is also poorly understood. Aims. We selected a large and representative sample of 806 radio-AGN from the MaNGA survey, which provides integral field unit (IFU) optical spectra for nearby galaxies. We define radio-AGN as sources having excess emission above the level that is expected from star formation. We aim to study the feedback driven by radio-AGN on the galaxy’s ionised gas, its location, and its relation to AGN properties. We also aim to disentangle the role of jets and radiation in these systems. Methods. We used a sample of nearby radio-AGN from L1.4 GHz ≈ 1021 − 1025 W Hz−1 to trace the kinematics of the warm ionised gas phase using their [O III] emission line. We measured the [O III] line width and compared it to the stellar velocity dispersion to determine the presence and location of the disturbed gas. We investigated the dependence of radial profiles of these properties on the presence of jets and radiation, along with their radio luminosities. Results. We mainly found disturbed [O III] kinematics and proportion of disturbed sources up to a radial distance of 0.25 Reff, when both radio- and optical-AGN are present in a source, and when the radio luminosity is greater than 1023 W Hz−1. When it is either only radio- or optical-AGN present, the impact on [O III] is milder. Irrespective of luminosity and the presence of an AGN, we find no evidence for feedback from radio-AGN on [O III] kinematics at radial distances larger than 0.25 Reff. Conclusions. The presence of more kinematically disturbed warm ionised gas in the central region of radio-AGN host galaxies is related to both jets and radiation in these sources. We propose that in moderate-radio-luminosity AGN (L1.4 GHz ≈ 1023 − 1025 W Hz−1), the gas clouds pushed to high velocities by the jets (radiation) are driven to even higher velocities by the impact of radiation (jets) when both radio- and optical-AGN are present. At lower luminosities (L1.4 GHz ≈ 1021 − 1023 W Hz−1), the correlation between the disturbed ionised gas and enhanced radio emission could either be due to wind-driven shocks powering the radio emission or low-power jets disturbing the gas. Finally, beyond 0.25 Reff, the lack of any disturbed [O III] suggests a weak coupling between the jets and the ionised gas in these sources.

STORI24: Constraining Explosive Nucleosynthesis by Indirect Reaction Methods at Storage Rings using unstable beams in batch mode

Abstract Nuclear reaction studies on unstable isotopes can strongly help in improving our understanding of nucleosynthesis in stars. Indirect approaches to determining astrophysical reaction rates are increasingly common-place and undergoing continuous refinement. Of particular interest is the use of such indirect techniques at storage rings, which, among other allow to recycle rare unstable beams. We propose to investigate reaction rates of astrophysical interest using indirect methods (surrogate, Trojan horse….) in reverse kinematics at the IMP-CAS storage ring. Long lived radioactive ion beams, produced remotely, can be accelerated, and made interacting with light targets. Proposed reactions are 85Kr(p,p’γ), 85Kr(d,pγ), constraining the neutron flux in an s-process branching point, 79Se(p,p’γ), 79Se(d,pγ), constraining the temperature in s-process nucleosyntheses, 59Fe(d,pγ), constraining core collapse supernovae.

Measurement of the sign of the magnetic moment for unstable nuclei using newly developed rotating radio-frequency field system

Abstract Nuclear magnetic moment (μ) measurements provide useful information on nuclear structures. For unstable nuclei, nuclear magnetic resonance (NMR) of in-beam polarized nuclei with beta asymmetry detection (β-NMR) is a powerful method to determine μ. In this method, the sign of μ can be determined using rotating radio-frequency (RF) fields. In this article, we developed a new system to apply rotating RF fields that can produce almost complete circular rotation, compared to that in previous systems. Using this system, we successfully determined the sign of μ for 29P and 25Al. For both nuclei, the sign of μ is positive, which is consistent with the predictions of the single particle shell model. This article details the new rotating RF field system.

STORI'24: Recent developments at the Rare-RI Ring facility

Abstract The Rare-RI Ring (R3) is an isochronous storage ring for the purpose of deriving the masses of extremely short-lived rare RIs by applying TOF measurement method. Since the successful commissioning experiment in 2015, the technical developments have been continued to improve the efficiency and precision for mass measurements. Through initial experiments using unstable nuclei with well-known masses conducted up to 2017, the mass derivation method was established [1]. After, experiments for unknown masses were started because realistic extraction yield and precise isochronous condition were achieved. Recent developments to further improve the efficiency of mass measurement, which were carried out in parallel with the experiments represented in [2], are described below.
The improved kicker system can perform an extraction kick with a long duration equal to revolution time of the ring. In addition to shortening the measurement time, it is essential for extracting extremely rare events whose extraction timing cannot be specified. It has been found that the extraction yields can be dramatically improved by tuning the injection optics with the vertical steering magnets. In addition, a new Schottky detector is able to detect single events in timeframes on the order of milliseconds. It will be useful not only for beam diagnostics of short-lived rare RIs, but also for lifetime measurement experiments for rare RIs planned as a future application of R3. Details of these developments will be presented.

References
[1] D. Nagae et al., Phys. Rev. C 110, 014310 (2024).
[2] H.F. Li et al., Phys. Rev. Lett. 128, 152701 (2022).

Calculation of alpha decay half-lives for even–even nuclei with modified Morse potential using Gamow theory

In this work, the modified Morse potential is proposed as a nuclear potential. An analytical study is carried out to calculate the alpha decay half-life of radioactive nuclei with the Morse potential using Gamow theory. To do this, the Wentzel–Kramers–Brillouin (WKB) approximation and Bohr–Sommerfeld quantization condition are used to determine the parameters of the nuclear potential and the expression of the normalization factor F. The calculations are based on the alpha decay half-lives of 118 even–even nuclei radioactive alpha emitting with atomic number Z ranging from 52 to 104. It is then established a correlation between the half-lives found and the energy Q of the emitted alpha particle. Finally, the results obtained are discussed in comparison with experimental results and the literature.

Velocity Structure Correlations between the Nebular, Molecular, and Atmospheric Gases in the Cores of Four Cool Core Clusters

Abstract We investigate the velocity structure of nebular gas in the central galaxies of four clusters: A1835, PKS 0745−191, A262, and RXJ0820.9+0752, using data from the Keck Cosmic Web Imager. Velocity structure functions (VSFs) of the [O ii] emission line are compared to VSFs of molecular clouds observed with the Atacama Large Millimeter/submillimeter Array. Apart from A262, where the gas is located in a circumnuclear disk, the nebular gas in the remaining galaxies lies in off-nuclear filamentary structures with VSFs steeper than the Kolmogorov slope. This steepening may be plausibly attributed to gravity, although other factors, such as magnetic stresses and bulk motion, may be significant. The VSFs of CO and [O ii] emission are similar in RXJ0820 and A262, indicating close coupling of the nebular and molecular gases. In contrast, the nebular and molecular gases are differentiated on most scales in PKS 0745 and A1835. This discrepancy is likely due to the radioactive galactic nucleus churning the gas. We compare the scale-dependent velocity amplitudes of the hot atmospheres constrained by X-ray surface brightness fluctuation analysis using Chandra observations to the nebular VSFs. The large-scale consistency in A1835 and RXJ0820 is consistent with condensation from the hot atmospheres. We explore substantial systematic biases, including projection effects, windowing, and smoothing effects, when comparing VSFs using different telescopes and instruments.

Bohr Hamiltonian with energy-dependent (ED) inverse square potential for $$\gamma $$-unstable nuclei

Bohr Hamiltonian with energy-dependent (ED) inverse square potential for $$\gamma $$-unstable nuclei

Explanation of the nature of the island of inversion exhibited by 32Mg at the Hartree-Fock-Bogoliubov level and beyond* *Partly supported by the Strategic Priority Research Program of Chinese Academy of Sciences (XDB34000000), the Fundamental Research Funds for the Central Universities (lzujbky-2023-stlt01), the National Natural Science Foundation of China (12275111,12075104), the National Key Research and Development (R&D) Program (2021YFA1601500)

This study presents an explanation of the nature of the island of inversion exhibited by the unstable nucleus 32Mg through the application of the axially deformed relativistic Hartree-Fock-Bogoliubov (D-RHFB) and configuration-interaction relativistic Hartree-Fock (CI-RHF) models, which correspond to the Hartree-Fock-Bogoliubov level and beyond, respectively. Using the same Lagrangian PKA1, the D-RHFB and CI-RHF models demonstrate an excellent agreement with experimental data for the ground-state deformation and the low-lying excitation energies of 32Mg. Furthermore, a new insight into the nature of the island of inversion is implemented from the breaking of the pseudo-spin symmetry (PSS) in addition to the cross-shell excitation, both of which are essential to obtaining a stable deformation and rotational collectivity for 32Mg. In particular, the exchange degrees of freedom, such as the ρ-tensor coupling in PKA1, are shown to be essential in determining the configuration interactions and binding of the nucleus.

The aluminium-26 distribution in a cosmological simulation of a Milky Way-type Galaxy

Context. The 1.8 MeV γ-rays corresponding to the decay of the radioactive isotope 26Al (with a half-life of 0.72 Myr ) have been observed by the SPI detector on the INTEGRAL spacecraft and extensively used as a tracer of star formation and current nucleosynthetic activity in the Milky Way Galaxy. Further information is encoded in the observation related to the higher 26Al content found in regions of the Galaxy with the highest line-of-sight (LoS) velocity relative to an observer located in the Solar System. However, this feature remains unexplained. Aims. We ran a cosmological “zoom-in” chemodynamical simulation of a Milky Way-type galaxy, including the production and decays of radioactive nuclei in a fully self-consistent way. We then analyzed the results to follow the evolution of 26Al throughout the lifetime of the simulated galaxy to provide a new method for interpreting the 26Al observations. Methods. We included the massive star sources of 26Al in the Galaxy and its radioactive decay into a state-of-the-art galactic chemical evolution model, coupled with cosmological growth and hydrodynamics. This approach allowed us to follow the spatial and temporal evolution of the 26Al content in the simulated galaxy. Results. Our results are in agreement with the observations with respect to the fact that gas particles in the simulation with relatively higher 26Al content also have the highest LoS velocities. On the other hand, gas particles with relatively lower 26Al content (i.e., not bright enough to be observed) generally display the lowest LoS velocities. However, this result is not conclusive because the overall rotational velocity of our simulated galaxy is higher than that observed for cold CO gas in the Milky Way Galaxy. Furthermore, we found no significant correlation between gas temperature, rotational velocity, and 26Al content at any given radius. We also found the presence of transient 26Al-rich spots at low LoS velocities and we show that one such spot had been captured by the INTEGRAL/SPI data. Based on our model, we present a prediction for the detection of 1.8 MeV γ-rays by the future COSI mission. We find that according to our model, the new instrument will be able to observe similar 26Al-emission patterns to those seen by INTEGRAL/SPI.

A Phenomenological Model, Quantum Mechanics and Complexity in the Cold Fusion Phenomenon – A Review

We have investigated the basis of the TNCF model, a phenomenological model proposed in 1994, using ideas and calculations we gave after the proposal of the model. We have pondered especially a mechanism of deexcitation of an unstable nucleus in transition-metal hydrides/deuterides by interaction with neutrons in neutron bands dissipating energy into lattice oscillation. The mechanism of dissipation of unstable nuclei in transition-metal hydrides seems overwhelmingly more effective than the mechanism of deexcitation by photon emission. The effectiveness seems enormous when there are a lot of neutrons in the neutron bands formed by the super-nuclear interaction between neutrons in lattice nuclei mediated by the strong neutron-proton/deuteron interaction, realized by the non-localized wavefunction of occluded proton/deuteron. The conditions for the formation of neutron bands where the wavefunctions of the occluded proton/deuterons overlap with that of neutrons in lattice nuclei collate closely with the peculiarity of physics and chemistry, such as the super-diffusivity of hydrogen and hydrogen electrode reaction, in transition-metal hydrides.

HEALTH SURVEILLANCE OF EXPOSED PERSONS IN AN HADRONTHERAPY CENTRE

The Centro Nazionale di Adroterapia Oncologica (CNAO) of Pavia is the only Italian structure capable of administering therapeutic radiotherapy treatments with heavy particles (carbon ions, protons) accelerated; in addition to this, it hosts significant research activity, both as basic research and for health-related applications.From the perspective of radioprotection, the most significant risk profile is that linked to external irradiation, from three categories of sources: accelerated external beams (in addition to the treatment beams there are conventional linear accelerators), materials activated following irradiation during treatment or during research activities, unstable isotopes used for diagnostic purposes. The CNAO building has been designed and built to guarantee maximum safety both to the operator and to the patient or visitor, with widely redundant systems in order to exclude the occurrence of accidental irradiation, and to minimize the risk of exposure to activated materials. The cohort of workers shows "atypical" characteristics for healthcareG Ital Med Lav Erg 2020; 42:4 facilities due to the absolute disproportion between classified and unclassified personnel, the homogeneity of training paths, and demographic characteristics. The health surveillance of the exposed, all classified in category B pursuant to Legislative Decree 230/95, is based on the adoption of the AIRM Protocol, tempered on the specific characteristics of the work process. The main critical issues related to the health surveillance of the exposed CNAO workers come from the energies used, with significant activation capacity, and from the presence of personnel in training.

Determination of nuclear charge radius by extreme-ultraviolet spectroscopy of Na-like ions

We report on a method for determining the absolute nuclear charge radius of high-Z elements using extreme-ultraviolet spectroscopy of highly charged Na-like ions in tandem with highly accurate atomic structure calculations of transition energy differences. The application of this method has reduced the nuclear charge radius uncertainty of Ir191 by a factor of 8 from the currently accepted literature value, with a recently reported charge radius of 5.442(12) fm. The result reduces the charge radius uncertainty along the full Ir isotopic chain when combined with prior optical isotope shift measurements. The technique utilizes only a few million ions stored in an ion trap, which should apply to measurements with small quantities of radioactive nuclei. Published by the American Physical Society 2025

Machine learning enabled measurements of astrophysical ( p,n ) reactions with the SECAR recoil separator

The synthesis of heavy elements in supernovae is affected by low-energy (n,p) and (p,n) reactions on unstable nuclei, yet experimental data on such reaction rates are scarce. The SECAR (SEparator for CApture Reactions) recoil separator at FRIB (Facility for Rare Isotope Beams) was originally designed to measure astrophysical reactions that change the mass of a nucleus significantly. We used a novel approach that integrates machine learning with ion-optical simulations to find an ion-optical solution for the separator that enables the measurement of (p,n) reactions, despite the reaction leaving the mass of the nucleus nearly unchanged. A new measurement of the Fe58(p,n)Co58 reaction in inverse kinematics with a 3.66±0.12 MeV/nucleon Fe58 beam (corresponding to 3.69±0.12 MeV proton energy in normal kinematics) yielded a cross-section of 20.3±6.3 mb and served as a proof of principle experiment for the new technique demonstrating its effectiveness in achieving the required performance criteria. This novel approach paves the way for studying astrophysically important (p,n) reactions on unstable nuclei produced at FRIB. Published by the American Physical Society 2025

A Review on Application of Radioisotopes in Cancer Therapy

Radioisotope therapy is a procedure where liquid radiation, such as Lutathera, along with amino acids to protect the kidneys, are administered through an infusion. The liquid radiation targets cancerous cells while causing minimal damage to surrounding healthy cells. Radiopharmaceutical are radioactive isotopes which are used to diagnose or work as a cancer therapy. Radioactive isotopes have unstable nucleus that decays or emit excess radiation or energy until the nucleus becomes stable. To date, researchers have discovered radioactive substances that can target various cancer like thyroid cancer, lymphoma, ovarian cancer, brain cancer or cancer which widespread to the bones. In the thyroid cancer the cause is unknown or poorly understood but may involve the genetic and environmental factors

Effects of nuclear deformation and surface polarization on proton-emission half-lives* *Supported by the National Key R&D Program of China (2023YFA1606503), the National Natural Science Foundation of China (12035011, 12447114, 12022517, 11975167) , and the Postdoctoral Fellowship Program of CPSF (GZB20240560)

Proton radioactivity is used to investigate the characteristics of unstable neutron-deficient nuclei beyond the proton dripline. Based on the tunneling of one proton through the potential barrier formed by Woods-Saxon plus expanded Coulomb potentials, the half-lives of various proton emitters are calculated using distorted wave Born approximations. In particular, deformation and nuclear surface polarization are considered in our calculation, and their effects on proton-emission half-lives are researched. An analytic formula expressing the relationship between spectroscopic factors and deformation and polarization, which significantly reduces the deviations of calculated half-lives from experimental data, is proposed as well. Moreover, inspired by the new experimental results for the first proton emitter ever discovered, [L. G. Sarmiento et al., Nat. Commun. 14, 5961 (2023)], we calculate its two proton-emission branches and interpret the partial half-lives. It is noteworthy that this high-spin isomer has some particular characteristics, including diminutive spectroscopic factors and stronger daughter-proton interactions, that considerably enhance the effects of deformation and polarization.

Building bridges between nuclear structure and reactions

The past couple of decades have seen tremendous advances in nuclear structure and reaction theory. Innovative theory frameworks for describing the nuclear many-body system, increasingly powerful computers, and opportunities for confronting theory predictions with data on unstable nuclei, have been driving the field. An important goal is to move from phenomenological ingredients in reaction calculations to predictive theories based on microscopic frameworks. We discuss ongoing efforts aimed at integrating microscopic descriptions of nuclear structure into reaction predictions for medium-mass and heavy nuclei. This contribution highlights areas where Eric Bauge, a champion for building bridges, has made important contributions by encouraging and enabling collaborations between communities with complementary expertise.

Nuclear reaction analyses for green chemistry: Evaluating environmental safety in charged particle interactions

The total stopping power, range and stopping time were calculated using relativity theory equation of Betha's at energies ranging from 1 MeV to 1000 MeV. Depending on the nuclear reactions that produce charged particles such as nuclei 2046Ca, 2246Ti and 1225Mg decompose into alpha-beta and a proton, respectively, where the nuclear energy levels and binding energies of the radioactive nuclei were calculated by NuShellX@MSU program to obtain the energies of the beta, alpha and proton particles as induced projectiles by the targets are water, benzene and sodium chloride molecules. We applied the density functional theory to carry out the analysis of the molecules by Density Functional Theory/Gaussian 09W and GaussView 5.8. Ionization potential, HOMO- LUMO level energy, total electronic density and electrostatic potential have been determined by Density Functional Theory method of target in calculation of the total stopping power, range and stopping time of charged particles. The total stopping power, impact range and stopping time calculations of water, benzene and sodium chloride molecules results have been done by computer code in MATLAB language. The best agreement between the obtained results in energy region above 10 MeV was achieved, the total stopping power decreases in the alpha and proton state. At 1 MeV to 1000 MeV energy range, our calculations to stopping power and time with range in water, benzene and sodium chloride molecules are in excellent agreement with obtained results as function of beta energy. The study shows the stopping power of these materials due to their importance and benefit, and provide the reason why these materials have a high stopping power for impacting charged particles.

Measurement of <sup>85</sup>Sr(n, γ) cross sections of unstable nuclei in HI-13 tandem accelerators by surrogate-reaction method

<sec>Neutron capture cross sections, as important parameters for describing the probability of neutron-nucleus reactions, play a key role in multiple scientific fields. In astrophysics, neutron capture cross section data are essential elements for understanding stellar nucleosynthesis processes. In particular, in extreme environments such as supernova explosions and neutron star mergers, accurate neutron capture cross sections can reveal the secrets of heavy element formation. In the field of national security, neutron capture cross sections are crucial for the design of nuclear weapons and the security of nuclear materials. By accurately grasping the neutron capture characteristics of different nuclides, the nuclear reaction process can be optimized to ensure strategic security. In addition, in the simulation of nuclear power generation, neutron capture cross section data are the basis of reactor design and operational analysis. Through in-depth research on and precise measurements of neutron capture cross sections, the safety and efficiency of nuclear reactors can be improved, thus promoting the sustainable development of nuclear energy. At present, there is little research on the neutron capture cross sections of nuclides with half-lives of only a few years or even shorter, mainly due to the complexity of measurement techniques and the instability of the nuclides themselves. The neutron capture cross section data of these nuclides are crucial for reactor design, nuclear medicine applications, and nuclear waste treatment. Further research requires the development of more advanced detection techniques and theoretical models to accurately measure and predict their neutron capture behavior.</sec><sec>The surrogate-reaction method, as an effective measurement means, plays an important role in studying reaction cross sections of short-lived nuclides. Its basic idea is to indirectly obtain the reaction cross section information of short-lived nuclides by measuring the specific particles emitted by stable nuclides. Specifically, when stable nuclides are bombarded by high-energy particles, nuclear reactions will occur and specific particles will be released. By accurately measuring the energies, angles, and numbers of these particles, the cross sections of short-lived nuclides in the corresponding reaction can be inferred. This method can not only overcome the technical difficulties in directly measuring short-lived nuclides, but also improve the accuracy and reliability of the measurement results, which provides important support for nuclear physics research. In addition, the surrogate-reaction method also shows broad application prospects in the fields of nuclear technology application and nuclear data assessment.</sec><sec>The experiment is carried out on the Beijing HI-13 tandem accelerator at the China Institute of Atomic Energy. <sup>89</sup>Y is bombarded with 22 MeV protons, and the <sup>85</sup>Sr(n, γ) cross section is measured through the (p, αγ) reaction. The telescope array composed of silicon strip detectors can effectively identify the reaction products. By precisely measuring parameters such as the energies and angles of particles, the array can distinguish different nuclides, thus determining the outgoing particles. Combined with the γ-ray energy spectrum analysis of the HPGe detector, the (n, γ) reaction cross section data of <sup>85</sup>Sr under the Weisskopf-Ewing (W-E) approximation are extracted. Due to the mismatch of the Jπ population between the existing alternative reactions and direct reactions, it is necessary to compensate for this mismatch and then correct the results. In order to obtain relatively reliable results, the Jπ population calculated by TALYS is used to revise the experimental data of the (n, γ) cross section.</sec><sec>These results indicate that the cross section of <sup>85</sup>Sr(n, γ) varies with neutron energy in a specific energy range, which is consistent with the trend of the existing international evaluation library data. This validates the effectiveness of cross section measurement as an alternative reaction method, thereby providing an important experimental basis for further exploring the nuclear reaction mechanism and nuclear data application. This method has reference significance for the cross section measurement of other nuclides.</sec>